/* Optimize jump instructions, for GNU compiler.
- Copyright (C) 1987, 88, 89, 91-99, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA. */
-
-/* This is the jump-optimization pass of the compiler.
- It is run two or three times: once before cse, sometimes once after cse,
- and once after reload (before final).
-
- jump_optimize deletes unreachable code and labels that are not used.
- It also deletes jumps that jump to the following insn,
- and simplifies jumps around unconditional jumps and jumps
- to unconditional jumps.
+/* This is the pathetic reminder of old fame of the jump-optimization pass
+ of the compiler. Now it contains basically set of utility function to
+ operate with jumps.
Each CODE_LABEL has a count of the times it is used
stored in the LABEL_NUSES internal field, and each JUMP_INSN
formerly used them. The JUMP_LABEL info is sometimes looked
at by later passes.
- Optionally, cross-jumping can be done. Currently it is done
- only the last time (when after reload and before final).
- In fact, the code for cross-jumping now assumes that register
- allocation has been done, since it uses `rtx_renumbered_equal_p'.
-
- Jump optimization is done after cse when cse's constant-propagation
- causes jumps to become unconditional or to be deleted.
-
- Unreachable loops are not detected here, because the labels
- have references and the insns appear reachable from the labels.
- find_basic_blocks in flow.c finds and deletes such loops.
-
The subroutines delete_insn, redirect_jump, and invert_jump are used
from other passes as well. */
#include "hard-reg-set.h"
#include "regs.h"
#include "insn-config.h"
-#include "insn-flags.h"
#include "insn-attr.h"
#include "recog.h"
#include "function.h"
#include "real.h"
#include "except.h"
#include "toplev.h"
+#include "reload.h"
+#include "predict.h"
-/* ??? Eventually must record somehow the labels used by jumps
- from nested functions. */
-/* Pre-record the next or previous real insn for each label?
- No, this pass is very fast anyway. */
-/* Condense consecutive labels?
- This would make life analysis faster, maybe. */
/* Optimize jump y; x: ... y: jumpif... x?
Don't know if it is worth bothering with. */
/* Optimize two cases of conditional jump to conditional jump?
or even change what is live at any point.
So perhaps let combiner do it. */
-/* Vector indexed by uid.
- For each CODE_LABEL, index by its uid to get first unconditional jump
- that jumps to the label.
- For each JUMP_INSN, index by its uid to get the next unconditional jump
- that jumps to the same label.
- Element 0 is the start of a chain of all return insns.
- (It is safe to use element 0 because insn uid 0 is not used. */
-
-static rtx *jump_chain;
-
-/* Maximum index in jump_chain. */
-
-static int max_jump_chain;
-
-/* Set nonzero by jump_optimize if control can fall through
- to the end of the function. */
-int can_reach_end;
-
-/* Indicates whether death notes are significant in cross jump analysis.
- Normally they are not significant, because of A and B jump to C,
- and R dies in A, it must die in B. But this might not be true after
- stack register conversion, and we must compare death notes in that
- case. */
-
-static int cross_jump_death_matters = 0;
-
static int init_label_info PARAMS ((rtx));
-static void delete_barrier_successors PARAMS ((rtx));
-static void mark_all_labels PARAMS ((rtx, int));
-static rtx delete_unreferenced_labels PARAMS ((rtx));
-static void delete_noop_moves PARAMS ((rtx));
-static int calculate_can_reach_end PARAMS ((rtx, int));
+static void mark_all_labels PARAMS ((rtx));
static int duplicate_loop_exit_test PARAMS ((rtx));
-static void find_cross_jump PARAMS ((rtx, rtx, int, rtx *, rtx *));
-static void do_cross_jump PARAMS ((rtx, rtx, rtx));
-static int jump_back_p PARAMS ((rtx, rtx));
-static int tension_vector_labels PARAMS ((rtx, int));
-static void mark_jump_label PARAMS ((rtx, rtx, int));
static void delete_computation PARAMS ((rtx));
-static void delete_from_jump_chain PARAMS ((rtx));
-static int delete_labelref_insn PARAMS ((rtx, rtx, int));
-static void mark_modified_reg PARAMS ((rtx, rtx, void *));
-static void redirect_tablejump PARAMS ((rtx, rtx));
-static void jump_optimize_1 PARAMS ((rtx, int, int, int, int));
-#if ! defined(HAVE_cc0) && ! defined(HAVE_conditional_arithmetic)
-static rtx find_insert_position PARAMS ((rtx, rtx));
-#endif
+static void redirect_exp_1 PARAMS ((rtx *, rtx, rtx, rtx));
+static int redirect_exp PARAMS ((rtx, rtx, rtx));
+static void invert_exp_1 PARAMS ((rtx));
+static int invert_exp PARAMS ((rtx));
static int returnjump_p_1 PARAMS ((rtx *, void *));
static void delete_prior_computation PARAMS ((rtx, rtx));
-
-/* Main external entry point into the jump optimizer. See comments before
- jump_optimize_1 for descriptions of the arguments. */
-void
-jump_optimize (f, cross_jump, noop_moves, after_regscan)
- rtx f;
- int cross_jump;
- int noop_moves;
- int after_regscan;
-{
- jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, 0);
-}
-
+static void mark_modified_reg PARAMS ((rtx, rtx, void *));
+\f
/* Alternate entry into the jump optimizer. This entry point only rebuilds
the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping
instructions. */
rebuild_jump_labels (f)
rtx f;
{
- jump_optimize_1 (f, 0, 0, 0, 1);
-}
-
-\f
-/* Delete no-op jumps and optimize jumps to jumps
- and jumps around jumps.
- Delete unused labels and unreachable code.
-
- If CROSS_JUMP is 1, detect matching code
- before a jump and its destination and unify them.
- If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes.
-
- If NOOP_MOVES is nonzero, delete no-op move insns.
-
- If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately
- after regscan, and it is safe to use regno_first_uid and regno_last_uid.
-
- If MARK_LABELS_ONLY is nonzero, then we only rebuild the jump chain
- and JUMP_LABEL field for jumping insns.
-
- If `optimize' is zero, don't change any code,
- just determine whether control drops off the end of the function.
- This case occurs when we have -W and not -O.
- It works because `delete_insn' checks the value of `optimize'
- and refrains from actually deleting when that is 0. */
-
-static void
-jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
- rtx f;
- int cross_jump;
- int noop_moves;
- int after_regscan;
- int mark_labels_only;
-{
- register rtx insn, next;
- int changed;
- int old_max_reg;
- int first = 1;
+ rtx insn;
int max_uid = 0;
- rtx last_insn;
- cross_jump_death_matters = (cross_jump == 2);
max_uid = init_label_info (f) + 1;
- /* If we are performing cross jump optimizations, then initialize
- tables mapping UIDs to EH regions to avoid incorrect movement
- of insns from one EH region to another. */
- if (flag_exceptions && cross_jump)
- init_insn_eh_region (f, max_uid);
-
- delete_barrier_successors (f);
-
- /* Leave some extra room for labels and duplicate exit test insns
- we make. */
- max_jump_chain = max_uid * 14 / 10;
- jump_chain = (rtx *) xcalloc (max_jump_chain, sizeof (rtx));
-
- mark_all_labels (f, cross_jump);
+ mark_all_labels (f);
- /* Keep track of labels used from static data;
- they cannot ever be deleted. */
+ /* Keep track of labels used from static data; we don't track them
+ closely enough to delete them here, so make sure their reference
+ count doesn't drop to zero. */
for (insn = forced_labels; insn; insn = XEXP (insn, 1))
- LABEL_NUSES (XEXP (insn, 0))++;
-
- check_exception_handler_labels ();
+ if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
+ LABEL_NUSES (XEXP (insn, 0))++;
/* Keep track of labels used for marking handlers for exception
regions; they cannot usually be deleted. */
for (insn = exception_handler_labels; insn; insn = XEXP (insn, 1))
- LABEL_NUSES (XEXP (insn, 0))++;
-
- /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL
- notes and recompute LABEL_NUSES. */
- if (mark_labels_only)
- goto end;
-
- exception_optimize ();
-
- last_insn = delete_unreferenced_labels (f);
-
-#ifdef HAVE_return
- if (optimize && HAVE_return)
+ if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
+ LABEL_NUSES (XEXP (insn, 0))++;
+}
+\f
+/* Some old code expects exactly one BARRIER as the NEXT_INSN of a
+ non-fallthru insn. This is not generally true, as multiple barriers
+ may have crept in, or the BARRIER may be separated from the last
+ real insn by one or more NOTEs.
+
+ This simple pass moves barriers and removes duplicates so that the
+ old code is happy.
+ */
+void
+cleanup_barriers ()
+{
+ rtx insn, next, prev;
+ for (insn = get_insns (); insn; insn = next)
{
- /* If we fall through to the epilogue, see if we can insert a RETURN insn
- in front of it. If the machine allows it at this point (we might be
- after reload for a leaf routine), it will improve optimization for it
- to be there. */
- insn = get_last_insn ();
- while (insn && GET_CODE (insn) == NOTE)
- insn = PREV_INSN (insn);
-
- if (insn && GET_CODE (insn) != BARRIER)
+ next = NEXT_INSN (insn);
+ if (GET_CODE (insn) == BARRIER)
{
- emit_jump_insn (gen_return ());
- emit_barrier ();
+ prev = prev_nonnote_insn (insn);
+ if (GET_CODE (prev) == BARRIER)
+ delete_barrier (insn);
+ else if (prev != PREV_INSN (insn))
+ reorder_insns (insn, insn, prev);
}
}
-#endif
-
- if (noop_moves)
- delete_noop_moves (f);
-
- /* If we haven't yet gotten to reload and we have just run regscan,
- delete any insn that sets a register that isn't used elsewhere.
- This helps some of the optimizations below by having less insns
- being jumped around. */
-
- if (optimize && ! reload_completed && after_regscan)
- for (insn = f; insn; insn = next)
- {
- rtx set = single_set (insn);
-
- next = NEXT_INSN (insn);
-
- if (set && GET_CODE (SET_DEST (set)) == REG
- && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER
- && REGNO_FIRST_UID (REGNO (SET_DEST (set))) == INSN_UID (insn)
- /* We use regno_last_note_uid so as not to delete the setting
- of a reg that's used in notes. A subsequent optimization
- might arrange to use that reg for real. */
- && REGNO_LAST_NOTE_UID (REGNO (SET_DEST (set))) == INSN_UID (insn)
- && ! side_effects_p (SET_SRC (set))
- && ! find_reg_note (insn, REG_RETVAL, 0)
- /* An ADDRESSOF expression can turn into a use of the internal arg
- pointer, so do not delete the initialization of the internal
- arg pointer yet. If it is truly dead, flow will delete the
- initializing insn. */
- && SET_DEST (set) != current_function_internal_arg_pointer)
- delete_insn (insn);
- }
-
+}
+\f
+void
+copy_loop_headers (f)
+ rtx f;
+{
+ rtx insn, next;
/* Now iterate optimizing jumps until nothing changes over one pass. */
- changed = 1;
- old_max_reg = max_reg_num ();
- while (changed)
+ for (insn = f; insn; insn = next)
{
- changed = 0;
-
- for (insn = f; insn; insn = next)
- {
- rtx reallabelprev;
- rtx temp, temp1, temp2 = NULL_RTX, temp3, temp4, temp5, temp6;
- rtx nlabel;
- int this_is_simplejump, this_is_condjump, reversep = 0;
- int this_is_condjump_in_parallel;
-
- next = NEXT_INSN (insn);
-
- /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional
- jump. Try to optimize by duplicating the loop exit test if so.
- This is only safe immediately after regscan, because it uses
- the values of regno_first_uid and regno_last_uid. */
- if (after_regscan && GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG
- && (temp1 = next_nonnote_insn (insn)) != 0
- && simplejump_p (temp1))
- {
- temp = PREV_INSN (insn);
- if (duplicate_loop_exit_test (insn))
- {
- changed = 1;
- next = NEXT_INSN (temp);
- continue;
- }
- }
-
- if (GET_CODE (insn) != JUMP_INSN)
- continue;
-
- this_is_simplejump = simplejump_p (insn);
- this_is_condjump = condjump_p (insn);
- this_is_condjump_in_parallel = condjump_in_parallel_p (insn);
-
- /* Tension the labels in dispatch tables. */
-
- if (GET_CODE (PATTERN (insn)) == ADDR_VEC)
- changed |= tension_vector_labels (PATTERN (insn), 0);
- if (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
- changed |= tension_vector_labels (PATTERN (insn), 1);
-
- /* See if this jump goes to another jump and redirect if so. */
- nlabel = follow_jumps (JUMP_LABEL (insn));
- if (nlabel != JUMP_LABEL (insn))
- changed |= redirect_jump (insn, nlabel);
-
- if (! optimize)
- continue;
-
- /* If a dispatch table always goes to the same place,
- get rid of it and replace the insn that uses it. */
-
- if (GET_CODE (PATTERN (insn)) == ADDR_VEC
- || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
- {
- int i;
- rtx pat = PATTERN (insn);
- int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC;
- int len = XVECLEN (pat, diff_vec_p);
- rtx dispatch = prev_real_insn (insn);
- rtx set;
-
- for (i = 0; i < len; i++)
- if (XEXP (XVECEXP (pat, diff_vec_p, i), 0)
- != XEXP (XVECEXP (pat, diff_vec_p, 0), 0))
- break;
-
- if (i == len
- && dispatch != 0
- && GET_CODE (dispatch) == JUMP_INSN
- && JUMP_LABEL (dispatch) != 0
- /* Don't mess with a casesi insn.
- XXX according to the comment before computed_jump_p(),
- all casesi insns should be a parallel of the jump
- and a USE of a LABEL_REF. */
- && ! ((set = single_set (dispatch)) != NULL
- && (GET_CODE (SET_SRC (set)) == IF_THEN_ELSE))
- && next_real_insn (JUMP_LABEL (dispatch)) == insn)
- {
- redirect_tablejump (dispatch,
- XEXP (XVECEXP (pat, diff_vec_p, 0), 0));
- changed = 1;
- }
- }
-
- /* If a jump references the end of the function, try to turn
- it into a RETURN insn, possibly a conditional one. */
- if (JUMP_LABEL (insn) != 0
- && (next_active_insn (JUMP_LABEL (insn)) == 0
- || GET_CODE (PATTERN (next_active_insn (JUMP_LABEL (insn))))
- == RETURN))
- changed |= redirect_jump (insn, NULL_RTX);
-
- reallabelprev = prev_active_insn (JUMP_LABEL (insn));
-
- /* Detect jump to following insn. */
- if (reallabelprev == insn && this_is_condjump)
- {
- next = next_real_insn (JUMP_LABEL (insn));
- delete_jump (insn);
- changed = 1;
- continue;
- }
-
- /* Detect a conditional jump going to the same place
- as an immediately following unconditional jump. */
- else if (this_is_condjump
- && (temp = next_active_insn (insn)) != 0
- && simplejump_p (temp)
- && (next_active_insn (JUMP_LABEL (insn))
- == next_active_insn (JUMP_LABEL (temp))))
- {
- /* Don't mess up test coverage analysis. */
- temp2 = temp;
- if (flag_test_coverage && !reload_completed)
- for (temp2 = insn; temp2 != temp; temp2 = NEXT_INSN (temp2))
- if (GET_CODE (temp2) == NOTE && NOTE_LINE_NUMBER (temp2) > 0)
- break;
-
- if (temp2 == temp)
- {
- delete_jump (insn);
- changed = 1;
- continue;
- }
- }
-
- /* Detect a conditional jump jumping over an unconditional jump. */
-
- else if ((this_is_condjump || this_is_condjump_in_parallel)
- && ! this_is_simplejump
- && reallabelprev != 0
- && GET_CODE (reallabelprev) == JUMP_INSN
- && prev_active_insn (reallabelprev) == insn
- && no_labels_between_p (insn, reallabelprev)
- && simplejump_p (reallabelprev))
- {
- /* When we invert the unconditional jump, we will be
- decrementing the usage count of its old label.
- Make sure that we don't delete it now because that
- might cause the following code to be deleted. */
- rtx prev_uses = prev_nonnote_insn (reallabelprev);
- rtx prev_label = JUMP_LABEL (insn);
-
- if (prev_label)
- ++LABEL_NUSES (prev_label);
-
- if (invert_jump (insn, JUMP_LABEL (reallabelprev)))
- {
- /* It is very likely that if there are USE insns before
- this jump, they hold REG_DEAD notes. These REG_DEAD
- notes are no longer valid due to this optimization,
- and will cause the life-analysis that following passes
- (notably delayed-branch scheduling) to think that
- these registers are dead when they are not.
-
- To prevent this trouble, we just remove the USE insns
- from the insn chain. */
-
- while (prev_uses && GET_CODE (prev_uses) == INSN
- && GET_CODE (PATTERN (prev_uses)) == USE)
- {
- rtx useless = prev_uses;
- prev_uses = prev_nonnote_insn (prev_uses);
- delete_insn (useless);
- }
-
- delete_insn (reallabelprev);
- changed = 1;
- }
-
- /* We can now safely delete the label if it is unreferenced
- since the delete_insn above has deleted the BARRIER. */
- if (prev_label && --LABEL_NUSES (prev_label) == 0)
- delete_insn (prev_label);
-
- next = NEXT_INSN (insn);
- }
-
- /* If we have an unconditional jump preceded by a USE, try to put
- the USE before the target and jump there. This simplifies many
- of the optimizations below since we don't have to worry about
- dealing with these USE insns. We only do this if the label
- being branch to already has the identical USE or if code
- never falls through to that label. */
-
- else if (this_is_simplejump
- && (temp = prev_nonnote_insn (insn)) != 0
- && GET_CODE (temp) == INSN
- && GET_CODE (PATTERN (temp)) == USE
- && (temp1 = prev_nonnote_insn (JUMP_LABEL (insn))) != 0
- && (GET_CODE (temp1) == BARRIER
- || (GET_CODE (temp1) == INSN
- && rtx_equal_p (PATTERN (temp), PATTERN (temp1))))
- /* Don't do this optimization if we have a loop containing
- only the USE instruction, and the loop start label has
- a usage count of 1. This is because we will redo this
- optimization everytime through the outer loop, and jump
- opt will never exit. */
- && ! ((temp2 = prev_nonnote_insn (temp)) != 0
- && temp2 == JUMP_LABEL (insn)
- && LABEL_NUSES (temp2) == 1))
- {
- if (GET_CODE (temp1) == BARRIER)
- {
- emit_insn_after (PATTERN (temp), temp1);
- temp1 = NEXT_INSN (temp1);
- }
-
- delete_insn (temp);
- redirect_jump (insn, get_label_before (temp1));
- reallabelprev = prev_real_insn (temp1);
- changed = 1;
- next = NEXT_INSN (insn);
- }
-
- /* Simplify if (...) x = a; else x = b; by converting it
- to x = b; if (...) x = a;
- if B is sufficiently simple, the test doesn't involve X,
- and nothing in the test modifies B or X.
-
- If we have small register classes, we also can't do this if X
- is a hard register.
-
- If the "x = b;" insn has any REG_NOTES, we don't do this because
- of the possibility that we are running after CSE and there is a
- REG_EQUAL note that is only valid if the branch has already been
- taken. If we move the insn with the REG_EQUAL note, we may
- fold the comparison to always be false in a later CSE pass.
- (We could also delete the REG_NOTES when moving the insn, but it
- seems simpler to not move it.) An exception is that we can move
- the insn if the only note is a REG_EQUAL or REG_EQUIV whose
- value is the same as "b".
-
- INSN is the branch over the `else' part.
