[PATCH] D124903: [X86][AMX] Replace PXOR instruction with SET0 in AMX pre config.

[LuoYuanke via Phabricator via llvm-commits]

LuoYuanke added inline comments.


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Comment at: llvm/test/CodeGen/X86/AMX/amx-config.ll:11
 ; Function Attrs: nounwind uwtable
-define dso_local void @test_api(i32 %0, i16 signext %1, i16 signext %2) {
+define <4 x i32> @test_api(i32 %0, i16 signext %1, i16 signext %2, <4 x i32> %xmm0) {
 ; AVX512-LABEL: test_api:
----------------
craig.topper wrote:
> LuoYuanke wrote:
> > craig.topper wrote:
> > > craig.topper wrote:
> > > > LuoYuanke wrote:
> > > > > xiangzhangllvm wrote:
> > > > > > Why change the void to return parameter %xmm0，I didn't see %xmm0 join any calculation.
> > > > > Because we want register other than xmm0 is allocated to V_SET0. I think it is to test if there is some potential issue in register allocation. @craig.topper, am I right?
> > > > > 
> > > > If you run this modified test without this patch, does it show the bug?
> > > I guess not because you're doing this after the Two Address Instruction Pass runs and you've left SSA?
> > This pass runs before Two Address Instruction Pass. It is in SSA form.
> My mistake, I guess it worked because the same vreg was used for src and dest even though we're in SSA form. Is that allowed because it is undef?
It seems invalid to declare it is in SSA form, while have src and dest tied to same vreg.


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  https://reviews.llvm.org/D124903/new/

https://reviews.llvm.org/D124903