On Thu, Feb 23, 2017 at 10:06 PM, Jeff Law <l...@redhat.com> wrote: > On 02/23/2017 02:02 AM, Richard Biener wrote: > >>> diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c >>> index 84c0b11..a82e164 100644 >>> --- a/gcc/tree-ssa-dse.c >>> +++ b/gcc/tree-ssa-dse.c >>> @@ -176,7 +176,7 @@ clear_bytes_written_by (sbitmap live_bytes, gimple >>> *stmt, ao_ref *ref) >>> /* Verify we have the same base memory address, the write >>> has a known size and overlaps with REF. */ >>> if (valid_ao_ref_for_dse (&write) >>> - && write.base == ref->base >>> + && operand_equal_p (write.base, ref->base, 0) >> >> >> As you've identified size and offset match you are really interested >> in comparing the base addresses and thus should use OEP_ADDRESS_OF. > > I pondered that, but (perhaps incorrectly) thought that OEP_ADDRESS_OF was > an optimization and that a more simple o_e_p with no flags was safer. > > I'm happy to change it, particularly if it's a correctness issue (in which > case I think we've designed a horrible API for o_e_p, but such is life). In > fact, I've already bootstrapped and regression tested that change.
It's indeed an optimization to use OEP_ADDRESS_OF and 0 is more conservative. Richard. > jeff >