-
- We set:
-
- TEMP to the jump insn preceding "x = a;"
- TEMP1 to X
- TEMP2 to the insn that sets "x = b;"
- TEMP3 to the insn that sets "x = a;"
- TEMP4 to the set of "x = b"; */
-
- if (this_is_simplejump
- && (temp3 = prev_active_insn (insn)) != 0
- && GET_CODE (temp3) == INSN
- && (temp4 = single_set (temp3)) != 0
- && GET_CODE (temp1 = SET_DEST (temp4)) == REG
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp1) >= FIRST_PSEUDO_REGISTER)
- && (temp2 = next_active_insn (insn)) != 0
- && GET_CODE (temp2) == INSN
- && (temp4 = single_set (temp2)) != 0
- && rtx_equal_p (SET_DEST (temp4), temp1)
- && ! side_effects_p (SET_SRC (temp4))
- && ! may_trap_p (SET_SRC (temp4))
- && (REG_NOTES (temp2) == 0
- || ((REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUAL
- || REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUIV)
- && XEXP (REG_NOTES (temp2), 1) == 0
- && rtx_equal_p (XEXP (REG_NOTES (temp2), 0),
- SET_SRC (temp4))))
- && (temp = prev_active_insn (temp3)) != 0
- && condjump_p (temp) && ! simplejump_p (temp)
- /* TEMP must skip over the "x = a;" insn */
- && prev_real_insn (JUMP_LABEL (temp)) == insn
- && no_labels_between_p (insn, JUMP_LABEL (temp))
- /* There must be no other entries to the "x = b;" insn. */
- && no_labels_between_p (JUMP_LABEL (temp), temp2)
- /* INSN must either branch to the insn after TEMP2 or the insn
- after TEMP2 must branch to the same place as INSN. */
- && (reallabelprev == temp2
- || ((temp5 = next_active_insn (temp2)) != 0
- && simplejump_p (temp5)
- && JUMP_LABEL (temp5) == JUMP_LABEL (insn))))
- {
- /* The test expression, X, may be a complicated test with
- multiple branches. See if we can find all the uses of
- the label that TEMP branches to without hitting a CALL_INSN
- or a jump to somewhere else. */
- rtx target = JUMP_LABEL (temp);
- int nuses = LABEL_NUSES (target);
- rtx p;
-#ifdef HAVE_cc0
- rtx q;
-#endif
-
- /* Set P to the first jump insn that goes around "x = a;". */
- for (p = temp; nuses && p; p = prev_nonnote_insn (p))
- {
- if (GET_CODE (p) == JUMP_INSN)
- {
- if (condjump_p (p) && ! simplejump_p (p)
- && JUMP_LABEL (p) == target)
- {
- nuses--;
- if (nuses == 0)
- break;
- }
- else
- break;
- }
- else if (GET_CODE (p) == CALL_INSN)
- break;
- }
-
-#ifdef HAVE_cc0
- /* We cannot insert anything between a set of cc and its use
- so if P uses cc0, we must back up to the previous insn. */
- q = prev_nonnote_insn (p);
- if (q && GET_RTX_CLASS (GET_CODE (q)) == 'i'
- && sets_cc0_p (PATTERN (q)))
- p = q;
-#endif
-
- if (p)
- p = PREV_INSN (p);
-
- /* If we found all the uses and there was no data conflict, we
- can move the assignment unless we can branch into the middle
- from somewhere. */
- if (nuses == 0 && p
- && no_labels_between_p (p, insn)
- && ! reg_referenced_between_p (temp1, p, NEXT_INSN (temp3))
- && ! reg_set_between_p (temp1, p, temp3)
- && (GET_CODE (SET_SRC (temp4)) == CONST_INT
- || ! modified_between_p (SET_SRC (temp4), p, temp2))
- /* Verify that registers used by the jump are not clobbered
- by the instruction being moved. */
- && ! regs_set_between_p (PATTERN (temp),
- PREV_INSN (temp2),
- NEXT_INSN (temp2)))
- {
- emit_insn_after_with_line_notes (PATTERN (temp2), p, temp2);
- delete_insn (temp2);
-
- /* Set NEXT to an insn that we know won't go away. */
- next = next_active_insn (insn);
-
- /* Delete the jump around the set. Note that we must do
- this before we redirect the test jumps so that it won't
- delete the code immediately following the assignment
- we moved (which might be a jump). */
-
- delete_insn (insn);
-
- /* We either have two consecutive labels or a jump to
- a jump, so adjust all the JUMP_INSNs to branch to where
- INSN branches to. */
- for (p = NEXT_INSN (p); p != next; p = NEXT_INSN (p))
- if (GET_CODE (p) == JUMP_INSN)
- redirect_jump (p, target);
-
- changed = 1;
- next = NEXT_INSN (insn);
- continue;
- }
- }
-
- /* Simplify if (...) { x = a; goto l; } x = b; by converting it
- to x = a; if (...) goto l; x = b;
- if A is sufficiently simple, the test doesn't involve X,
- and nothing in the test modifies A or X.
-
- If we have small register classes, we also can't do this if X
- is a hard register.
-
- If the "x = a;" insn has any REG_NOTES, we don't do this because
- of the possibility that we are running after CSE and there is a
- REG_EQUAL note that is only valid if the branch has already been
- taken. If we move the insn with the REG_EQUAL note, we may
- fold the comparison to always be false in a later CSE pass.
- (We could also delete the REG_NOTES when moving the insn, but it
- seems simpler to not move it.) An exception is that we can move
- the insn if the only note is a REG_EQUAL or REG_EQUIV whose
- value is the same as "a".
-
- INSN is the goto.
-
- We set:
-
- TEMP to the jump insn preceding "x = a;"
- TEMP1 to X
- TEMP2 to the insn that sets "x = b;"
- TEMP3 to the insn that sets "x = a;"
- TEMP4 to the set of "x = a"; */
-
- if (this_is_simplejump
- && (temp2 = next_active_insn (insn)) != 0
- && GET_CODE (temp2) == INSN
- && (temp4 = single_set (temp2)) != 0
- && GET_CODE (temp1 = SET_DEST (temp4)) == REG
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp1) >= FIRST_PSEUDO_REGISTER)
- && (temp3 = prev_active_insn (insn)) != 0
- && GET_CODE (temp3) == INSN
- && (temp4 = single_set (temp3)) != 0
- && rtx_equal_p (SET_DEST (temp4), temp1)
- && ! side_effects_p (SET_SRC (temp4))
- && ! may_trap_p (SET_SRC (temp4))
- && (REG_NOTES (temp3) == 0
- || ((REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUAL
- || REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUIV)
- && XEXP (REG_NOTES (temp3), 1) == 0
- && rtx_equal_p (XEXP (REG_NOTES (temp3), 0),
- SET_SRC (temp4))))
- && (temp = prev_active_insn (temp3)) != 0
- && condjump_p (temp) && ! simplejump_p (temp)
- /* TEMP must skip over the "x = a;" insn */
- && prev_real_insn (JUMP_LABEL (temp)) == insn
- && no_labels_between_p (temp, insn))
- {
- rtx prev_label = JUMP_LABEL (temp);
- rtx insert_after = prev_nonnote_insn (temp);
-
-#ifdef HAVE_cc0
- /* We cannot insert anything between a set of cc and its use. */
- if (insert_after && GET_RTX_CLASS (GET_CODE (insert_after)) == 'i'
- && sets_cc0_p (PATTERN (insert_after)))
- insert_after = prev_nonnote_insn (insert_after);
-#endif
- ++LABEL_NUSES (prev_label);
-
- if (insert_after
- && no_labels_between_p (insert_after, temp)
- && ! reg_referenced_between_p (temp1, insert_after, temp3)
- && ! reg_referenced_between_p (temp1, temp3,
- NEXT_INSN (temp2))
- && ! reg_set_between_p (temp1, insert_after, temp)
- && ! modified_between_p (SET_SRC (temp4), insert_after, temp)
- /* Verify that registers used by the jump are not clobbered
- by the instruction being moved. */
- && ! regs_set_between_p (PATTERN (temp),
- PREV_INSN (temp3),
- NEXT_INSN (temp3))
- && invert_jump (temp, JUMP_LABEL (insn)))
- {
- emit_insn_after_with_line_notes (PATTERN (temp3),
- insert_after, temp3);
- delete_insn (temp3);
- delete_insn (insn);
- /* Set NEXT to an insn that we know won't go away. */
- next = temp2;
- changed = 1;
- }
- if (prev_label && --LABEL_NUSES (prev_label) == 0)
- delete_insn (prev_label);
- if (changed)
- continue;
- }
-
-#if !defined(HAVE_cc0) && !defined(HAVE_conditional_arithmetic)
-
- /* If we have if (...) x = exp; and branches are expensive,
- EXP is a single insn, does not have any side effects, cannot
- trap, and is not too costly, convert this to
- t = exp; if (...) x = t;
-
- Don't do this when we have CC0 because it is unlikely to help
- and we'd need to worry about where to place the new insn and
- the potential for conflicts. We also can't do this when we have
- notes on the insn for the same reason as above.
-
- If we have conditional arithmetic, this will make this
- harder to optimize later and isn't needed, so don't do it
- in that case either.
-
- We set:
-
- TEMP to the "x = exp;" insn.
- TEMP1 to the single set in the "x = exp;" insn.
- TEMP2 to "x". */
-
- if (! reload_completed
- && this_is_condjump && ! this_is_simplejump
- && BRANCH_COST >= 3
- && (temp = next_nonnote_insn (insn)) != 0
- && GET_CODE (temp) == INSN
- && REG_NOTES (temp) == 0
- && (reallabelprev == temp
- || ((temp2 = next_active_insn (temp)) != 0
- && simplejump_p (temp2)
- && JUMP_LABEL (temp2) == JUMP_LABEL (insn)))
- && (temp1 = single_set (temp)) != 0
- && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG)
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp2) >= FIRST_PSEUDO_REGISTER)
- && GET_CODE (SET_SRC (temp1)) != REG
- && GET_CODE (SET_SRC (temp1)) != SUBREG
- && GET_CODE (SET_SRC (temp1)) != CONST_INT
- && ! side_effects_p (SET_SRC (temp1))
- && ! may_trap_p (SET_SRC (temp1))
- && rtx_cost (SET_SRC (temp1), SET) < 10)
- {
- rtx new = gen_reg_rtx (GET_MODE (temp2));
-
- if ((temp3 = find_insert_position (insn, temp))
- && validate_change (temp, &SET_DEST (temp1), new, 0))
- {
- next = emit_insn_after (gen_move_insn (temp2, new), insn);
- emit_insn_after_with_line_notes (PATTERN (temp),
- PREV_INSN (temp3), temp);
- delete_insn (temp);
- reallabelprev = prev_active_insn (JUMP_LABEL (insn));
-
- if (after_regscan)
- {
- reg_scan_update (temp3, NEXT_INSN (next), old_max_reg);
- old_max_reg = max_reg_num ();
- }
- }
- }
-
- /* Similarly, if it takes two insns to compute EXP but they
- have the same destination. Here TEMP3 will be the second
- insn and TEMP4 the SET from that insn. */
-
- if (! reload_completed
- && this_is_condjump && ! this_is_simplejump
- && BRANCH_COST >= 4
- && (temp = next_nonnote_insn (insn)) != 0
- && GET_CODE (temp) == INSN
- && REG_NOTES (temp) == 0
- && (temp3 = next_nonnote_insn (temp)) != 0
- && GET_CODE (temp3) == INSN
- && REG_NOTES (temp3) == 0
- && (reallabelprev == temp3
- || ((temp2 = next_active_insn (temp3)) != 0
- && simplejump_p (temp2)
- && JUMP_LABEL (temp2) == JUMP_LABEL (insn)))
- && (temp1 = single_set (temp)) != 0
- && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG)
- && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp2) >= FIRST_PSEUDO_REGISTER)
- && ! side_effects_p (SET_SRC (temp1))
- && ! may_trap_p (SET_SRC (temp1))
- && rtx_cost (SET_SRC (temp1), SET) < 10
- && (temp4 = single_set (temp3)) != 0
- && rtx_equal_p (SET_DEST (temp4), temp2)
- && ! side_effects_p (SET_SRC (temp4))
- && ! may_trap_p (SET_SRC (temp4))
- && rtx_cost (SET_SRC (temp4), SET) < 10)
- {
- rtx new = gen_reg_rtx (GET_MODE (temp2));
-
- if ((temp5 = find_insert_position (insn, temp))
- && (temp6 = find_insert_position (insn, temp3))
- && validate_change (temp, &SET_DEST (temp1), new, 0))
- {
- /* Use the earliest of temp5 and temp6. */
- if (temp5 != insn)
- temp6 = temp5;
- next = emit_insn_after (gen_move_insn (temp2, new), insn);
- emit_insn_after_with_line_notes (PATTERN (temp),
- PREV_INSN (temp6), temp);
- emit_insn_after_with_line_notes
- (replace_rtx (PATTERN (temp3), temp2, new),
- PREV_INSN (temp6), temp3);
- delete_insn (temp);
- delete_insn (temp3);
- reallabelprev = prev_active_insn (JUMP_LABEL (insn));
-
- if (after_regscan)
- {
- reg_scan_update (temp6, NEXT_INSN (next), old_max_reg);
- old_max_reg = max_reg_num ();
- }
- }
- }
-
- /* Finally, handle the case where two insns are used to
- compute EXP but a temporary register is used. Here we must
- ensure that the temporary register is not used anywhere else. */
-
- if (! reload_completed
- && after_regscan
- && this_is_condjump && ! this_is_simplejump
- && BRANCH_COST >= 4
- && (temp = next_nonnote_insn (insn)) != 0
- && GET_CODE (temp) == INSN
- && REG_NOTES (temp) == 0
- && (temp3 = next_nonnote_insn (temp)) != 0
- && GET_CODE (temp3) == INSN
- && REG_NOTES (temp3) == 0
- && (reallabelprev == temp3
- || ((temp2 = next_active_insn (temp3)) != 0
- && simplejump_p (temp2)
- && JUMP_LABEL (temp2) == JUMP_LABEL (insn)))
- && (temp1 = single_set (temp)) != 0
- && (temp5 = SET_DEST (temp1),
- (GET_CODE (temp5) == REG
- || (GET_CODE (temp5) == SUBREG
- && (temp5 = SUBREG_REG (temp5),
- GET_CODE (temp5) == REG))))
- && REGNO (temp5) >= FIRST_PSEUDO_REGISTER
- && REGNO_FIRST_UID (REGNO (temp5)) == INSN_UID (temp)
- && REGNO_LAST_UID (REGNO (temp5)) == INSN_UID (temp3)
- && ! side_effects_p (SET_SRC (temp1))
- && ! may_trap_p (SET_SRC (temp1))
- && rtx_cost (SET_SRC (temp1), SET) < 10
- && (temp4 = single_set (temp3)) != 0
- && (temp2 = SET_DEST (temp4), GET_CODE (temp2) == REG)
- && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp2) >= FIRST_PSEUDO_REGISTER)
- && rtx_equal_p (SET_DEST (temp4), temp2)
- && ! side_effects_p (SET_SRC (temp4))
- && ! may_trap_p (SET_SRC (temp4))
- && rtx_cost (SET_SRC (temp4), SET) < 10)
- {
- rtx new = gen_reg_rtx (GET_MODE (temp2));
-
- if ((temp5 = find_insert_position (insn, temp))
- && (temp6 = find_insert_position (insn, temp3))
- && validate_change (temp3, &SET_DEST (temp4), new, 0))
- {
- /* Use the earliest of temp5 and temp6. */
- if (temp5 != insn)
- temp6 = temp5;
- next = emit_insn_after (gen_move_insn (temp2, new), insn);
- emit_insn_after_with_line_notes (PATTERN (temp),
- PREV_INSN (temp6), temp);
- emit_insn_after_with_line_notes (PATTERN (temp3),
- PREV_INSN (temp6), temp3);
- delete_insn (temp);
- delete_insn (temp3);
- reallabelprev = prev_active_insn (JUMP_LABEL (insn));
-
- if (after_regscan)
- {
- reg_scan_update (temp6, NEXT_INSN (next), old_max_reg);
- old_max_reg = max_reg_num ();
- }
- }
- }
-#endif /* HAVE_cc0 */
-
-#ifdef HAVE_conditional_arithmetic
- /* ??? This is disabled in genconfig, as this simple-minded
- transformation can incredibly lengthen register lifetimes.
-
- Consider this example from cexp.c's yyparse:
-
- 234 (set (pc)
- (if_then_else (ne (reg:DI 149) (const_int 0 [0x0]))
- (label_ref 248) (pc)))
- 237 (set (reg/i:DI 0 $0) (const_int 1 [0x1]))
- 239 (set (pc) (label_ref 2382))
- 248 (code_label ("yybackup"))
-
- This will be transformed to:
-
- 237 (set (reg/i:DI 0 $0)
- (if_then_else:DI (eq (reg:DI 149) (const_int 0 [0x0]))
- (const_int 1 [0x1]) (reg/i:DI 0 $0)))
- 239 (set (pc)
- (if_then_else (eq (reg:DI 149) (const_int 0 [0x0]))
- (label_ref 2382) (pc)))
-
- which, from this narrow viewpoint looks fine. Except that
- between this and 3 other ocurrences of the same pattern, $0
- is now live for basically the entire function, and we'll
- get an abort in caller_save.
-
- Any replacement for this code should recall that a set of
- a register that is not live need not, and indeed should not,
- be conditionalized. Either that, or delay the transformation
- until after register allocation. */
-
- /* See if this is a conditional jump around a small number of
- instructions that we can conditionalize. Don't do this before
- the initial CSE pass or after reload.
-
- We reject any insns that have side effects or may trap.
- Strictly speaking, this is not needed since the machine may
- support conditionalizing these too, but we won't deal with that
- now. Specifically, this means that we can't conditionalize a
- CALL_INSN, which some machines, such as the ARC, can do, but
- this is a very minor optimization. */
- if (this_is_condjump && ! this_is_simplejump
- && cse_not_expected && ! reload_completed
- && BRANCH_COST > 2
- && can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (insn)), 0),
- insn))
- {
- rtx ourcond = XEXP (SET_SRC (PATTERN (insn)), 0);
- int num_insns = 0;
- char *storage = (char *) oballoc (0);
- int last_insn = 0, failed = 0;
- rtx changed_jump = 0;
-
- ourcond = gen_rtx (reverse_condition (GET_CODE (ourcond)),
- VOIDmode, XEXP (ourcond, 0),
- XEXP (ourcond, 1));
-
- /* Scan forward BRANCH_COST real insns looking for the JUMP_LABEL
- of this insn. We see if we think we can conditionalize the
- insns we pass. For now, we only deal with insns that have
- one SET. We stop after an insn that modifies anything in
- OURCOND, if we have too many insns, or if we have an insn
- with a side effect or that may trip. Note that we will
- be modifying any unconditional jumps we encounter to be
- conditional; this will have the effect of also doing this
- optimization on the "else" the next time around. */
- for (temp1 = NEXT_INSN (insn);
- num_insns <= BRANCH_COST && ! failed && temp1 != 0
- && GET_CODE (temp1) != CODE_LABEL;
- temp1 = NEXT_INSN (temp1))
- {
- /* Ignore everything but an active insn. */
- if (GET_RTX_CLASS (GET_CODE (temp1)) != 'i'
- || GET_CODE (PATTERN (temp1)) == USE
- || GET_CODE (PATTERN (temp1)) == CLOBBER)
- continue;
-
- /* If this was an unconditional jump, record it since we'll
- need to remove the BARRIER if we succeed. We can only
- have one such jump since there must be a label after
- the BARRIER and it's either ours, in which case it's the
- only one or some other, in which case we'd fail.
- Likewise if it's a CALL_INSN followed by a BARRIER. */
-
- if (simplejump_p (temp1)
- || (GET_CODE (temp1) == CALL_INSN
- && NEXT_INSN (temp1) != 0
- && GET_CODE (NEXT_INSN (temp1)) == BARRIER))
- {
- if (changed_jump == 0)
- changed_jump = temp1;
- else
- changed_jump
- = gen_rtx_INSN_LIST (VOIDmode, temp1, changed_jump);
- }
-
- /* See if we are allowed another insn and if this insn
- if one we think we may be able to handle. */
- if (++num_insns > BRANCH_COST
- || last_insn
- || (((temp2 = single_set (temp1)) == 0
- || side_effects_p (SET_SRC (temp2))
- || may_trap_p (SET_SRC (temp2)))
- && GET_CODE (temp1) != CALL_INSN))
- failed = 1;
- else if (temp2 != 0)
- validate_change (temp1, &SET_SRC (temp2),
- gen_rtx_IF_THEN_ELSE
- (GET_MODE (SET_DEST (temp2)),
- copy_rtx (ourcond),
- SET_SRC (temp2), SET_DEST (temp2)),
- 1);
- else
- {
- /* This is a CALL_INSN that doesn't have a SET. */
- rtx *call_loc = &PATTERN (temp1);
-
- if (GET_CODE (*call_loc) == PARALLEL)
- call_loc = &XVECEXP (*call_loc, 0, 0);
-
- validate_change (temp1, call_loc,
- gen_rtx_IF_THEN_ELSE
- (VOIDmode, copy_rtx (ourcond),
- *call_loc, const0_rtx),
- 1);
- }
-
-
- if (modified_in_p (ourcond, temp1))
- last_insn = 1;
- }
-
- /* If we've reached our jump label, haven't failed, and all
- the changes above are valid, we can delete this jump
- insn. Also remove a BARRIER after any jump that used
- to be unconditional and remove any REG_EQUAL or REG_EQUIV
- that might have previously been present on insns we
- made conditional. */
- if (temp1 == JUMP_LABEL (insn) && ! failed
- && apply_change_group ())
- {
- for (temp1 = NEXT_INSN (insn); temp1 != JUMP_LABEL (insn);
- temp1 = NEXT_INSN (temp1))
- if (GET_RTX_CLASS (GET_CODE (temp1)) == 'i')
- for (temp2 = REG_NOTES (temp1); temp2 != 0;
- temp2 = XEXP (temp2, 1))
- if (REG_NOTE_KIND (temp2) == REG_EQUAL
- || REG_NOTE_KIND (temp2) == REG_EQUIV)
- remove_note (temp1, temp2);
-
- if (changed_jump != 0)
- {
- while (GET_CODE (changed_jump) == INSN_LIST)
- {
- delete_barrier (NEXT_INSN (XEXP (changed_jump, 0)));
- changed_jump = XEXP (changed_jump, 1);
- }
-
- delete_barrier (NEXT_INSN (changed_jump));
- }
-
- delete_insn (insn);
- changed = 1;
- continue;
- }
- else
- {
- cancel_changes (0);
- obfree (storage);
- }
- }
-#endif
- /* If branches are expensive, convert
- if (foo) bar++; to bar += (foo != 0);
- and similarly for "bar--;"
-
- INSN is the conditional branch around the arithmetic. We set:
-
- TEMP is the arithmetic insn.
- TEMP1 is the SET doing the arithmetic.
- TEMP2 is the operand being incremented or decremented.
- TEMP3 to the condition being tested.
- TEMP4 to the earliest insn used to find the condition. */
-
- if ((BRANCH_COST >= 2
-#ifdef HAVE_incscc
- || HAVE_incscc
-#endif
-#ifdef HAVE_decscc
- || HAVE_decscc
-#endif
- )
- && ! reload_completed
- && this_is_condjump && ! this_is_simplejump
- && (temp = next_nonnote_insn (insn)) != 0
- && (temp1 = single_set (temp)) != 0
- && (temp2 = SET_DEST (temp1),
- GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT)
- && GET_CODE (SET_SRC (temp1)) == PLUS
- && (XEXP (SET_SRC (temp1), 1) == const1_rtx
- || XEXP (SET_SRC (temp1), 1) == constm1_rtx)
- && rtx_equal_p (temp2, XEXP (SET_SRC (temp1), 0))
- && ! side_effects_p (temp2)
- && ! may_trap_p (temp2)
- /* INSN must either branch to the insn after TEMP or the insn
- after TEMP must branch to the same place as INSN. */
- && (reallabelprev == temp
- || ((temp3 = next_active_insn (temp)) != 0
- && simplejump_p (temp3)
- && JUMP_LABEL (temp3) == JUMP_LABEL (insn)))
- && (temp3 = get_condition (insn, &temp4)) != 0
- /* We must be comparing objects whose modes imply the size.
