/* Control flow optimization code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011
Free Software Foundation, Inc.
This file is part of GCC.
#include "flags.h"
#include "recog.h"
#include "diagnostic-core.h"
-#include "toplev.h"
#include "cselib.h"
#include "params.h"
#include "tm_p.h"
information; we should run df_analyze to enable more opportunities. */
static bool block_was_dirty;
-static bool try_crossjump_to_edge (int, edge, edge);
+static bool try_crossjump_to_edge (int, edge, edge, enum replace_direction);
static bool try_crossjump_bb (int, basic_block);
static bool outgoing_edges_match (int, basic_block, basic_block);
-static bool old_insns_match_p (int, rtx, rtx);
+static enum replace_direction old_insns_match_p (int, rtx, rtx);
static void merge_blocks_move_predecessor_nojumps (basic_block, basic_block);
static void merge_blocks_move_successor_nojumps (basic_block, basic_block);
{
dest = XEXP (exp, 0);
regno = REGNO (dest);
- CLEAR_REGNO_REG_SET (nonequal, regno);
- if (regno < FIRST_PSEUDO_REGISTER)
- {
- int n = hard_regno_nregs[regno][GET_MODE (dest)];
- while (--n > 0)
- CLEAR_REGNO_REG_SET (nonequal, regno + n);
- }
+ if (HARD_REGISTER_NUM_P (regno))
+ bitmap_clear_range (nonequal, regno,
+ hard_regno_nregs[regno][GET_MODE (dest)]);
+ else
+ bitmap_clear_bit (nonequal, regno);
}
return false;
if (!REG_P (dest))
return true;
regno = REGNO (dest);
- SET_REGNO_REG_SET (nonequal, regno);
- if (regno < FIRST_PSEUDO_REGISTER)
- {
- int n = hard_regno_nregs[regno][GET_MODE (dest)];
- while (--n > 0)
- SET_REGNO_REG_SET (nonequal, regno + n);
- }
+ if (HARD_REGISTER_NUM_P (regno))
+ bitmap_set_range (nonequal, regno,
+ hard_regno_nregs[regno][GET_MODE (dest)]);
+ else
+ bitmap_set_bit (nonequal, regno);
return false;
default:
{
/* When not optimizing, ensure that edges or forwarder
blocks with different locus are not optimized out. */
- int locus = single_succ_edge (target)->goto_locus;
+ int new_locus = single_succ_edge (target)->goto_locus;
+ int locus = goto_locus;
- if (locus && goto_locus && !locator_eq (locus, goto_locus))
- counter = n_basic_blocks;
- else if (locus)
- goto_locus = locus;
-
- if (INSN_P (BB_END (target)))
+ if (new_locus && locus && !locator_eq (new_locus, locus))
+ new_target = NULL;
+ else
{
- locus = INSN_LOCATOR (BB_END (target));
+ rtx last;
- if (locus && goto_locus
- && !locator_eq (locus, goto_locus))
- counter = n_basic_blocks;
- else if (locus)
- goto_locus = locus;
+ if (new_locus)
+ locus = new_locus;
+
+ last = BB_END (target);
+ if (DEBUG_INSN_P (last))
+ last = prev_nondebug_insn (last);
+
+ new_locus = last && INSN_P (last)
+ ? INSN_LOCATOR (last) : 0;
+
+ if (new_locus && locus && !locator_eq (new_locus, locus))
+ new_target = NULL;
+ else
+ {
+ if (new_locus)
+ locus = new_locus;
+
+ goto_locus = locus;
+ }
}
}
}
+ REG_BR_PROB_BASE / 2)
/ REG_BR_PROB_BASE);
- if (!FORWARDER_BLOCK_P (b) && forwarder_block_p (b))
- b->flags |= BB_FORWARDER_BLOCK;
-
do
{
edge t;
ei_next (&ei);
