/* Control flow graph manipulation code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of GCC.
#include "toplev.h"
#include "tm_p.h"
#include "obstack.h"
+#include "insn-config.h"
/* Stubs in case we don't have a return insn. */
#ifndef HAVE_return
static int can_delete_note_p PARAMS ((rtx));
static int can_delete_label_p PARAMS ((rtx));
-static void commit_one_edge_insertion PARAMS ((edge));
+static void commit_one_edge_insertion PARAMS ((edge, int));
static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block));
static rtx last_loop_beg_note PARAMS ((rtx));
static bool back_edge_of_syntactic_loop_p PARAMS ((basic_block, basic_block));
/* User declared labels must be preserved. */
&& LABEL_NAME (label) == 0
&& !in_expr_list_p (forced_labels, label)
- && !in_expr_list_p (label_value_list, label)
- && !in_expr_list_p (exception_handler_labels, label));
+ && !in_expr_list_p (label_value_list, label));
}
/* Delete INSN by patching it out. Return the next insn. */
return next;
}
+/* Like delete_insn but also purge dead edges from BB. */
+rtx
+delete_insn_and_edges (insn)
+ rtx insn;
+{
+ rtx x;
+ bool purge = false;
+
+ if (basic_block_for_insn
+ && INSN_P (insn)
+ && (unsigned int)INSN_UID (insn) < basic_block_for_insn->num_elements
+ && BLOCK_FOR_INSN (insn)
+ && BLOCK_FOR_INSN (insn)->end == insn)
+ purge = true;
+ x = delete_insn (insn);
+ if (purge)
+ purge_dead_edges (BLOCK_FOR_INSN (insn));
+ return x;
+}
+
/* Unlink a chain of insns between START and FINISH, leaving notes
that must be paired. */
start = next;
}
}
+
+/* Like delete_insn but also purge dead edges from BB. */
+void
+delete_insn_chain_and_edges (first, last)
+ rtx first, last;
+{
+ bool purge = false;
+
+ if (basic_block_for_insn
+ && INSN_P (last)
+ && (unsigned int)INSN_UID (last) < basic_block_for_insn->num_elements
+ && BLOCK_FOR_INSN (last)
+ && BLOCK_FOR_INSN (last)->end == last)
+ purge = true;
+ delete_insn_chain (first, last);
+ if (purge)
+ purge_dead_edges (BLOCK_FOR_INSN (last));
+}
\f
/* Create a new basic block consisting of the instructions between HEAD and END
inclusive. This function is designed to allow fast BB construction - reuses
to post-process the stream to remove empty blocks, loops, ranges, etc. */
int
-flow_delete_block (b)
+flow_delete_block_noexpunge (b)
basic_block b;
{
int deleted_handler = 0;
b->pred = NULL;
b->succ = NULL;
+ return deleted_handler;
+}
+
+int
+flow_delete_block (b)
+ basic_block b;
+{
+ int deleted_handler = flow_delete_block_noexpunge (b);
+
/* Remove the basic block from the array, and compact behind it. */
expunge_block (b);
propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0);
COPY_REG_SET (bb->global_live_at_end,
new_bb->global_live_at_start);
+#ifdef HAVE_conditional_execution
+ /* In the presence of conditional execution we are not able to update
+ liveness precisely. */
+ if (reload_completed)
+ {
+ bb->flags |= BB_DIRTY;
+ new_bb->flags |= BB_DIRTY;
+ }
+#endif
}
return new_edge;
rtx x;
for (x = a_end; x != b_end; x = NEXT_INSN (x))
- BLOCK_FOR_INSN (x) = a;
+ set_block_for_insn (x, a);
- BLOCK_FOR_INSN (b_end) = a;
+ set_block_for_insn (b_end, a);
}
a_end = b_end;
/* Update the CFG for the instructions queued on edge E. */
static void
-commit_one_edge_insertion (e)
+commit_one_edge_insertion (e, watch_calls)
edge e;
+ int watch_calls;
{
rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
basic_block bb;
insns = e->insns;
e->insns = NULL_RTX;
- /* Figure out where to put these things. If the destination has
- one predecessor, insert there. Except for the exit block. */
