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| author | Jakub Jelinek <jakub@redhat.com> | 2019-04-29 16:18:55 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2019-04-29 16:18:55 +0200 |
| commit | 1008df90cca4a4f49f2a898115f8756fafff3187 (patch) | |
| tree | 65b74e56f1a118c9e0f26cb15c7ca45a6794cce3 /gcc/cfgrtl.c | |
| parent | 4e29671cb258f486e498a0697f88861ff351de50 (diff) | |
| download | gcc-1008df90cca4a4f49f2a898115f8756fafff3187.zip gcc-1008df90cca4a4f49f2a898115f8756fafff3187.tar.gz gcc-1008df90cca4a4f49f2a898115f8756fafff3187.tar.bz2 | |
re PR rtl-optimization/90257 (8% degradation on cpu2006 403.gcc starting with r270484)
PR rtl-optimization/90257
* cfgrtl.c (flow_active_insn_p): Return true for USE of a function
return value.
Revert the revert:
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.
From-SVN: r270653
Diffstat (limited to 'gcc/cfgrtl.c')
| -rw-r--r-- | gcc/cfgrtl.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c index 08e534f..e06fb8d 100644 --- a/gcc/cfgrtl.c +++ b/gcc/cfgrtl.c @@ -543,7 +543,7 @@ update_bb_for_insn (basic_block bb) } -/* Like active_insn_p, except keep the return value clobber around +/* Like active_insn_p, except keep the return value use or clobber around even after reload. */ static bool @@ -556,8 +556,12 @@ flow_active_insn_p (const rtx_insn *insn) programs that fail to return a value. Its effect is to keep the return value from being live across the entire function. If we allow it to be skipped, we introduce the - possibility for register lifetime confusion. */ - if (GET_CODE (PATTERN (insn)) == CLOBBER + possibility for register lifetime confusion. + Similarly, keep a USE of the function return value, otherwise + the USE is dropped and we could fail to thread jump if USE + appears on some paths and not on others, see PR90257. */ + if ((GET_CODE (PATTERN (insn)) == CLOBBER + || GET_CODE (PATTERN (insn)) == USE) && REG_P (XEXP (PATTERN (insn), 0)) && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) return true; |