[llvm] [InstCombine] Canonicalize gep scaling factor (PR #180216)

[Nikita Popov via llvm-commits]

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@@ -320,7 +325,11 @@ define ptr @geps_combinable_scalable_vector_array(ptr %a, i64 %idx) {
 
 define i1 @compare_geps_same_indices(ptr %a, ptr %b, i64 %idx) {
 ; CHECK-LABEL: @compare_geps_same_indices(
-; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[TMP1:%.*]] = shl i64 [[IDX:%.*]], 2
+; CHECK-NEXT:    [[A:%.*]] = getelementptr i8, ptr [[A1:%.*]], i64 [[TMP1]]
+; CHECK-NEXT:    [[TMP2:%.*]] = shl i64 [[IDX]], 2
+; CHECK-NEXT:    [[B:%.*]] = getelementptr i8, ptr [[B1:%.*]], i64 [[TMP2]]
+; CHECK-NEXT:    [[C:%.*]] = icmp eq ptr [[A]], [[B]]
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nikic wrote:

Regression, but only in the absence of CSE.

https://github.com/llvm/llvm-project/pull/180216