[llvm] r276952 - [InstCombine] Handle failures from ConstantFoldConstantExpression

[Hans Wennborg via llvm-commits]

Something for 3.9?

On Wed, Jul 27, 2016 at 7:29 PM, David Majnemer via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: majnemer
> Date: Wed Jul 27 21:29:06 2016
> New Revision: 276952
>
> URL: http://llvm.org/viewvc/llvm-project?rev=276952&view=rev
> Log:
> [InstCombine] Handle failures from ConstantFoldConstantExpression
>
> ConstantFoldConstantExpression returns null when folding fails.
>
> This fixes PR28745.
>
> Modified:
>     llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
>     llvm/trunk/test/Transforms/InstCombine/cast.ll
>
> Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp?rev=276952&r1=276951&r2=276952&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp (original)
> +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp Wed Jul 27 21:29:06 2016
> @@ -162,7 +162,8 @@ Value *InstCombiner::EvaluateInDifferent
>      C = ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/);
>      // If we got a constantexpr back, try to simplify it with DL info.
>      if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
> -      C = ConstantFoldConstantExpression(CE, DL, TLI);
> +      if (Constant *FoldedC = ConstantFoldConstantExpression(CE, DL, TLI))
> +        C = FoldedC;
>      return C;
>    }
>
>
> Modified: llvm/trunk/test/Transforms/InstCombine/cast.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/cast.ll?rev=276952&r1=276951&r2=276952&view=diff
> ==============================================================================
> --- llvm/trunk/test/Transforms/InstCombine/cast.ll (original)
> +++ llvm/trunk/test/Transforms/InstCombine/cast.ll Wed Jul 27 21:29:06 2016
> @@ -1372,3 +1372,11 @@ define i16 @PR24763(i8 %V) {
>    %t = trunc i32 %l to i16
>    ret i16 %t
>  }
> +
> +define i64 @PR28745() {
> +; CHECK-LABEL: @PR28745(
> +; CHECK-NEXT:    ret i64 zext (i32 extractvalue ({ i32 } select (i1 icmp eq (i16 extractelement (<2 x i16> bitcast (<1 x i32> <i32 1> to <2 x i16>), i32 0), i16 0), { i32 } { i32 1 }, { i32 } zeroinitializer), 0) to i64)
> +
> +  %b = zext i32 extractvalue ({ i32 } select (i1 icmp eq (i16 extractelement (<2 x i16> bitcast (<1 x i32> <i32 1> to <2 x i16>), i32 0), i16 0), { i32 } { i32 1 }, { i32 } zeroinitializer), 0) to i64
> +  ret i64 %b
> +}
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits