[llvm] [SLP]Improve minbitwidth analysis for abs/smin/smax/umin/umax intrinsics. (PR #86135)

[Craig Topper via llvm-commits]

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@@ -13,14 +13,13 @@ define i32 @test(ptr noalias %in, ptr noalias %inn, ptr %out) {
 ; CHECK-NEXT:    [[TMP5:%.*]] = shufflevector <2 x i8> [[TMP3]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 poison, i32 poison>
 ; CHECK-NEXT:    [[TMP6:%.*]] = shufflevector <2 x i8> [[TMP2]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 poison, i32 poison>
 ; CHECK-NEXT:    [[TMP7:%.*]] = shufflevector <4 x i8> [[TMP5]], <4 x i8> [[TMP6]], <4 x i32> <i32 0, i32 1, i32 4, i32 5>
-; CHECK-NEXT:    [[TMP8:%.*]] = sext <4 x i8> [[TMP7]] to <4 x i32>
+; CHECK-NEXT:    [[TMP8:%.*]] = sext <4 x i8> [[TMP7]] to <4 x i16>
 ; CHECK-NEXT:    [[TMP9:%.*]] = shufflevector <2 x i8> [[TMP1]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 poison, i32 poison>
 ; CHECK-NEXT:    [[TMP10:%.*]] = shufflevector <2 x i8> [[TMP4]], <2 x i8> poison, <4 x i32> <i32 0, i32 1, i32 poison, i32 poison>
 ; CHECK-NEXT:    [[TMP11:%.*]] = shufflevector <4 x i8> [[TMP9]], <4 x i8> [[TMP10]], <4 x i32> <i32 0, i32 1, i32 4, i32 5>
-; CHECK-NEXT:    [[TMP12:%.*]] = sext <4 x i8> [[TMP11]] to <4 x i32>
-; CHECK-NEXT:    [[TMP13:%.*]] = sub <4 x i32> [[TMP12]], [[TMP8]]
-; CHECK-NEXT:    [[TMP14:%.*]] = call <4 x i32> @llvm.abs.v4i32(<4 x i32> [[TMP13]], i1 true)
-; CHECK-NEXT:    [[TMP15:%.*]] = trunc <4 x i32> [[TMP14]] to <4 x i16>
+; CHECK-NEXT:    [[TMP12:%.*]] = sext <4 x i8> [[TMP11]] to <4 x i16>
+; CHECK-NEXT:    [[TMP13:%.*]] = sub <4 x i16> [[TMP12]], [[TMP8]]
+; CHECK-NEXT:    [[TMP15:%.*]] = call <4 x i16> @llvm.abs.v4i16(<4 x i16> [[TMP13]], i1 true)
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topperc wrote:

If the you have abs

(i8 (trunc (i16 (abs (sext (i8 X)), true)))) will you turn it into (i8 (abs X, true) or (i8 (abs X, false)) or will you leave it alone?

https://github.com/llvm/llvm-project/pull/86135