vp3: don't compile mmx IDCT functions on x86-64.

64-bit CPUs always have SSE2, and a SSE2 version exists, thus the MMX
version will never be used.

libavcodec/x86/vp3dsp.asm

@@ -607,8 +607,11 @@ cglobal vp3_idct_add, 3, 4, 9
     RET
 %endmacro
 
+%if ARCH_X86_32
 INIT_MMX mmx
 vp3_idct_funcs
+%endif
+
 INIT_XMM sse2
 vp3_idct_funcs
 

libavcodec/x86/vp3dsp_init.c

@@ -41,11 +41,13 @@ av_cold void ff_vp3dsp_init_x86(VP3DSPContext *c, int flags)
 #if HAVE_YASM
     int cpuflags = av_get_cpu_flags();
 
+#if ARCH_X86_32
     if (HAVE_MMX && cpuflags & AV_CPU_FLAG_MMX) {
         c->idct_put  = ff_vp3_idct_put_mmx;
         c->idct_add  = ff_vp3_idct_add_mmx;
         c->idct_perm = FF_PARTTRANS_IDCT_PERM;
     }
+#endif
 
     if (HAVE_MMX2 && cpuflags & AV_CPU_FLAG_MMX2) {
         c->idct_dc_add = ff_vp3_idct_dc_add_mmx2;