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| author | H.J. Lu <hongjiu.lu@intel.com> | 2019-04-21 18:23:00 +0000 |
|---|---|---|
| committer | H.J. Lu <hjl@gcc.gnu.org> | 2019-04-21 11:23:00 -0700 |
| commit | f94302e90b09bc30d5ba357d4f84aa37f7a75ad1 (patch) | |
| tree | 9ddd83f023197d5d210e4a65188cb15843813408 /gcc | |
| parent | 6397d8df302d964740dca942445165d4c2a6c0aa (diff) | |
| download | gcc-f94302e90b09bc30d5ba357d4f84aa37f7a75ad1.zip gcc-f94302e90b09bc30d5ba357d4f84aa37f7a75ad1.tar.gz gcc-f94302e90b09bc30d5ba357d4f84aa37f7a75ad1.tar.bz2 | |
LRA: Revert "Remove useless move insns"
Useless move insn removal was added to LRA just to avoid wasting CPU
cycles on such insn processing afterwards. Such insns are removed
anyway later in the pass pipeline. The CPU time savings are tiny but
the removal creates too many problems including PR target/90178.
Vladimir pre-approved the patch to remove the code:
https://gcc.gnu.org/ml/gcc-patches/2019-04/msg00834.html
gcc/
PR target/90178
Revert:
2018-11-21 Uros Bizjak <ubizjak@gmail.com>
Revert the revert:
2013-10-26 Vladimir Makarov <vmakarov@redhat.com>
Revert:
2013-10-25 Vladimir Makarov <vmakarov@redhat.com>
* lra-spills.c (lra_final_code_change): Remove useless move insns.
gcc/testsuite/
PR target/90178
* gcc.target/i386/pr90178.c: New test.
From-SVN: r270484
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 14 | ||||
| -rw-r--r-- | gcc/lra-spills.c | 15 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/i386/pr90178.c | 13 |
4 files changed, 32 insertions, 15 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8b09eec..d244681 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,17 @@ +2019-04-21 H.J. Lu <hongjiu.lu@intel.com> + + PR target/90178 + Revert: + 2018-11-21 Uros Bizjak <ubizjak@gmail.com> + + Revert the revert: + 2013-10-26 Vladimir Makarov <vmakarov@redhat.com> + + Revert: + 2013-10-25 Vladimir Makarov <vmakarov@redhat.com> + + * lra-spills.c (lra_final_code_change): Remove useless move insns. + 2019-04-21 Iain Sandoe <iain@sandoe.co.uk> * config/rs6000/rs6000.md (group_end_nop): Emit insn register diff --git a/gcc/lra-spills.c b/gcc/lra-spills.c index c19b76a..18db79e7 100644 --- a/gcc/lra-spills.c +++ b/gcc/lra-spills.c @@ -740,7 +740,6 @@ lra_final_code_change (void) int i, hard_regno; basic_block bb; rtx_insn *insn, *curr; - rtx set; int max_regno = max_reg_num (); for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) @@ -819,19 +818,5 @@ lra_final_code_change (void) } if (insn_change_p) lra_update_operator_dups (id); - - if ((set = single_set (insn)) != NULL - && REG_P (SET_SRC (set)) && REG_P (SET_DEST (set)) - && REGNO (SET_SRC (set)) == REGNO (SET_DEST (set))) - { - /* Remove an useless move insn. IRA can generate move - insns involving pseudos. It is better remove them - earlier to speed up compiler a bit. It is also - better to do it here as they might not pass final RTL - check in LRA, (e.g. insn moving a control register - into itself). */ - lra_invalidate_insn_data (insn); - delete_insn (insn); - } } } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ee1281e..9833824 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-04-21 H.J. Lu <hongjiu.lu@intel.com> + + PR target/90178 + * gcc.target/i386/pr90178.c: New test. + 2019-04-20 Sandra Loosemore <sandra@codesourcery.com> * g++.dg/ipa/pr89009.C: Add dg-require-effective-target fpic. diff --git a/gcc/testsuite/gcc.target/i386/pr90178.c b/gcc/testsuite/gcc.target/i386/pr90178.c new file mode 100644 index 0000000..1df36af --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr90178.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mavx -mvzeroupper" } */ + +int* +find_ptr (int* mem, int sz, int val) +{ + for (int i = 0; i < sz; i++) + if (mem[i] == val) + return &mem[i]; + return 0; +} + +/* { dg-final { scan-assembler-times "xorl\[\\t \]*\\\%eax,\[\\t \]*%eax" 1 } } */ |