}
- if (threaded_edges)
- free (threaded_edges);
+ free (threaded_edges);
return changed;
}
\f
edge tmp_edge, b_fallthru_edge;
bool c_has_outgoing_fallthru;
bool b_has_incoming_fallthru;
- edge_iterator ei;
/* Avoid overactive code motion, as the forwarder blocks should be
eliminated by edge redirection instead. One exception might have
and loop notes. This is done by squeezing out all the notes
and leaving them there to lie. Not ideal, but functional. */
- FOR_EACH_EDGE (tmp_edge, ei, c->succs)
- if (tmp_edge->flags & EDGE_FALLTHRU)
- break;
-
+ tmp_edge = find_fallthru_edge (c->succs);
c_has_outgoing_fallthru = (tmp_edge != NULL);
- FOR_EACH_EDGE (tmp_edge, ei, b->preds)
- if (tmp_edge->flags & EDGE_FALLTHRU)
- break;
-
+ tmp_edge = find_fallthru_edge (b->preds);
b_has_incoming_fallthru = (tmp_edge != NULL);
b_fallthru_edge = tmp_edge;
next = b->prev_bb;
MEM_ATTRS (x) = 0;
else
{
- rtx mem_size;
+ HOST_WIDE_INT mem_size;
if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
{
{
set_mem_expr (x, 0);
set_mem_expr (y, 0);
- set_mem_offset (x, 0);
- set_mem_offset (y, 0);
+ clear_mem_offset (x);
+ clear_mem_offset (y);
}
- else if (MEM_OFFSET (x) != MEM_OFFSET (y))
+ else if (MEM_OFFSET_KNOWN_P (x) != MEM_OFFSET_KNOWN_P (y)
+ || (MEM_OFFSET_KNOWN_P (x)
+ && MEM_OFFSET (x) != MEM_OFFSET (y)))
{
- set_mem_offset (x, 0);
- set_mem_offset (y, 0);
+ clear_mem_offset (x);
+ clear_mem_offset (y);
}
- if (!MEM_SIZE (x))
- mem_size = NULL_RTX;
- else if (!MEM_SIZE (y))
- mem_size = NULL_RTX;
+ if (MEM_SIZE_KNOWN_P (x) && MEM_SIZE_KNOWN_P (y))
+ {
+ mem_size = MAX (MEM_SIZE (x), MEM_SIZE (y));
+ set_mem_size (x, mem_size);
+ set_mem_size (y, mem_size);
+ }
else
- mem_size = GEN_INT (MAX (INTVAL (MEM_SIZE (x)),
- INTVAL (MEM_SIZE (y))));
- set_mem_size (x, mem_size);
- set_mem_size (y, mem_size);
+ {
+ clear_mem_size (x);
+ clear_mem_size (y);
+ }
set_mem_align (x, MIN (MEM_ALIGN (x), MEM_ALIGN (y)));
set_mem_align (y, MEM_ALIGN (x));
}
-/* Return true if I1 and I2 are equivalent and thus can be crossjumped. */
+ /* Checks if patterns P1 and P2 are equivalent, apart from the possibly
+ different single sets S1 and S2. */
static bool
+equal_different_set_p (rtx p1, rtx s1, rtx p2, rtx s2)
+{
+ int i;
+ rtx e1, e2;
+
+ if (p1 == s1 && p2 == s2)
+ return true;
+
+ if (GET_CODE (p1) != PARALLEL || GET_CODE (p2) != PARALLEL)
+ return false;
+
+ if (XVECLEN (p1, 0) != XVECLEN (p2, 0))
+ return false;
+
+ for (i = 0; i < XVECLEN (p1, 0); i++)
+ {
+ e1 = XVECEXP (p1, 0, i);
+ e2 = XVECEXP (p2, 0, i);
+ if (e1 == s1 && e2 == s2)
+ continue;
+ if (reload_completed
+ ? rtx_renumbered_equal_p (e1, e2) : rtx_equal_p (e1, e2))
+ continue;
+
+ return false;
+ }
+
+ return true;
+}
+
+/* Examine register notes on I1 and I2 and return:
+ - dir_forward if I1 can be replaced by I2, or
+ - dir_backward if I2 can be replaced by I1, or
+ - dir_both if both are the case. */
+
+static enum replace_direction
+can_replace_by (rtx i1, rtx i2)
+{
