[llvm] [SLP] Fix handling of strided loads during re-vectorization (PR #191294)

[Ryan Buchner via llvm-commits]

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@@ -50,7 +51,12 @@ entry:
 define void @too_wide(ptr %in0, ptr %out0) {
 ; CHECK-LABEL: @too_wide(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = call <16 x i16> @llvm.experimental.vp.strided.load.v16i16.p0.i64(ptr align 2 [[IN0:%.*]], i64 32, <16 x i1> splat (i1 true), i32 16)
+; CHECK-NEXT:    [[IN1:%.*]] = getelementptr i16, ptr [[IN0:%.*]], i64 16
+; CHECK-NEXT:    [[TMP4:%.*]] = insertelement <2 x ptr> poison, ptr [[IN0]], i32 0
+; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x ptr> [[TMP4]], ptr [[IN1]], i32 1
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x ptr> [[TMP1]], <2 x ptr> poison, <16 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>
+; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr i16, <16 x ptr> [[TMP2]], <16 x i64> <i64 0, i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 0, i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7>
+; CHECK-NEXT:    [[TMP0:%.*]] = call <16 x i16> @llvm.masked.gather.v16i16.v16p0(<16 x ptr> align 2 [[TMP3]], <16 x i1> splat (i1 true), <16 x i16> poison)
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bababuck wrote:

Not a regression. Only considered profitable in this case because `-slp-threshold=-100`.

https://github.com/llvm/llvm-project/pull/191294