- if (e->dest->pred->pred_next == NULL
- && e->dest != EXIT_BLOCK_PTR)
+ /* Special case -- avoid inserting code between call and storing
+ its return value. */
+ if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next
+ && e->src != ENTRY_BLOCK_PTR
+ && GET_CODE (e->src->end) == CALL_INSN)
{
+ rtx next = next_nonnote_insn (e->src->end);
+
+ after = e->dest->head;
+ /* The first insn after the call may be a stack pop, skip it. */
+ while (next
+ && keep_with_call_p (next))
+ {
+ after = next;
+ next = next_nonnote_insn (next);
+ }
bb = e->dest;
-
- /* Get the location correct wrt a code label, and "nice" wrt
- a basic block note, and before everything else. */
- tmp = bb->head;
- if (GET_CODE (tmp) == CODE_LABEL)
- tmp = NEXT_INSN (tmp);
- if (NOTE_INSN_BASIC_BLOCK_P (tmp))
- tmp = NEXT_INSN (tmp);
- if (tmp == bb->head)
- before = tmp;
- else
- after = PREV_INSN (tmp);
}
-
- /* If the source has one successor and the edge is not abnormal,
- insert there. Except for the entry block. */
- else if ((e->flags & EDGE_ABNORMAL) == 0
- && e->src->succ->succ_next == NULL
- && e->src != ENTRY_BLOCK_PTR)
+ if (!before && !after)
{
- bb = e->src;
-
- /* It is possible to have a non-simple jump here. Consider a target
- where some forms of unconditional jumps clobber a register. This
- happens on the fr30 for example.
-
- We know this block has a single successor, so we can just emit
- the queued insns before the jump. */
- if (GET_CODE (bb->end) == JUMP_INSN)
- for (before = bb->end;
- GET_CODE (PREV_INSN (before)) == NOTE
- && NOTE_LINE_NUMBER (PREV_INSN (before)) == NOTE_INSN_LOOP_BEG;
- before = PREV_INSN (before))
- ;
- else
+ /* Figure out where to put these things. If the destination has
+ one predecessor, insert there. Except for the exit block. */
+ if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR)
{
- /* We'd better be fallthru, or we've lost track of what's what. */
- if ((e->flags & EDGE_FALLTHRU) == 0)
- abort ();
+ bb = e->dest;
+
+ /* Get the location correct wrt a code label, and "nice" wrt
+ a basic block note, and before everything else. */
+ tmp = bb->head;
+ if (GET_CODE (tmp) == CODE_LABEL)
+ tmp = NEXT_INSN (tmp);
+ if (NOTE_INSN_BASIC_BLOCK_P (tmp))
+ tmp = NEXT_INSN (tmp);
+ if (tmp == bb->head)
+ before = tmp;
+ else if (tmp)
+ after = PREV_INSN (tmp);
+ else
+ after = get_last_insn ();
+ }
+ /* If the source has one successor and the edge is not abnormal,
+ insert there. Except for the entry block. */
+ else if ((e->flags & EDGE_ABNORMAL) == 0
+ && e->src->succ->succ_next == NULL
+ && e->src != ENTRY_BLOCK_PTR)
+ {
+ bb = e->src;
+
+ /* It is possible to have a non-simple jump here. Consider a target
+ where some forms of unconditional jumps clobber a register. This
+ happens on the fr30 for example.
+
+ We know this block has a single successor, so we can just emit
+ the queued insns before the jump. */
+ if (GET_CODE (bb->end) == JUMP_INSN)
+ for (before = bb->end;
+ GET_CODE (PREV_INSN (before)) == NOTE
+ && NOTE_LINE_NUMBER (PREV_INSN (before)) ==
+ NOTE_INSN_LOOP_BEG; before = PREV_INSN (before))
+ ;
+ else
+ {
+ /* We'd better be fallthru, or we've lost track of what's what. */
+ if ((e->flags & EDGE_FALLTHRU) == 0)
+ abort ();
+
+ after = bb->end;
+ }
+ }
+ /* Otherwise we must split the edge. */
+ else
+ {
+ bb = split_edge (e);
after = bb->end;
}
}
- /* Otherwise we must split the edge. */
- else
- {
- bb = split_edge (e);
- after = bb->end;
- }
-
/* Now that we've found the spot, do the insertion. */
if (before)
{
/* ??? Remove all outgoing edges from BB and add one for EXIT.