- We could handle BLKmode if (1) emit_store_flag could
- and (2) we could find the size reliably. */
- && GET_MODE (XEXP (temp3, 0)) != BLKmode
- && can_reverse_comparison_p (temp3, insn))
- {
- rtx temp6, target = 0, seq, init_insn = 0, init = temp2;
- enum rtx_code code = reverse_condition (GET_CODE (temp3));
-
- start_sequence ();
-
- /* It must be the case that TEMP2 is not modified in the range
- [TEMP4, INSN). The one exception we make is if the insn
- before INSN sets TEMP2 to something which is also unchanged
- in that range. In that case, we can move the initialization
- into our sequence. */
-
- if ((temp5 = prev_active_insn (insn)) != 0
- && no_labels_between_p (temp5, insn)
- && GET_CODE (temp5) == INSN
- && (temp6 = single_set (temp5)) != 0
- && rtx_equal_p (temp2, SET_DEST (temp6))
- && (CONSTANT_P (SET_SRC (temp6))
- || GET_CODE (SET_SRC (temp6)) == REG
- || GET_CODE (SET_SRC (temp6)) == SUBREG))
- {
- emit_insn (PATTERN (temp5));
- init_insn = temp5;
- init = SET_SRC (temp6);
- }
-
- if (CONSTANT_P (init)
- || ! reg_set_between_p (init, PREV_INSN (temp4), insn))
- target = emit_store_flag (gen_reg_rtx (GET_MODE (temp2)), code,
- XEXP (temp3, 0), XEXP (temp3, 1),
- VOIDmode,
- (code == LTU || code == LEU
- || code == GTU || code == GEU), 1);
-
- /* If we can do the store-flag, do the addition or
- subtraction. */
-
- if (target)
- target = expand_binop (GET_MODE (temp2),
- (XEXP (SET_SRC (temp1), 1) == const1_rtx
- ? add_optab : sub_optab),
- temp2, target, temp2, 0, OPTAB_WIDEN);
-
- if (target != 0)
- {
- /* Put the result back in temp2 in case it isn't already.
- Then replace the jump, possible a CC0-setting insn in
- front of the jump, and TEMP, with the sequence we have
- made. */
-
- if (target != temp2)
- emit_move_insn (temp2, target);
-
- seq = get_insns ();
- end_sequence ();
-
- emit_insns_before (seq, temp4);
- delete_insn (temp);
-
- if (init_insn)
- delete_insn (init_insn);
-
- next = NEXT_INSN (insn);
-#ifdef HAVE_cc0
- delete_insn (prev_nonnote_insn (insn));
-#endif
- delete_insn (insn);
-
- if (after_regscan)
- {
- reg_scan_update (seq, NEXT_INSN (next), old_max_reg);
- old_max_reg = max_reg_num ();
- }
-
- changed = 1;
- continue;
- }
- else
- end_sequence ();
- }
-
- /* Try to use a conditional move (if the target has them), or a
- store-flag insn. If the target has conditional arithmetic as
- well as conditional move, the above code will have done something.
- Note that we prefer the above code since it is more general: the
- code below can make changes that require work to undo.
-
- The general case here is:
-
- 1) x = a; if (...) x = b; and
- 2) if (...) x = b;
-
- If the jump would be faster, the machine should not have defined
- the movcc or scc insns!. These cases are often made by the
- previous optimization.
-
- The second case is treated as x = x; if (...) x = b;.
-
- INSN here is the jump around the store. We set:
-
- TEMP to the "x op= b;" insn.
- TEMP1 to X.
- TEMP2 to B.
- TEMP3 to A (X in the second case).
- TEMP4 to the condition being tested.
- TEMP5 to the earliest insn used to find the condition.
- TEMP6 to the SET of TEMP. */
-
- if (/* We can't do this after reload has completed. */
- ! reload_completed
-#ifdef HAVE_conditional_arithmetic
- /* Defer this until after CSE so the above code gets the
- first crack at it. */
- && cse_not_expected
-#endif
- && this_is_condjump && ! this_is_simplejump
- /* Set TEMP to the "x = b;" insn. */
- && (temp = next_nonnote_insn (insn)) != 0
- && GET_CODE (temp) == INSN
- && (temp6 = single_set (temp)) != NULL_RTX
- && GET_CODE (temp1 = SET_DEST (temp6)) == REG
- && (! SMALL_REGISTER_CLASSES
- || REGNO (temp1) >= FIRST_PSEUDO_REGISTER)
- && ! side_effects_p (temp2 = SET_SRC (temp6))
- && ! may_trap_p (temp2)
- /* Allow either form, but prefer the former if both apply.
- There is no point in using the old value of TEMP1 if
- it is a register, since cse will alias them. It can
- lose if the old value were a hard register since CSE
- won't replace hard registers. Avoid using TEMP3 if
- small register classes and it is a hard register. */
- && (((temp3 = reg_set_last (temp1, insn)) != 0
- && ! (SMALL_REGISTER_CLASSES && GET_CODE (temp3) == REG
- && REGNO (temp3) < FIRST_PSEUDO_REGISTER))
- /* Make the latter case look like x = x; if (...) x = b; */
- || (temp3 = temp1, 1))
- /* INSN must either branch to the insn after TEMP or the insn
- after TEMP must branch to the same place as INSN. */
- && (reallabelprev == temp
- || ((temp4 = next_active_insn (temp)) != 0
- && simplejump_p (temp4)
- && JUMP_LABEL (temp4) == JUMP_LABEL (insn)))
- && (temp4 = get_condition (insn, &temp5)) != 0
- /* We must be comparing objects whose modes imply the size.
- We could handle BLKmode if (1) emit_store_flag could
- and (2) we could find the size reliably. */
- && GET_MODE (XEXP (temp4, 0)) != BLKmode
- /* Even if branches are cheap, the store_flag optimization
- can win when the operation to be performed can be
- expressed directly. */
-#ifdef HAVE_cc0
- /* If the previous insn sets CC0 and something else, we can't
- do this since we are going to delete that insn. */
-
- && ! ((temp6 = prev_nonnote_insn (insn)) != 0
- && GET_CODE (temp6) == INSN
- && (sets_cc0_p (PATTERN (temp6)) == -1
- || (sets_cc0_p (PATTERN (temp6)) == 1
- && FIND_REG_INC_NOTE (temp6, NULL_RTX))))
-#endif
- )
- {
-#ifdef HAVE_conditional_move
- /* First try a conditional move. */
- {
- enum rtx_code code = GET_CODE (temp4);
- rtx var = temp1;
- rtx cond0, cond1, aval, bval;
- rtx target, new_insn;
-
- /* Copy the compared variables into cond0 and cond1, so that
- any side effects performed in or after the old comparison,
- will not affect our compare which will come later. */
- /* ??? Is it possible to just use the comparison in the jump
- insn? After all, we're going to delete it. We'd have
- to modify emit_conditional_move to take a comparison rtx
- instead or write a new function. */
- cond0 = gen_reg_rtx (GET_MODE (XEXP (temp4, 0)));
- /* We want the target to be able to simplify comparisons with
- zero (and maybe other constants as well), so don't create
- pseudos for them. There's no need to either. */
- if (GET_CODE (XEXP (temp4, 1)) == CONST_INT
- || GET_CODE (XEXP (temp4, 1)) == CONST_DOUBLE)
- cond1 = XEXP (temp4, 1);
- else
- cond1 = gen_reg_rtx (GET_MODE (XEXP (temp4, 1)));
-
- /* Careful about copying these values -- an IOR or what may
- need to do other things, like clobber flags. */
- /* ??? Assume for the moment that AVAL is ok. */
- aval = temp3;
-
- start_sequence ();
-
- /* We're dealing with a single_set insn with no side effects
- on SET_SRC. We do need to be reasonably certain that if
- we need to force BVAL into a register that we won't
- clobber the flags -- general_operand should suffice. */
- if (general_operand (temp2, GET_MODE (var)))
- bval = temp2;
- else
- {
- bval = gen_reg_rtx (GET_MODE (var));
- new_insn = copy_rtx (temp);
- temp6 = single_set (new_insn);
- SET_DEST (temp6) = bval;
- emit_insn (PATTERN (new_insn));
- }
-
- target = emit_conditional_move (var, code,
- cond0, cond1, VOIDmode,
- aval, bval, GET_MODE (var),
- (code == LTU || code == GEU
- || code == LEU || code == GTU));
-
- if (target)
- {
- rtx seq1, seq2, last;
- int copy_ok;
-
- /* Save the conditional move sequence but don't emit it
- yet. On some machines, like the alpha, it is possible
- that temp5 == insn, so next generate the sequence that
- saves the compared values and then emit both
- sequences ensuring seq1 occurs before seq2. */
- seq2 = get_insns ();
- end_sequence ();
-
- /* "Now that we can't fail..." Famous last words.
- Generate the copy insns that preserve the compared
- values. */
- start_sequence ();
- emit_move_insn (cond0, XEXP (temp4, 0));
- if (cond1 != XEXP (temp4, 1))
- emit_move_insn (cond1, XEXP (temp4, 1));
- seq1 = get_insns ();
- end_sequence ();
-
- /* Validate the sequence -- this may be some weird
- bit-extract-and-test instruction for which there
- exists no complimentary bit-extract insn. */
- copy_ok = 1;
- for (last = seq1; last ; last = NEXT_INSN (last))
- if (recog_memoized (last) < 0)
- {
- copy_ok = 0;
- break;
- }
-
- if (copy_ok)
- {
- emit_insns_before (seq1, temp5);
-
- /* Insert conditional move after insn, to be sure
- that the jump and a possible compare won't be
- separated. */
- last = emit_insns_after (seq2, insn);
-
- /* ??? We can also delete the insn that sets X to A.
- Flow will do it too though. */
- delete_insn (temp);
- next = NEXT_INSN (insn);
- delete_jump (insn);
-
- if (after_regscan)
- {
- reg_scan_update (seq1, NEXT_INSN (last),
- old_max_reg);
- old_max_reg = max_reg_num ();
- }
-
- changed = 1;
- continue;
- }
- }
- else
- end_sequence ();
- }
-#endif
-
- /* That didn't work, try a store-flag insn.
-
- We further divide the cases into:
-
- 1) x = a; if (...) x = b; and either A or B is zero,
- 2) if (...) x = 0; and jumps are expensive,
- 3) x = a; if (...) x = b; and A and B are constants where all
- the set bits in A are also set in B and jumps are expensive,
- 4) x = a; if (...) x = b; and A and B non-zero, and jumps are
- more expensive, and
- 5) if (...) x = b; if jumps are even more expensive. */
-
- if (GET_MODE_CLASS (GET_MODE (temp1)) == MODE_INT
- /* We will be passing this as operand into expand_and. No
- good if it's not valid as an operand. */
- && general_operand (temp2, GET_MODE (temp2))
- && ((GET_CODE (temp3) == CONST_INT)
- /* Make the latter case look like
- x = x; if (...) x = 0; */
- || (temp3 = temp1,
- ((BRANCH_COST >= 2
- && temp2 == const0_rtx)
- || BRANCH_COST >= 3)))
- /* If B is zero, OK; if A is zero, can only do (1) if we
- can reverse the condition. See if (3) applies possibly
- by reversing the condition. Prefer reversing to (4) when
- branches are very expensive. */
- && (((BRANCH_COST >= 2
- || STORE_FLAG_VALUE == -1
- || (STORE_FLAG_VALUE == 1
- /* Check that the mask is a power of two,
- so that it can probably be generated
- with a shift. */
- && GET_CODE (temp3) == CONST_INT
- && exact_log2 (INTVAL (temp3)) >= 0))
- && (reversep = 0, temp2 == const0_rtx))
- || ((BRANCH_COST >= 2
- || STORE_FLAG_VALUE == -1
- || (STORE_FLAG_VALUE == 1
- && GET_CODE (temp2) == CONST_INT
- && exact_log2 (INTVAL (temp2)) >= 0))
- && temp3 == const0_rtx
- && (reversep = can_reverse_comparison_p (temp4, insn)))
- || (BRANCH_COST >= 2
- && GET_CODE (temp2) == CONST_INT
- && GET_CODE (temp3) == CONST_INT
- && ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp2)
- || ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp3)
- && (reversep = can_reverse_comparison_p (temp4,
- insn)))))
- || BRANCH_COST >= 3)
- )
- {
- enum rtx_code code = GET_CODE (temp4);
- rtx uval, cval, var = temp1;
- int normalizep;
- rtx target;
-
- /* If necessary, reverse the condition. */
- if (reversep)
- code = reverse_condition (code), uval = temp2, cval = temp3;
- else
- uval = temp3, cval = temp2;
-
- /* If CVAL is non-zero, normalize to -1. Otherwise, if UVAL
- is the constant 1, it is best to just compute the result
- directly. If UVAL is constant and STORE_FLAG_VALUE
- includes all of its bits, it is best to compute the flag
- value unnormalized and `and' it with UVAL. Otherwise,
- normalize to -1 and `and' with UVAL. */
- normalizep = (cval != const0_rtx ? -1
- : (uval == const1_rtx ? 1
- : (GET_CODE (uval) == CONST_INT
- && (INTVAL (uval) & ~STORE_FLAG_VALUE) == 0)
- ? 0 : -1));
-
- /* We will be putting the store-flag insn immediately in
- front of the comparison that was originally being done,
- so we know all the variables in TEMP4 will be valid.
- However, this might be in front of the assignment of
- A to VAR. If it is, it would clobber the store-flag
- we will be emitting.
-
- Therefore, emit into a temporary which will be copied to
- VAR immediately after TEMP. */
-
- start_sequence ();
- target = emit_store_flag (gen_reg_rtx (GET_MODE (var)), code,
- XEXP (temp4, 0), XEXP (temp4, 1),
- VOIDmode,
- (code == LTU || code == LEU
- || code == GEU || code == GTU),
- normalizep);
- if (target)
- {
- rtx seq;
- rtx before = insn;
-
- seq = get_insns ();
- end_sequence ();
-
- /* Put the store-flag insns in front of the first insn
- used to compute the condition to ensure that we
- use the same values of them as the current
- comparison. However, the remainder of the insns we
- generate will be placed directly in front of the
- jump insn, in case any of the pseudos we use
- are modified earlier. */
-
- emit_insns_before (seq, temp5);
-
- start_sequence ();
-
- /* Both CVAL and UVAL are non-zero. */
- if (cval != const0_rtx && uval != const0_rtx)
- {
- rtx tem1, tem2;
-
- tem1 = expand_and (uval, target, NULL_RTX);
- if (GET_CODE (cval) == CONST_INT
- && GET_CODE (uval) == CONST_INT
- && (INTVAL (cval) & INTVAL (uval)) == INTVAL (cval))
- tem2 = cval;
- else
- {
- tem2 = expand_unop (GET_MODE (var), one_cmpl_optab,
- target, NULL_RTX, 0);
- tem2 = expand_and (cval, tem2,
- (GET_CODE (tem2) == REG
- ? tem2 : 0));
- }
-
- /* If we usually make new pseudos, do so here. This
- turns out to help machines that have conditional
- move insns. */
- /* ??? Conditional moves have already been handled.
- This may be obsolete. */
-
- if (flag_expensive_optimizations)
- target = 0;
-
- target = expand_binop (GET_MODE (var), ior_optab,
- tem1, tem2, target,
- 1, OPTAB_WIDEN);
- }
- else if (normalizep != 1)
- {
- /* We know that either CVAL or UVAL is zero. If
- UVAL is zero, negate TARGET and `and' with CVAL.
- Otherwise, `and' with UVAL. */
- if (uval == const0_rtx)
- {
- target = expand_unop (GET_MODE (var), one_cmpl_optab,
- target, NULL_RTX, 0);
- uval = cval;
- }
-
- target = expand_and (uval, target,
- (GET_CODE (target) == REG
- && ! preserve_subexpressions_p ()
- ? target : NULL_RTX));
- }
-
- emit_move_insn (var, target);
- seq = get_insns ();
- end_sequence ();
-#ifdef HAVE_cc0
- /* If INSN uses CC0, we must not separate it from the
- insn that sets cc0. */
- if (reg_mentioned_p (cc0_rtx, PATTERN (before)))
- before = prev_nonnote_insn (before);
-#endif
- emit_insns_before (seq, before);
-
- delete_insn (temp);
- next = NEXT_INSN (insn);
- delete_jump (insn);
-
- if (after_regscan)
- {
- reg_scan_update (seq, NEXT_INSN (next), old_max_reg);
- old_max_reg = max_reg_num ();
- }
-
- changed = 1;
- continue;
- }
- else
- end_sequence ();
- }
- }
-
-
- /* Simplify if (...) x = 1; else {...} if (x) ...
- We recognize this case scanning backwards as well.
-
- TEMP is the assignment to x;
- TEMP1 is the label at the head of the second if. */
- /* ?? This should call get_condition to find the values being
- compared, instead of looking for a COMPARE insn when HAVE_cc0
- is not defined. This would allow it to work on the m88k. */
- /* ?? This optimization is only safe before cse is run if HAVE_cc0
- is not defined and the condition is tested by a separate compare
- insn. This is because the code below assumes that the result
- of the compare dies in the following branch.
-
- Not only that, but there might be other insns between the
- compare and branch whose results are live. Those insns need
- to be executed.
-
- A way to fix this is to move the insns at JUMP_LABEL (insn)
- to before INSN. If we are running before flow, they will
- be deleted if they aren't needed. But this doesn't work
- well after flow.
-
- This is really a special-case of jump threading, anyway. The
- right thing to do is to replace this and jump threading with
- much simpler code in cse.
-
- This code has been turned off in the non-cc0 case in the
- meantime. */
-
-#ifdef HAVE_cc0
- else if (this_is_simplejump
- /* Safe to skip USE and CLOBBER insns here
- since they will not be deleted. */
- && (temp = prev_active_insn (insn))
- && no_labels_between_p (temp, insn)
- && GET_CODE (temp) == INSN
- && GET_CODE (PATTERN (temp)) == SET
- && GET_CODE (SET_DEST (PATTERN (temp))) == REG
- && CONSTANT_P (SET_SRC (PATTERN (temp)))
- && (temp1 = next_active_insn (JUMP_LABEL (insn)))
- /* If we find that the next value tested is `x'
- (TEMP1 is the insn where this happens), win. */
- && GET_CODE (temp1) == INSN
- && GET_CODE (PATTERN (temp1)) == SET
-#ifdef HAVE_cc0
- /* Does temp1 `tst' the value of x? */
- && SET_SRC (PATTERN (temp1)) == SET_DEST (PATTERN (temp))
- && SET_DEST (PATTERN (temp1)) == cc0_rtx
- && (temp1 = next_nonnote_insn (temp1))
-#else
- /* Does temp1 compare the value of x against zero? */
- && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE
- && XEXP (SET_SRC (PATTERN (temp1)), 1) == const0_rtx
- && (XEXP (SET_SRC (PATTERN (temp1)), 0)
- == SET_DEST (PATTERN (temp)))
- && GET_CODE (SET_DEST (PATTERN (temp1))) == REG
- && (temp1 = find_next_ref (SET_DEST (PATTERN (temp1)), temp1))
-#endif
- && condjump_p (temp1))
- {
- /* Get the if_then_else from the condjump. */
- rtx choice = SET_SRC (PATTERN (temp1));
- if (GET_CODE (choice) == IF_THEN_ELSE)
- {
- enum rtx_code code = GET_CODE (XEXP (choice, 0));
- rtx val = SET_SRC (PATTERN (temp));
- rtx cond
- = simplify_relational_operation (code, GET_MODE (SET_DEST (PATTERN (temp))),
- val, const0_rtx);
- rtx ultimate;
-
- if (cond == const_true_rtx)
- ultimate = XEXP (choice, 1);
- else if (cond == const0_rtx)
- ultimate = XEXP (choice, 2);
- else
- ultimate = 0;
-
- if (ultimate == pc_rtx)
- ultimate = get_label_after (temp1);
- else if (ultimate && GET_CODE (ultimate) != RETURN)
- ultimate = XEXP (ultimate, 0);
-
- if (ultimate && JUMP_LABEL(insn) != ultimate)
- changed |= redirect_jump (insn, ultimate);
- }
- }
-#endif
-
-#if 0
- /* @@ This needs a bit of work before it will be right.
-
- Any type of comparison can be accepted for the first and
- second compare. When rewriting the first jump, we must
- compute the what conditions can reach label3, and use the
- appropriate code. We can not simply reverse/swap the code
- of the first jump. In some cases, the second jump must be
- rewritten also.
-
- For example,
- < == converts to > ==
- < != converts to == >
- etc.
-
- If the code is written to only accept an '==' test for the second
- compare, then all that needs to be done is to swap the condition
- of the first branch.
-
- It is questionable whether we want this optimization anyways,
- since if the user wrote code like this because he/she knew that
- the jump to label1 is taken most of the time, then rewriting
- this gives slower code. */
- /* @@ This should call get_condition to find the values being
- compared, instead of looking for a COMPARE insn when HAVE_cc0
- is not defined. This would allow it to work on the m88k. */
- /* @@ This optimization is only safe before cse is run if HAVE_cc0
- is not defined and the condition is tested by a separate compare
- insn. This is because the code below assumes that the result
- of the compare dies in the following branch. */
-
- /* Simplify test a ~= b
- condjump label1;
- test a == b
- condjump label2;
- jump label3;
- label1:
-
- rewriting as
- test a ~~= b
- condjump label3
- test a == b
- condjump label2
- label1:
-
- where ~= is an inequality, e.g. >, and ~~= is the swapped
- inequality, e.g. <.