+ rtx s1, s2, d1, d2, src1, src2, note1, note2;
+ bool c1, c2;
+
+ /* Check for 2 sets. */
+ s1 = single_set (i1);
+ s2 = single_set (i2);
+ if (s1 == NULL_RTX || s2 == NULL_RTX)
+ return dir_none;
+
+ /* Check that the 2 sets set the same dest. */
+ d1 = SET_DEST (s1);
+ d2 = SET_DEST (s2);
+ if (!(reload_completed
+ ? rtx_renumbered_equal_p (d1, d2) : rtx_equal_p (d1, d2)))
+ return dir_none;
+
+ /* Find identical req_equiv or reg_equal note, which implies that the 2 sets
+ set dest to the same value. */
+ note1 = find_reg_equal_equiv_note (i1);
+ note2 = find_reg_equal_equiv_note (i2);
+ if (!note1 || !note2 || !rtx_equal_p (XEXP (note1, 0), XEXP (note2, 0))
+ || !CONST_INT_P (XEXP (note1, 0)))
+ return dir_none;
+
+ if (!equal_different_set_p (PATTERN (i1), s1, PATTERN (i2), s2))
+ return dir_none;
+
+ /* Although the 2 sets set dest to the same value, we cannot replace
+ (set (dest) (const_int))
+ by
+ (set (dest) (reg))
+ because we don't know if the reg is live and has the same value at the
+ location of replacement. */
+ src1 = SET_SRC (s1);
+ src2 = SET_SRC (s2);
+ c1 = CONST_INT_P (src1);
+ c2 = CONST_INT_P (src2);
+ if (c1 && c2)
+ return dir_both;
+ else if (c2)
+ return dir_forward;
+ else if (c1)
+ return dir_backward;
+
+ return dir_none;
+}
+
+/* Merges directions A and B. */
+
+static enum replace_direction
+merge_dir (enum replace_direction a, enum replace_direction b)
+{
+ /* Implements the following table:
+ |bo fw bw no
+ ---+-----------
+ bo |bo fw bw no
+ fw |-- fw no no
+ bw |-- -- bw no
+ no |-- -- -- no. */
+
+ if (a == b)
+ return a;
+
+ if (a == dir_both)
+ return b;
+ if (b == dir_both)
+ return a;
+
+ return dir_none;
+}
+
+/* Examine I1 and I2 and return:
+ - dir_forward if I1 can be replaced by I2, or
+ - dir_backward if I2 can be replaced by I1, or
+ - dir_both if both are the case. */
+
+static enum replace_direction
old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx i1, rtx i2)
{
rtx p1, p2;
/* Verify that I1 and I2 are equivalent. */
if (GET_CODE (i1) != GET_CODE (i2))
- return false;
+ return dir_none;
/* __builtin_unreachable() may lead to empty blocks (ending with
NOTE_INSN_BASIC_BLOCK). They may be crossjumped. */
if (NOTE_INSN_BASIC_BLOCK_P (i1) && NOTE_INSN_BASIC_BLOCK_P (i2))
- return true;
+ return dir_both;
+
+ /* ??? Do not allow cross-jumping between different stack levels. */
+ p1 = find_reg_note (i1, REG_ARGS_SIZE, NULL);
+ p2 = find_reg_note (i2, REG_ARGS_SIZE, NULL);
+ if (p1 && p2)
+ {
+ p1 = XEXP (p1, 0);
+ p2 = XEXP (p2, 0);
+ if (!rtx_equal_p (p1, p2))
+ return dir_none;
+
+ /* ??? Worse, this adjustment had better be constant lest we
+ have differing incoming stack levels. */
+ if (!frame_pointer_needed
+ && find_args_size_adjust (i1) == HOST_WIDE_INT_MIN)
+ return dir_none;
+ }
+ else if (p1 || p2)
+ return dir_none;
p1 = PATTERN (i1);
p2 = PATTERN (i2);
if (GET_CODE (p1) != GET_CODE (p2))
- return false;
+ return dir_none;
/* If this is a CALL_INSN, compare register usage information.
