[SeparateConstOffsetFromGEP] Fixed a bug related to unsigned modulo

[oota-llvm.git] / test / Transforms / SeparateConstOffsetFromGEP / NVPTX / split-gep.ll

diff --git a/test/Transforms/SeparateConstOffsetFromGEP/NVPTX/split-gep.ll b/test/Transforms/SeparateConstOffsetFromGEP/NVPTX/split-gep.ll
index 4d07ab35b51e53dfef0976c60b20a2d5d80a05fc..ea0d3f5673a59594efd7296f914bf85500e2704f 100644 (file)
--- a/test/Transforms/SeparateConstOffsetFromGEP/NVPTX/split-gep.ll
+++ b/test/Transforms/SeparateConstOffsetFromGEP/NVPTX/split-gep.ll
@@ -253,3 +253,27 @@ entry:
   ret float* %p
 ; CHECK-NEXT: ret
 }
+
+; The source code used to be buggy in checking
+; (AccumulativeByteOffset % ElementTypeSizeOfGEP == 0)
+; where AccumulativeByteOffset is signed but ElementTypeSizeOfGEP is unsigned.
+; The compiler would promote AccumulativeByteOffset to unsigned, causing
+; unexpected results. For example, while -64 % (int64_t)24 != 0,
+; -64 % (uint64_t)24 == 0.
+%struct3 = type { i64, i32 }
+%struct2 = type { %struct3, i32 }
+%struct1 = type { i64, %struct2 }
+%struct0 = type { i32, i32, i64*, [100 x %struct1] }
+define %struct2* @sign_mod_unsign(%struct0* %ptr, i64 %idx) {
+; CHECK-LABEL: @sign_mod_unsign(
+entry:
+  %arrayidx = add nsw i64 %idx, -2
+; CHECK-NOT: add
+  %ptr2 = getelementptr inbounds %struct0* %ptr, i64 0, i32 3, i64 %arrayidx, i32 1
+; CHECK: [[PTR:%[a-zA-Z0-9]+]] = getelementptr %struct0* %ptr, i64 0, i32 3, i64 %idx, i32 1
+; CHECK: [[PTR1:%[a-zA-Z0-9]+]] = bitcast %struct2* [[PTR]] to i8*
+; CHECK: getelementptr i8* [[PTR1]], i64 -64
+; CHECK: bitcast
+  ret %struct2* %ptr2
+; CHECK-NEXT: ret
+}