-
- We recognize this case scanning backwards.
-
- TEMP is the conditional jump to `label2';
- TEMP1 is the test for `a == b';
- TEMP2 is the conditional jump to `label1';
- TEMP3 is the test for `a ~= b'. */
- else if (this_is_simplejump
- && (temp = prev_active_insn (insn))
- && no_labels_between_p (temp, insn)
- && condjump_p (temp)
- && (temp1 = prev_active_insn (temp))
- && no_labels_between_p (temp1, temp)
- && GET_CODE (temp1) == INSN
- && GET_CODE (PATTERN (temp1)) == SET
-#ifdef HAVE_cc0
- && sets_cc0_p (PATTERN (temp1)) == 1
-#else
- && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE
- && GET_CODE (SET_DEST (PATTERN (temp1))) == REG
- && (temp == find_next_ref (SET_DEST (PATTERN (temp1)), temp1))
-#endif
- && (temp2 = prev_active_insn (temp1))
- && no_labels_between_p (temp2, temp1)
- && condjump_p (temp2)
- && JUMP_LABEL (temp2) == next_nonnote_insn (NEXT_INSN (insn))
- && (temp3 = prev_active_insn (temp2))
- && no_labels_between_p (temp3, temp2)
- && GET_CODE (PATTERN (temp3)) == SET
- && rtx_equal_p (SET_DEST (PATTERN (temp3)),
- SET_DEST (PATTERN (temp1)))
- && rtx_equal_p (SET_SRC (PATTERN (temp1)),
- SET_SRC (PATTERN (temp3)))
- && ! inequality_comparisons_p (PATTERN (temp))
- && inequality_comparisons_p (PATTERN (temp2)))
- {
- rtx fallthrough_label = JUMP_LABEL (temp2);
-
- ++LABEL_NUSES (fallthrough_label);
- if (swap_jump (temp2, JUMP_LABEL (insn)))
- {
- delete_insn (insn);
- changed = 1;
- }
-
- if (--LABEL_NUSES (fallthrough_label) == 0)
- delete_insn (fallthrough_label);
- }
-#endif
- /* Simplify if (...) {... x = 1;} if (x) ...
-
- We recognize this case backwards.
-
- TEMP is the test of `x';
- TEMP1 is the assignment to `x' at the end of the
- previous statement. */
- /* @@ This should call get_condition to find the values being
- compared, instead of looking for a COMPARE insn when HAVE_cc0
- is not defined. This would allow it to work on the m88k. */
- /* @@ This optimization is only safe before cse is run if HAVE_cc0
- is not defined and the condition is tested by a separate compare
- insn. This is because the code below assumes that the result
- of the compare dies in the following branch. */
-
- /* ??? This has to be turned off. The problem is that the
- unconditional jump might indirectly end up branching to the
- label between TEMP1 and TEMP. We can't detect this, in general,
- since it may become a jump to there after further optimizations.
- If that jump is done, it will be deleted, so we will retry
- this optimization in the next pass, thus an infinite loop.
-
- The present code prevents this by putting the jump after the
- label, but this is not logically correct. */
-#if 0
- else if (this_is_condjump
- /* Safe to skip USE and CLOBBER insns here
- since they will not be deleted. */
- && (temp = prev_active_insn (insn))
- && no_labels_between_p (temp, insn)
- && GET_CODE (temp) == INSN
- && GET_CODE (PATTERN (temp)) == SET
-#ifdef HAVE_cc0
- && sets_cc0_p (PATTERN (temp)) == 1
- && GET_CODE (SET_SRC (PATTERN (temp))) == REG
-#else
- /* Temp must be a compare insn, we can not accept a register
- to register move here, since it may not be simply a
- tst insn. */
- && GET_CODE (SET_SRC (PATTERN (temp))) == COMPARE
- && XEXP (SET_SRC (PATTERN (temp)), 1) == const0_rtx
- && GET_CODE (XEXP (SET_SRC (PATTERN (temp)), 0)) == REG
- && GET_CODE (SET_DEST (PATTERN (temp))) == REG
- && insn == find_next_ref (SET_DEST (PATTERN (temp)), temp)
-#endif
- /* May skip USE or CLOBBER insns here
- for checking for opportunity, since we
- take care of them later. */
- && (temp1 = prev_active_insn (temp))
- && GET_CODE (temp1) == INSN
- && GET_CODE (PATTERN (temp1)) == SET
-#ifdef HAVE_cc0
- && SET_SRC (PATTERN (temp)) == SET_DEST (PATTERN (temp1))
-#else
- && (XEXP (SET_SRC (PATTERN (temp)), 0)
- == SET_DEST (PATTERN (temp1)))
-#endif
- && CONSTANT_P (SET_SRC (PATTERN (temp1)))
- /* If this isn't true, cse will do the job. */
- && ! no_labels_between_p (temp1, temp))
- {
- /* Get the if_then_else from the condjump. */
- rtx choice = SET_SRC (PATTERN (insn));
- if (GET_CODE (choice) == IF_THEN_ELSE
- && (GET_CODE (XEXP (choice, 0)) == EQ
- || GET_CODE (XEXP (choice, 0)) == NE))
- {
- int want_nonzero = (GET_CODE (XEXP (choice, 0)) == NE);
- rtx last_insn;
- rtx ultimate;
- rtx p;
-
- /* Get the place that condjump will jump to
- if it is reached from here. */
- if ((SET_SRC (PATTERN (temp1)) != const0_rtx)
- == want_nonzero)
- ultimate = XEXP (choice, 1);
- else
- ultimate = XEXP (choice, 2);
- /* Get it as a CODE_LABEL. */
- if (ultimate == pc_rtx)
- ultimate = get_label_after (insn);
- else
- /* Get the label out of the LABEL_REF. */
- ultimate = XEXP (ultimate, 0);
-
- /* Insert the jump immediately before TEMP, specifically
- after the label that is between TEMP1 and TEMP. */
- last_insn = PREV_INSN (temp);
-
- /* If we would be branching to the next insn, the jump
- would immediately be deleted and the re-inserted in
- a subsequent pass over the code. So don't do anything
- in that case. */
- if (next_active_insn (last_insn)
- != next_active_insn (ultimate))
- {
- emit_barrier_after (last_insn);
- p = emit_jump_insn_after (gen_jump (ultimate),
- last_insn);
- JUMP_LABEL (p) = ultimate;
- ++LABEL_NUSES (ultimate);
- if (INSN_UID (ultimate) < max_jump_chain
- && INSN_CODE (p) < max_jump_chain)
- {
- jump_chain[INSN_UID (p)]
- = jump_chain[INSN_UID (ultimate)];
- jump_chain[INSN_UID (ultimate)] = p;
- }
- changed = 1;
- continue;
- }
- }
- }
-#endif
-#ifdef HAVE_trap
- /* Detect a conditional jump jumping over an unconditional trap. */
- else if (HAVE_trap
- && this_is_condjump && ! this_is_simplejump
- && reallabelprev != 0
- && GET_CODE (reallabelprev) == INSN
- && GET_CODE (PATTERN (reallabelprev)) == TRAP_IF
- && TRAP_CONDITION (PATTERN (reallabelprev)) == const_true_rtx
- && prev_active_insn (reallabelprev) == insn
- && no_labels_between_p (insn, reallabelprev)
- && (temp2 = get_condition (insn, &temp4))
- && can_reverse_comparison_p (temp2, insn))
- {
- rtx new = gen_cond_trap (reverse_condition (GET_CODE (temp2)),
- XEXP (temp2, 0), XEXP (temp2, 1),
- TRAP_CODE (PATTERN (reallabelprev)));
-
- if (new)
- {
- emit_insn_before (new, temp4);
- delete_insn (reallabelprev);
- delete_jump (insn);
- changed = 1;
- continue;
- }
- }
- /* Detect a jump jumping to an unconditional trap. */
- else if (HAVE_trap && this_is_condjump
- && (temp = next_active_insn (JUMP_LABEL (insn)))
- && GET_CODE (temp) == INSN
- && GET_CODE (PATTERN (temp)) == TRAP_IF
- && (this_is_simplejump
- || (temp2 = get_condition (insn, &temp4))))
- {
- rtx tc = TRAP_CONDITION (PATTERN (temp));
-
- if (tc == const_true_rtx
- || (! this_is_simplejump && rtx_equal_p (temp2, tc)))
- {
- rtx new;
- /* Replace an unconditional jump to a trap with a trap. */
- if (this_is_simplejump)
- {
- emit_barrier_after (emit_insn_before (gen_trap (), insn));
- delete_jump (insn);
- changed = 1;
- continue;
- }
- new = gen_cond_trap (GET_CODE (temp2), XEXP (temp2, 0),
- XEXP (temp2, 1),
- TRAP_CODE (PATTERN (temp)));
- if (new)
- {
- emit_insn_before (new, temp4);
- delete_jump (insn);
- changed = 1;
- continue;
- }
- }
- /* If the trap condition and jump condition are mutually
- exclusive, redirect the jump to the following insn. */
- else if (GET_RTX_CLASS (GET_CODE (tc)) == '<'
- && ! this_is_simplejump
- && swap_condition (GET_CODE (temp2)) == GET_CODE (tc)
- && rtx_equal_p (XEXP (tc, 0), XEXP (temp2, 0))
- && rtx_equal_p (XEXP (tc, 1), XEXP (temp2, 1))
- && redirect_jump (insn, get_label_after (temp)))
- {
- changed = 1;
- continue;
- }
- }
-#endif
- else
- {
- /* Now that the jump has been tensioned,
- try cross jumping: check for identical code
- before the jump and before its target label. */
-
- /* First, cross jumping of conditional jumps: */
-
- if (cross_jump && condjump_p (insn))
- {
- rtx newjpos, newlpos;
- rtx x = prev_real_insn (JUMP_LABEL (insn));
-
- /* A conditional jump may be crossjumped
- only if the place it jumps to follows
- an opposing jump that comes back here. */
-
- if (x != 0 && ! jump_back_p (x, insn))
- /* We have no opposing jump;
- cannot cross jump this insn. */
- x = 0;
-
- newjpos = 0;
- /* TARGET is nonzero if it is ok to cross jump
- to code before TARGET. If so, see if matches. */
- if (x != 0)
- find_cross_jump (insn, x, 2,
- &newjpos, &newlpos);
-
- if (newjpos != 0)
- {
- do_cross_jump (insn, newjpos, newlpos);
- /* Make the old conditional jump
- into an unconditional one. */
- SET_SRC (PATTERN (insn))
- = gen_rtx_LABEL_REF (VOIDmode, JUMP_LABEL (insn));
- INSN_CODE (insn) = -1;
- emit_barrier_after (insn);
- /* Add to jump_chain unless this is a new label
- whose UID is too large. */
- if (INSN_UID (JUMP_LABEL (insn)) < max_jump_chain)
- {
- jump_chain[INSN_UID (insn)]
- = jump_chain[INSN_UID (JUMP_LABEL (insn))];
- jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn;
- }
- changed = 1;
- next = insn;
- }
- }
-
- /* Cross jumping of unconditional jumps:
- a few differences. */
-
- if (cross_jump && simplejump_p (insn))
- {
- rtx newjpos, newlpos;
- rtx target;
-
- newjpos = 0;
-
- /* TARGET is nonzero if it is ok to cross jump
- to code before TARGET. If so, see if matches. */
- find_cross_jump (insn, JUMP_LABEL (insn), 1,
- &newjpos, &newlpos);
-
- /* If cannot cross jump to code before the label,
- see if we can cross jump to another jump to
- the same label. */
- /* Try each other jump to this label. */
- if (INSN_UID (JUMP_LABEL (insn)) < max_uid)
- for (target = jump_chain[INSN_UID (JUMP_LABEL (insn))];
- target != 0 && newjpos == 0;
- target = jump_chain[INSN_UID (target)])
- if (target != insn
- && JUMP_LABEL (target) == JUMP_LABEL (insn)
- /* Ignore TARGET if it's deleted. */
- && ! INSN_DELETED_P (target))
- find_cross_jump (insn, target, 2,
- &newjpos, &newlpos);
-
- if (newjpos != 0)
- {
- do_cross_jump (insn, newjpos, newlpos);
- changed = 1;
- next = insn;
- }
- }
-
- /* This code was dead in the previous jump.c! */
- if (cross_jump && GET_CODE (PATTERN (insn)) == RETURN)
- {
- /* Return insns all "jump to the same place"
- so we can cross-jump between any two of them. */
-
- rtx newjpos, newlpos, target;
-
- newjpos = 0;
-
- /* If cannot cross jump to code before the label,
- see if we can cross jump to another jump to
- the same label. */
- /* Try each other jump to this label. */
- for (target = jump_chain[0];
- target != 0 && newjpos == 0;
- target = jump_chain[INSN_UID (target)])
- if (target != insn
- && ! INSN_DELETED_P (target)
- && GET_CODE (PATTERN (target)) == RETURN)
- find_cross_jump (insn, target, 2,
- &newjpos, &newlpos);
-
- if (newjpos != 0)
- {
- do_cross_jump (insn, newjpos, newlpos);
- changed = 1;
- next = insn;
- }
- }
- }
- }
-
- first = 0;
- }
-
- /* Delete extraneous line number notes.
- Note that two consecutive notes for different lines are not really
- extraneous. There should be some indication where that line belonged,
- even if it became empty. */
+ rtx temp, temp1;
- {
- rtx last_note = 0;
+ next = NEXT_INSN (insn);
- for (insn = f; insn; insn = NEXT_INSN (insn))
- if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0)
+ /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional
+ jump. Try to optimize by duplicating the loop exit test if so.
+ This is only safe immediately after regscan, because it uses
+ the values of regno_first_uid and regno_last_uid. */
+ if (GET_CODE (insn) == NOTE
+ && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG
+ && (temp1 = next_nonnote_insn (insn)) != 0
+ && any_uncondjump_p (temp1) && onlyjump_p (temp1))
{
- /* Delete this note if it is identical to previous note. */
- if (last_note
- && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note)
- && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note))
+ temp = PREV_INSN (insn);
+ if (duplicate_loop_exit_test (insn))
{
- delete_insn (insn);
- continue;
+ next = NEXT_INSN (temp);
}
-
- last_note = insn;
- }
- }
-
-#ifdef HAVE_return
- if (HAVE_return)
- {
- /* If we fall through to the epilogue, see if we can insert a RETURN insn
- in front of it. If the machine allows it at this point (we might be
- after reload for a leaf routine), it will improve optimization for it
- to be there. We do this both here and at the start of this pass since
- the RETURN might have been deleted by some of our optimizations. */
- insn = get_last_insn ();
- while (insn && GET_CODE (insn) == NOTE)
- insn = PREV_INSN (insn);
-
- if (insn && GET_CODE (insn) != BARRIER)
- {
- emit_jump_insn (gen_return ());
- emit_barrier ();
}
}
-#endif
+}
+
+void
+purge_line_number_notes (f)
+ rtx f;
+{
+ rtx last_note = 0;
+ rtx insn;
+ /* Delete extraneous line number notes.
+ Note that two consecutive notes for different lines are not really
+ extraneous. There should be some indication where that line belonged,
+ even if it became empty. */
- /* CAN_REACH_END is persistent for each function. Once set it should
- not be cleared. This is especially true for the case where we
- delete the NOTE_FUNCTION_END note. CAN_REACH_END is cleared by
- the front-end before compiling each function. */
- if (calculate_can_reach_end (last_insn, optimize != 0))
- can_reach_end = 1;
+ for (insn = f; insn; insn = NEXT_INSN (insn))
+ if (GET_CODE (insn) == NOTE)
+ {
+ if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
+ /* Any previous line note was for the prologue; gdb wants a new
+ note after the prologue even if it is for the same line. */
+ last_note = NULL_RTX;
+ else if (NOTE_LINE_NUMBER (insn) >= 0)
+ {
+ /* Delete this note if it is identical to previous note. */
+ if (last_note
+ && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note)
+ && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note))
+ {
+ delete_related_insns (insn);
+ continue;
+ }
-end:
- /* Clean up. */
- free (jump_chain);
- jump_chain = 0;
+ last_note = insn;
+ }
+ }
}
\f
/* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL
return largest_uid;
}
-/* Delete insns following barriers, up to next label.
-
- Also delete no-op jumps created by gcse. */
-static void
-delete_barrier_successors (f)
- rtx f;
-{
- rtx insn;
-
- for (insn = f; insn;)
- {
- if (GET_CODE (insn) == BARRIER)
- {
- insn = NEXT_INSN (insn);
-
- never_reached_warning (insn);
-
- while (insn != 0 && GET_CODE (insn) != CODE_LABEL)
- {
- if (GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END)
- insn = NEXT_INSN (insn);
- else
- insn = delete_insn (insn);
- }
- /* INSN is now the code_label. */
- }
- /* Also remove (set (pc) (pc)) insns which can be created by
- gcse. We eliminate such insns now to avoid having them
- cause problems later. */
- else if (GET_CODE (insn) == JUMP_INSN
- && GET_CODE (PATTERN (insn)) == SET
- && SET_SRC (PATTERN (insn)) == pc_rtx
- && SET_DEST (PATTERN (insn)) == pc_rtx)
- insn = delete_insn (insn);
-
- else
- insn = NEXT_INSN (insn);
- }
-}
-
/* Mark the label each jump jumps to.
- Combine consecutive labels, and count uses of labels.
-
- For each label, make a chain (using `jump_chain')
- of all the *unconditional* jumps that jump to it;
- also make a chain of all returns.
-
- CROSS_JUMP indicates whether we are doing cross jumping
- and if we are whether we will be paying attention to
- death notes or not. */
+ Combine consecutive labels, and count uses of labels. */
static void
-mark_all_labels (f, cross_jump)
+mark_all_labels (f)
rtx f;
- int cross_jump;
{
rtx insn;
for (insn = f; insn; insn = NEXT_INSN (insn))
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ if (INSN_P (insn))
{
- mark_jump_label (PATTERN (insn), insn, cross_jump);
- if (! INSN_DELETED_P (insn) && GET_CODE (insn) == JUMP_INSN)
+ if (GET_CODE (insn) == CALL_INSN
+ && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
{
- if (JUMP_LABEL (insn) != 0 && simplejump_p (insn))
+ mark_all_labels (XEXP (PATTERN (insn), 0));
+ mark_all_labels (XEXP (PATTERN (insn), 1));
+ mark_all_labels (XEXP (PATTERN (insn), 2));
+
+ /* Canonicalize the tail recursion label attached to the
+ CALL_PLACEHOLDER insn. */
+ if (XEXP (PATTERN (insn), 3))
{
- jump_chain[INSN_UID (insn)]
- = jump_chain[INSN_UID (JUMP_LABEL (insn))];
- jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn;
+ rtx label_ref = gen_rtx_LABEL_REF (VOIDmode,
+ XEXP (PATTERN (insn), 3));
+ mark_jump_label (label_ref, insn, 0);
+ XEXP (PATTERN (insn), 3) = XEXP (label_ref, 0);
}
- if (GET_CODE (PATTERN (insn)) == RETURN)
+
+ continue;
+ }
+
+ mark_jump_label (PATTERN (insn), insn, 0);
+ if (! INSN_DELETED_P (insn) && GET_CODE (insn) == JUMP_INSN)
+ {
+ /* When we know the LABEL_REF contained in a REG used in
+ an indirect jump, we'll have a REG_LABEL note so that
+ flow can tell where it's going. */
+ if (JUMP_LABEL (insn) == 0)
{
- jump_chain[INSN_UID (insn)] = jump_chain[0];
- jump_chain[0] = insn;
+ rtx label_note = find_reg_note (insn, REG_LABEL, NULL_RTX);
+ if (label_note)
+ {
+ /* But a LABEL_REF around the REG_LABEL note, so
+ that we can canonicalize it. */
+ rtx label_ref = gen_rtx_LABEL_REF (VOIDmode,
+ XEXP (label_note, 0));
+
+ mark_jump_label (label_ref, insn, 0);
+ XEXP (label_note, 0) = XEXP (label_ref, 0);
+ JUMP_LABEL (insn) = XEXP (label_note, 0);
+ }
}
}
}
}
-/* Delete all labels already not referenced.
