x86: Add and use more convenience macros to check CPU extension availability

libavutil/x86/cpu.h

@@ -26,6 +26,19 @@
 #define AV_CPU_FLAG_AMD3DNOW    AV_CPU_FLAG_3DNOW
 #define AV_CPU_FLAG_AMD3DNOWEXT AV_CPU_FLAG_3DNOWEXT
 
+#define X86_AMD3DNOW(flags)         CPUEXT(flags, AMD3DNOW)
+#define X86_AMD3DNOWEXT(flags)      CPUEXT(flags, AMD3DNOWEXT)
+#define X86_MMX(flags)              CPUEXT(flags, MMX)
+#define X86_MMXEXT(flags)           CPUEXT(flags, MMXEXT)
+#define X86_SSE(flags)              CPUEXT(flags, SSE)
+#define X86_SSE2(flags)             CPUEXT(flags, SSE2)
+#define X86_SSE3(flags)             CPUEXT(flags, SSE3)
+#define X86_SSSE3(flags)            CPUEXT(flags, SSSE3)
+#define X86_SSE4(flags)             CPUEXT(flags, SSE4)
+#define X86_SSE42(flags)            CPUEXT(flags, SSE42)
+#define X86_AVX(flags)              CPUEXT(flags, AVX)
+#define X86_FMA4(flags)             CPUEXT(flags, FMA4)
+
 #define EXTERNAL_AMD3DNOW(flags)    CPUEXT_SUFFIX(flags, _EXTERNAL, AMD3DNOW)
 #define EXTERNAL_AMD3DNOWEXT(flags) CPUEXT_SUFFIX(flags, _EXTERNAL, AMD3DNOWEXT)
 #define EXTERNAL_MMX(flags)         CPUEXT_SUFFIX(flags, _EXTERNAL, MMX)

libswscale/utils.c

@@ -1120,8 +1120,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
         } else
 #endif /* HAVE_MMXEXT_INLINE */
         {
-            const int filterAlign =
-                (HAVE_MMX && cpu_flags & AV_CPU_FLAG_MMX) ? 4 :
+            const int filterAlign = X86_MMX(cpu_flags)     ? 4 :
                                     PPC_ALTIVEC(cpu_flags) ? 8 : 1;
 
             if (initFilter(&c->hLumFilter, &c->hLumFilterPos,
@@ -1143,8 +1142,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
 
     /* precalculate vertical scaler filter coefficients */
     {
-        const int filterAlign =
-            (HAVE_MMX && cpu_flags & AV_CPU_FLAG_MMX) ? 2 :
+        const int filterAlign = X86_MMX(cpu_flags)     ? 2 :
                                 PPC_ALTIVEC(cpu_flags) ? 8 : 1;
 
         if (initFilter(&c->vLumFilter, &c->vLumFilterPos, &c->vLumFilterSize,