Re: [Mingw-users] help on inline assmebly

[TAMURA K. <ke...@ha...>]

In message "[Mingw-users] help on inline assmebly"
    on 01/10/26, "cateroc" <ca...@16...> writes:
> there was no error when i compile it with with msvc compiler (cl.exe).
> but i got many warning and errors when i compile it with gcc (version
> 2.95.3-6 (mingw special)).

The syntax of assembly and inline assembly of gcc is different
from that of VC++.

MinGW distribution has "as" manual, info-html\as.html, and gcc
manual has information about inline assembly, info-html\gcc.html
-> C Extensions -> Extended Asm.

Here is an example for MinGW:

int mmxIsEnabled() {
    register int ret __asm__ ("%eax");
    __asm__ volatile (
       "pushfl
	popl	%%eax
	movl	%%eax,%%ebx
	xorl	$0x00200000,%%eax
	pushl	%%eax
	popfl
	pushfl
	popl	%%eax
	subl	%%ebx,%%eax
	jz	0f
	movl	$1,%%eax
	cpuid
	and	$0x00800000,%%edx
	movl	%%edx,%%eax
0:"
       : "=r" (ret)
       : /* no inputs */
       : "%ebx", "%edx" /* broken registers */);
    return ret;
}

-- 
TAMURA Kent <ke...@ha...> <ke...@ne...>