x86: Simplify some arch conditionals

libavcodec/x86/h264_qpel.c

@@ -544,7 +544,7 @@ void ff_h264qpel_init_x86(H264QpelContext *c, int bit_depth)
             SET_QPEL_FUNCS(avg_h264_qpel, 1,  8, mmxext, );
             SET_QPEL_FUNCS(avg_h264_qpel, 2,  4, mmxext, );
         } else if (bit_depth == 10) {
-#if !ARCH_X86_64
+#if ARCH_X86_32
             SET_QPEL_FUNCS(avg_h264_qpel, 0, 16, 10_mmxext, ff_);
             SET_QPEL_FUNCS(put_h264_qpel, 0, 16, 10_mmxext, ff_);
             SET_QPEL_FUNCS(put_h264_qpel, 1,  8, 10_mmxext, ff_);

libavcodec/x86/idct_sse2_xvid.c

@@ -377,7 +377,7 @@ inline void ff_idct_xvid_sse2(short *block)
     JZ("%%esi", "1f")
     "5:                                                          \n\t"
     iMTX_MULT("7*16(%0)", MANGLE(iTab2), ROUND(walkenIdctRounders+5*16), PUT_ODD(ROW7))
-#if !ARCH_X86_64
+#if ARCH_X86_32
     iLLM_HEAD
 #endif
     iLLM_PASS("%0")