llvm dev - Oct 2009 - [LLVMdev] Help with gcc SSE intrinsics

Ok, I've been looking at this for hours and can't figure it out.  I know
I'm
missing something obvious.

I've been spending the past few days beefing up the vector support in the C
Backend.  This should help us debug vector code that's miscompiled.  But
gcc doesn't like this fragment:

  ((double *)(&llvm_cbe_r1147))[0u] = 
(((llvm_cbe_r1146__BITCAST_TEMPORARY.Int64 = 4ull, 
llvm_cbe_r1146__BITCAST_TEMPORARY .Double)));
  llvm_cbe_r1148 = __builtin_ia32_movddup(llvm_cbe_r1147);

prog.linked.c:10393: error: incompatible types when assigning to type
'double
__vector__'
 from type 'int'

  double  __attribute__((vector_size(16 ))) llvm_cbe_r1147;
  double  __attribute__((vector_size(16 ))) llvm_cbe_r1148;

Any ideas what gcc is complaining about?  I'm running gcc with -msse3.

                            -Dave

On Oct 9, 2009, at 4:26 PM, David Greene wrote:
> Ok, I've been looking at this for hours and can't figure it out.  I
> know I'm
> missing something obvious.
>
> I've been spending the past few days beefing up the vector support  
> in the C
> Backend.  This should help us debug vector code that's miscompiled.   
> But
> gcc doesn't like this fragment:
>
>  ((double *)(&llvm_cbe_r1147))[0u] >
(((llvm_cbe_r1146__BITCAST_TEMPORARY.Int64 = 4ull,
> llvm_cbe_r1146__BITCAST_TEMPORARY .Double)));
>  llvm_cbe_r1148 = __builtin_ia32_movddup(llvm_cbe_r1147);
>
> prog.linked.c:10393: error: incompatible types when assigning to  
> type 'double
> __vector__'
> from type 'int'
>
>  double  __attribute__((vector_size(16 ))) llvm_cbe_r1147;
>  double  __attribute__((vector_size(16 ))) llvm_cbe_r1148;
>
> Any ideas what gcc is complaining about?  I'm running gcc with -msse3.

As far as I can tell, GCC 4.x no longer predeclares  
__builtin_ia32_movddup.  g++ gives a clearer error, but in C the  
function is implicitly declared as a returning int (because of the  
call), and so you get the type mismatch again.

At least, that's my guess (I'm not familiar with GCC internals).

	Daveed

On Oct 9, 2009, at 1:26 PMPDT, David Greene wrote:
> Ok, I've been looking at this for hours and can't figure it out.  I
> know I'm
> missing something obvious.
>
> I've been spending the past few days beefing up the vector support  
> in the C
> Backend.  This should help us debug vector code that's miscompiled.   
> But
> gcc doesn't like this fragment:
>
>  ((double *)(&llvm_cbe_r1147))[0u] >
(((llvm_cbe_r1146__BITCAST_TEMPORARY.Int64 = 4ull,
> llvm_cbe_r1146__BITCAST_TEMPORARY .Double)));
>  llvm_cbe_r1148 = __builtin_ia32_movddup(llvm_cbe_r1147);
I don't see __builtin_ia32_movddup defined anywhere in the llvm-gcc  
sources.  That's probably it.
> prog.linked.c:10393: error: incompatible types when assigning to  
> type 'double
> __vector__'
> from type 'int'
>
>  double  __attribute__((vector_size(16 ))) llvm_cbe_r1147;
>  double  __attribute__((vector_size(16 ))) llvm_cbe_r1148;
>
> Any ideas what gcc is complaining about?  I'm running gcc with -msse3.
>
>                            -Dave
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

On Friday 09 October 2009 15:47, Dale Johannesen wrote:
> On Oct 9, 2009, at 1:26 PMPDT, David Greene wrote:
> > Ok, I've been looking at this for hours and can't figure it
out.  I
> > know I'm
> > missing something obvious.
> >
> > I've been spending the past few days beefing up the vector support
> > in the C
> > Backend.  This should help us debug vector code that's
miscompiled.
> > But
> > gcc doesn't like this fragment:
> >
> >  ((double *)(&llvm_cbe_r1147))[0u] > >
(((llvm_cbe_r1146__BITCAST_TEMPORARY.Int64 = 4ull,
> > llvm_cbe_r1146__BITCAST_TEMPORARY .Double)));
> >  llvm_cbe_r1148 = __builtin_ia32_movddup(llvm_cbe_r1147);
>
> I don't see __builtin_ia32_movddup defined anywhere in the llvm-gcc
> sources.  That's probably it.
Not llvm-gcc.  GNU gcc.  It's documented here:

http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/X86-Built_002din-Functions.html#X86-Built_002din-Functions

                                 -Dave