- Also find and return the last insn. */
-
-static rtx
-delete_unreferenced_labels (f)
- rtx f;
-{
- rtx final = NULL_RTX;
- rtx insn;
-
- for (insn = f; insn; )
- {
- if (GET_CODE (insn) == CODE_LABEL
- && LABEL_NUSES (insn) == 0
- && LABEL_ALTERNATE_NAME (insn) == NULL)
- insn = delete_insn (insn);
- else
- {
- final = insn;
- insn = NEXT_INSN (insn);
- }
- }
-
- return final;
-}
-
-/* Delete various simple forms of moves which have no necessary
- side effect. */
-
-static void
-delete_noop_moves (f)
- rtx f;
-{
- rtx insn, next;
-
- for (insn = f; insn; )
- {
- next = NEXT_INSN (insn);
-
- if (GET_CODE (insn) == INSN)
- {
- register rtx body = PATTERN (insn);
-
-/* Combine stack_adjusts with following push_insns. */
-#ifdef PUSH_ROUNDING
- if (GET_CODE (body) == SET
- && SET_DEST (body) == stack_pointer_rtx
- && GET_CODE (SET_SRC (body)) == PLUS
- && XEXP (SET_SRC (body), 0) == stack_pointer_rtx
- && GET_CODE (XEXP (SET_SRC (body), 1)) == CONST_INT
- && INTVAL (XEXP (SET_SRC (body), 1)) > 0)
- {
- rtx p;
- rtx stack_adjust_insn = insn;
- int stack_adjust_amount = INTVAL (XEXP (SET_SRC (body), 1));
- int total_pushed = 0;
- int pushes = 0;
-
- /* Find all successive push insns. */
- p = insn;
- /* Don't convert more than three pushes;
- that starts adding too many displaced addresses
- and the whole thing starts becoming a losing
- proposition. */
- while (pushes < 3)
- {
- rtx pbody, dest;
- p = next_nonnote_insn (p);
- if (p == 0 || GET_CODE (p) != INSN)
- break;
- pbody = PATTERN (p);
- if (GET_CODE (pbody) != SET)
- break;
- dest = SET_DEST (pbody);
- /* Allow a no-op move between the adjust and the push. */
- if (GET_CODE (dest) == REG
- && GET_CODE (SET_SRC (pbody)) == REG
- && REGNO (dest) == REGNO (SET_SRC (pbody)))
- continue;
- if (! (GET_CODE (dest) == MEM
- && GET_CODE (XEXP (dest, 0)) == POST_INC
- && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx))
- break;
- pushes++;
- if (total_pushed + GET_MODE_SIZE (GET_MODE (SET_DEST (pbody)))
- > stack_adjust_amount)
- break;
- total_pushed += GET_MODE_SIZE (GET_MODE (SET_DEST (pbody)));
- }
-
- /* Discard the amount pushed from the stack adjust;
- maybe eliminate it entirely. */
- if (total_pushed >= stack_adjust_amount)
- {
- delete_computation (stack_adjust_insn);
- total_pushed = stack_adjust_amount;
- }
- else
- XEXP (SET_SRC (PATTERN (stack_adjust_insn)), 1)
- = GEN_INT (stack_adjust_amount - total_pushed);
-
- /* Change the appropriate push insns to ordinary stores. */
- p = insn;
- while (total_pushed > 0)
- {
- rtx pbody, dest;
- p = next_nonnote_insn (p);
- if (GET_CODE (p) != INSN)
- break;
- pbody = PATTERN (p);
- if (GET_CODE (pbody) != SET)
- break;
- dest = SET_DEST (pbody);
- /* Allow a no-op move between the adjust and the push. */
- if (GET_CODE (dest) == REG
- && GET_CODE (SET_SRC (pbody)) == REG
- && REGNO (dest) == REGNO (SET_SRC (pbody)))
- continue;
- if (! (GET_CODE (dest) == MEM
- && GET_CODE (XEXP (dest, 0)) == POST_INC
- && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx))
- break;
- total_pushed -= GET_MODE_SIZE (GET_MODE (SET_DEST (pbody)));
- /* If this push doesn't fully fit in the space
- of the stack adjust that we deleted,
- make another stack adjust here for what we
- didn't use up. There should be peepholes
- to recognize the resulting sequence of insns. */
- if (total_pushed < 0)
- {
- emit_insn_before (gen_add2_insn (stack_pointer_rtx,
- GEN_INT (- total_pushed)),
- p);
- break;
- }
- XEXP (dest, 0)
- = plus_constant (stack_pointer_rtx, total_pushed);
- }
- }
-#endif
-
- /* Detect and delete no-op move instructions
- resulting from not allocating a parameter in a register. */
-
- if (GET_CODE (body) == SET
- && (SET_DEST (body) == SET_SRC (body)
- || (GET_CODE (SET_DEST (body)) == MEM
- && GET_CODE (SET_SRC (body)) == MEM
- && rtx_equal_p (SET_SRC (body), SET_DEST (body))))
- && ! (GET_CODE (SET_DEST (body)) == MEM
- && MEM_VOLATILE_P (SET_DEST (body)))
- && ! (GET_CODE (SET_SRC (body)) == MEM
- && MEM_VOLATILE_P (SET_SRC (body))))
- delete_computation (insn);
-
- /* Detect and ignore no-op move instructions
- resulting from smart or fortuitous register allocation. */
-
- else if (GET_CODE (body) == SET)
- {
- int sreg = true_regnum (SET_SRC (body));
- int dreg = true_regnum (SET_DEST (body));
-
- if (sreg == dreg && sreg >= 0)
- delete_insn (insn);
- else if (sreg >= 0 && dreg >= 0)
- {
- rtx trial;
- rtx tem = find_equiv_reg (NULL_RTX, insn, 0,
- sreg, NULL_PTR, dreg,
- GET_MODE (SET_SRC (body)));
-
- if (tem != 0
- && GET_MODE (tem) == GET_MODE (SET_DEST (body)))
- {
- /* DREG may have been the target of a REG_DEAD note in
- the insn which makes INSN redundant. If so, reorg
- would still think it is dead. So search for such a
- note and delete it if we find it. */
- if (! find_regno_note (insn, REG_UNUSED, dreg))
- for (trial = prev_nonnote_insn (insn);
- trial && GET_CODE (trial) != CODE_LABEL;
- trial = prev_nonnote_insn (trial))
- if (find_regno_note (trial, REG_DEAD, dreg))
- {
- remove_death (dreg, trial);
- break;
- }
-
- /* Deleting insn could lose a death-note for SREG. */
- if ((trial = find_regno_note (insn, REG_DEAD, sreg)))
- {
- /* Change this into a USE so that we won't emit
- code for it, but still can keep the note. */
- PATTERN (insn)
- = gen_rtx_USE (VOIDmode, XEXP (trial, 0));
- INSN_CODE (insn) = -1;
- /* Remove all reg notes but the REG_DEAD one. */
- REG_NOTES (insn) = trial;
- XEXP (trial, 1) = NULL_RTX;
- }
- else
- delete_insn (insn);
- }
- }
- else if (dreg >= 0 && CONSTANT_P (SET_SRC (body))
- && find_equiv_reg (SET_SRC (body), insn, 0, dreg,
- NULL_PTR, 0,
- GET_MODE (SET_DEST (body))))
- {
- /* This handles the case where we have two consecutive
- assignments of the same constant to pseudos that didn't
- get a hard reg. Each SET from the constant will be
- converted into a SET of the spill register and an
- output reload will be made following it. This produces
- two loads of the same constant into the same spill
- register. */
-
- rtx in_insn = insn;
-
- /* Look back for a death note for the first reg.
- If there is one, it is no longer accurate. */
- while (in_insn && GET_CODE (in_insn) != CODE_LABEL)
- {
- if ((GET_CODE (in_insn) == INSN
- || GET_CODE (in_insn) == JUMP_INSN)
- && find_regno_note (in_insn, REG_DEAD, dreg))
- {
- remove_death (dreg, in_insn);
- break;
- }
- in_insn = PREV_INSN (in_insn);
- }
-
- /* Delete the second load of the value. */
- delete_insn (insn);
- }
- }
- else if (GET_CODE (body) == PARALLEL)
- {
- /* If each part is a set between two identical registers or
- a USE or CLOBBER, delete the insn. */
- int i, sreg, dreg;
- rtx tem;
-
- for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
- {
- tem = XVECEXP (body, 0, i);
- if (GET_CODE (tem) == USE || GET_CODE (tem) == CLOBBER)
- continue;
-
- if (GET_CODE (tem) != SET
- || (sreg = true_regnum (SET_SRC (tem))) < 0
- || (dreg = true_regnum (SET_DEST (tem))) < 0
- || dreg != sreg)
- break;
- }
-
- if (i < 0)
- delete_insn (insn);
- }
- /* Also delete insns to store bit fields if they are no-ops. */
- /* Not worth the hair to detect this in the big-endian case. */
- else if (! BYTES_BIG_ENDIAN
- && GET_CODE (body) == SET
- && GET_CODE (SET_DEST (body)) == ZERO_EXTRACT
- && XEXP (SET_DEST (body), 2) == const0_rtx
- && XEXP (SET_DEST (body), 0) == SET_SRC (body)
- && ! (GET_CODE (SET_SRC (body)) == MEM
- && MEM_VOLATILE_P (SET_SRC (body))))
- delete_insn (insn);
- }
- insn = next;
- }
-}
-
-/* See if there is still a NOTE_INSN_FUNCTION_END in this function.
- If so indicate that this function can drop off the end by returning
- 1, else return 0.
-
- CHECK_DELETED indicates whether we must check if the note being
- searched for has the deleted flag set.
-
- DELETE_FINAL_NOTE indicates whether we should delete the note
- if we find it. */
-
-static int
-calculate_can_reach_end (last, delete_final_note)
- rtx last;
- int delete_final_note;
-{
- rtx insn = last;
- int n_labels = 1;
-
- while (insn != NULL_RTX)
- {
- int ok = 0;
-
- /* One label can follow the end-note: the return label. */
- if (GET_CODE (insn) == CODE_LABEL && n_labels-- > 0)
- ok = 1;
- /* Ordinary insns can follow it if returning a structure. */
- else if (GET_CODE (insn) == INSN)
- ok = 1;
- /* If machine uses explicit RETURN insns, no epilogue,
- then one of them follows the note. */
- else if (GET_CODE (insn) == JUMP_INSN
- && GET_CODE (PATTERN (insn)) == RETURN)
- ok = 1;
- /* A barrier can follow the return insn. */
- else if (GET_CODE (insn) == BARRIER)
- ok = 1;
- /* Other kinds of notes can follow also. */
- else if (GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END)
- ok = 1;
-
- if (ok != 1)
- break;
-
- insn = PREV_INSN (insn);
- }
-
- /* See if we backed up to the appropriate type of note. */
- if (insn != NULL_RTX
- && GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END)
- {
- if (delete_final_note)
- delete_insn (insn);
- return 1;
- }
-
- return 0;
-}
-
/* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional
jump. Assume that this unconditional jump is to the exit test code. If
the code is sufficiently simple, make a copy of it before INSN,
rtx lastexit;
int max_reg = max_reg_num ();
rtx *reg_map = 0;
+ rtx loop_pre_header_label;
/* Scan the exit code. We do not perform this optimization if any insn:
reg_map[REGNO (reg)] = gen_reg_rtx (GET_MODE (reg));
}
}
+ loop_pre_header_label = gen_label_rtx ();
/* Now copy each insn. */
for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn))
NOTE_SOURCE_FILE (copy) = NOTE_SOURCE_FILE (insn);
}
break;
-
+
case INSN:
copy = emit_insn_before (copy_insn (PATTERN (insn)), loop_start);
if (reg_map)
replace_regs (PATTERN (copy), reg_map, max_reg, 1);
-
+
mark_jump_label (PATTERN (copy), copy, 0);
-
+
/* Copy all REG_NOTES except REG_LABEL since mark_jump_label will
make them. */
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) != REG_LABEL)
- REG_NOTES (copy)
- = copy_insn_1 (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link),
- XEXP (link, 0),
- REG_NOTES (copy)));
+ {
+ if (GET_CODE (link) == EXPR_LIST)
+ REG_NOTES (copy)
+ = copy_insn_1 (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link),
+ XEXP (link, 0),
+ REG_NOTES (copy)));
+ else
+ REG_NOTES (copy)
+ = copy_insn_1 (gen_rtx_INSN_LIST (REG_NOTE_KIND (link),
+ XEXP (link, 0),
+ REG_NOTES (copy)));
+ }
+
if (reg_map && REG_NOTES (copy))
replace_regs (REG_NOTES (copy), reg_map, max_reg, 1);
break;
-
+
case JUMP_INSN:
- copy = emit_jump_insn_before (copy_insn (PATTERN (insn)), loop_start);
+ copy = emit_jump_insn_before (copy_insn (PATTERN (insn)),
+ loop_start);
if (reg_map)
replace_regs (PATTERN (copy), reg_map, max_reg, 1);
mark_jump_label (PATTERN (copy), copy, 0);
if (reg_map)
replace_regs (REG_NOTES (copy), reg_map, max_reg, 1);
}
-
- /* If this is a simple jump, add it to the jump chain. */
-
- if (INSN_UID (copy) < max_jump_chain && JUMP_LABEL (copy)
- && simplejump_p (copy))
+
+ /* Predict conditional jump that do make loop looping as taken.
+ Other jumps are probably exit conditions, so predict
+ them as untaken. */
+ if (any_condjump_p (copy))
{
- jump_chain[INSN_UID (copy)]
- = jump_chain[INSN_UID (JUMP_LABEL (copy))];
- jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy;
+ rtx label = JUMP_LABEL (copy);
+ if (label)
+ {
+ /* The jump_insn after loop_start should be followed
+ by barrier and loopback label. */
+ if (prev_nonnote_insn (label)
+ && (prev_nonnote_insn (prev_nonnote_insn (label))
+ == next_nonnote_insn (loop_start)))
+ {
+ predict_insn_def (copy, PRED_LOOP_HEADER, TAKEN);
+ /* To keep pre-header, we need to redirect all loop
+ entrances before the LOOP_BEG note. */
+ redirect_jump (copy, loop_pre_header_label, 0);
+ }
+ else
+ predict_insn_def (copy, PRED_LOOP_HEADER, NOT_TAKEN);
+ }
}
break;
-
+
default:
abort ();
}
first_copy = copy;
mark_jump_label (PATTERN (copy), copy, 0);
- if (INSN_UID (copy) < max_jump_chain
- && INSN_UID (JUMP_LABEL (copy)) < max_jump_chain)
- {
- jump_chain[INSN_UID (copy)]
- = jump_chain[INSN_UID (JUMP_LABEL (copy))];
- jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy;
- }
emit_barrier_before (loop_start);
}
- /* Now scan from the first insn we copied to the last insn we copied
- (copy) for new pseudo registers. Do this after the code to jump to
- the end label since that might create a new pseudo too. */
- reg_scan_update (first_copy, copy, max_reg);
-
- /* Mark the exit code as the virtual top of the converted loop. */
- emit_note_before (NOTE_INSN_LOOP_VTOP, exitcode);
-
- delete_insn (next_nonnote_insn (loop_start));
-
- /* Clean up. */
- if (reg_map)
- free (reg_map);
-
- return 1;
-}
-\f
-/* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, and
- loop-end notes between START and END out before START. Assume that
- END is not such a note. START may be such a note. Returns the value
- of the new starting insn, which may be different if the original start
- was such a note. */
-
-rtx
-squeeze_notes (start, end)
- rtx start, end;
-{
- rtx insn;
- rtx next;
-
- for (insn = start; insn != end; insn = next)
- {
- next = NEXT_INSN (insn);
- if (GET_CODE (insn) == NOTE
- && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_VTOP))
- {
- if (insn == start)
- start = next;
- else
- {
- rtx prev = PREV_INSN (insn);
- PREV_INSN (insn) = PREV_INSN (start);
- NEXT_INSN (insn) = start;
- NEXT_INSN (PREV_INSN (insn)) = insn;
- PREV_INSN (NEXT_INSN (insn)) = insn;
- NEXT_INSN (prev) = next;
- PREV_INSN (next) = prev;
- }
- }
- }
-
- return start;
-}
-\f
-/* Compare the instructions before insn E1 with those before E2
- to find an opportunity for cross jumping.
- (This means detecting identical sequences of insns followed by
- jumps to the same place, or followed by a label and a jump
- to that label, and replacing one with a jump to the other.)
-
- Assume E1 is a jump that jumps to label E2
- (that is not always true but it might as well be).
- Find the longest possible equivalent sequences
- and store the first insns of those sequences into *F1 and *F2.
- Store zero there if no equivalent preceding instructions are found.
-
- We give up if we find a label in stream 1.
- Actually we could transfer that label into stream 2. */
-
-static void
-find_cross_jump (e1, e2, minimum, f1, f2)
- rtx e1, e2;
- int minimum;
- rtx *f1, *f2;
-{
- register rtx i1 = e1, i2 = e2;
- register rtx p1, p2;
- int lose = 0;
-
- rtx last1 = 0, last2 = 0;
- rtx afterlast1 = 0, afterlast2 = 0;
-
- *f1 = 0;
- *f2 = 0;
-
- while (1)
- {
- i1 = prev_nonnote_insn (i1);
-
- i2 = PREV_INSN (i2);
- while (i2 && (GET_CODE (i2) == NOTE || GET_CODE (i2) == CODE_LABEL))
- i2 = PREV_INSN (i2);
-
- if (i1 == 0)
- break;
-
- /* Don't allow the range of insns preceding E1 or E2
- to include the other (E2 or E1). */
- if (i2 == e1 || i1 == e2)
- break;
-
- /* If we will get to this code by jumping, those jumps will be
- tensioned to go directly to the new label (before I2),
- so this cross-jumping won't cost extra. So reduce the minimum. */
- if (GET_CODE (i1) == CODE_LABEL)
- {
- --minimum;
- break;
- }
-
- if (i2 == 0 || GET_CODE (i1) != GET_CODE (i2))
- break;
-
- /* Avoid moving insns across EH regions if either of the insns
- can throw. */
- if (flag_exceptions
- && (asynchronous_exceptions || GET_CODE (i1) == CALL_INSN)
- && !in_same_eh_region (i1, i2))
- break;
-
- p1 = PATTERN (i1);
- p2 = PATTERN (i2);
-
- /* If this is a CALL_INSN, compare register usage information.
- If we don't check this on stack register machines, the two
- CALL_INSNs might be merged leaving reg-stack.c with mismatching
- numbers of stack registers in the same basic block.
- If we don't check this on machines with delay slots, a delay slot may
- be filled that clobbers a parameter expected by the subroutine.
-
- ??? We take the simple route for now and assume that if they're
- equal, they were constructed identically. */
-
- if (GET_CODE (i1) == CALL_INSN
- && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1),
- CALL_INSN_FUNCTION_USAGE (i2)))
- lose = 1;
-
-#ifdef STACK_REGS
- /* If cross_jump_death_matters is not 0, the insn's mode
- indicates whether or not the insn contains any stack-like
- regs. */
-
- if (!lose && cross_jump_death_matters && stack_regs_mentioned (i1))
- {
- /* If register stack conversion has already been done, then
- death notes must also be compared before it is certain that
- the two instruction streams match. */
-
- rtx note;
- HARD_REG_SET i1_regset, i2_regset;
-
- CLEAR_HARD_REG_SET (i1_regset);
- CLEAR_HARD_REG_SET (i2_regset);
-
- for (note = REG_NOTES (i1); note; note = XEXP (note, 1))
- if (REG_NOTE_KIND (note) == REG_DEAD
- && STACK_REG_P (XEXP (note, 0)))
- SET_HARD_REG_BIT (i1_regset, REGNO (XEXP (note, 0)));
-
- for (note = REG_NOTES (i2); note; note = XEXP (note, 1))
- if (REG_NOTE_KIND (note) == REG_DEAD
- && STACK_REG_P (XEXP (note, 0)))
- SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0)));
-
- GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done);
-
- lose = 1;
-
- done:
- ;
- }
-#endif
-
- /* Don't allow old-style asm or volatile extended asms to be accepted
- for cross jumping purposes. It is conceptually correct to allow
- them, since cross-jumping preserves the dynamic instruction order
- even though it is changing the static instruction order. However,
- if an asm is being used to emit an assembler pseudo-op, such as
- the MIPS `.set reorder' pseudo-op, then the static instruction order
- matters and it must be preserved. */
- if (GET_CODE (p1) == ASM_INPUT || GET_CODE (p2) == ASM_INPUT
- || (GET_CODE (p1) == ASM_OPERANDS && MEM_VOLATILE_P (p1))
- || (GET_CODE (p2) == ASM_OPERANDS && MEM_VOLATILE_P (p2)))
- lose = 1;
-
- if (lose || GET_CODE (p1) != GET_CODE (p2)
- || ! rtx_renumbered_equal_p (p1, p2))
- {
- /* The following code helps take care of G++ cleanups. */
- rtx equiv1;
- rtx equiv2;
-
- if (!lose && GET_CODE (p1) == GET_CODE (p2)
- && ((equiv1 = find_reg_note (i1, REG_EQUAL, NULL_RTX)) != 0
- || (equiv1 = find_reg_note (i1, REG_EQUIV, NULL_RTX)) != 0)
- && ((equiv2 = find_reg_note (i2, REG_EQUAL, NULL_RTX)) != 0
- || (equiv2 = find_reg_note (i2, REG_EQUIV, NULL_RTX)) != 0)
- /* If the equivalences are not to a constant, they may
- reference pseudos that no longer exist, so we can't
- use them. */
- && CONSTANT_P (XEXP (equiv1, 0))
- && rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0)))
- {
- rtx s1 = single_set (i1);
- rtx s2 = single_set (i2);
- if (s1 != 0 && s2 != 0
- && rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2)))
- {
- validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1);
- validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1);
- if (! rtx_renumbered_equal_p (p1, p2))
- cancel_changes (0);
- else if (apply_change_group ())
- goto win;
- }
- }
+ emit_label_before (loop_pre_header_label, loop_start);
- /* Insns fail to match; cross jumping is limited to the following
- insns. */
+ /* Now scan from the first insn we copied to the last insn we copied
+ (copy) for new pseudo registers. Do this after the code to jump to
+ the end label since that might create a new pseudo too. */
+ reg_scan_update (first_copy, copy, max_reg);
-#ifdef HAVE_cc0
- /* Don't allow the insn after a compare to be shared by
- cross-jumping unless the compare is also shared.
