[LLVMdev] Small problem with intrinsics

[Nicolas Geoffray]

Hi Bart,

I guess that's because the value of the last argument of llvm.memcpy has 
to be known at compile time.

Nicolas

Bart Coppens wrote:
> Hello,
>
> I'm getting the impression that I'm misunderstanding something about 
> intrinsics. I have the following reduced testcase in mind:
>
> declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
>
> define void @foo(i8* %a, i8* %b, i32 %c, i32 %d) {
> entry:
>   ;call void @llvm.memcpy.i32( i8* %a, i8* %b, i32 %c, i32 %d )
>   ;call void @llvm.memcpy.i32( i8* %a, i8* %b, i32 0, i32 0 )
>   ret void
> }
>
> I compile this with
>
> llvm-as memcpy-intrinsic.ll -f -o memcpy-intrinsic.bc && llc -f -o 
> memcpy-intrinsic.s memcpy-intrinsic.bc
>
> Now, if I uncomment the lowermost memcpy, this produces no errors. If I 
> uncomment the uppermost memcpy instead, I get during lcc:
>
> llc: /var/bcoppens/llvm/llvm-svn/llvm/include/llvm/Support/Casting.h:199: 
> typename llvm::cast_retty<To, From>::ret_type llvm::cast(const Y&) [with X = 
> llvm::ConstantInt, Y = llvm::Value*]: Assertion `isa<X>(Val) && "cast<Ty>() 
> argument of incompatible type!"' failed.
>
> I can't see why this would happen. Both times, the function signature I call 
> is seemingly correct to my eyes. Does anybody see what I'm missing here?
>
> Thanks,
> Bart Coppens
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