[llvm] [SDag] Notify listeners when deleting a node (PR #66991)

[Simon Pilgrim via llvm-commits]

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@@ -4353,8 +4353,8 @@ define <16 x i16> @shuffle_v16i16_06_06_07_05_01_06_04_11_14_14_15_13_09_14_12_1
 ;
 ; AVX2-SLOW-LABEL: shuffle_v16i16_06_06_07_05_01_06_04_11_14_14_15_13_09_14_12_11:
 ; AVX2-SLOW:       # %bb.0:
-; AVX2-SLOW-NEXT:    vpmovsxbd {{.*#+}} ymm1 = [0,5,2,3,4,5,6,7]
-; AVX2-SLOW-NEXT:    vpermd %ymm0, %ymm1, %ymm0
+; AVX2-SLOW-NEXT:    vpermq {{.*#+}} ymm1 = ymm0[2,3,2,3]
+; AVX2-SLOW-NEXT:    vpblendd {{.*#+}} ymm0 = ymm0[0],ymm1[1],ymm0[2,3,4],ymm1[5],ymm0[6,7]
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RKSimon wrote:

This is good - its precisely what we'd expect on AVX2-SLOW/AVX2-FAST-PERLANE targets - as long as AVX2-FAST still merges to VPERMD

https://github.com/llvm/llvm-project/pull/66991