This is not currently a problem because this only happens
- for the (single) epilogue, which already has a fallthru edge
- to EXIT. */
+ for the (single) epilogue, which already has a fallthru edge
+ to EXIT. */
e = bb->succ;
if (e->dest != EXIT_BLOCK_PTR
- || e->succ_next != NULL
- || (e->flags & EDGE_FALLTHRU) == 0)
+ || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0)
abort ();
e->flags &= ~EDGE_FALLTHRU;
{
next = e->succ_next;
if (e->insns)
- commit_one_edge_insertion (e);
+ commit_one_edge_insertion (e, false);
+ }
+
+ if (++i >= n_basic_blocks)
+ break;
+ bb = BASIC_BLOCK (i);
+ }
+}
+\f
+/* Update the CFG for all queued instructions, taking special care of inserting
+ code on edges between call and storing its return value. */
+
+void
+commit_edge_insertions_watch_calls ()
+{
+ int i;
+ basic_block bb;
+
+#ifdef ENABLE_CHECKING
+ verify_flow_info ();
+#endif
+
+ i = -1;
+ bb = ENTRY_BLOCK_PTR;
+ while (1)
+ {
+ edge e, next;
+
+ for (e = bb->succ; e; e = next)
+ {
+ next = e->succ_next;
+ if (e->insns)
+ commit_one_edge_insertion (e, true);
}
if (++i >= n_basic_blocks)
for (i = n_basic_blocks - 1; i >= 0; i--)
{
basic_block bb = BASIC_BLOCK (i);
- int has_fallthru = 0;
+ int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0;
edge e;
+ rtx note;
+ if (INSN_P (bb->end)
+ && (note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX))
+ && any_condjump_p (bb->end))
+ {
+ if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability)
+ {
+ error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i",
+ INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability);
+ err = 1;
+ }
+ }
+ if (bb->count < 0)
+ {
+ error ("verify_flow_info: Wrong count of block %i %i",
+ bb->index, (int)bb->count);
+ err = 1;
+ }
+ if (bb->frequency < 0)
+ {
+ error ("verify_flow_info: Wrong frequency of block %i %i",
+ bb->index, bb->frequency);
+ err = 1;
+ }
for (e = bb->succ; e; e = e->succ_next)
{
if (last_visited [e->dest->index + 2] == bb)
e->src->index, e->dest->index);
err = 1;
}
+ if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
+ {
+ error ("verify_flow_info: Wrong probability of edge %i->%i %i",
+ e->src->index, e->dest->index, e->probability);
+ err = 1;
+ }
+ if (e->count < 0)
+ {
+ error ("verify_flow_info: Wrong count of edge %i->%i %i",
+ e->src->index, e->dest->index, (int)e->count);
+ err = 1;
+ }
last_visited [e->dest->index + 2] = bb;
if (e->flags & EDGE_FALLTHRU)
- has_fallthru = 1;
+ n_fallthru++;
+
+ if ((e->flags & ~EDGE_DFS_BACK) == 0)
+ n_branch++;
+
+ if (e->flags & EDGE_ABNORMAL_CALL)
+ n_call++;
+
+ if (e->flags & EDGE_EH)
+ n_eh++;
+ else if (e->flags & EDGE_ABNORMAL)
+ n_abnormal++;
if ((e->flags & EDGE_FALLTHRU)
&& e->src != ENTRY_BLOCK_PTR
edge_checksum[e->dest->index + 2] += (size_t) e;
}
- if (!has_fallthru)
+ if (n_eh && GET_CODE (PATTERN (bb->end)) != RESX
+ && !find_reg_note (bb->end, REG_EH_REGION, NULL_RTX))
+ {
+ error ("Missing REG_EH_REGION note in the end of bb %i", bb->index);
+ err = 1;
+ }
+ if (n_branch
+ && (GET_CODE (bb->end) != JUMP_INSN
+ || (n_branch > 1 && (any_uncondjump_p (bb->end)
+ || any_condjump_p (bb->end)))))
+ {
+ error ("Too many outgoing branch edges from bb %i", bb->index);
+ err = 1;
+ }
+ if (n_fallthru && any_uncondjump_p (bb->end))
+ {
+ error ("Fallthru edge after unconditional jump %i", bb->index);
+ err = 1;
+ }
+ if (n_branch != 1 && any_uncondjump_p (bb->end))
