#include "tree-pass.h"
#include "df.h"
-static int perhaps_ends_bb_p (rtx);
static int optimize_reg_copy_1 (rtx, rtx, rtx);
static void optimize_reg_copy_2 (rtx, rtx, rtx);
static void optimize_reg_copy_3 (rtx, rtx, rtx);
static void copy_src_to_dest (rtx, rtx, rtx);
+enum match_use
+{
+ READ,
+ WRITE,
+ READWRITE
+};
+
struct match {
int with[MAX_RECOG_OPERANDS];
- enum { READ, WRITE, READWRITE } use[MAX_RECOG_OPERANDS];
+ enum match_use use[MAX_RECOG_OPERANDS];
int commutative[MAX_RECOG_OPERANDS];
int early_clobber[MAX_RECOG_OPERANDS];
};
static int find_matches (rtx, struct match *);
-static int regclass_compatible_p (int, int);
static int fixup_match_2 (rtx, rtx, rtx, rtx);
/* Return nonzero if registers with CLASS1 and CLASS2 can be merged without
causing too much register allocation problems. */
static int
-regclass_compatible_p (int class0, int class1)
+regclass_compatible_p (enum reg_class class0, enum reg_class class1)
{
return (class0 == class1
|| (reg_class_subset_p (class0, class1)
if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS
&& XEXP (XEXP (x, 0), 0) == reg
- && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
+ && CONST_INT_P (XEXP (XEXP (x, 0), 1))
&& INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst)
return x;
changed. */
rtx note = find_reg_note (insn, REG_DEAD, reg);
if (note)
- PUT_MODE (note, REG_UNUSED);
+ PUT_REG_NOTE_KIND (note, REG_UNUSED);
add_reg_note (insn, REG_INC, reg);
\f
static int *regno_src_regno;
-\f
-/* Return 1 if INSN might end a basic block. */
-
-static int perhaps_ends_bb_p (rtx insn)
-{
- switch (GET_CODE (insn))
- {
- case CODE_LABEL:
- case JUMP_INSN:
- /* These always end a basic block. */
- return 1;
-
- case CALL_INSN:
- /* A CALL_INSN might be the last insn of a basic block, if it is inside
- an EH region or if there are nonlocal gotos. Note that this test is
- very conservative. */
- if (nonlocal_goto_handler_labels)
- return 1;
- /* Fall through. */
- default:
- return can_throw_internal (insn);
- }
-}
-\f
/* INSN is a copy from SRC to DEST, both registers, and SRC does not die
in INSN.
rtx dest_death = 0;
int sregno = REGNO (src);
int dregno = REGNO (dest);
+ basic_block bb = BLOCK_FOR_INSN (insn);
/* We don't want to mess with hard regs if register classes are small. */
if (sregno == dregno
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- /* ??? We can't scan past the end of a basic block without updating
- the register lifetime info (REG_DEAD/basic_block_live_at_start). */
- if (perhaps_ends_bb_p (p))
- break;
- else if (! INSN_P (p))
+ if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
if (reg_set_p (src, p) || reg_set_p (dest, p)
/* If SRC is an asm-declared register, it must not be replaced
/* For SREGNO, count the total number of insns scanned.
For DREGNO, count the total number of insns scanned after
passing the death note for DREGNO. */
- s_length++;
- if (dest_death)
- d_length++;
+ if (!DEBUG_INSN_P (p))
+ {
+ s_length++;
+ if (dest_death)
+ d_length++;
+ }
/* If the insn in which SRC dies is a CALL_INSN, don't count it
as a call that has been crossed. Otherwise, count it. */
rtx set;
int sregno = REGNO (src);
int dregno = REGNO (dest);
+ basic_block bb = BLOCK_FOR_INSN (insn);
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- /* ??? We can't scan past the end of a basic block without updating
- the register lifetime info (REG_DEAD/basic_block_live_at_start). */
- if (perhaps_ends_bb_p (p))
- break;
- else if (! INSN_P (p))
+ if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
set = single_set (p);
if (set && SET_SRC (set) == dest && SET_DEST (set) == src
int dst_no = REGNO (dest);
rtx p, set;
enum machine_mode old_mode;
+ basic_block bb = BLOCK_FOR_INSN (insn);
if (src_no < FIRST_PSEUDO_REGISTER
|| dst_no < FIRST_PSEUDO_REGISTER
|| REG_N_DEATHS (src_no) != 1
|| REG_N_SETS (src_no) != 1)
return;
+
for (p = PREV_INSN (insn); p && ! reg_set_p (src_reg, p); p = PREV_INSN (p))
- /* ??? We can't scan past the end of a basic block without updating
- the register lifetime info (REG_DEAD/basic_block_live_at_start). */
- if (perhaps_ends_bb_p (p))
+ if (INSN_P (p) && BLOCK_FOR_INSN (p) != bb)
break;
-
- if (! p)
+
+ if (! p || BLOCK_FOR_INSN (p) != bb)
return;
