llvm dev - Mar 2013 - [LLVMdev] Question about InlineAsm

Hello,

I'm new with the llvm, and I trying to write a transformation adding
some lines of asm to a code.

My code is like this,

   Type *VoidTy = llvm::Type::getVoidTy(getGlobalContext());
   llvm::FunctionType *ty = llvm::FunctionType::get(VoidTy, false);
   InlineAsm *iv = InlineAsm::get( ty, "mov $55, %eax", "",
true ); //
<----- here
   SmallVector<llvm::Value*, 4> ArgList;
   llvm::CallInst::Create( iv , ArgList, "", &ins);

It work perfect, but when I compiled I found the next error:

opt -load /home/david/LLVM/build_all/Release+Asserts/lib/LLVMHello.so
-hello < hello.bc > hello.t.bc 2> AAA
llc hello.t.bc -o hello.t.s
LLVM ERROR: Invalid $ operand number in inline asm string: 'mov $55,
%eax'
make: *** [opt] Error 1

If I remove the symbol "$", it works properly, but does not be the
corrected att syntax, because in att syntax the constants are prefixed
by $.

It is possible to write a inline asm instrucction to load a constant
in a register?


Thanks in advance.
David.

Hello,

On 03/11/2013 12:56 PM, David Gonzalez Marquez wrote:
> If I remove the symbol "$", it works properly, but does not be
the
> corrected att syntax, because in att syntax the constants are prefixed
> by $.
The bitcode inline-asm syntax is different from the C source code 
syntax, clang does some translation there. In bitcode, $<nr> is always 
used to refer to the arguments. If you want to emit a $ symbol in asm, 
you need to escape it with $, i.e., 'mov $$55, %eax'.

Cheers,
  Stefan