+ {
+ error ("Wrong amount of branch edges after unconditional jump %i", bb->index);
+ err = 1;
+ }
+ if (n_branch != 1 && any_condjump_p (bb->end)
+ && JUMP_LABEL (bb->end) != BASIC_BLOCK (bb->index + 1)->head)
+ {
+ error ("Wrong amount of branch edges after conditional jump %i", bb->index);
+ err = 1;
+ }
+ if (n_call && GET_CODE (bb->end) != CALL_INSN)
+ {
+ error ("Call edges for non-call insn in bb %i", bb->index);
+ err = 1;
+ }
+ if (n_abnormal
+ && (GET_CODE (bb->end) != CALL_INSN && n_call != n_abnormal)
+ && (GET_CODE (bb->end) != JUMP_INSN
+ || any_condjump_p (bb->end)
+ || any_uncondjump_p (bb->end)))
+ {
+ error ("Abnormal edges for no purpose in bb %i", bb->index);
+ err = 1;
+ }
+
+ if (!n_fallthru)
{
rtx insn;
rtx insn = bb->end, note;
bool purged = false;
- /* ??? This makes no sense since the later test includes more cases. */
- if (GET_CODE (insn) == JUMP_INSN && !simplejump_p (insn))
- return false;
+ /* If this instruction cannot trap, remove REG_EH_REGION notes. */
+ if (GET_CODE (insn) == INSN
+ && (note = find_reg_note (insn, REG_EH_REGION, NULL)))
+ {
+ rtx eqnote;
+
+ if (! may_trap_p (PATTERN (insn))
+ || ((eqnote = find_reg_equal_equiv_note (insn))
+ && ! may_trap_p (XEXP (eqnote, 0))))
+ remove_note (insn, note);
+ }
+
+ /* Cleanup abnormal edges caused by throwing insns that have been
+ eliminated. */
+ if (! can_throw_internal (bb->end))
+ for (e = bb->succ; e; e = next)
+ {
+ next = e->succ_next;
+ if (e->flags & EDGE_EH)
+ {
+ remove_edge (e);
+ bb->flags |= BB_DIRTY;
+ purged = true;
+ }
+ }
if (GET_CODE (insn) == JUMP_INSN)
{
if (!any_condjump_p (insn)
&& !returnjump_p (insn)
&& !simplejump_p (insn))
- return false;
+ return purged;
+
+ /* Branch probability/prediction notes are defined only for
+ condjumps. We've possibly turned condjump into simplejump. */
+ if (simplejump_p (insn))
+ {
+ note = find_reg_note (insn, REG_BR_PROB, NULL);
+ if (note)
+ remove_note (insn, note);
+ while ((note = find_reg_note (insn, REG_BR_PRED, NULL)))
+ remove_note (insn, note);
+ }
for (e = bb->succ; e; e = next)
{
&& returnjump_p (insn))
continue;
+ bb->flags |= BB_DIRTY;
purged = true;
remove_edge (e);
}
if (!bb->succ || !purged)
- return false;
+ return purged;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index);
return purged;
}
- /* If this instruction cannot trap, remove REG_EH_REGION notes. */
- if (GET_CODE (insn) == INSN
- && (note = find_reg_note (insn, REG_EH_REGION, NULL)))
- {
- rtx eqnote;
-
- if (! may_trap_p (PATTERN (insn))
- || ((eqnote = find_reg_equal_equiv_note (insn))
- && ! may_trap_p (XEXP (eqnote, 0))))
- remove_note (insn, note);
- }
-
- /* Cleanup abnormal edges caused by throwing insns that have been
- eliminated. */
- if (! can_throw_internal (bb->end))
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (e->flags & EDGE_EH)
- {
- remove_edge (e);
- purged = true;
- }
- }
-
/* If we don't see a jump insn, we don't know exactly why the block would
have been broken at this point. Look for a simple, non-fallthru edge,
as these are only created by conditional branches. If we find such an
{
next = e->succ_next;
if (!(e->flags & EDGE_FALLTHRU))
- remove_edge (e), purged = true;
+ {
+ bb->flags |= BB_DIRTY;
+ remove_edge (e);
+ purged = true;
+ }
}
if (!bb->succ || bb->succ->succ_next)
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