if (! (set = single_set (p))
{
rtx p, dst_death = 0;
int length, num_calls = 0, freq_calls = 0;
+ basic_block bb = BLOCK_FOR_INSN (insn);
/* If SRC dies in INSN, we'd have to move the death note. This is
considered to be very unlikely, so we just skip the optimization
{
rtx pset;
- /* ??? We can't scan past the end of a basic block without updating
- the register lifetime info (REG_DEAD/basic_block_live_at_start). */
- if (perhaps_ends_bb_p (p))
- break;
- else if (! INSN_P (p))
+ if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
if (find_regno_note (p, REG_DEAD, REGNO (dst)))
dst_death = p;
- if (! dst_death)
+ if (! dst_death && !DEBUG_INSN_P (p))
length++;
pset = single_set (p);
if (pset && SET_DEST (pset) == dst
&& GET_CODE (SET_SRC (pset)) == PLUS
&& XEXP (SET_SRC (pset), 0) == src
- && GET_CODE (XEXP (SET_SRC (pset), 1)) == CONST_INT)
+ && CONST_INT_P (XEXP (SET_SRC (pset), 1)))
{
HOST_WIDE_INT newconst
= INTVAL (offset) - INTVAL (XEXP (SET_SRC (pset), 1));
#ifdef AUTO_INC_DEC
for (p = PREV_INSN (insn); p; p = PREV_INSN (p))
{
- if (LABEL_P (p)
- || JUMP_P (p))
- break;
if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
if (reg_overlap_mentioned_p (dst, PATTERN (p)))
{
if (try_auto_increment (p, insn, 0, dst, newconst, 0))
}
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- if (LABEL_P (p)
- || JUMP_P (p))
- break;
if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
if (reg_overlap_mentioned_p (dst, PATTERN (p)))
{
try_auto_increment (p, insn, 0, dst, newconst, 1);
return 0;
}
-/* Main entry for the register move optimization.
- F is the first instruction.
- NREGS is one plus the highest pseudo-reg number used in the instruction.
- REGMOVE_DUMP_FILE is a stream for output of a trace of actions taken
- (or 0 if none should be output). */
+/* A forward pass. Replace output operands with input operands. */
static void
-regmove_optimize (rtx f, int nregs)
+regmove_forward_pass (void)
{
+ basic_block bb;
rtx insn;
- struct match match;
- int pass;
- int i;
- rtx copy_src, copy_dst;
- /* ??? Hack. Regmove doesn't examine the CFG, and gets mightily
- confused by non-call exceptions ending blocks. */
- if (flag_non_call_exceptions)
+ if (! flag_expensive_optimizations)
return;
- df_note_add_problem ();
- df_analyze ();
-
- regstat_init_n_sets_and_refs ();
- regstat_compute_ri ();
-
- regno_src_regno = XNEWVEC (int, nregs);
- for (i = nregs; --i >= 0; )
- regno_src_regno[i] = -1;
-
- /* A forward/backward pass. Replace output operands with input operands. */
+ if (dump_file)
+ fprintf (dump_file, "Starting forward pass...\n");
- for (pass = 0; pass <= 2; pass++)
+ FOR_EACH_BB (bb)
{
- if (! flag_regmove && pass >= flag_expensive_optimizations)
- goto done;
-
- if (dump_file)
- fprintf (dump_file, "Starting %s pass...\n",
- pass ? "backward" : "forward");
-
- for (insn = pass ? get_last_insn () : f; insn;
- insn = pass ? PREV_INSN (insn) : NEXT_INSN (insn))
+ FOR_BB_INSNS (bb, insn)
{
- rtx set;
-
- set = single_set (insn);
+ rtx set = single_set (insn);
if (! set)
continue;
- if (flag_expensive_optimizations && ! pass
- && (GET_CODE (SET_SRC (set)) == SIGN_EXTEND
- || GET_CODE (SET_SRC (set)) == ZERO_EXTEND)
+ if ((GET_CODE (SET_SRC (set)) == SIGN_EXTEND
+ || GET_CODE (SET_SRC (set)) == ZERO_EXTEND)
&& REG_P (XEXP (SET_SRC (set), 0))
&& REG_P (SET_DEST (set)))
optimize_reg_copy_3 (insn, SET_DEST (set), SET_SRC (set));
- if (flag_expensive_optimizations && ! pass
- && REG_P (SET_SRC (set))
+ if (REG_P (SET_SRC (set))
&& REG_P (SET_DEST (set)))
{
/* If this is a register-register copy where SRC is not dead,
}
}
}
+}
- /* A backward pass. Replace input operands with output operands. */
+/* A backward pass. Replace input operands with output operands. */
+
+static void
+regmove_backward_pass (void)
+{
+ basic_block bb;
+ rtx insn, prev;
if (dump_file)
fprintf (dump_file, "Starting backward pass...\n");
- for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
+ FOR_EACH_BB_REVERSE (bb)
{
- if (INSN_P (insn))
+ /* ??? Use the safe iterator because fixup_match_2 can remove
+ insns via try_auto_increment. */
+ FOR_BB_INSNS_REVERSE_SAFE (bb, insn, prev)
{
+ struct match match;
+ rtx copy_src, copy_dst;
int op_no, match_no;
int success = 0;
+ if (! INSN_P (insn))
+ continue;