If we don't check this on stack register machines, the two
rtx n2 = find_reg_note (i2, REG_EH_REGION, 0);
if (!n1 && n2)
- return false;
+ return dir_none;
if (n1 && (!n2 || XEXP (n1, 0) != XEXP (n2, 0)))
- return false;
+ return dir_none;
if (!rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1),
CALL_INSN_FUNCTION_USAGE (i2))
|| SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2))
- return false;
+ return dir_none;
}
#ifdef STACK_REGS
SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0)));
if (!hard_reg_set_equal_p (i1_regset, i2_regset))
- return false;
+ return dir_none;
}
#endif
if (reload_completed
? rtx_renumbered_equal_p (p1, p2) : rtx_equal_p (p1, p2))
- return true;
+ return dir_both;
- return false;
+ return can_replace_by (i1, i2);
}
\f
/* When comparing insns I1 and I2 in flow_find_cross_jump or
}
}
+ /* Walks from I1 in BB1 backward till the next non-debug insn, and returns the
+ resulting insn in I1, and the corresponding bb in BB1. At the head of a
+ bb, if there is a predecessor bb that reaches this bb via fallthru, and
+ FOLLOW_FALLTHRU, walks further in the predecessor bb and registers this in
+ DID_FALLTHRU. Otherwise, stops at the head of the bb. */
+
+static void
+walk_to_nondebug_insn (rtx *i1, basic_block *bb1, bool follow_fallthru,
+ bool *did_fallthru)
+{
+ edge fallthru;
+
+ *did_fallthru = false;
+
+ /* Ignore notes. */
+ while (!NONDEBUG_INSN_P (*i1))
+ {
+ if (*i1 != BB_HEAD (*bb1))
+ {
+ *i1 = PREV_INSN (*i1);
+ continue;
+ }
+
+ if (!follow_fallthru)
+ return;
+
+ fallthru = find_fallthru_edge ((*bb1)->preds);
+ if (!fallthru || fallthru->src == ENTRY_BLOCK_PTR_FOR_FUNCTION (cfun)
+ || !single_succ_p (fallthru->src))
+ return;
+
+ *bb1 = fallthru->src;
+ *i1 = BB_END (*bb1);
+ *did_fallthru = true;
+ }
+}
+
/* Look through the insns at the end of BB1 and BB2 and find the longest
- sequence that are equivalent. Store the first insns for that sequence
- in *F1 and *F2 and return the sequence length.
+ sequence that are either equivalent, or allow forward or backward
+ replacement. Store the first insns for that sequence in *F1 and *F2 and
+ return the sequence length.
+
+ DIR_P indicates the allowed replacement direction on function entry, and
+ the actual replacement direction on function exit. If NULL, only equivalent
+ sequences are allowed.
To simplify callers of this function, if the blocks match exactly,
store the head of the blocks in *F1 and *F2. */
int
-flow_find_cross_jump (basic_block bb1, basic_block bb2, rtx *f1, rtx *f2)
+flow_find_cross_jump (basic_block bb1, basic_block bb2, rtx *f1, rtx *f2,
+ enum replace_direction *dir_p)
{
rtx i1, i2, last1, last2, afterlast1, afterlast2;
int ninsns = 0;
+ rtx p1;
+ enum replace_direction dir, last_dir, afterlast_dir;
+ bool follow_fallthru, did_fallthru;
+
+ if (dir_p)
+ dir = *dir_p;
+ else
+ dir = dir_both;
+ afterlast_dir = dir;
+ last_dir = afterlast_dir;
/* Skip simple jumps at the end of the blocks. Complex jumps still
need to be compared for equivalence, which we'll do below. */
while (true)
{
- /* Ignore notes. */
- while (!NONDEBUG_INSN_P (i1) && i1 != BB_HEAD (bb1))
- i1 = PREV_INSN (i1);
-
- while (!NONDEBUG_INSN_P (i2) && i2 != BB_HEAD (bb2))
- i2 = PREV_INSN (i2);
+ /* In the following example, we can replace all jumps to C by jumps to A.
