[FFmpeg-devel] [PATCH] Fix compilation with llvm-gcc on x86_64

Måns Rullgård mans
Sun Nov 1 18:30:49 CET 2009

Michael Niedermayer <michaelni at gmx.at> writes:

> On Sun, Nov 01, 2009 at 04:45:11PM +0000, Mans Rullgard wrote:
>> Apparently llvm dislikes +g constraints with int operands.  This uses
> compiler bug?

I'm inclined to say no.  The g constraint allows either memory or
register operands, which in this case will have different sizes.  I
don't see how that can be done in a sane way.

>> a temporary x86_reg variable to avoid that situation.  Using a cast is
> this slows the code down, x86_reg might be a different number of bits than
> int. For example the int function argument may be 32bit on the stack and
> if g now is feeded wih 64bit then there has to be a memory read and a memory
> write if no register is left.

Forget this patch.  It breaks with gcc (obviously should have tested
before sending).

M?ns Rullg?rd
mans at mansr.com

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