+
if (! find_matches (insn, &match))
continue;
if (REGNO (src) < FIRST_PSEUDO_REGISTER)
{
if (GET_CODE (SET_SRC (set)) == PLUS
- && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT
+ && CONST_INT_P (XEXP (SET_SRC (set), 1))
&& XEXP (SET_SRC (set), 0) == src
&& fixup_match_2 (insn, dst, src,
XEXP (SET_SRC (set), 1)))
{
rtx pset;
- /* ??? We can't scan past the end of a basic block without
- updating the register lifetime info
- (REG_DEAD/basic_block_live_at_start). */
- if (perhaps_ends_bb_p (p))
- break;
- else if (! INSN_P (p))
+ if (! INSN_P (p))
continue;
+ if (BLOCK_FOR_INSN (p) != bb)
+ break;
- length++;
+ if (!DEBUG_INSN_P (p))
+ length++;
/* ??? See if all of SRC is set in P. This test is much
more conservative than it needs to be. */
if (pset && SET_DEST (pset) == src)
{
/* We use validate_replace_rtx, in case there
- are multiple identical source operands. All of
- them have to be changed at the same time. */
+ are multiple identical source operands. All
+ of them have to be changed at the same time:
+ when validate_replace_rtx() calls
+ apply_change_group(). */
+ validate_change (p, &SET_DEST (pset), dst, 1);
if (validate_replace_rtx (src, dst, insn))
- {
- if (validate_change (p, &SET_DEST (pset),
- dst, 0))
- success = 1;
- else
- {
- /* Change all source operands back.
- This modifies the dst as a side-effect. */
- validate_replace_rtx (dst, src, insn);
- /* Now make sure the dst is right. */
- validate_change (insn,
- recog_data.operand_loc[match_no],
- dst, 0);
- }
- }
+ success = 1;
break;
}
- /* We can't make this change if SRC is read or
+ /* We can't make this change if DST is mentioned at
+ all in P, since we are going to change its value.
+ We can't make this change if SRC is read or
partially written in P, since we are going to
- eliminate SRC. We can't make this change
- if DST is mentioned at all in P,
- since we are going to change its value. */
- if (reg_overlap_mentioned_p (src, PATTERN (p))
- || reg_mentioned_p (dst, PATTERN (p)))
- break;
+ eliminate SRC. However, if it's a debug insn, we
+ can't refrain from making the change, for this
+ would cause codegen differences, so instead we
+ invalidate debug expressions that reference DST,
+ and adjust references to SRC in them so that they
+ become references to DST. */
+ if (reg_mentioned_p (dst, PATTERN (p)))
+ {
+ if (DEBUG_INSN_P (p))
+ validate_change (p, &INSN_VAR_LOCATION_LOC (p),
+ gen_rtx_UNKNOWN_VAR_LOC (), 1);
+ else
+ break;
+ }
+ if (reg_overlap_mentioned_p (src, PATTERN (p)))
+ {
+ if (DEBUG_INSN_P (p))
+ validate_replace_rtx_group (src, dst, p);
+ else
+ break;
+ }
/* If we have passed a call instruction, and the
pseudo-reg DST is not already live across a call,
break;
}
+ else if (num_changes_pending () > 0)
+ cancel_changes (0);
}
/* If we weren't able to replace any of the alternatives, try an
copy_src_to_dest (insn, copy_src, copy_dst);
}
}
+}
+
+/* Main entry for the register move optimization. */
+
+static unsigned int
+regmove_optimize (void)
+{
+ int i;
+ int nregs = max_reg_num ();
+
+ df_note_add_problem ();
+ df_analyze ();
+
+ regstat_init_n_sets_and_refs ();
+ regstat_compute_ri ();
+
+ regno_src_regno = XNEWVEC (int, nregs);
+ for (i = nregs; --i >= 0; )
+ regno_src_regno[i] = -1;
+
+ /* A forward pass. Replace output operands with input operands. */
+ regmove_forward_pass ();
+
+ /* A backward pass. Replace input operands with output operands. */
+ regmove_backward_pass ();
- done:
/* Clean up. */
free (regno_src_regno);
if (reg_set_in_bb)
}
regstat_free_n_sets_and_refs ();
regstat_free_ri ();
+ return 0;
}
/* Returns nonzero if INSN's pattern has matching constraints for any operand.
return (optimize > 0 && flag_regmove);
}
-/* Register allocation pre-pass, to reduce number of moves necessary
- for two-address machines. */
-static unsigned int
-rest_of_handle_regmove (void)
-{
- regmove_optimize (get_insns (), max_reg_num ());
- return 0;
-}
struct rtl_opt_pass pass_regmove =
{
RTL_PASS,
"regmove", /* name */
gate_handle_regmove, /* gate */
- rest_of_handle_regmove, /* execute */
+ regmove_optimize, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
TODO_ggc_collect /* todo_flags_finish */
}
};
-
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