[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp

[Chris Lattner]

> 1. Use APInt::getSignBit to reduce clutter (patch by Sheng Zhou)
> 2. Replace uses of the "isPositive" utility function with  
> APInt::isPositive

Oooh, beautiful.  Nice work guys,

-Chris

>
> ---
> Diffs of the changes:  (+4 -8)
>
>  InstructionCombining.cpp |   12 ++++--------
>  1 files changed, 4 insertions(+), 8 deletions(-)
>
>
> Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
> diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.663  
> llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.664
> --- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.663	Mon  
> Mar 19 15:47:50 2007
> +++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp	Mon Mar 19  
> 15:58:18 2007
> @@ -2760,7 +2760,7 @@
>  // highest order bit set.
>  static bool isSignBit(ConstantInt *CI) {
>    unsigned NumBits = CI->getType()->getPrimitiveSizeInBits();
> -  return (CI->getZExtValue() & (~0ULL >> (64-NumBits))) == (1ULL  
> << (NumBits-1));
> +  return CI->getValue() == APInt::getSignBit(NumBits);
>  }
>
>  Instruction *InstCombiner::visitSub(BinaryOperator &I) {
> @@ -4925,10 +4925,6 @@
>    return Changed ? &I : 0;
>  }
>
> -static bool isPositive(ConstantInt *C) {
> -  return C->getSExtValue() >= 0;
> -}
> -
>  /// AddWithOverflow - Compute Result = In1+In2, returning true if  
> the result
>  /// overflowed for this type.
>  static bool AddWithOverflow(ConstantInt *&Result, ConstantInt *In1,
> @@ -5707,12 +5703,12 @@
>              LoBound = Prod;
>              LoOverflow = ProdOV;
>              HiOverflow = ProdOV || AddWithOverflow(HiBound,  
> LoBound, DivRHS);
> -          } else if (isPositive(DivRHS)) { // Divisor is > 0.
> +          } else if (DivRHS->getValue().isPositive()) { // Divisor  
> is > 0.
>              if (CI->isNullValue()) {       // (X / pos) op 0
>                // Can't overflow.
>                LoBound = cast<ConstantInt>(ConstantExpr::getNeg 
> (SubOne(DivRHS)));
>                HiBound = DivRHS;
> -            } else if (isPositive(CI)) {   // (X / pos) op pos
> +            } else if (CI->getValue().isPositive()) {   // (X /  
> pos) op pos
>                LoBound = Prod;
>                LoOverflow = ProdOV;
>                HiOverflow = ProdOV || AddWithOverflow(HiBound,  
> Prod, DivRHS);
> @@ -5729,7 +5725,7 @@
>                HiBound = cast<ConstantInt>(ConstantExpr::getNeg 
> (DivRHS));
>                if (HiBound == DivRHS)
>                  LoBound = 0;               // - INTMIN = INTMIN
> -            } else if (isPositive(CI)) {   // (X / neg) op pos
> +            } else if (CI->getValue().isPositive()) {   // (X /  
> neg) op pos
>                HiOverflow = LoOverflow = ProdOV;
>                if (!LoOverflow)
>                  LoOverflow = AddWithOverflow(LoBound, Prod, AddOne 
> (DivRHS));
>
>
>
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