[llvm-commits] [llvm] r50239 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/2008-04-24-MemCpyBug.ll

[Bill Wendling]

Hi Evan,

Please apply this to the Tak branch as well. Thanks!

-bw

On Thu, Apr 24, 2008 at 5:26 PM, Evan Cheng <evan.cheng at apple.com> wrote:
> Author: evancheng
>  Date: Thu Apr 24 19:26:43 2008
>  New Revision: 50239
>
>  URL: http://llvm.org/viewvc/llvm-project?rev=50239&view=rev
>  Log:
>  Fix bug in x86 memcpy / memset lowering. If there are trailing bytes not handled by rep instructions, a new memcpy / memset is introduced for them. However, since source / destination addresses are already adjusted, their offsets should be zero.
>
>  Added:
>     llvm/trunk/test/CodeGen/X86/2008-04-24-MemCpyBug.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=50239&r1=50238&r2=50239&view=diff
>
>  ==============================================================================
>  --- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
>  +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Apr 24 19:26:43 2008
>  @@ -4822,7 +4822,7 @@
>                                        DAG.getConstant(Offset, AddrVT)),
>                            Src,
>                            DAG.getConstant(BytesLeft, SizeVT),
>  -                          Align, DstSV, Offset);
>  +                          Align, DstSV, 0);
>    }
>
>    // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain.
>  @@ -4847,8 +4847,6 @@
>    if (!AlwaysInline && SizeVal > getSubtarget()->getMaxInlineSizeThreshold())
>      return SDOperand();
>
>  -  SmallVector<SDOperand, 4> Results;
>  -
>    MVT::ValueType AVT;
>    unsigned BytesLeft = 0;
>    if (Align >= 8 && Subtarget->is64Bit())
>  @@ -4881,25 +4879,24 @@
>    Ops.push_back(Chain);
>    Ops.push_back(DAG.getValueType(AVT));
>    Ops.push_back(InFlag);
>  -  Results.push_back(DAG.getNode(X86ISD::REP_MOVS, Tys, &Ops[0], Ops.size()));
>  +  SDOperand RepMovs = DAG.getNode(X86ISD::REP_MOVS, Tys, &Ops[0], Ops.size());
>
>  +  SmallVector<SDOperand, 4> Results;
>  +  Results.push_back(RepMovs);
>    if (BytesLeft) {
>      // Handle the last 1 - 7 bytes.
>      unsigned Offset = SizeVal - BytesLeft;
>      MVT::ValueType DstVT = Dst.getValueType();
>      MVT::ValueType SrcVT = Src.getValueType();
>      MVT::ValueType SizeVT = Size.getValueType();
>  -
>  -    Results.push_back(DAG.getMemcpy(Chain,
>  +    Results.push_back(DAG.getMemcpy(Chain,
>                                      DAG.getNode(ISD::ADD, DstVT, Dst,
>  -                                                DAG.getConstant(Offset,
>  -                                                                DstVT)),
>  +                                                DAG.getConstant(Offset, DstVT)),
>                                      DAG.getNode(ISD::ADD, SrcVT, Src,
>  -                                                DAG.getConstant(Offset,
>  -                                                                SrcVT)),
>  +                                                DAG.getConstant(Offset, SrcVT)),
>                                      DAG.getConstant(BytesLeft, SizeVT),
>                                      Align, AlwaysInline,
>  -                                    DstSV, Offset, SrcSV, Offset));
>  +                                    DstSV, 0, SrcSV, 0));
>    }
>
>    return DAG.getNode(ISD::TokenFactor, MVT::Other, &Results[0], Results.size());
>
>  Added: llvm/trunk/test/CodeGen/X86/2008-04-24-MemCpyBug.ll
>  URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-04-24-MemCpyBug.ll?rev=50239&view=auto
>
>  ==============================================================================
>  --- llvm/trunk/test/CodeGen/X86/2008-04-24-MemCpyBug.ll (added)
>  +++ llvm/trunk/test/CodeGen/X86/2008-04-24-MemCpyBug.ll Thu Apr 24 19:26:43 2008
>  @@ -0,0 +1,12 @@
>  +; RUN: llvm-as < %s | llc -march=x86 | not grep 120
>  +; Don't accidentally add the offset twice for trailing bytes.
>  +
>  +       %struct.S63 = type { [63 x i8] }
>  + at g1s63 = external global %struct.S63           ; <%struct.S63*> [#uses=1]
>  +
>  +declare void @test63(%struct.S63* byval align 4 ) nounwind
>  +
>  +define void @testit63_entry_2E_ce() nounwind  {
>  +       tail call void @test63( %struct.S63* byval align 4  @g1s63 ) nounwind
>  +       ret void
>  +}
>
>
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