On Wed, Jan 25, 2017 at 3:56 PM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: > Hi! > > I was worried this patch would prevent too many other optimisations, > so I looked into better options. I didn't find any. I tested the > effects of the patch on 31 architectures (building GCC and then Linux Thanks very much for this, that's a lot of testing work. I will revise the patch by explaining why is the change, as well as the impact.
Thanks, bin > with it; 6 errored out building the kernel). There were exactly zero > differences in generated code. > > The patch is fine for mainline. Thanks Bin! > > > Segher > > > On Thu, Dec 01, 2016 at 09:47:51AM +0000, Bin Cheng wrote: >> 2016-12-01 Bin Cheng <bin.ch...@arm.com> >> >> PR rtl-optimization/78559 >> * combine.c (try_combine): Discard REG_EQUAL and REG_EQUIV for >> other_insn in combine. > >> diff --git a/gcc/combine.c b/gcc/combine.c >> index 22fb7a9..93b0901 100644 >> --- a/gcc/combine.c >> +++ b/gcc/combine.c >> @@ -4138,7 +4138,9 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, >> rtx_insn *i0, >> PATTERN (undobuf.other_insn))) >> ||(REG_NOTE_KIND (note) == REG_UNUSED >> && !reg_set_p (XEXP (note, 0), >> - PATTERN (undobuf.other_insn)))) >> + PATTERN (undobuf.other_insn))) >> + || REG_NOTE_KIND (note) == REG_EQUAL >> + || REG_NOTE_KIND (note) == REG_EQUIV) >> remove_note (undobuf.other_insn, note); >> }
