[llvm] r299121 - [InstSimplify] Use m_SignBit instead of calling getSignBit and using m_Specific. NFCI

[Friedman, Eli via llvm-commits]

Oh, you're right.  Nevermind.

-Eli

On 3/30/2017 3:46 PM, Craig Topper wrote:
> If Ty is a vector type wasn't that ConstantInt::get in the original 
> code going to create a splat of the Constant?
>
> ~Craig
>
> On Thu, Mar 30, 2017 at 3:44 PM, Friedman, Eli 
> <efriedma at codeaurora.org <mailto:efriedma at codeaurora.org>> wrote:
>
>     On 3/30/2017 3:21 PM, Craig Topper via llvm-commits wrote:
>
>         Author: ctopper
>         Date: Thu Mar 30 17:21:16 2017
>         New Revision: 299121
>
>         URL: http://llvm.org/viewvc/llvm-project?rev=299121&view=rev
>         <http://llvm.org/viewvc/llvm-project?rev=299121&view=rev>
>         Log:
>         [InstSimplify] Use m_SignBit instead of calling getSignBit and
>         using m_Specific. NFCI
>
>         Modified:
>              llvm/trunk/lib/Analysis/InstructionSimplify.cpp
>
>         Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
>         URL:
>         http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=299121&r1=299120&r2=299121&view=diff
>         <http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=299121&r1=299120&r2=299121&view=diff>
>         ==============================================================================
>         --- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
>         +++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Thu Mar 30
>         17:21:16 2017
>         @@ -565,10 +565,8 @@ static Value *SimplifyAddInst(Value *Op0
>             // add nsw/nuw (xor Y, signbit), signbit --> Y
>             // The no-wrapping add guarantees that the top bit will be
>         set by the add.
>             // Therefore, the xor must be clearing the already set
>         sign bit of Y.
>         -  Constant *SignBit =
>         -      ConstantInt::get(Ty,
>         APInt::getSignBit(Ty->getScalarSizeInBits()));
>         -  if ((isNSW || isNUW) && match(Op1, m_Specific(SignBit)) &&
>         -      match(Op0, m_Xor(m_Value(Y), m_Specific(SignBit))))
>         +  if ((isNSW || isNUW) && match(Op1, m_SignBit()) &&
>         +      match(Op0, m_Xor(m_Value(Y), m_SignBit())))
>               return Y;
>
>
>     Are you certain there's no functional change here? m_SignBit()
>     also matches vectors.
>
>     -Eli
>
>     -- 
>     Employee of Qualcomm Innovation Center, Inc.
>     Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>     a Linux Foundation Collaborative Project
>
>


-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project

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