- Here, if either of these non-matching insns is a compare,
- exclude the following insn from possible cross-jumping. */
- if (sets_cc0_p (p1) || sets_cc0_p (p2))
- last1 = afterlast1, last2 = afterlast2, ++minimum;
-#endif
+ /* Mark the exit code as the virtual top of the converted loop. */
+ emit_note_before (NOTE_INSN_LOOP_VTOP, exitcode);
- /* If cross-jumping here will feed a jump-around-jump
- optimization, this jump won't cost extra, so reduce
- the minimum. */
- if (GET_CODE (i1) == JUMP_INSN
- && JUMP_LABEL (i1)
- && prev_real_insn (JUMP_LABEL (i1)) == e1)
- --minimum;
- break;
- }
+ delete_related_insns (next_nonnote_insn (loop_start));
- win:
- if (GET_CODE (p1) != USE && GET_CODE (p1) != CLOBBER)
- {
- /* Ok, this insn is potentially includable in a cross-jump here. */
- afterlast1 = last1, afterlast2 = last2;
- last1 = i1, last2 = i2, --minimum;
- }
- }
+ /* Clean up. */
+ if (reg_map)
+ free (reg_map);
- if (minimum <= 0 && last1 != 0 && last1 != e1)
- *f1 = last1, *f2 = last2;
+ return 1;
}
+\f
+/* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, loop-end,
+ notes between START and END out before START. START and END may be such
+ notes. Returns the values of the new starting and ending insns, which
+ may be different if the original ones were such notes. */
-static void
-do_cross_jump (insn, newjpos, newlpos)
- rtx insn, newjpos, newlpos;
+void
+squeeze_notes (startp, endp)
+ rtx* startp;
+ rtx* endp;
{
- /* Find an existing label at this point
- or make a new one if there is none. */
- register rtx label = get_label_before (newlpos);
+ rtx start = *startp;
+ rtx end = *endp;
+
+ rtx insn;
+ rtx next;
+ rtx last = NULL;
+ rtx past_end = NEXT_INSN (end);
- /* Make the same jump insn jump to the new point. */
- if (GET_CODE (PATTERN (insn)) == RETURN)
+ for (insn = start; insn != past_end; insn = next)
{
- /* Remove from jump chain of returns. */
- delete_from_jump_chain (insn);
- /* Change the insn. */
- PATTERN (insn) = gen_jump (label);
- INSN_CODE (insn) = -1;
- JUMP_LABEL (insn) = label;
- LABEL_NUSES (label)++;
- /* Add to new the jump chain. */
- if (INSN_UID (label) < max_jump_chain
- && INSN_UID (insn) < max_jump_chain)
+ next = NEXT_INSN (insn);
+ if (GET_CODE (insn) == NOTE
+ && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END
+ || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
+ || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG
+ || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END
+ || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT
+ || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_VTOP))
{
- jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (label)];
- jump_chain[INSN_UID (label)] = insn;
+ if (insn == start)
+ start = next;
+ else
+ {
+ rtx prev = PREV_INSN (insn);
+ PREV_INSN (insn) = PREV_INSN (start);
+ NEXT_INSN (insn) = start;
+ NEXT_INSN (PREV_INSN (insn)) = insn;
+ PREV_INSN (NEXT_INSN (insn)) = insn;
+ NEXT_INSN (prev) = next;
+ PREV_INSN (next) = prev;
+ }
}
+ else
+ last = insn;
}
- else
- redirect_jump (insn, label);
- /* Delete the matching insns before the jump. Also, remove any REG_EQUAL
- or REG_EQUIV note in the NEWLPOS stream that isn't also present in
- the NEWJPOS stream. */
+ /* There were no real instructions, and we can't represent an empty
+ range. Die. */
+ if (start == past_end)
+ abort ();
- while (newjpos != insn)
- {
- rtx lnote;
-
- for (lnote = REG_NOTES (newlpos); lnote; lnote = XEXP (lnote, 1))
- if ((REG_NOTE_KIND (lnote) == REG_EQUAL
- || REG_NOTE_KIND (lnote) == REG_EQUIV)
- && ! find_reg_note (newjpos, REG_EQUAL, XEXP (lnote, 0))
- && ! find_reg_note (newjpos, REG_EQUIV, XEXP (lnote, 0)))
- remove_note (newlpos, lnote);
-
- delete_insn (newjpos);
- newjpos = next_real_insn (newjpos);
- newlpos = next_real_insn (newlpos);
- }
+ end = last;
+
+ *startp = start;
+ *endp = end;
}
\f
/* Return the label before INSN, or put a new label there. */
return label;
}
\f
-/* Return 1 if INSN is a jump that jumps to right after TARGET
- only on the condition that TARGET itself would drop through.
- Assumes that TARGET is a conditional jump. */
-
-static int
-jump_back_p (insn, target)
- rtx insn, target;
+/* Given a comparison (CODE ARG0 ARG1), inside an insn, INSN, return a code
+ of reversed comparison if it is possible to do so. Otherwise return UNKNOWN.
+ UNKNOWN may be returned in case we are having CC_MODE compare and we don't
+ know whether it's source is floating point or integer comparison. Machine
+ description should define REVERSIBLE_CC_MODE and REVERSE_CONDITION macros
+ to help this function avoid overhead in these cases. */
+enum rtx_code
+reversed_comparison_code_parts (code, arg0, arg1, insn)
+ rtx insn, arg0, arg1;
+ enum rtx_code code;
{
- rtx cinsn, ctarget;
- enum rtx_code codei, codet;
+ enum machine_mode mode;
- if (simplejump_p (insn) || ! condjump_p (insn)
- || simplejump_p (target)
- || target != prev_real_insn (JUMP_LABEL (insn)))
- return 0;
-
- cinsn = XEXP (SET_SRC (PATTERN (insn)), 0);
- ctarget = XEXP (SET_SRC (PATTERN (target)), 0);
+ /* If this is not actually a comparison, we can't reverse it. */
+ if (GET_RTX_CLASS (code) != '<')
+ return UNKNOWN;
- codei = GET_CODE (cinsn);
- codet = GET_CODE (ctarget);
+ mode = GET_MODE (arg0);
+ if (mode == VOIDmode)
+ mode = GET_MODE (arg1);
- if (XEXP (SET_SRC (PATTERN (insn)), 1) == pc_rtx)
+ /* First see if machine description supply us way to reverse the comparison.
+ Give it priority over everything else to allow machine description to do
+ tricks. */
+#ifdef REVERSIBLE_CC_MODE
+ if (GET_MODE_CLASS (mode) == MODE_CC
+ && REVERSIBLE_CC_MODE (mode))
{
- if (! can_reverse_comparison_p (cinsn, insn))
- return 0;
- codei = reverse_condition (codei);
+#ifdef REVERSE_CONDITION
+ return REVERSE_CONDITION (code, mode);
+#endif
+ return reverse_condition (code);
}
+#endif
- if (XEXP (SET_SRC (PATTERN (target)), 2) == pc_rtx)
+ /* Try a few special cases based on the comparison code. */
+ switch (code)
{
- if (! can_reverse_comparison_p (ctarget, target))
- return 0;
- codet = reverse_condition (codet);
+ case GEU:
+ case GTU:
+ case LEU:
+ case LTU:
+ case NE:
+ case EQ:
+ /* It is always safe to reverse EQ and NE, even for the floating
+ point. Similary the unsigned comparisons are never used for
+ floating point so we can reverse them in the default way. */
+ return reverse_condition (code);
+ case ORDERED:
+ case UNORDERED:
+ case LTGT:
+ case UNEQ:
+ /* In case we already see unordered comparison, we can be sure to
+ be dealing with floating point so we don't need any more tests. */
+ return reverse_condition_maybe_unordered (code);
+ case UNLT:
+ case UNLE:
+ case UNGT:
+ case UNGE:
+ /* We don't have safe way to reverse these yet. */
+ return UNKNOWN;
+ default:
+ break;
}
- return (codei == codet
- && rtx_renumbered_equal_p (XEXP (cinsn, 0), XEXP (ctarget, 0))
- && rtx_renumbered_equal_p (XEXP (cinsn, 1), XEXP (ctarget, 1)));
-}
-\f
-/* Given a comparison, COMPARISON, inside a conditional jump insn, INSN,
- return non-zero if it is safe to reverse this comparison. It is if our
- floating-point is not IEEE, if this is an NE or EQ comparison, or if
- this is known to be an integer comparison. */
-
-int
-can_reverse_comparison_p (comparison, insn)
- rtx comparison;
- rtx insn;
-{
- rtx arg0;
-
- /* If this is not actually a comparison, we can't reverse it. */
- if (GET_RTX_CLASS (GET_CODE (comparison)) != '<')
- return 0;
-
+ /* In case we give up IEEE compatibility, all comparisons are reversible. */
if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- /* If this is an NE comparison, it is safe to reverse it to an EQ
- comparison and vice versa, even for floating point. If no operands
- are NaNs, the reversal is valid. If some operand is a NaN, EQ is
- always false and NE is always true, so the reversal is also valid. */
- || flag_fast_math
- || GET_CODE (comparison) == NE
- || GET_CODE (comparison) == EQ)
- return 1;
-
- arg0 = XEXP (comparison, 0);
-
- /* Make sure ARG0 is one of the actual objects being compared. If we
- can't do this, we can't be sure the comparison can be reversed.
+ || flag_unsafe_math_optimizations)
+ return reverse_condition (code);
- Handle cc0 and a MODE_CC register. */
- if ((GET_CODE (arg0) == REG && GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC)
+ if (GET_MODE_CLASS (mode) == MODE_CC
#ifdef HAVE_cc0
|| arg0 == cc0_rtx
#endif
)
{
- rtx prev = prev_nonnote_insn (insn);
- rtx set;
+ rtx prev;
+ /* Try to search for the comparison to determine the real mode.
+ This code is expensive, but with sane machine description it
+ will be never used, since REVERSIBLE_CC_MODE will return true
+ in all cases. */
+ if (! insn)
+ return UNKNOWN;
- /* First see if the condition code mode alone if enough to say we can
- reverse the condition. If not, then search backwards for a set of
- ARG0. We do not need to check for an insn clobbering it since valid
- code will contain set a set with no intervening clobber. But
- stop when we reach a label. */
-#ifdef REVERSIBLE_CC_MODE
- if (GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC
- && REVERSIBLE_CC_MODE (GET_MODE (arg0)))
- return 1;
-#endif
-
for (prev = prev_nonnote_insn (insn);
prev != 0 && GET_CODE (prev) != CODE_LABEL;
prev = prev_nonnote_insn (prev))
- if ((set = single_set (prev)) != 0
- && rtx_equal_p (SET_DEST (set), arg0))
- {
- arg0 = SET_SRC (set);
+ {
+ rtx set = set_of (arg0, prev);
+ if (set && GET_CODE (set) == SET
+ && rtx_equal_p (SET_DEST (set), arg0))
+ {
+ rtx src = SET_SRC (set);
- if (GET_CODE (arg0) == COMPARE)
- arg0 = XEXP (arg0, 0);
- break;
- }
+ if (GET_CODE (src) == COMPARE)
+ {
+ rtx comparison = src;
+ arg0 = XEXP (src, 0);
+ mode = GET_MODE (arg0);
+ if (mode == VOIDmode)
+ mode = GET_MODE (XEXP (comparison, 1));
+ break;
+ }
+ /* We can get past reg-reg moves. This may be usefull for model
+ of i387 comparisons that first move flag registers around. */
+ if (REG_P (src))
+ {
+ arg0 = src;
+ continue;
+ }
+ }
+ /* If register is clobbered in some ununderstandable way,
+ give up. */
+ if (set)
+ return UNKNOWN;
+ }
}
- /* We can reverse this if ARG0 is a CONST_INT or if its mode is
- not VOIDmode and neither a MODE_CC nor MODE_FLOAT type. */
- return (GET_CODE (arg0) == CONST_INT
- || (GET_MODE (arg0) != VOIDmode
- && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_CC
- && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_FLOAT));
+ /* An integer condition. */
+ if (GET_CODE (arg0) == CONST_INT
+ || (GET_MODE (arg0) != VOIDmode
+ && GET_MODE_CLASS (mode) != MODE_CC
+ && ! FLOAT_MODE_P (mode)))
+ return reverse_condition (code);
+
+ return UNKNOWN;
}
+/* An wrapper around the previous function to take COMPARISON as rtx
+ expression. This simplifies many callers. */
+enum rtx_code
+reversed_comparison_code (comparison, insn)
+ rtx comparison, insn;
+{
+ if (GET_RTX_CLASS (GET_CODE (comparison)) != '<')
+ return UNKNOWN;
+ return reversed_comparison_code_parts (GET_CODE (comparison),
+ XEXP (comparison, 0),
+ XEXP (comparison, 1), insn);
+}
+\f
/* Given an rtx-code for a comparison, return the code for the negated
comparison. If no such code exists, return UNKNOWN.
WATCH OUT! reverse_condition is not safe to use on a jump that might
be acting on the results of an IEEE floating point comparison, because
- of the special treatment of non-signaling nans in comparisons.
- Use can_reverse_comparison_p to be sure. */
+ of the special treatment of non-signaling nans in comparisons.
+ Use reversed_comparison_code instead. */
enum rtx_code
reverse_condition (code)
return UNGT;
case LTGT:
return UNEQ;
- case GTU:
- return LEU;
- case GEU:
- return LTU;
- case LTU:
- return GEU;
- case LEU:
- return GTU;
case UNORDERED:
return ORDERED;
case ORDERED:
comparison_dominates_p (code1, code2)
enum rtx_code code1, code2;
{
+ /* UNKNOWN comparison codes can happen as a result of trying to revert
+ comparison codes.
+ They can't match anything, so we have to reject them here. */
+ if (code1 == UNKNOWN || code2 == UNKNOWN)
+ return 0;
+
if (code1 == code2)
return 1;
switch (code1)
{
+ case UNEQ:
+ if (code2 == UNLE || code2 == UNGE)
+ return 1;
+ break;
+
case EQ:
if (code2 == LE || code2 == LEU || code2 == GE || code2 == GEU
|| code2 == ORDERED)
return 1;
break;
+ case UNLT:
+ if (code2 == UNLE || code2 == NE)
+ return 1;
+ break;
+
case LT:
- if (code2 == LE || code2 == NE || code2 == ORDERED)
+ if (code2 == LE || code2 == NE || code2 == ORDERED || code2 == LTGT)
+ return 1;
+ break;
+
+ case UNGT:
+ if (code2 == UNGE || code2 == NE)
return 1;
break;
case GT:
- if (code2 == GE || code2 == NE || code2 == ORDERED)
+ if (code2 == GE || code2 == NE || code2 == ORDERED || code2 == LTGT)
return 1;
break;
break;
case UNORDERED:
- if (code2 == NE)
+ if (code2 == NE || code2 == UNEQ || code2 == UNLE || code2 == UNLT
+ || code2 == UNGE || code2 == UNGT)
return 1;
break;
-
+
default:
break;
}
}
/* Return nonzero if INSN is a (possibly) conditional jump
- and nothing more. */
+ and nothing more.
+
+ Use this function is deprecated, since we need to support combined
+ branch and compare insns. Use any_condjump_p instead whenever possible. */
int
condjump_p (insn)
rtx insn;
{
- register rtx x = PATTERN (insn);
+ rtx x = PATTERN (insn);
if (GET_CODE (x) != SET
|| GET_CODE (SET_DEST (x)) != PC)
x = SET_SRC (x);
if (GET_CODE (x) == LABEL_REF)
return 1;
- else return (GET_CODE (x) == IF_THEN_ELSE
- && ((GET_CODE (XEXP (x, 2)) == PC
- && (GET_CODE (XEXP (x, 1)) == LABEL_REF
- || GET_CODE (XEXP (x, 1)) == RETURN))
- || (GET_CODE (XEXP (x, 1)) == PC
- && (GET_CODE (XEXP (x, 2)) == LABEL_REF
- || GET_CODE (XEXP (x, 2)) == RETURN))));
+ else
+ return (GET_CODE (x) == IF_THEN_ELSE
+ && ((GET_CODE (XEXP (x, 2)) == PC
+ && (GET_CODE (XEXP (x, 1)) == LABEL_REF
+ || GET_CODE (XEXP (x, 1)) == RETURN))
+ || (GET_CODE (XEXP (x, 1)) == PC
+ && (GET_CODE (XEXP (x, 2)) == LABEL_REF
+ || GET_CODE (XEXP (x, 2)) == RETURN))));
return 0;
}
/* Return nonzero if INSN is a (possibly) conditional jump inside a
- PARALLEL. */
+ PARALLEL.
+
+ Use this function is deprecated, since we need to support combined
+ branch and compare insns. Use any_condjump_p instead whenever possible. */
int
condjump_in_parallel_p (insn)
rtx insn;
{
- register rtx x = PATTERN (insn);
+ rtx x = PATTERN (insn);
if (GET_CODE (x) != PARALLEL)
return 0;
return 0;
}
+/* Return set of PC, otherwise NULL. */
+
+rtx
+pc_set (insn)
+ rtx insn;
+{
+ rtx pat;
+ if (GET_CODE (insn) != JUMP_INSN)
+ return NULL_RTX;
+ pat = PATTERN (insn);
+
+ /* The set is allowed to appear either as the insn pattern or
+ the first set in a PARALLEL. */
+ if (GET_CODE (pat) == PARALLEL)
+ pat = XVECEXP (pat, 0, 0);
+ if (GET_CODE (pat) == SET && GET_CODE (SET_DEST (pat)) == PC)
+ return pat;
+
+ return NULL_RTX;
+}
+
+/* Return true when insn is an unconditional direct jump,
+ possibly bundled inside a PARALLEL. */
+
+int
+any_uncondjump_p (insn)
+ rtx insn;
+{
+ rtx x = pc_set (insn);
+ if (!x)
+ return 0;
+ if (GET_CODE (SET_SRC (x)) != LABEL_REF)
+ return 0;
+ return 1;
+}
+
+/* Return true when insn is a conditional jump. This function works for
+ instructions containing PC sets in PARALLELs. The instruction may have
+ various other effects so before removing the jump you must verify
+ onlyjump_p.
+
+ Note that unlike condjump_p it returns false for unconditional jumps. */
+
+int
+any_condjump_p (insn)
+ rtx insn;
+{
+ rtx x = pc_set (insn);
+ enum rtx_code a, b;
+
+ if (!x)
+ return 0;
+ if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE)
+ return 0;
+
+ a = GET_CODE (XEXP (SET_SRC (x), 1));
+ b = GET_CODE (XEXP (SET_SRC (x), 2));
+
+ return ((b == PC && (a == LABEL_REF || a == RETURN))
+ || (a == PC && (b == LABEL_REF || b == RETURN)));
+}
+
/* Return the label of a conditional jump. */
rtx
condjump_label (insn)
rtx insn;
{
- register rtx x = PATTERN (insn);
+ rtx x = pc_set (insn);
- if (GET_CODE (x) == PARALLEL)
- x = XVECEXP (x, 0, 0);
- if (GET_CODE (x) != SET)
- return NULL_RTX;
- if (GET_CODE (SET_DEST (x)) != PC)
+ if (!x)
return NULL_RTX;
x = SET_SRC (x);
if (GET_CODE (x) == LABEL_REF)
returnjump_p (insn)
rtx insn;
{
+ if (GET_CODE (insn) != JUMP_INSN)
+ return 0;
return for_each_rtx (&PATTERN (insn), returnjump_p_1, NULL);
}
#ifdef HAVE_cc0
+/* Return non-zero if X is an RTX that only sets the condition codes
+ and has no side effects. */
+
+int
+only_sets_cc0_p (x)
+ rtx x;
+{
+
+ if (! x)
+ return 0;
+
+ if (INSN_P (x))
+ x = PATTERN (x);
+
+ return sets_cc0_p (x) == 1 && ! side_effects_p (x);
+}
+
/* Return 1 if X is an RTX that does nothing but set the condition codes
and CLOBBER or USE registers.
Return -1 if X does explicitly set the condition codes,
int
sets_cc0_p (x)
- rtx x ATTRIBUTE_UNUSED;
+ rtx x;
{
+
+ if (! x)
+ return 0;
+
+ if (INSN_P (x))
+ x = PATTERN (x);
+
if (GET_CODE (x) == SET && SET_DEST (x) == cc0_rtx)
return 1;
if (GET_CODE (x) == PARALLEL)
follow_jumps (label)
rtx label;
{
- register rtx insn;
- register rtx next;
- register rtx value = label;
- register int depth;
+ rtx insn;
+ rtx next;
+ rtx value = label;
+ int depth;
for (depth = 0;
(depth < 10
&& (insn = next_active_insn (value)) != 0
&& GET_CODE (insn) == JUMP_INSN
- && ((JUMP_LABEL (insn) != 0 && simplejump_p (insn))
+ && ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn)
+ && onlyjump_p (insn))
|| GET_CODE (PATTERN (insn)) == RETURN)
&& (next = NEXT_INSN (insn))
&& GET_CODE (next) == BARRIER);
return value;
}
-/* Assuming that field IDX of X is a vector of label_refs,
- replace each of them by the ultimate label reached by it.
- Return nonzero if a change is made.
- If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */
-
-static int
-tension_vector_labels (x, idx)
- register rtx x;
- register int idx;
-{
- int changed = 0;
- register int i;
- for (i = XVECLEN (x, idx) - 1; i >= 0; i--)
- {
- register rtx olabel = XEXP (XVECEXP (x, idx, i), 0);
- register rtx nlabel = follow_jumps (olabel);
- if (nlabel && nlabel != olabel)
- {
- XEXP (XVECEXP (x, idx, i), 0) = nlabel;
- ++LABEL_NUSES (nlabel);
- if (--LABEL_NUSES (olabel) == 0)
- delete_insn (olabel);
- changed = 1;
- }
- }
- return changed;
-}
\f
/* Find all CODE_LABELs referred to in X, and increment their use counts.
If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced
must be kept distinct if we have not yet done loop-optimization,
because the gap between them is where loop-optimize
will want to move invariant code to. CROSS_JUMP tells us
- that loop-optimization is done with.