+
+ This removes 4 duplicate insns.
+ [bb A] insn1 [bb C] insn1
+ insn2 insn2
+ [bb B] insn3 insn3
+ insn4 insn4
+ jump_insn jump_insn
+
+ We could also replace all jumps to A by jumps to C, but that leaves B
+ alive, and removes only 2 duplicate insns. In a subsequent crossjump
+ step, all jumps to B would be replaced with jumps to the middle of C,
+ achieving the same result with more effort.
+ So we allow only the first possibility, which means that we don't allow
+ fallthru in the block that's being replaced. */
+
+ follow_fallthru = dir_p && dir != dir_forward;
+ walk_to_nondebug_insn (&i1, &bb1, follow_fallthru, &did_fallthru);
+ if (did_fallthru)
+ dir = dir_backward;
+
+ follow_fallthru = dir_p && dir != dir_backward;
+ walk_to_nondebug_insn (&i2, &bb2, follow_fallthru, &did_fallthru);
+ if (did_fallthru)
+ dir = dir_forward;
if (i1 == BB_HEAD (bb1) || i2 == BB_HEAD (bb2))
break;
- if (!old_insns_match_p (0, i1, i2))
+ dir = merge_dir (dir, old_insns_match_p (0, i1, i2));
+ if (dir == dir_none || (!dir_p && dir != dir_both))
break;
merge_memattrs (i1, i2);
afterlast1 = last1, afterlast2 = last2;
last1 = i1, last2 = i2;
- ninsns++;
+ afterlast_dir = last_dir;
+ last_dir = dir;
+ p1 = PATTERN (i1);
+ if (!(GET_CODE (p1) == USE || GET_CODE (p1) == CLOBBER))
+ ninsns++;
}
i1 = PREV_INSN (i1);
/* Don't allow the insn after a compare to be shared by
cross-jumping unless the compare is also shared. */
if (ninsns && reg_mentioned_p (cc0_rtx, last1) && ! sets_cc0_p (last1))
- last1 = afterlast1, last2 = afterlast2, ninsns--;
+ last1 = afterlast1, last2 = afterlast2, last_dir = afterlast_dir, ninsns--;
#endif
/* Include preceding notes and labels in the cross-jump. One,
Two, it keeps line number notes as matched as may be. */
if (ninsns)
{
+ bb1 = BLOCK_FOR_INSN (last1);
while (last1 != BB_HEAD (bb1) && !NONDEBUG_INSN_P (PREV_INSN (last1)))
last1 = PREV_INSN (last1);
if (last1 != BB_HEAD (bb1) && LABEL_P (PREV_INSN (last1)))
last1 = PREV_INSN (last1);
+ bb2 = BLOCK_FOR_INSN (last2);
while (last2 != BB_HEAD (bb2) && !NONDEBUG_INSN_P (PREV_INSN (last2)))
last2 = PREV_INSN (last2);
*f2 = last2;
}
+ if (dir_p)
+ *dir_p = last_dir;
return ninsns;
}
while (true)
{
- /* Ignore notes. */
+ /* Ignore notes, except NOTE_INSN_EPILOGUE_BEG. */
while (!NONDEBUG_INSN_P (i1) && i1 != BB_END (bb1))
- i1 = NEXT_INSN (i1);
+ {
+ if (NOTE_P (i1) && NOTE_KIND (i1) == NOTE_INSN_EPILOGUE_BEG)
+ break;
+ i1 = NEXT_INSN (i1);
+ }
while (!NONDEBUG_INSN_P (i2) && i2 != BB_END (bb2))
- i2 = NEXT_INSN (i2);
+ {
+ if (NOTE_P (i2) && NOTE_KIND (i2) == NOTE_INSN_EPILOGUE_BEG)
+ break;
+ i2 = NEXT_INSN (i2);
+ }
if ((i1 == BB_END (bb1) && !NONDEBUG_INSN_P (i1))
|| (i2 == BB_END (bb2) && !NONDEBUG_INSN_P (i2)))
&& nehedges1 != nehedges2))
break;
- if (!old_insns_match_p (0, i1, i2))
+ if (old_insns_match_p (0, i1, i2) != dir_both)
break;
merge_memattrs (i1, i2);
rr.update_label_nuses = false;
for_each_rtx (&BB_END (bb1), replace_label, &rr);
