[llvm] [VectorCombine] foldShuffleOfBinops - add support for length changing shuffles (PR #88899)

[Simon Pilgrim via llvm-commits]

================
@@ -564,32 +563,33 @@ define void @v8f64interleave(i64 %0, ptr %1, ptr %x, double %z) {
 ; CHECK-NEXT:    [[STRIDED_VEC40:%.*]] = shufflevector <16 x double> [[WIDE_VEC34]], <16 x double> poison, <2 x i32> <i32 5, i32 13>
 ; CHECK-NEXT:    [[STRIDED_VEC41:%.*]] = shufflevector <16 x double> [[WIDE_VEC34]], <16 x double> poison, <2 x i32> <i32 6, i32 14>
 ; CHECK-NEXT:    [[STRIDED_VEC42:%.*]] = shufflevector <16 x double> [[WIDE_VEC34]], <16 x double> poison, <2 x i32> <i32 7, i32 15>
-; CHECK-NEXT:    [[TMP4:%.*]] = fadd fast <2 x double> [[STRIDED_VEC35]], [[TMP2]]
-; CHECK-NEXT:    [[TMP5:%.*]] = fmul fast <2 x double> [[STRIDED_VEC27]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP6:%.*]] = fadd fast <2 x double> [[STRIDED_VEC36]], [[TMP5]]
-; CHECK-NEXT:    [[TMP7:%.*]] = fmul fast <2 x double> [[STRIDED_VEC28]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP8:%.*]] = fadd fast <2 x double> [[STRIDED_VEC37]], [[TMP7]]
-; CHECK-NEXT:    [[TMP9:%.*]] = fmul fast <2 x double> [[STRIDED_VEC29]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP10:%.*]] = fadd fast <2 x double> [[STRIDED_VEC38]], [[TMP9]]
-; CHECK-NEXT:    [[TMP11:%.*]] = fmul fast <2 x double> [[STRIDED_VEC30]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP12:%.*]] = fadd fast <2 x double> [[STRIDED_VEC39]], [[TMP11]]
-; CHECK-NEXT:    [[TMP13:%.*]] = fmul fast <2 x double> [[STRIDED_VEC31]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP14:%.*]] = fadd fast <2 x double> [[STRIDED_VEC40]], [[TMP13]]
-; CHECK-NEXT:    [[TMP15:%.*]] = fmul fast <2 x double> [[STRIDED_VEC32]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP16:%.*]] = fadd fast <2 x double> [[STRIDED_VEC41]], [[TMP15]]
-; CHECK-NEXT:    [[TMP17:%.*]] = or disjoint i64 [[TMP0]], 7
-; CHECK-NEXT:    [[TMP18:%.*]] = fmul fast <2 x double> [[STRIDED_VEC33]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT:    [[TMP19:%.*]] = getelementptr inbounds double, ptr [[X]], i64 [[TMP17]]
-; CHECK-NEXT:    [[TMP20:%.*]] = fadd fast <2 x double> [[STRIDED_VEC42]], [[TMP18]]
-; CHECK-NEXT:    [[TMP21:%.*]] = getelementptr inbounds i8, ptr [[TMP19]], i64 -56
-; CHECK-NEXT:    [[TMP22:%.*]] = shufflevector <2 x double> [[TMP4]], <2 x double> [[TMP6]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
-; CHECK-NEXT:    [[TMP23:%.*]] = shufflevector <2 x double> [[TMP8]], <2 x double> [[TMP10]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
-; CHECK-NEXT:    [[TMP24:%.*]] = shufflevector <2 x double> [[TMP12]], <2 x double> [[TMP14]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
-; CHECK-NEXT:    [[TMP25:%.*]] = shufflevector <2 x double> [[TMP16]], <2 x double> [[TMP20]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
-; CHECK-NEXT:    [[TMP26:%.*]] = shufflevector <4 x double> [[TMP22]], <4 x double> [[TMP23]], <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT:    [[TMP27:%.*]] = shufflevector <4 x double> [[TMP24]], <4 x double> [[TMP25]], <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT:    [[INTERLEAVED_VEC:%.*]] = shufflevector <8 x double> [[TMP26]], <8 x double> [[TMP27]], <16 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14, i32 1, i32 3, i32 5, i32 7, i32 9, i32 11, i32 13, i32 15>
-; CHECK-NEXT:    store <16 x double> [[INTERLEAVED_VEC]], ptr [[TMP21]], align 8
+; CHECK-NEXT:    [[TMP3:%.*]] = or disjoint i64 [[TMP0]], 7
----------------
RKSimon wrote:

I've updated to `NewCost >= OldCost`

https://github.com/llvm/llvm-project/pull/88899