[llvm] 2b9c158 - [InstCombine] Add test for miscompile in gep-of-gep fold (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2024-05-30T15:25:28+02:00
New Revision: 2b9c158efa33a225af38407adde6319fb26858e4

URL: https://github.com/llvm/llvm-project/commit/2b9c158efa33a225af38407adde6319fb26858e4
DIFF: https://github.com/llvm/llvm-project/commit/2b9c158efa33a225af38407adde6319fb26858e4.diff

LOG: [InstCombine] Add test for miscompile in gep-of-gep fold (NFC)

Added: 
    

Modified: 
    llvm/test/Transforms/InstCombine/getelementptr.ll

Removed: 
    


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diff  --git a/llvm/test/Transforms/InstCombine/getelementptr.ll b/llvm/test/Transforms/InstCombine/getelementptr.ll
index e82c168ced016..33ab1c37a2f43 100644
--- a/llvm/test/Transforms/InstCombine/getelementptr.ll
+++ b/llvm/test/Transforms/InstCombine/getelementptr.ll
@@ -1680,4 +1680,15 @@ if.else:
   ret i64 0
 }
 
+
+ at g = external global i8
+
+; FIXME: This is a miscompile
+define ptr @constexpr_gep_of_gep_with_narrow_type() {
+; CHECK-LABEL: @constexpr_gep_of_gep_with_narrow_type(
+; CHECK-NEXT:    ret ptr getelementptr (i8, ptr @g, i64 -2)
+;
+  ret ptr getelementptr (i8, ptr getelementptr (i8, ptr @g, i8 127), i8 127)
+}
+
 !0 = !{!"branch_weights", i32 2, i32 10}