diff options
| author | Bernd Schmidt <bernds_cb1@t-online.de> | 2019-11-27 03:31:24 +0000 |
|---|---|---|
| committer | Bernd Schmidt <bernds_cb1@t-online.de> | 2019-11-27 03:31:24 +0000 |
| commit | 502f2827400f6fcb10ac39c4828d86a1b4a294af (patch) | |
| tree | 9102d9d21057f8555f20342ab2bcfcb106ac4025 | |
| parent | 934392e344650668683ee8add798068ce0c68ed1 (diff) | |
Allow autoinc in jumps, but only when using reload.
* auto-inc-dec.c (merge_in_block): Allow autoinc in jumps unless
LRA is enabled.
* combine.c (can_combine_p): Disallow autoinc in jumps unless LRA is
disabled.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@278756 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/auto-inc-dec.c | 7 | ||||
| -rw-r--r-- | gcc/combine.c | 8 |
3 files changed, 16 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ecade7ba155..358602d744e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2019-11-27 Bernd Schmidt <bernds_cb1@t-online.de> + + * auto-inc-dec.c (merge_in_block): Allow autoinc in jumps unless + LRA is enabled. + * combine.c (can_combine_p): Disallow autoinc in jumps unless LRA is + disabled. + 2019-11-27 Jakub Jelinek <jakub@redhat.com> PR debug/92664 diff --git a/gcc/auto-inc-dec.c b/gcc/auto-inc-dec.c index bdb6efab520..1b224cc9777 100644 --- a/gcc/auto-inc-dec.c +++ b/gcc/auto-inc-dec.c @@ -1441,10 +1441,9 @@ merge_in_block (int max_reg, basic_block bb) continue; } - /* This continue is deliberate. We do not want the uses of the - jump put into reg_next_use because it is not considered safe to - combine a preincrement with a jump. */ - if (JUMP_P (insn)) + /* Reload should handle auto-inc within a jump correctly, while LRA + is known to have issues with autoinc. */ + if (JUMP_P (insn) && targetm.lra_p ()) continue; if (dump_file) diff --git a/gcc/combine.c b/gcc/combine.c index 2e21459f504..3fbd84fcb80 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2117,12 +2117,16 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED, /* If INSN contains an autoincrement or autodecrement, make sure that register is not used between there and I3, and not already used in - I3 either. Neither must it be used in PRED or SUCC, if they exist. */ + I3 either. Neither must it be used in PRED or SUCC, if they exist. + Also insist that I3 not be a jump if using LRA; if it were one + and the incremented register were spilled, we would lose. + Reload handles this correctly. */ if (AUTO_INC_DEC) for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) if (REG_NOTE_KIND (link) == REG_INC - && (reg_used_between_p (XEXP (link, 0), insn, i3) + && ((JUMP_P (i3) && targetm.lra_p ()) + || reg_used_between_p (XEXP (link, 0), insn, i3) || (pred != NULL_RTX && reg_overlap_mentioned_p (XEXP (link, 0), PATTERN (pred))) || (pred2 != NULL_RTX |