[llvm] [VPlan] Simplify BLEND %a, %b, NOT(%m) -> BLEND %b, %a, %m. (PR #128375)

[via llvm-commits]

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@@ -36,16 +36,16 @@ define float @test(ptr nocapture readonly %pA, ptr nocapture readonly %pB, i32 %
 ; CHECK-NEXT:    [[NEXT_GEP6:%.*]] = getelementptr i8, ptr [[PB]], i32 [[OFFSET_IDX5]]
 ; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x float>, ptr [[NEXT_GEP]], align 4
 ; CHECK-NEXT:    [[WIDE_LOAD7:%.*]] = load <4 x float>, ptr [[NEXT_GEP6]], align 4
-; CHECK-NEXT:    [[TMP2:%.*]] = fcmp fast oeq <4 x float> [[WIDE_LOAD]], zeroinitializer
-; CHECK-NEXT:    [[TMP3:%.*]] = fcmp fast oeq <4 x float> [[WIDE_LOAD7]], zeroinitializer
-; CHECK-NEXT:    [[DOTNOT9:%.*]] = select <4 x i1> [[TMP2]], <4 x i1> [[TMP3]], <4 x i1> zeroinitializer
+; CHECK-NEXT:    [[TMP18:%.*]] = fcmp fast une <4 x float> [[WIDE_LOAD]], zeroinitializer
+; CHECK-NEXT:    [[TMP19:%.*]] = fcmp fast une <4 x float> [[WIDE_LOAD7]], zeroinitializer
+; CHECK-NEXT:    [[TMP20:%.*]] = select <4 x i1> [[TMP18]], <4 x i1> splat (i1 true), <4 x i1> [[TMP19]]
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ayalz wrote:

This NOTing of `DOTNOT9` which involves both NOTing its first select operand and flipping the order of its last two operands, and NOTing each of these two operands (including replacing zeroinitializer with splat (i1 true)) is intended, and profitable?

https://github.com/llvm/llvm-project/pull/128375