- match = old_insns_match_p (mode, BB_END (bb1), BB_END (bb2));
+ match = (old_insns_match_p (mode, BB_END (bb1), BB_END (bb2))
+ == dir_both);
if (dump_file && match)
fprintf (dump_file,
"Tablejumps in bb %i and %i match.\n",
/* First ensure that the instructions match. There may be many outgoing
edges so this test is generally cheaper. */
- if (!old_insns_match_p (mode, BB_END (bb1), BB_END (bb2)))
+ if (old_insns_match_p (mode, BB_END (bb1), BB_END (bb2)) != dir_both)
return false;
/* Search the outgoing edges, ensure that the counts do match, find possible
/* E1 and E2 are edges with the same destination block. Search their
predecessors for common code. If found, redirect control flow from
- (maybe the middle of) E1->SRC to (maybe the middle of) E2->SRC. */
+ (maybe the middle of) E1->SRC to (maybe the middle of) E2->SRC (dir_forward),
+ or the other way around (dir_backward). DIR specifies the allowed
+ replacement direction. */
static bool
-try_crossjump_to_edge (int mode, edge e1, edge e2)
+try_crossjump_to_edge (int mode, edge e1, edge e2,
+ enum replace_direction dir)
{
int nmatch;
basic_block src1 = e1->src, src2 = e2->src;
basic_block redirect_to, redirect_from, to_remove;
+ basic_block osrc1, osrc2, redirect_edges_to, tmp;
rtx newpos1, newpos2;
edge s;
edge_iterator ei;
return false;
/* ... and part the second. */
- nmatch = flow_find_cross_jump (src1, src2, &newpos1, &newpos2);
+ nmatch = flow_find_cross_jump (src1, src2, &newpos1, &newpos2, &dir);
+
+ osrc1 = src1;
+ osrc2 = src2;
+ if (newpos1 != NULL_RTX)
+ src1 = BLOCK_FOR_INSN (newpos1);
+ if (newpos2 != NULL_RTX)
+ src2 = BLOCK_FOR_INSN (newpos2);
+
+ if (dir == dir_backward)
+ {
+#define SWAP(T, X, Y) do { T tmp = (X); (X) = (Y); (Y) = tmp; } while (0)
+ SWAP (basic_block, osrc1, osrc2);
+ SWAP (basic_block, src1, src2);
+ SWAP (edge, e1, e2);
+ SWAP (rtx, newpos1, newpos2);
+#undef SWAP
+ }
/* Don't proceed with the crossjump unless we found a sufficient number
of matching instructions or the 'from' block was totally matched
rtx label1, label2;
rtx table1, table2;
- if (tablejump_p (BB_END (src1), &label1, &table1)
- && tablejump_p (BB_END (src2), &label2, &table2)
+ if (tablejump_p (BB_END (osrc1), &label1, &table1)
+ && tablejump_p (BB_END (osrc2), &label2, &table2)
&& label1 != label2)
{
replace_label_data rr;
/* Do not replace the label in SRC1->END because when deleting
a block whose end is a tablejump, the tablejump referenced
from the instruction is deleted too. */
- if (insn != BB_END (src1))
+ if (insn != BB_END (osrc1))
for_each_rtx (&insn, replace_label, &rr);
}
}
/* We may have some registers visible through the block. */
df_set_bb_dirty (redirect_to);
+ if (osrc2 == src2)
+ redirect_edges_to = redirect_to;
+ else
+ redirect_edges_to = osrc2;
+
/* Recompute the frequencies and counts of outgoing edges. */
- FOR_EACH_EDGE (s, ei, redirect_to->succs)
+ FOR_EACH_EDGE (s, ei, redirect_edges_to->succs)
{
edge s2;
edge_iterator ei;
s2->dest->count = 0;
}
