llvm dev - Feb 2011 - [LLVMdev] conversion from 'const llvm::Value*' to 'llvm::Constant*'

Hi Duncan

Many many thanks, it works now!
But there are still some details I must be missing. I'm getting an assertion
when I try the following assignment in my script:

   global c = cos(1);

Assertion failed: isa<X>(Val) && "cast<Ty>() argument
of incompatible
type!", file c:/llvm-source-2.7/include/llvm/Support/Casting.h, line 200

However, running for example
   cos(1);
   global a = 0.5403023058681398; # cos(1) = 0.5403023058681398
   global b = 1 + 1;
works fine
   @a = global double 0x3FE14A280FB5068C ; <double*> [#uses=0]
   @b = global double 2.000000e+000 ; <double*> [#uses=0]
   define double @0() {
   entry:
      ret double 0x3FE14A280FB5068C
   }

The relevant code is
    ...
    Value *InitVal;
  InitVal = Init->Codegen();
  GlobalVariable * globval = *new* *GlobalVariable*(*TheModule,
InitVal->getType(), *false*,
     llvm::GlobalValue::*ExternalLinkage*, cast<Constant>(InitVal),
Twine(GlobalName) );

Any help, as always, would be really much appreciated!

Anton Skvorts

2011/2/12 Duncan Sands <baldrick at free.fr>

> Hi Anton,
>
>  > I'm getting the following error
> >
> >     error: invalid conversion from `const llvm::Value*' to
> `llvm::Constant*'
> >
> > How may I make this conversion? Any help would be much appreciated!
>
>
> cast<Constant>(whatever)
>
> Ciao, Duncan.
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
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Hi Anton,
> But there are still some details I must be missing. I'm getting an
assertion
> when I try the following assignment in my script:
>     global c = cos(1);
> Assertion failed: isa<X>(Val) && "cast<Ty>()
argument of incompatible type!",
I think this is telling you that cos(1) is not a constant.

Ciao, Duncan.

Oh, I thought that after "codegening" cos(0) would get me double 1.0
(assigment is working for anything like: global a = 1/3 + 2 /3 for
example)   What would be the best way to make assigments involving
functions, like  global a = cos(0);
without getting the assertion arising from  InitVal
cast<Constant>(Init->Codegen()); ?

I made some changes and now my code basically works, except in
assigments like the one above. It is a little bit frustrating because
is the main thing preventing me finishing my little silly scripting
language for monte carlo simulations.

Value *GlobalExprAST::Codegen() {
for (unsigned i = 0, e = GlobalNames.size(); i != e; ++i) {
  const std::string &GlobalName = GlobalNames[i].first;
  ExprAST *Init = GlobalNames[i].second;
  Constant *InitVal;
  InitVal = cast<Constant>(Init->Codegen());
  if (InitVal == 0) return 0;

GlobalVariable * globval = new GlobalVariable(*TheModule,
InitVal->getType(), false, llvm::GlobalValue::ExternalLinkage,
InitVal, Twine(GlobalName) );
}
}

Thank you very much for our help
Anton

2011/2/13 Duncan Sands <baldrick at free.fr>:
> Hi Anton,
>
>> But there are still some details I must be missing. I'm getting an
assertion
>> when I try the following assignment in my script:
>>     global c = cos(1);
>> Assertion failed: isa<X>(Val) && "cast<Ty>()
argument of incompatible type!",
>
> I think this is telling you that cos(1) is not a constant.
>
> Ciao, Duncan.
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>