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inline asm mmx: how to movq from memory to %mmX
- From: "Jack Andrews" <effbiae at gmail dot com>
- To: gcc-help at gcc dot gnu dot org
- Date: Tue, 17 Apr 2007 23:14:09 +1000
- Subject: inline asm mmx: how to movq from memory to %mmX
following up on my previous post...
i am trying to do some vector addition using MMX and inline assembly
in GCC. my code follows.
i want the function 'simd' to do the same as 'sisd'
i get these errors when i try to compile:
[jack@fedora i]$ gcc -mmmx v.c
/tmp/ccWXntVc.s: Assembler messages:
/tmp/ccWXntVc.s:19: Error: suffix or operands invalid for `movq'
/tmp/ccWXntVc.s:20: Error: junk `%mm0' after register
[jack@fedora i]$ gcc -v
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/u
sr/share/info --enable-shared --enable-threads=posix --enable-checking=release -
-with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-
libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable
-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.
0/jre --with-cpu=generic --host=i386-redhat-linux
Thread model: posix
gcc version 4.1.0 20060304 (Red Hat 4.1.0-3)
[jack@fedora i]$ cat v.c
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
typedef long I;
typedef char C;
#define IZ sizeof(I)
#define W 2
simd(n, is)
I *is;
{ I i;
asm("pxor %mm0,%mm0");
for (i=0; i < n; i += W) {
asm("movq %0 %%mm1\n\t"
"paddq %%mm1 %%mm0"
:
:"m"(is[i]) );
}
return 0;
}
sisd(n, is)
I *is;
{
I i = 0, j = 0;
for (i = 0; i < n; i++)
j += is[i];
return j;
}
main(c, v)
C **v;
{
I n = atol(v[1]),
z = atol(v[2]), m = atol(v[3]), *is = malloc(IZ * (z *= W));
I result;
printf("IZ=%d, %s\n",IZ,m?"SIMD":"SISD");
while (n--)
result=m?simd(z, is):sisd(z, is);
printf("%d\n",result);
}