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| author | Xionghu Luo <luoxhu@linux.ibm.com> | 2021-12-29 20:02:12 -0600 |
|---|---|---|
| committer | Xionghu Luo <luoxhu@linux.ibm.com> | 2021-12-29 20:02:12 -0600 |
| commit | dc1969dab392661cdac1170bbb8c9f83f388580d (patch) | |
| tree | 24af75f03a990f00ce001c92fd271f2bc07aa742 /gcc | |
| parent | be475aa0aae468df7370db9cfa8590776d901d1d (diff) | |
| download | gcc-dc1969dab392661cdac1170bbb8c9f83f388580d.zip gcc-dc1969dab392661cdac1170bbb8c9f83f388580d.tar.gz gcc-dc1969dab392661cdac1170bbb8c9f83f388580d.tar.bz2 | |
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')
| -rw-r--r-- | gcc/loop-invariant.c | 17 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/loop-invariant-2.c | 20 |
2 files changed, 34 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)); } diff --git a/gcc/testsuite/gcc.dg/loop-invariant-2.c b/gcc/testsuite/gcc.dg/loop-invariant-2.c new file mode 100644 index 0000000..df3d845 --- /dev/null +++ b/gcc/testsuite/gcc.dg/loop-invariant-2.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-rtl-loop2_invariant" } */ + +volatile int x; +void +bar (int, char *, char *); +void +foo (int *a, int n, int k) +{ + int i; + + for (i = 0; i < n; i++) + { + if (__builtin_expect (x, 0)) + bar (k / 5, "one", "two"); + a[i] = k; + } +} + +/* { dg-final { scan-rtl-dump "Don't move invariant from bb: .*out of loop" "loop2_invariant" } } */ |