+ that loop-optimization is done with. */
- Once reload has completed (CROSS_JUMP non-zero), we need not consider
- two labels distinct if they are separated by only USE or CLOBBER insns. */
-
-static void
-mark_jump_label (x, insn, cross_jump)
- register rtx x;
+void
+mark_jump_label (x, insn, in_mem)
+ rtx x;
rtx insn;
- int cross_jump;
+ int in_mem;
{
- register RTX_CODE code = GET_CODE (x);
- register int i;
- register const char *fmt;
+ RTX_CODE code = GET_CODE (x);
+ int i;
+ const char *fmt;
switch (code)
{
case REG:
case SUBREG:
case CONST_INT:
- case SYMBOL_REF:
case CONST_DOUBLE:
case CLOBBER:
case CALL:
return;
case MEM:
+ in_mem = 1;
+ break;
+
+ case SYMBOL_REF:
+ if (!in_mem)
+ return;
+
/* If this is a constant-pool reference, see if it is a label. */
- if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
- && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
- mark_jump_label (get_pool_constant (XEXP (x, 0)), insn, cross_jump);
+ if (CONSTANT_POOL_ADDRESS_P (x))
+ mark_jump_label (get_pool_constant (x), insn, in_mem);
break;
case LABEL_REF:
{
rtx label = XEXP (x, 0);
- rtx olabel = label;
- rtx note;
- rtx next;
+
+ /* Ignore remaining references to unreachable labels that
+ have been deleted. */
+ if (GET_CODE (label) == NOTE
+ && NOTE_LINE_NUMBER (label) == NOTE_INSN_DELETED_LABEL)
+ break;
if (GET_CODE (label) != CODE_LABEL)
abort ();
if (LABEL_REF_NONLOCAL_P (x))
break;
- /* If there are other labels following this one,
- replace it with the last of the consecutive labels. */
- for (next = NEXT_INSN (label); next; next = NEXT_INSN (next))
- {
- if (GET_CODE (next) == CODE_LABEL)
- label = next;
- else if (cross_jump && GET_CODE (next) == INSN
- && (GET_CODE (PATTERN (next)) == USE
- || GET_CODE (PATTERN (next)) == CLOBBER))
- continue;
- else if (GET_CODE (next) != NOTE)
- break;
- else if (! cross_jump
- && (NOTE_LINE_NUMBER (next) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (next) == NOTE_INSN_FUNCTION_END
- /* ??? Optional. Disables some optimizations, but
- makes gcov output more accurate with -O. */
- || (flag_test_coverage && NOTE_LINE_NUMBER (next) > 0)))
- break;
- }
-
XEXP (x, 0) = label;
if (! insn || ! INSN_DELETED_P (insn))
++LABEL_NUSES (label);
{
if (GET_CODE (insn) == JUMP_INSN)
JUMP_LABEL (insn) = label;
-
- /* If we've changed OLABEL and we had a REG_LABEL note
- for it, update it as well. */
- else if (label != olabel
- && (note = find_reg_note (insn, REG_LABEL, olabel)) != 0)
- XEXP (note, 0) = label;
-
- /* Otherwise, add a REG_LABEL note for LABEL unless there already
- is one. */
- else if (! find_reg_note (insn, REG_LABEL, label))
+ else
{
- /* This code used to ignore labels which refered to dispatch
- tables to avoid flow.c generating worse code.
-
- However, in the presense of global optimizations like
- gcse which call find_basic_blocks without calling
- life_analysis, not recording such labels will lead
- to compiler aborts because of inconsistencies in the
- flow graph. So we go ahead and record the label.
-
- It may also be the case that the optimization argument
- is no longer valid because of the more accurate cfg
- we build in find_basic_blocks -- it no longer pessimizes
- code when it finds a REG_LABEL note. */
- REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_LABEL, label,
- REG_NOTES (insn));
+ /* Add a REG_LABEL note for LABEL unless there already
+ is one. All uses of a label, except for labels
+ that are the targets of jumps, must have a
+ REG_LABEL note. */
+ if (! find_reg_note (insn, REG_LABEL, label))
+ REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, label,
+ REG_NOTES (insn));
}
}
return;
int eltnum = code == ADDR_DIFF_VEC ? 1 : 0;
for (i = 0; i < XVECLEN (x, eltnum); i++)
- mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, cross_jump);
+ mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, in_mem);
}
return;
-
+
default:
break;
}
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
- mark_jump_label (XEXP (x, i), insn, cross_jump);
+ mark_jump_label (XEXP (x, i), insn, in_mem);
else if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = 0; j < XVECLEN (x, i); j++)
- mark_jump_label (XVECEXP (x, i, j), insn, cross_jump);
+ mark_jump_label (XVECEXP (x, i, j), insn, in_mem);
}
}
}
delete_jump (insn)
rtx insn;
{
- register rtx set = single_set (insn);
+ rtx set = single_set (insn);
if (set && GET_CODE (SET_DEST (set)) == PC)
delete_computation (insn);
/* If we reach a CALL which is not calling a const function
or the callee pops the arguments, then give up. */
if (GET_CODE (our_prev) == CALL_INSN
- && (! CONST_CALL_P (our_prev)
+ && (! CONST_OR_PURE_CALL_P (our_prev)
|| GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL))
break;
{
int dest_regno = REGNO (SET_DEST (pat));
int dest_endregno
- = dest_regno + (dest_regno < FIRST_PSEUDO_REGISTER
+ = (dest_regno
+ + (dest_regno < FIRST_PSEUDO_REGISTER
? HARD_REGNO_NREGS (dest_regno,
- GET_MODE (SET_DEST (pat))) : 1);
+ GET_MODE (SET_DEST (pat))) : 1));
int regno = REGNO (reg);
- int endregno = regno + (regno < FIRST_PSEUDO_REGISTER
- ? HARD_REGNO_NREGS (regno, GET_MODE (reg)) : 1);
+ int endregno
+ = (regno
+ + (regno < FIRST_PSEUDO_REGISTER
+ ? HARD_REGNO_NREGS (regno, GET_MODE (reg)) : 1));
if (dest_regno >= regno
&& dest_endregno <= endregno)
int i;
REG_NOTES (our_prev)
- = gen_rtx_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (our_prev));
+ = gen_rtx_EXPR_LIST (REG_UNUSED, reg,
+ REG_NOTES (our_prev));
for (i = dest_regno; i < dest_endregno; i++)
if (! find_regno_note (our_prev, REG_UNUSED, i))
rtx insn;
{
rtx note, next;
- rtx set;
#ifdef HAVE_cc0
if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
}
#endif
-#ifdef INSN_SCHEDULING
- /* ?!? The schedulers do not keep REG_DEAD notes accurate after
- reload has completed. The schedulers need to be fixed. Until
- they are, we must not rely on the death notes here. */
- if (reload_completed && flag_schedule_insns_after_reload)
- {
- delete_insn (insn);
- return;
- }
-#endif
-
- /* The REG_DEAD note may have been omitted for a register
- which is both set and used by the insn. */
- set = single_set (insn);
- if (set && GET_CODE (SET_DEST (set)) == REG)
- {
- int dest_regno = REGNO (SET_DEST (set));
- int dest_endregno
- = dest_regno + (dest_regno < FIRST_PSEUDO_REGISTER
- ? HARD_REGNO_NREGS (dest_regno,
- GET_MODE (SET_DEST (set))) : 1);
- int i;
-
- for (i = dest_regno; i < dest_endregno; i++)
- {
- if (! refers_to_regno_p (i, i + 1, SET_SRC (set), NULL_PTR)
- || find_regno_note (insn, REG_DEAD, i))
- continue;
-
- note = gen_rtx_EXPR_LIST (REG_DEAD, (i < FIRST_PSEUDO_REGISTER
- ? gen_rtx_REG (reg_raw_mode[i], i)
- : SET_DEST (set)), NULL_RTX);
- delete_prior_computation (note, insn);
- }
- }
-
for (note = REG_NOTES (insn); note; note = next)
{
next = XEXP (note, 1);
delete_prior_computation (note, insn);
}
- delete_insn (insn);
+ delete_related_insns (insn);
}
\f
-/* Delete insn INSN from the chain of insns and update label ref counts.
- May delete some following insns as a consequence; may even delete
- a label elsewhere and insns that follow it.
+/* Delete insn INSN from the chain of insns and update label ref counts
+ and delete insns now unreachable.
- Returns the first insn after INSN that was not deleted. */
+ Returns the first insn after INSN that was not deleted.
+
+ Usage of this instruction is deprecated. Use delete_insn instead and
+ subsequent cfg_cleanup pass to delete unreachable code if needed. */
rtx
-delete_insn (insn)
- register rtx insn;
+delete_related_insns (insn)
+ rtx insn;
{
- register rtx next = NEXT_INSN (insn);
- register rtx prev = PREV_INSN (insn);
- register int was_code_label = (GET_CODE (insn) == CODE_LABEL);
- register int dont_really_delete = 0;
+ int was_code_label = (GET_CODE (insn) == CODE_LABEL);
+ rtx note;
+ rtx next = NEXT_INSN (insn), prev = PREV_INSN (insn);
while (next && INSN_DELETED_P (next))
next = NEXT_INSN (next);
if (INSN_DELETED_P (insn))
return next;
- if (was_code_label)
- remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels);
-
- /* Don't delete user-declared labels. Convert them to special NOTEs
- instead. */
- if (was_code_label && LABEL_NAME (insn) != 0 && ! dont_really_delete)
- {
- PUT_CODE (insn, NOTE);
- NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL;
- NOTE_SOURCE_FILE (insn) = 0;
- dont_really_delete = 1;
- }
- else
- /* Mark this insn as deleted. */
- INSN_DELETED_P (insn) = 1;
-
- /* If this is an unconditional jump, delete it from the jump chain. */
- if (simplejump_p (insn))
- delete_from_jump_chain (insn);
+ delete_insn (insn);
/* If instruction is followed by a barrier,
delete the barrier too. */
if (next != 0 && GET_CODE (next) == BARRIER)
- {
- INSN_DELETED_P (next) = 1;
- next = NEXT_INSN (next);
- }
-
- /* Patch out INSN (and the barrier if any) */
-
- if (! dont_really_delete)
- {
- if (prev)
- {
- NEXT_INSN (prev) = next;
- if (GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SEQUENCE)
- NEXT_INSN (XVECEXP (PATTERN (prev), 0,
- XVECLEN (PATTERN (prev), 0) - 1)) = next;
- }
-
- if (next)
- {
- PREV_INSN (next) = prev;
- if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE)
- PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = prev;
- }
-
- if (prev && NEXT_INSN (prev) == 0)
- set_last_insn (prev);
- }
+ delete_insn (next);
/* If deleting a jump, decrement the count of the label,
and delete the label if it is now unused. */
{
rtx lab = JUMP_LABEL (insn), lab_next;
- if (--LABEL_NUSES (lab) == 0)
+ if (LABEL_NUSES (lab) == 0)
{
/* This can delete NEXT or PREV,
either directly if NEXT is JUMP_LABEL (INSN),
or indirectly through more levels of jumps. */
- delete_insn (lab);
+ delete_related_insns (lab);
/* I feel a little doubtful about this loop,
but I see no clean and sure alternative way
We may not be able to kill the label immediately preceeding
just yet, as it might be referenced in code leading up to
the tablejump. */
- delete_insn (lab_next);
+ delete_related_insns (lab_next);
}
}
int len = XVECLEN (pat, diff_vec_p);
for (i = 0; i < len; i++)
- if (--LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0)
- delete_insn (XEXP (XVECEXP (pat, diff_vec_p, i), 0));
+ if (LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0)
+ delete_related_insns (XEXP (XVECEXP (pat, diff_vec_p, i), 0));
while (next && INSN_DELETED_P (next))
next = NEXT_INSN (next);
return next;
}
+ /* Likewise for an ordinary INSN / CALL_INSN with a REG_LABEL note. */
+ if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN)
+ for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_LABEL
+ /* This could also be a NOTE_INSN_DELETED_LABEL note. */
+ && GET_CODE (XEXP (note, 0)) == CODE_LABEL)
+ if (LABEL_NUSES (XEXP (note, 0)) == 0)
+ delete_related_insns (XEXP (note, 0));
+
while (prev && (INSN_DELETED_P (prev) || GET_CODE (prev) == NOTE))
prev = PREV_INSN (prev);
&& GET_CODE (NEXT_INSN (insn)) == JUMP_INSN
&& (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC
|| GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC))
- next = delete_insn (NEXT_INSN (insn));
+ next = delete_related_insns (NEXT_INSN (insn));
/* If INSN was a label, delete insns following it if now unreachable. */
if (was_code_label && prev && GET_CODE (prev) == BARRIER)
{
- register RTX_CODE code;
+ RTX_CODE code;
while (next != 0
&& (GET_RTX_CLASS (code = GET_CODE (next)) == 'i'
|| code == NOTE || code == BARRIER
deletion of unreachable code, after a different label.
As long as the value from this recursive call is correct,
this invocation functions correctly. */
- next = delete_insn (next);
+ next = delete_related_insns (next);
}
}
void
delete_for_peephole (from, to)
- register rtx from, to;
+ rtx from, to;
{
- register rtx insn = from;
+ rtx insn = from;
while (1)
{
- register rtx next = NEXT_INSN (insn);
- register rtx prev = PREV_INSN (insn);
+ rtx next = NEXT_INSN (insn);
+ rtx prev = PREV_INSN (insn);
if (GET_CODE (insn) != NOTE)
{
rtx a_line_note = NULL;
int two_avoided_lines = 0;
int contains_insn = 0;
-
+
if (! warn_notreached)
return;
/* Scan forwards, looking at LINE_NUMBER notes, until
we hit a LABEL or we run out of insns. */
-
+
for (insn = avoided_insn; insn != NULL; insn = NEXT_INSN (insn))
{
- if (GET_CODE (insn) == CODE_LABEL)
- break;
- else if (GET_CODE (insn) == NOTE /* A line number note? */
- && NOTE_LINE_NUMBER (insn) >= 0)
+ if (GET_CODE (insn) == CODE_LABEL)
+ break;
+ else if (GET_CODE (insn) == NOTE /* A line number note? */
+ && NOTE_LINE_NUMBER (insn) >= 0)
{
if (a_line_note == NULL)
a_line_note = insn;
two_avoided_lines |= (NOTE_LINE_NUMBER (a_line_note)
!= NOTE_LINE_NUMBER (insn));
}
- else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
- contains_insn = 1;
+ else if (INSN_P (insn))
+ contains_insn = 1;
}
if (two_avoided_lines && contains_insn)
warning_with_file_and_line (NOTE_SOURCE_FILE (a_line_note),
"will never be executed");
}
\f
-/* Invert the condition of the jump JUMP, and make it jump
- to label NLABEL instead of where it jumps now. */
+/* Throughout LOC, redirect OLABEL to NLABEL. Treat null OLABEL or
+ NLABEL as a return. Accrue modifications into the change group. */
-int
-invert_jump (jump, nlabel)
- rtx jump, nlabel;
+static void
+redirect_exp_1 (loc, olabel, nlabel, insn)
+ rtx *loc;
+ rtx olabel, nlabel;
+ rtx insn;
{
- /* We have to either invert the condition and change the label or
- do neither. Either operation could fail. We first try to invert
- the jump. If that succeeds, we try changing the label. If that fails,
- we invert the jump back to what it was. */
-
- if (! invert_exp (PATTERN (jump), jump))
- return 0;
+ rtx x = *loc;
+ RTX_CODE code = GET_CODE (x);
+ int i;
+ const char *fmt;
- if (redirect_jump (jump, nlabel))
+ if (code == LABEL_REF)
{
- if (flag_branch_probabilities)
+ if (XEXP (x, 0) == olabel)
{
- rtx note = find_reg_note (jump, REG_BR_PROB, 0);
-
- /* An inverted jump means that a probability taken becomes a
- probability not taken. Subtract the branch probability from the
- probability base to convert it back to a taken probability.
- (We don't flip the probability on a branch that's never taken. */
- if (note && XINT (XEXP (note, 0), 0) >= 0)
- XINT (XEXP (note, 0), 0) = REG_BR_PROB_BASE - XINT (XEXP (note, 0), 0);
- }
+ rtx n;
+ if (nlabel)
+ n = gen_rtx_LABEL_REF (VOIDmode, nlabel);
+ else
+ n = gen_rtx_RETURN (VOIDmode);
- return 1;
+ validate_change (insn, loc, n, 1);
+ return;
+ }
}
-
- if (! invert_exp (PATTERN (jump), jump))
- /* This should just be putting it back the way it was. */
- abort ();
-
- return 0;
-}
-
-/* Invert the jump condition of rtx X contained in jump insn, INSN.
-
- Return 1 if we can do so, 0 if we cannot find a way to do so that
- matches a pattern. */
-
-int
-invert_exp (x, insn)
- rtx x;
- rtx insn;
-{
- register RTX_CODE code;
- register int i;
- register const char *fmt;
-
- code = GET_CODE (x);
-
- if (code == IF_THEN_ELSE)
+ else if (code == RETURN && olabel == 0)
{
- register rtx comp = XEXP (x, 0);
- register rtx tem;
-
- /* We can do this in two ways: The preferable way, which can only
- be done if this is not an integer comparison, is to reverse
- the comparison code. Otherwise, swap the THEN-part and ELSE-part
- of the IF_THEN_ELSE. If we can't do either, fail. */
+ x = gen_rtx_LABEL_REF (VOIDmode, nlabel);
+ if (loc == &PATTERN (insn))
+ x = gen_rtx_SET (VOIDmode, pc_rtx, x);
+ validate_change (insn, loc, x, 1);
+ return;
+ }
- if (can_reverse_comparison_p (comp, insn)
- && validate_change (insn, &XEXP (x, 0),
- gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp)),
- GET_MODE (comp), XEXP (comp, 0),
- XEXP (comp, 1)), 0))
- return 1;
-
- tem = XEXP (x, 1);
- validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1);
- validate_change (insn, &XEXP (x, 2), tem, 1);
- return apply_change_group ();
+ if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx
+ && GET_CODE (SET_SRC (x)) == LABEL_REF
+ && XEXP (SET_SRC (x), 0) == olabel)
+ {
+ validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 1);
+ return;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
- {
- if (! invert_exp (XEXP (x, i), insn))
- return 0;
- }
+ redirect_exp_1 (&XEXP (x, i), olabel, nlabel, insn);
else if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = 0; j < XVECLEN (x, i); j++)
- if (!invert_exp (XVECEXP (x, i, j), insn))
- return 0;
+ redirect_exp_1 (&XVECEXP (x, i, j), olabel, nlabel, insn);
}
}
+}
- return 1;
+/* Similar, but apply the change group and report success or failure. */
+
+static int
+redirect_exp (olabel, nlabel, insn)
+ rtx olabel, nlabel;
+ rtx insn;
+{
+ rtx *loc;
+
+ if (GET_CODE (PATTERN (insn)) == PARALLEL)
+ loc = &XVECEXP (PATTERN (insn), 0, 0);
+ else
+ loc = &PATTERN (insn);
+
+ redirect_exp_1 (loc, olabel, nlabel, insn);
+ if (num_validated_changes () == 0)
+ return 0;
+
+ return apply_change_group ();
}
-\f
-/* Make jump JUMP jump to label NLABEL instead of where it jumps now.
- If the old jump target label is unused as a result,
- it and the code following it may be deleted.
+
+/* Make JUMP go to NLABEL instead of where it jumps now. Accrue
+ the modifications into the change group. Return false if we did
+ not see how to do that. */
+
+int
+redirect_jump_1 (jump, nlabel)
+ rtx jump, nlabel;
+{
+ int ochanges = num_validated_changes ();
+ rtx *loc;
+
+ if (GET_CODE (PATTERN (jump)) == PARALLEL)
+ loc = &XVECEXP (PATTERN (jump), 0, 0);
+ else
+ loc = &PATTERN (jump);
+
+ redirect_exp_1 (loc, JUMP_LABEL (jump), nlabel, jump);
+ return num_validated_changes () > ochanges;
+}
+
+/* Make JUMP go to NLABEL instead of where it jumps now. If the old
+ jump target label is unused as a result, it and the code following
+ it may be deleted.
If NLABEL is zero, we are to turn the jump into a (possibly conditional)
RETURN insn.
- The return value will be 1 if the change was made, 0 if it wasn't (this
- can only occur for NLABEL == 0). */
+ The return value will be 1 if the change was made, 0 if it wasn't
+ (this can only occur for NLABEL == 0). */
int
-redirect_jump (jump, nlabel)
+redirect_jump (jump, nlabel, delete_unused)
rtx jump, nlabel;
+ int delete_unused;
{
- register rtx olabel = JUMP_LABEL (jump);
+ rtx olabel = JUMP_LABEL (jump);
if (nlabel == olabel)
return 1;
- if (! redirect_exp (&PATTERN (jump), olabel, nlabel, jump))
+ if (! redirect_exp (olabel, nlabel, jump))
return 0;
- /* If this is an unconditional branch, delete it from the jump_chain of
- OLABEL and add it to the jump_chain of NLABEL (assuming both labels
- have UID's in range and JUMP_CHAIN is valid). */
- if (jump_chain && (simplejump_p (jump)
- || GET_CODE (PATTERN (jump)) == RETURN))
- {
- int label_index = nlabel ? INSN_UID (nlabel) : 0;
-
- delete_from_jump_chain (jump);
- if (label_index < max_jump_chain
- && INSN_UID (jump) < max_jump_chain)
- {
- jump_chain[INSN_UID (jump)] = jump_chain[label_index];
- jump_chain[label_index] = jump;
- }
- }
-
JUMP_LABEL (jump) = nlabel;
if (nlabel)
++LABEL_NUSES (nlabel);
- if (olabel && --LABEL_NUSES (olabel) == 0)
- delete_insn (olabel);
+ /* If we're eliding the jump over exception cleanups at the end of a
+ function, move the function end note so that -Wreturn-type works. */
+ if (olabel && nlabel
+ && NEXT_INSN (olabel)
+ && GET_CODE (NEXT_INSN (olabel)) == NOTE
+ && NOTE_LINE_NUMBER (NEXT_INSN (olabel)) == NOTE_INSN_FUNCTION_END)
+ emit_note_after (NOTE_INSN_FUNCTION_END, nlabel);
+
+ if (olabel && --LABEL_NUSES (olabel) == 0 && delete_unused)
+ delete_related_insns (olabel);
return 1;
}
-/* Delete the instruction JUMP from any jump chain it might be on. */
+/* Invert the jump condition of rtx X contained in jump insn, INSN.
