diff options
| -rw-r--r-- | llvm/test/Transforms/InstCombine/cast.ll | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/cast.ll b/llvm/test/Transforms/InstCombine/cast.ll index a4375a5cd57..74ea67ac72b 100644 --- a/llvm/test/Transforms/InstCombine/cast.ll +++ b/llvm/test/Transforms/InstCombine/cast.ll @@ -1470,3 +1470,42 @@ define i32 @test93(i32 %A) { %D = trunc i96 %C to i32 ret i32 %D } + +; The following three tests show a miscompile of sext + lshr + trunc patterns. +; PR33078 + +define i8 @pr33078_1(i8 %A) { +; CHECK-LABEL: @pr33078_1( +; CHECK-NEXT: [[C:%.*]] = ashr i8 [[A:%.*]], 7 +; CHECK-NEXT: ret i8 [[C]] +; + %B = sext i8 %A to i16 + %C = lshr i16 %B, 8 + %D = trunc i16 %C to i8 + ret i8 %D +} + +define i12 @pr33078_2(i8 %A) { +; CHECK-LABEL: @pr33078_2( +; CHECK-NEXT: [[C:%.*]] = ashr i8 [[A:%.*]], 4 +; CHECK-NEXT: [[D:%.*]] = sext i8 [[C]] to i12 +; CHECK-NEXT: ret i12 [[D]] +; + %B = sext i8 %A to i16 + %C = lshr i16 %B, 4 + %D = trunc i16 %C to i12 + ret i12 %D +} + +define i4 @pr33078_3(i8 %A) { +; CHECK-LABEL: @pr33078_3( +; CHECK-NEXT: [[B:%.*]] = sext i8 [[A:%.*]] to i16 +; CHECK-NEXT: [[C:%.*]] = lshr i16 [[B]], 12 +; CHECK-NEXT: [[D:%.*]] = trunc i16 [[C]] to i4 +; CHECK-NEXT: ret i4 [[D]] +; + %B = sext i8 %A to i16 + %C = lshr i16 %B, 12 + %D = trunc i16 %C to i4 + ret i4 %D +} |