- if (!redirect_to->frequency && !src1->frequency)
+ if (!redirect_edges_to->frequency && !src1->frequency)
s->probability = (s->probability + s2->probability) / 2;
else
s->probability
- = ((s->probability * redirect_to->frequency +
+ = ((s->probability * redirect_edges_to->frequency +
s2->probability * src1->frequency)
- / (redirect_to->frequency + src1->frequency));
+ / (redirect_edges_to->frequency + src1->frequency));
}
/* Adjust count and frequency for the block. An earlier jump
threading pass may have left the profile in an inconsistent
state (see update_bb_profile_for_threading) so we must be
prepared for overflows. */
- redirect_to->count += src1->count;
- redirect_to->frequency += src1->frequency;
- if (redirect_to->frequency > BB_FREQ_MAX)
- redirect_to->frequency = BB_FREQ_MAX;
- update_br_prob_note (redirect_to);
+ tmp = redirect_to;
+ do
+ {
+ tmp->count += src1->count;
+ tmp->frequency += src1->frequency;
+ if (tmp->frequency > BB_FREQ_MAX)
+ tmp->frequency = BB_FREQ_MAX;
+ if (tmp == redirect_edges_to)
+ break;
+ tmp = find_fallthru_edge (tmp->succs)->dest;
+ }
+ while (true);
+ update_br_prob_note (redirect_edges_to);
/* Edit SRC1 to go to REDIRECT_TO at NEWPOS1. */
edge e, e2, fallthru;
bool changed;
unsigned max, ix, ix2;
- basic_block ev, ev2;
- edge_iterator ei;
/* Nothing to do if there is not at least two incoming edges. */
if (EDGE_COUNT (bb->preds) < 2)
if (EDGE_COUNT (bb->preds) > max)
return false;
- FOR_EACH_EDGE (e, ei, bb->preds)
- {
- if (e->flags & EDGE_FALLTHRU)
- {
- fallthru = e;
- break;
- }
- }
+ fallthru = find_fallthru_edge (bb->preds);
changed = false;
- for (ix = 0, ev = bb; ix < EDGE_COUNT (ev->preds); )
+ for (ix = 0; ix < EDGE_COUNT (bb->preds);)
{
- e = EDGE_PRED (ev, ix);
+ e = EDGE_PRED (bb, ix);
ix++;
/* As noted above, first try with the fallthru predecessor (or, a
|| (fallthru->src->flags & BB_MODIFIED)))
continue;
- if (try_crossjump_to_edge (mode, e, fallthru))
+ if (try_crossjump_to_edge (mode, e, fallthru, dir_forward))
{
changed = true;
ix = 0;
- ev = bb;
continue;
}
}
if (EDGE_SUCC (e->src, 0) != e)
continue;
- for (ix2 = 0, ev2 = bb; ix2 < EDGE_COUNT (ev2->preds); )
+ for (ix2 = 0; ix2 < EDGE_COUNT (bb->preds); ix2++)
{
- e2 = EDGE_PRED (ev2, ix2);
- ix2++;
+ e2 = EDGE_PRED (bb, ix2);
if (e2 == e)
continue;
|| (e2->src->flags & BB_MODIFIED)))
continue;
- if (try_crossjump_to_edge (mode, e, e2))
+ /* Both e and e2 are not fallthru edges, so we can crossjump in either
+ direction. */
+ if (try_crossjump_to_edge (mode, e, e2, dir_both))
{
changed = true;
- ev2 = bb;
ix = 0;
break;
}
basic_block final_dest_bb = NULL;
int max_match = INT_MAX;
edge e0;
- rtx *headptr, *currptr;
+ rtx *headptr, *currptr, *nextptr;
bool changed, moveall;
unsigned ix;
rtx e0_last_head, cond, move_before;
cond = get_condition (jump, &move_before, true, false);
if (cond == NULL_RTX)
- move_before = jump;
+ {
+#ifdef HAVE_cc0
+ if (reg_mentioned_p (cc0_rtx, jump))
+ move_before = prev_nonnote_nondebug_insn (jump);
+ else