+ Accrue the modifications into the change group. */
static void
-delete_from_jump_chain (jump)
- rtx jump;
+invert_exp_1 (insn)
+ rtx insn;
{
- int index;
- rtx olabel = JUMP_LABEL (jump);
-
- /* Handle unconditional jumps. */
- if (jump_chain && olabel != 0
- && INSN_UID (olabel) < max_jump_chain
- && simplejump_p (jump))
- index = INSN_UID (olabel);
- /* Handle return insns. */
- else if (jump_chain && GET_CODE (PATTERN (jump)) == RETURN)
- index = 0;
- else return;
-
- if (jump_chain[index] == jump)
- jump_chain[index] = jump_chain[INSN_UID (jump)];
- else
- {
- rtx insn;
+ RTX_CODE code;
+ rtx x = pc_set (insn);
- for (insn = jump_chain[index];
- insn != 0;
- insn = jump_chain[INSN_UID (insn)])
- if (jump_chain[INSN_UID (insn)] == jump)
- {
- jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (jump)];
- break;
- }
- }
-}
+ if (!x)
+ abort ();
+ x = SET_SRC (x);
-/* If NLABEL is nonzero, throughout the rtx at LOC,
- alter (LABEL_REF OLABEL) to (LABEL_REF NLABEL). If OLABEL is
- zero, alter (RETURN) to (LABEL_REF NLABEL).
+ code = GET_CODE (x);
- If NLABEL is zero, alter (LABEL_REF OLABEL) to (RETURN) and check
- validity with validate_change. Convert (set (pc) (label_ref olabel))
- to (return).
+ if (code == IF_THEN_ELSE)
+ {
+ rtx comp = XEXP (x, 0);
+ rtx tem;
+ enum rtx_code reversed_code;
- Return 0 if we found a change we would like to make but it is invalid.
- Otherwise, return 1. */
+ /* We can do this in two ways: The preferable way, which can only
+ be done if this is not an integer comparison, is to reverse
+ the comparison code. Otherwise, swap the THEN-part and ELSE-part
+ of the IF_THEN_ELSE. If we can't do either, fail. */
-int
-redirect_exp (loc, olabel, nlabel, insn)
- rtx *loc;
- rtx olabel, nlabel;
- rtx insn;
-{
- register rtx x = *loc;
- register RTX_CODE code = GET_CODE (x);
- register int i;
- register const char *fmt;
+ reversed_code = reversed_comparison_code (comp, insn);
- if (code == LABEL_REF)
- {
- if (XEXP (x, 0) == olabel)
+ if (reversed_code != UNKNOWN)
{
- if (nlabel)
- XEXP (x, 0) = nlabel;
- else
- return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0);
- return 1;
+ validate_change (insn, &XEXP (x, 0),
+ gen_rtx_fmt_ee (reversed_code,
+ GET_MODE (comp), XEXP (comp, 0),
+ XEXP (comp, 1)),
+ 1);
+ return;
}
+
+ tem = XEXP (x, 1);
+ validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1);
+ validate_change (insn, &XEXP (x, 2), tem, 1);
}
- else if (code == RETURN && olabel == 0)
- {
- x = gen_rtx_LABEL_REF (VOIDmode, nlabel);
- if (loc == &PATTERN (insn))
- x = gen_rtx_SET (VOIDmode, pc_rtx, x);
- return validate_change (insn, loc, x, 0);
- }
+ else
+ abort ();
+}
- if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx
- && GET_CODE (SET_SRC (x)) == LABEL_REF
- && XEXP (SET_SRC (x), 0) == olabel)
- return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0);
+/* Invert the jump condition of conditional jump insn, INSN.
- fmt = GET_RTX_FORMAT (code);
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e')
- {
- if (! redirect_exp (&XEXP (x, i), olabel, nlabel, insn))
- return 0;
- }
- else if (fmt[i] == 'E')
- {
- register int j;
- for (j = 0; j < XVECLEN (x, i); j++)
- if (! redirect_exp (&XVECEXP (x, i, j), olabel, nlabel, insn))
- return 0;
- }
- }
+ Return 1 if we can do so, 0 if we cannot find a way to do so that
+ matches a pattern. */
- return 1;
+static int
+invert_exp (insn)
+ rtx insn;
+{
+ invert_exp_1 (insn);
+ if (num_validated_changes () == 0)
+ return 0;
+
+ return apply_change_group ();
}
-\f
-/* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump.
- If the old jump target label (before the dispatch table) becomes unused,
- it and the dispatch table may be deleted. In that case, find the insn
- before the jump references that label and delete it and logical successors
- too. */
+/* Invert the condition of the jump JUMP, and make it jump to label
+ NLABEL instead of where it jumps now. Accrue changes into the
+ change group. Return false if we didn't see how to perform the
+ inversion and redirection. */
-static void
-redirect_tablejump (jump, nlabel)
+int
+invert_jump_1 (jump, nlabel)
rtx jump, nlabel;
{
- register rtx olabel = JUMP_LABEL (jump);
-
- /* Add this jump to the jump_chain of NLABEL. */
- if (jump_chain && INSN_UID (nlabel) < max_jump_chain
- && INSN_UID (jump) < max_jump_chain)
- {
- jump_chain[INSN_UID (jump)] = jump_chain[INSN_UID (nlabel)];
- jump_chain[INSN_UID (nlabel)] = jump;
- }
+ int ochanges;
- PATTERN (jump) = gen_jump (nlabel);
- JUMP_LABEL (jump) = nlabel;
- ++LABEL_NUSES (nlabel);
- INSN_CODE (jump) = -1;
+ ochanges = num_validated_changes ();
+ invert_exp_1 (jump);
+ if (num_validated_changes () == ochanges)
+ return 0;
- if (--LABEL_NUSES (olabel) == 0)
- {
- delete_labelref_insn (jump, olabel, 0);
- delete_insn (olabel);
- }
+ return redirect_jump_1 (jump, nlabel);
}
-/* Find the insn referencing LABEL that is a logical predecessor of INSN.
- If we found one, delete it and then delete this insn if DELETE_THIS is
- non-zero. Return non-zero if INSN or a predecessor references LABEL. */
+/* Invert the condition of the jump JUMP, and make it jump to label
+ NLABEL instead of where it jumps now. Return true if successful. */
-static int
-delete_labelref_insn (insn, label, delete_this)
- rtx insn, label;
- int delete_this;
+int
+invert_jump (jump, nlabel, delete_unused)
+ rtx jump, nlabel;
+ int delete_unused;
{
- int deleted = 0;
- rtx link;
+ /* We have to either invert the condition and change the label or
+ do neither. Either operation could fail. We first try to invert
+ the jump. If that succeeds, we try changing the label. If that fails,
+ we invert the jump back to what it was. */
+
+ if (! invert_exp (jump))
+ return 0;
- if (GET_CODE (insn) != NOTE
- && reg_mentioned_p (label, PATTERN (insn)))
+ if (redirect_jump (jump, nlabel, delete_unused))
{
- if (delete_this)
- {
- delete_insn (insn);
- deleted = 1;
- }
- else
- return 1;
+ invert_br_probabilities (jump);
+
+ return 1;
}
- for (link = LOG_LINKS (insn); link; link = XEXP (link, 1))
- if (delete_labelref_insn (XEXP (link, 0), label, 1))
- {
- if (delete_this)
- {
- delete_insn (insn);
- deleted = 1;
- }
- else
- return 1;
- }
+ if (! invert_exp (jump))
+ /* This should just be putting it back the way it was. */
+ abort ();
- return deleted;
+ return 0;
}
+
\f
/* Like rtx_equal_p except that it considers two REGs as equal
if they renumber to the same value and considers two commutative
rtx_renumbered_equal_p (x, y)
rtx x, y;
{
- register int i;
- register RTX_CODE code = GET_CODE (x);
- register const char *fmt;
-
+ int i;
+ RTX_CODE code = GET_CODE (x);
+ const char *fmt;
+
if (x == y)
return 1;
&& GET_CODE (SUBREG_REG (y)) == REG)))
{
int reg_x = -1, reg_y = -1;
- int word_x = 0, word_y = 0;
+ int byte_x = 0, byte_y = 0;
if (GET_MODE (x) != GET_MODE (y))
return 0;
if (code == SUBREG)
{
reg_x = REGNO (SUBREG_REG (x));
- word_x = SUBREG_WORD (x);
+ byte_x = SUBREG_BYTE (x);
if (reg_renumber[reg_x] >= 0)
{
- reg_x = reg_renumber[reg_x] + word_x;
- word_x = 0;
+ reg_x = subreg_regno_offset (reg_renumber[reg_x],
+ GET_MODE (SUBREG_REG (x)),
+ byte_x,
+ GET_MODE (x));
+ byte_x = 0;
}
}
-
else
{
reg_x = REGNO (x);
if (GET_CODE (y) == SUBREG)
{
reg_y = REGNO (SUBREG_REG (y));
- word_y = SUBREG_WORD (y);
+ byte_y = SUBREG_BYTE (y);
if (reg_renumber[reg_y] >= 0)
{
- reg_y = reg_renumber[reg_y];
- word_y = 0;
+ reg_y = subreg_regno_offset (reg_renumber[reg_y],
+ GET_MODE (SUBREG_REG (y)),
+ byte_y,
+ GET_MODE (y));
+ byte_y = 0;
}
}
-
else
{
reg_y = REGNO (y);
reg_y = reg_renumber[reg_y];
}
- return reg_x >= 0 && reg_x == reg_y && word_x == word_y;
+ return reg_x >= 0 && reg_x == reg_y && byte_x == byte_y;
}
- /* Now we have disposed of all the cases
+ /* Now we have disposed of all the cases
in which different rtx codes can match. */
if (code != GET_CODE (y))
return 0;
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
- register int j;
+ int j;
switch (fmt[i])
{
case 'w':
return 0;
break;
+ case 't':
+ if (XTREE (x, i) != XTREE (y, i))
+ return 0;
+ break;
+
case 's':
if (strcmp (XSTR (x, i), XSTR (y, i)))
return 0;
{
int base = true_regnum (SUBREG_REG (x));
if (base >= 0 && base < FIRST_PSEUDO_REGISTER)
- return SUBREG_WORD (x) + base;
+ return base + subreg_regno_offset (REGNO (SUBREG_REG (x)),
+ GET_MODE (SUBREG_REG (x)),
+ SUBREG_BYTE (x), GET_MODE (x));
}
return -1;
}
In general, if the first test fails, the program can branch
directly to `foo' and skip the second try which is doomed to fail.
We run this after loop optimization and before flow analysis. */
-
+
/* When comparing the insn patterns, we track the fact that different
pseudo-register numbers may have been used in each computation.
The following array stores an equivalence -- same_regs[I] == J means
static int modified_mem;
-/* Called via note_stores on each insn between the target of the first
+/* Called via note_stores on each insn between the target of the first
branch and the second branch. It marks any changed registers. */
static void
mark_modified_reg (dest, x, data)
rtx dest;
- rtx x ATTRIBUTE_UNUSED;
+ rtx x;
void *data ATTRIBUTE_UNUSED;
{
- int regno, i;
+ int regno;
+ unsigned int i;
if (GET_CODE (dest) == SUBREG)
dest = SUBREG_REG (dest);
regno = REGNO (dest);
if (regno >= FIRST_PSEUDO_REGISTER)
modified_regs[regno] = 1;
- else
+ /* Don't consider a hard condition code register as modified,
+ if it is only being set. thread_jumps will check if it is set
+ to the same value. */
+ else if (GET_MODE_CLASS (GET_MODE (dest)) != MODE_CC
+ || GET_CODE (x) != SET
+ || ! rtx_equal_p (dest, SET_DEST (x))
+ || HARD_REGNO_NREGS (regno, GET_MODE (dest)) != 1)
for (i = 0; i < HARD_REGNO_NREGS (regno, GET_MODE (dest)); i++)
modified_regs[regno + i] = 1;
}
/* F is the first insn in the chain of insns. */
-
+
void
thread_jumps (f, max_reg, flag_before_loop)
rtx f;
will either always succeed or always fail depending on the relative
senses of the two branches. So adjust the first branch accordingly
in this case. */
-
+
rtx label, b1, b2, t1, t2;
enum rtx_code code1, code2;
rtx b1op0, b1op1, b2op0, b2op1;
int changed = 1;
int i;
int *all_reset;
+ enum rtx_code reversed_code1, reversed_code2;
/* Allocate register tables and quick-reset table. */
modified_regs = (char *) xmalloc (max_reg * sizeof (char));
all_reset = (int *) xmalloc (max_reg * sizeof (int));
for (i = 0; i < max_reg; i++)
all_reset[i] = -1;
-
+
while (changed)
{
changed = 0;
for (b1 = f; b1; b1 = NEXT_INSN (b1))
{
+ rtx set;
+ rtx set2;
+
/* Get to a candidate branch insn. */
if (GET_CODE (b1) != JUMP_INSN
- || ! condjump_p (b1) || simplejump_p (b1)
- || JUMP_LABEL (b1) == 0)
+ || ! any_condjump_p (b1) || JUMP_LABEL (b1) == 0)
continue;
- bzero (modified_regs, max_reg * sizeof (char));
+ memset (modified_regs, 0, max_reg * sizeof (char));
modified_mem = 0;
- bcopy ((char *) all_reset, (char *) same_regs,
- max_reg * sizeof (int));
+ memcpy (same_regs, all_reset, max_reg * sizeof (int));
num_same_regs = 0;
label = JUMP_LABEL (b1);
{
/* If this is an unconditional jump and is the only use of
its target label, we can follow it. */
- if (simplejump_p (b2)
+ if (any_uncondjump_p (b2)
+ && onlyjump_p (b2)
&& JUMP_LABEL (b2) != 0
&& LABEL_NUSES (JUMP_LABEL (b2)) == 1)
{
if (b2 == 0
|| GET_CODE (b2) != JUMP_INSN
|| b2 == b1
- || ! condjump_p (b2)
- || simplejump_p (b2))
+ || !any_condjump_p (b2)
+ || !onlyjump_p (b2))
continue;
+ set = pc_set (b1);
+ set2 = pc_set (b2);
/* Get the comparison codes and operands, reversing the
codes if appropriate. If we don't have comparison codes,
we can't do anything. */
- b1op0 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 0);
- b1op1 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 1);
- code1 = GET_CODE (XEXP (SET_SRC (PATTERN (b1)), 0));
- if (XEXP (SET_SRC (PATTERN (b1)), 1) == pc_rtx)
- code1 = reverse_condition (code1);
-
- b2op0 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 0);
- b2op1 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 1);
- code2 = GET_CODE (XEXP (SET_SRC (PATTERN (b2)), 0));
- if (XEXP (SET_SRC (PATTERN (b2)), 1) == pc_rtx)
- code2 = reverse_condition (code2);
+ b1op0 = XEXP (XEXP (SET_SRC (set), 0), 0);
+ b1op1 = XEXP (XEXP (SET_SRC (set), 0), 1);
+ code1 = GET_CODE (XEXP (SET_SRC (set), 0));
+ reversed_code1 = code1;
+ if (XEXP (SET_SRC (set), 1) == pc_rtx)
+ code1 = reversed_comparison_code (XEXP (SET_SRC (set), 0), b1);
+ else
+ reversed_code1 = reversed_comparison_code (XEXP (SET_SRC (set), 0), b1);
+
+ b2op0 = XEXP (XEXP (SET_SRC (set2), 0), 0);
+ b2op1 = XEXP (XEXP (SET_SRC (set2), 0), 1);
+ code2 = GET_CODE (XEXP (SET_SRC (set2), 0));
+ reversed_code2 = code2;
+ if (XEXP (SET_SRC (set2), 1) == pc_rtx)
+ code2 = reversed_comparison_code (XEXP (SET_SRC (set2), 0), b2);
+ else
+ reversed_code2 = reversed_comparison_code (XEXP (SET_SRC (set2), 0), b2);
/* If they test the same things and knowing that B1 branches
tells us whether or not B2 branches, check if we
if (rtx_equal_for_thread_p (b1op0, b2op0, b2)
&& rtx_equal_for_thread_p (b1op1, b2op1, b2)
&& (comparison_dominates_p (code1, code2)
- || (can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (b1)),
- 0),
- b1)
- && comparison_dominates_p (code1, reverse_condition (code2)))))
+ || comparison_dominates_p (code1, reversed_code2)))
{
t1 = prev_nonnote_insn (b1);
t2 = prev_nonnote_insn (b2);
-
+
while (t1 != 0 && t2 != 0)
{
if (t2 == label)
break;
if (comparison_dominates_p (code1, code2))
- new_label = JUMP_LABEL (b2);
+ new_label = JUMP_LABEL (b2);
else
new_label = get_label_after (b2);
new_label = gen_label_rtx ();
emit_label_after (new_label, PREV_INSN (prev));
}
- changed |= redirect_jump (b1, new_label);
+ changed |= redirect_jump (b1, new_label, 1);
}
break;
}
-
+
/* If either of these is not a normal insn (it might be
a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs
have already been skipped above.) Similarly, fail
|| ! rtx_equal_for_thread_p (PATTERN (t1),
PATTERN (t2), t2))
break;
-
+
t1 = prev_nonnote_insn (t1);
t2 = prev_nonnote_insn (t2);
}
/* This is like RTX_EQUAL_P except that it knows about our handling of
possibly equivalent registers and knows to consider volatile and
modified objects as not equal.
-
+
YINSN is the insn containing Y. */
int
rtx x, y;
rtx yinsn;
{
- register int i;
- register int j;
- register enum rtx_code code;
- register const char *fmt;
+ int i;
+ int j;
+ enum rtx_code code;
+ const char *fmt;
code = GET_CODE (x);
/* Rtx's of different codes cannot be equal. */
pessimistic, but this pass would only rarely do anything for FP
anyway. */
if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
- && FLOAT_MODE_P (GET_MODE (x)) && ! flag_fast_math)
+ && FLOAT_MODE_P (GET_MODE (x)) && ! flag_unsafe_math_optimizations)
return 0;
/* For commutative operations, the RTX match if the operand match in any
num_same_regs++;
/* If this is the first time we are seeing a register on the `Y'
- side, see if it is the last use. If not, we can't thread the
+ side, see if it is the last use. If not, we can't thread the
jump, so mark it as not equivalent. */
if (REGNO_LAST_UID (REGNO (y)) != INSN_UID (yinsn))
return 0;
return 1;
}
else
- return (same_regs[REGNO (x)] == REGNO (y));
+ return (same_regs[REGNO (x)] == (int) REGNO (y));
break;
if (GET_CODE (SET_DEST (x)) == REG
&& GET_CODE (SET_DEST (y)) == REG)
{
- if (same_regs[REGNO (SET_DEST (x))] == REGNO (SET_DEST (y)))
+ if (same_regs[REGNO (SET_DEST (x))] == (int) REGNO (SET_DEST (y)))
{
same_regs[REGNO (SET_DEST (x))] = -1;
num_same_regs--;
return 0;
}
else
- if (rtx_equal_for_thread_p (SET_DEST (x), SET_DEST (y), yinsn) == 0)
- return 0;
+ {
+ if (rtx_equal_for_thread_p (SET_DEST (x), SET_DEST (y), yinsn) == 0)
+ return 0;
+ }
return rtx_equal_for_thread_p (SET_SRC (x), SET_SRC (y), yinsn);
case SYMBOL_REF:
return XSTR (x, 0) == XSTR (y, 0);
-
+
default:
break;
}
/* And the corresponding elements must match. */
for (j = 0; j < XVECLEN (x, i); j++)
if (rtx_equal_for_thread_p (XVECEXP (x, i, j),
- XVECEXP (y, i, j), yinsn) == 0)
+ XVECEXP (y, i, j), yinsn) == 0)
return 0;
break;
}
return 1;
}
-\f
-
-#if !defined(HAVE_cc0) && !defined(HAVE_conditional_arithmetic)
-/* Return the insn that NEW can be safely inserted in front of starting at
- the jump insn INSN. Return 0 if it is not safe to do this jump
- optimization. Note that NEW must contain a single set. */
-
-static rtx
-find_insert_position (insn, new)
- rtx insn;
- rtx new;
-{
- int i;
- rtx prev;
-
- /* If NEW does not clobber, it is safe to insert NEW before INSN. */
- if (GET_CODE (PATTERN (new)) != PARALLEL)
- return insn;
-
- for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--)
- if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER
- && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0),
- insn))
- break;
-
- if (i < 0)
- return insn;
-
- /* There is a good chance that the previous insn PREV sets the thing
- being clobbered (often the CC in a hard reg). If PREV does not
- use what NEW sets, we can insert NEW before PREV. */
-
- prev = prev_active_insn (insn);
- for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--)
- if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER
- && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0),
- insn)
- && ! modified_in_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0),
- prev))
- return 0;
-
- return reg_mentioned_p (SET_DEST (single_set (new)), prev) ? 0 : prev;
-}
-#endif /* !HAVE_cc0 */
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