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

[Hans Wennborg via llvm-commits]

Ping?

Apologies if this has been mentioned somewhere else. Should we merge
this, or is it an ancient/hard-to-hit bug?

On Mon, Aug 1, 2016 at 1:39 PM, Hans Wennborg <hwennborg at google.com> wrote:
> Ping?
>
> On Thu, Jul 28, 2016 at 8:51 AM, Hans Wennborg <hwennborg at google.com> wrote:
>> 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