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| author | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-06-02 16:00:27 +0000 |
|---|---|---|
| committer | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-06-02 16:00:27 +0000 |
| commit | 0bedfa456a7421940818224bcd0b61245c5c5568 (patch) | |
| tree | a91f99472c873bac95dac4ceb4218d3c21377236 | |
| parent | d958619a2dbc7422fcd342849a898790a0bb082b (diff) | |
| download | llvm-0bedfa456a7421940818224bcd0b61245c5c5568.tar.gz llvm-0bedfa456a7421940818224bcd0b61245c5c5568.tar.bz2 llvm-0bedfa456a7421940818224bcd0b61245c5c5568.tar.xz | |
[X86] Fix checked arithmetic for i8 on X86.
When lowering a ISD::BRCOND into a test+branch, make sure that we
always use the correct condition code to emit the test operation.
This fixes PR19858: "i8 checked mul is wrong on x86".
Patch by Keno Fisher!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210032 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 5 | ||||
| -rw-r--r-- | test/CodeGen/X86/i8-umulo.ll | 24 |
2 files changed, 27 insertions, 2 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 82ae28d915..610be3f0e1 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -11482,8 +11482,9 @@ SDValue X86TargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { } if (addTest) { - CC = DAG.getConstant(X86::COND_NE, MVT::i8); - Cond = EmitTest(Cond, X86::COND_NE, dl, DAG); + X86::CondCode X86Cond = Inverted ? X86::COND_E : X86::COND_NE; + CC = DAG.getConstant(X86Cond, MVT::i8); + Cond = EmitTest(Cond, X86Cond, dl, DAG); } Cond = ConvertCmpIfNecessary(Cond, DAG); return DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(), diff --git a/test/CodeGen/X86/i8-umulo.ll b/test/CodeGen/X86/i8-umulo.ll new file mode 100644 index 0000000000..ba846f3e9b --- /dev/null +++ b/test/CodeGen/X86/i8-umulo.ll @@ -0,0 +1,24 @@ +; RUN: llc -mcpu=generic -march=x86 < %s | FileCheck %s +; PR19858 + +declare {i8, i1} @llvm.umul.with.overflow.i8(i8 %a, i8 %b) +define i8 @testumulo(i32 %argc) { +; CHECK: imulw +; CHECK: testb %{{.+}}, %{{.+}} +; CHECK: je [[NOOVERFLOWLABEL:.+]] +; CHECK: {{.*}}[[NOOVERFLOWLABEL]]: +; CHECK-NEXT: movb +; CHECK-NEXT: retl +top: + %RHS = trunc i32 %argc to i8 + %umul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 25, i8 %RHS) + %ex = extractvalue { i8, i1 } %umul, 1 + br i1 %ex, label %overflow, label %nooverlow + +overflow: + ret i8 %RHS + +nooverlow: + %umul.value = extractvalue { i8, i1 } %umul, 0 + ret i8 %umul.value +} |