[llvm] [InstCombine] Split GEPs with multiple variable indices (PR #137297)

[Nikita Popov via llvm-commits]

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@@ -548,10 +548,10 @@ define i64 @fold_ptrtoint_nested_array_two_vars(i64 %x, i64 %y) {
 ;
 ; INSTCOMBINE-LABEL: define {{[^@]+}}@fold_ptrtoint_nested_array_two_vars
 ; INSTCOMBINE-SAME: (i64 [[X:%.*]], i64 [[Y:%.*]]) {
-; INSTCOMBINE-NEXT:    [[PTR_IDX:%.*]] = shl i64 [[X]], 2
-; INSTCOMBINE-NEXT:    [[PTR_IDX1:%.*]] = shl i64 [[Y]], 1
-; INSTCOMBINE-NEXT:    [[PTR_OFFS:%.*]] = add i64 [[PTR_IDX]], [[PTR_IDX1]]
-; INSTCOMBINE-NEXT:    ret i64 [[PTR_OFFS]]
+; INSTCOMBINE-NEXT:    [[PTR_SPLIT:%.*]] = getelementptr [2 x i16], ptr addrspace(1) null, i64 [[X]]
+; INSTCOMBINE-NEXT:    [[PTR:%.*]] = getelementptr [2 x i16], ptr addrspace(1) [[PTR_SPLIT]], i64 0, i64 [[Y]]
+; INSTCOMBINE-NEXT:    [[RET:%.*]] = ptrtoint ptr addrspace(1) [[PTR]] to i64
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nikic wrote:

Regression: Fail to fold ptrtoint of gep null if more than one gep involved.

https://github.com/llvm/llvm-project/pull/137297