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| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/combine.c | 4 |
2 files changed, 11 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 55e9bc81e58..afb4a523472 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,12 @@ 2017-03-20 Segher Boessenkool <segher@kernel.crashing.org> + PR rtl-optimization/79910 + * combine.c (can_combine_p): Do not allow combining an I0 or I1 + if its dest is used by an insn before I2 (other than the combined + insns themselves, which are properly handled already). + +2017-03-20 Segher Boessenkool <segher@kernel.crashing.org> + Revert: 2017-03-17 Bernd Schmidt <bschmidt@redhat.com> diff --git a/gcc/combine.c b/gcc/combine.c index 66215a607bd..17258f0e0c5 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1953,6 +1953,10 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED, || (succ2 && FIND_REG_INC_NOTE (succ2, dest)) /* Don't substitute into a non-local goto, this confuses CFG. */ || (JUMP_P (i3) && find_reg_note (i3, REG_NON_LOCAL_GOTO, NULL_RTX)) + /* Make sure that DEST is not used after INSN but before SUCC, or + between SUCC and SUCC2. */ + || (succ && reg_used_between_p (dest, insn, succ)) + || (succ2 && reg_used_between_p (dest, succ, succ2)) /* Make sure that DEST is not used after SUCC but before I3. */ || (!all_adjacent && ((succ2 |