+#endif
+ move_before = jump;
+ }
for (ix = 0; ix < nedges; ix++)
if (EDGE_SUCC (bb, ix)->dest == EXIT_BLOCK_PTR)
currptr = XNEWVEC (rtx, nedges);
headptr = XNEWVEC (rtx, nedges);
+ nextptr = XNEWVEC (rtx, nedges);
for (ix = 0; ix < nedges; ix++)
{
jump, e0->dest, live_union,
NULL, &move_upto);
if (!moveall)
- e0_last_head = move_upto;
+ {
+ if (move_upto == NULL_RTX)
+ goto out;
+
+ while (e0_last_head != move_upto)
+ {
+ df_simulate_one_insn_backwards (e0->dest, e0_last_head,
+ live_union);
+ e0_last_head = PREV_INSN (e0_last_head);
+ }
+ }
if (e0_last_head == NULL_RTX)
goto out;
jump = BB_END (final_dest_bb);
cond = get_condition (jump, &move_before, true, false);
if (cond == NULL_RTX)
- move_before = jump;
+ {
+#ifdef HAVE_cc0
+ if (reg_mentioned_p (cc0_rtx, jump))
+ move_before = prev_nonnote_nondebug_insn (jump);
+ else
+#endif
+ move_before = jump;
+ }
}
do
/* Try again, using a different insertion point. */
move_before = jump;
+
+#ifdef HAVE_cc0
+ /* Don't try moving before a cc0 user, as that may invalidate
+ the cc0. */
+ if (reg_mentioned_p (cc0_rtx, jump))
+ break;
+#endif
+
continue;
}
}
}
+ /* If we can't currently move all of the identical insns, remember
+ each insn after the range that we'll merge. */
+ if (!moveall)
+ for (ix = 0; ix < nedges; ix++)
+ {
+ rtx curr = currptr[ix];
+ do
+ curr = NEXT_INSN (curr);
+ while (!NONDEBUG_INSN_P (curr));
+ nextptr[ix] = curr;
+ }
+
reorder_insns (headptr[0], currptr[0], PREV_INSN (move_before));
df_set_bb_dirty (EDGE_SUCC (bb, 0)->dest);
if (final_dest_bb != NULL)
if (jump == move_before)
break;
- /* Try again, using a different insertion point. */
+ /* For the unmerged insns, try a different insertion point. */
move_before = jump;
+
+#ifdef HAVE_cc0
+ /* Don't try moving before a cc0 user, as that may invalidate
+ the cc0. */
+ if (reg_mentioned_p (cc0_rtx, jump))
+ break;
+#endif
+
for (ix = 0; ix < nedges; ix++)
- {
- rtx curr = currptr[ix];
- do
- curr = NEXT_INSN (curr);
- while (!NONDEBUG_INSN_P (curr));
- currptr[ix] = headptr[ix] = curr;
- }
+ currptr[ix] = headptr[ix] = nextptr[ix];
}
}
while (!moveall);
out:
free (currptr);
free (headptr);
+ free (nextptr);
crossjumps_occured |= changed;
}
}
delete_basic_block (b);
- if (!(mode & CLEANUP_CFGLAYOUT))
- changed = true;
+ changed = true;
/* Avoid trying to remove ENTRY_BLOCK_PTR. */
b = (c == ENTRY_BLOCK_PTR ? c->next_bb : c);
continue;
continue;
}
+ /* Merge B with its single successor, if any. */
if (single_succ_p (b)
&& (s = single_succ_edge (b))
&& !(s->flags & EDGE_COMPLEX)
/* Simplify branch to branch. */
if (try_forward_edges (mode, b))
- changed_here = true;
+ {
+ update_forwarder_flag (b);
+ changed_here = true;
+ }
/* Look for shared code between blocks. */
if ((mode & CLEANUP_CROSSJUMP)
0, /* properties_provided */
0, /* properties_destroyed */
TODO_ggc_collect, /* todo_flags_start */
- TODO_dump_func | TODO_verify_rtl_sharing,/* todo_flags_finish */
+ TODO_verify_rtl_sharing, /* todo_flags_finish */
}
};
-
-