[llvm-commits] [llvm] r108113 - in /llvm/trunk: lib/Analysis/ConstantFolding.cpp test/Transforms/InstCombine/load3.ll

[Chandler Carruth]

On Sun, Jul 11, 2010 at 5:22 PM, Chris Lattner <sabre at nondot.org> wrote:
> Author: lattner
> Date: Sun Jul 11 19:22:51 2010
> New Revision: 108113
>
> URL: http://llvm.org/viewvc/llvm-project?rev=108113&view=rev
> Log:
> fix PR7429, a crash turning a load from a string into a float.
>
> Modified:
>    llvm/trunk/lib/Analysis/ConstantFolding.cpp
>    llvm/trunk/test/Transforms/InstCombine/load3.ll
>
> Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=108113&r1=108112&r2=108113&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
> +++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Sun Jul 11 19:22:51 2010
> @@ -436,8 +436,10 @@
>     unsigned StrLen = Str.length();
>     const Type *Ty = cast<PointerType>(CE->getType())->getElementType();
>     unsigned NumBits = Ty->getPrimitiveSizeInBits();
> -    // Replace LI with immediate integer store.
> -    if ((NumBits >> 3) == StrLen + 1) {
> +    // Replace load with immediate integer if the result is an integer or fp
> +    // value.
> +    if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 &&
> +        isa<IntegerType>(Ty) || Ty->isFloatingPointTy()) {

GCC warns about the && and || operators being used w/o parentheses.
Sometimes, this is just pedantic, but did you mean to have ()s around
the 'isa<IntegerType>(Ty) || Ty->isFloatingPointTy()' here? As it
stands, won't an fp value bypass the checks on NumBits?

>       APInt StrVal(NumBits, 0);
>       APInt SingleChar(NumBits, 0);
>       if (TD->isLittleEndian()) {
> @@ -454,7 +456,11 @@
>         SingleChar = 0;
>         StrVal = (StrVal << 8) | SingleChar;
>       }
> -      return ConstantInt::get(CE->getContext(), StrVal);
> +
> +      Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
> +      if (Ty->isFloatingPointTy())
> +        Res = ConstantExpr::getBitCast(Res, Ty);
> +      return Res;
>     }
>   }
>
>
> Modified: llvm/trunk/test/Transforms/InstCombine/load3.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/load3.ll?rev=108113&r1=108112&r2=108113&view=diff
> ==============================================================================
> --- llvm/trunk/test/Transforms/InstCombine/load3.ll (original)
> +++ llvm/trunk/test/Transforms/InstCombine/load3.ll Sun Jul 11 19:22:51 2010
> @@ -1,4 +1,6 @@
>  ; RUN: opt < %s -instcombine -S | FileCheck %s
> +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
> +target triple = "x86_64-apple-darwin10.0.0"
>
>  ; Instcombine should be able to do trivial CSE of loads.
>
> @@ -12,3 +14,14 @@
>  ; CHECK: @test1
>  ; CHECK: ret i32 0
>  }
> +
> +
> +; PR7429
> + at .str = private constant [4 x i8] c"XYZ\00"
> +define float @test2() {
> +  %tmp = load float* bitcast ([4 x i8]* @.str to float*), align 1
> +  ret float %tmp
> +
> +; CHECK: @test2
> +; CHECK: ret float 0x3806965600000000
> +}
> \ No newline at end of file
>
>
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