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authorXionghu Luo <luoxhu@linux.ibm.com>2021-12-29 20:02:12 -0600
committerXionghu Luo <luoxhu@linux.ibm.com>2021-12-29 20:02:12 -0600
commitdc1969dab392661cdac1170bbb8c9f83f388580d (patch)
tree24af75f03a990f00ce001c92fd271f2bc07aa742 /gcc/loop-invariant.c
parentbe475aa0aae468df7370db9cfa8590776d901d1d (diff)
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loop-invariant: Don't move cold bb instructions to preheader in RTL
gcc/ChangeLog: 2021-12-30 Xionghu Luo <luoxhu@linux.ibm.com> * loop-invariant.c (find_invariants_bb): Check profile count before motion. (find_invariants_body): Add argument. gcc/testsuite/ChangeLog: 2021-12-30 Xionghu Luo <luoxhu@linux.ibm.com> * gcc.dg/loop-invariant-2.c: New.
Diffstat (limited to 'gcc/loop-invariant.c')
-rw-r--r--gcc/loop-invariant.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index be95155..d69a0c1 100644
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -1183,9 +1183,21 @@ find_invariants_insn (rtx_insn *insn, bool always_reached, bool always_executed)
call. */
static void
-find_invariants_bb (basic_block bb, bool always_reached, bool always_executed)
+find_invariants_bb (class loop *loop, basic_block bb, bool always_reached,
+ bool always_executed)
{
rtx_insn *insn;
+ basic_block preheader = loop_preheader_edge (loop)->src;
+
+ /* Don't move insn of cold BB out of loop to preheader to reduce calculations
+ and register live range in hot loop with cold BB. */
+ if (!always_executed && preheader->count > bb->count)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Don't move invariant from bb: %d out of loop %d\n",
+ bb->index, loop->num);
+ return;
+ }
FOR_BB_INSNS (bb, insn)
{
@@ -1214,8 +1226,7 @@ find_invariants_body (class loop *loop, basic_block *body,
unsigned i;
for (i = 0; i < loop->num_nodes; i++)
- find_invariants_bb (body[i],
- bitmap_bit_p (always_reached, i),
+ find_invariants_bb (loop, body[i], bitmap_bit_p (always_reached, i),
bitmap_bit_p (always_executed, i));
}