[llvm] r210032 - [X86] Fix checked arithmetic for i8 on X86.
Andrea Di Biagio
Andrea_DiBiagio at sn.scee.net
Mon Jun 2 09:00:28 PDT 2014
Author: adibiagio
Date: Mon Jun 2 11:00:27 2014
New Revision: 210032
URL: http://llvm.org/viewvc/llvm-project?rev=210032&view=rev
Log:
[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!
Added:
llvm/trunk/test/CodeGen/X86/i8-umulo.ll
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=210032&r1=210031&r2=210032&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Jun 2 11:00:27 2014
@@ -11482,8 +11482,9 @@ SDValue X86TargetLowering::LowerBRCOND(S
}
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(),
Added: llvm/trunk/test/CodeGen/X86/i8-umulo.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/i8-umulo.ll?rev=210032&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/i8-umulo.ll (added)
+++ llvm/trunk/test/CodeGen/X86/i8-umulo.ll Mon Jun 2 11:00:27 2014
@@ -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
+}
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