[llvm] [SLP]Add support for strided loads. (PR #80310)

[Philip Reames via llvm-commits]

================
@@ -30,7 +30,7 @@ define void @test() {
 ; CHECK-SLP-THRESHOLD:       bb:
 ; CHECK-SLP-THRESHOLD-NEXT:    [[TMP0:%.*]] = insertelement <4 x ptr> poison, ptr [[COND_IN_V]], i32 0
 ; CHECK-SLP-THRESHOLD-NEXT:    [[TMP1:%.*]] = shufflevector <4 x ptr> [[TMP0]], <4 x ptr> poison, <4 x i32> zeroinitializer
-; CHECK-SLP-THRESHOLD-NEXT:    [[TMP2:%.*]] = getelementptr i64, <4 x ptr> [[TMP1]], <4 x i64> <i64 0, i64 4, i64 8, i64 12>
+; CHECK-SLP-THRESHOLD-NEXT:    [[TMP2:%.*]] = getelementptr i64, <4 x ptr> [[TMP1]], <4 x i64> <i64 12, i64 8, i64 4, i64 0>
----------------
preames wrote:

I'd missed this was an X86 test.

Why do we need this change for an X86 test at all?  Shouldn't the default cost of illegal prevent any of the new code for kicking in for X86?

https://github.com/llvm/llvm-project/pull/80310