[llvm] [DAG] Fold trunc(abdu(x, y)) and trunc(abds(x, y)) if they have sufficient leading zero/sign bits (PR #151471)

[via llvm-commits]

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@@ -51,6 +45,10 @@ define <8 x i16> @abdu_const_lhs(<8 x i16> %src1) {
 define <8 x i16> @abdu_const_zero(<8 x i16> %src1) {
 ; CHECK-LABEL: abdu_const_zero:
 ; CHECK:       // %bb.0:
+; CHECK-NEXT:    ext v1.16b, v0.16b, v0.16b, #8
+; CHECK-NEXT:    abs v0.4h, v0.4h
+; CHECK-NEXT:    abs v1.4h, v1.4h
+; CHECK-NEXT:    mov v0.d[1], v1.d[0]
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woruyu wrote:

Done!

https://github.com/llvm/llvm-project/pull/151471