replace a few mov + psrlq with pshufw, there are more cases which could benefit from this but they would require us to duplicate some functions ...

the trick is from various places (my own code in libpostproc, a patch on the x264 list, ...)

Originally committed as revision 4608 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/i386/dsputil_mmx.c

@@ -1621,11 +1621,9 @@ static int hadamard8_diff_mmx2(void *s, uint8_t *src1, uint8_t *src2, int stride
         "movq 64(%1), %%mm1		\n\t"
         MMABS_SUM_MMX2(%%mm1, %%mm7, %%mm0)
         
-        "movq %%mm0, %%mm1		\n\t"
-        "psrlq $32, %%mm0		\n\t"
+        "pshufw $0x0E, %%mm0, %%mm1     \n\t"
         "paddusw %%mm1, %%mm0		\n\t"
-        "movq %%mm0, %%mm1		\n\t"
-        "psrlq $16, %%mm0		\n\t"
+        "pshufw $0x01, %%mm0, %%mm1     \n\t"
         "paddusw %%mm1, %%mm0		\n\t"
         "movd %%mm0, %0			\n\t"
                 

libavcodec/i386/mpegvideo_mmx_template.c

@@ -22,7 +22,11 @@
 #ifdef HAVE_MMX2
 #define SPREADW(a) "pshufw $0, " #a ", " #a " \n\t"
 #define PMAXW(a,b) "pmaxsw " #a ", " #b " \n\t"
-
+#define PMAX(a,b) \
+            "pshufw $0x0E," #a ", " #b "		\n\t"\
+	    PMAXW(b, a)\
+            "pshufw $0x01," #a ", " #b "		\n\t"\
+	    PMAXW(b, a)
 #else
 #define SPREADW(a) \
 	"punpcklwd " #a ", " #a " \n\t"\
@@ -30,6 +34,14 @@
 #define PMAXW(a,b) \
 	"psubusw " #a ", " #b " \n\t"\
 	"paddw " #a ", " #b " \n\t"
+#define PMAX(a,b)  \
+            "movq " #a ", " #b "		\n\t"\
+            "psrlq $32, " #a "			\n\t"\
+	    PMAXW(b, a)\
+            "movq " #a ", " #b "		\n\t"\
+            "psrlq $16, " #a "			\n\t"\
+	    PMAXW(b, a)
+
 #endif
 
 static int RENAME(dct_quantize)(MpegEncContext *s,
@@ -119,12 +131,7 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
 	    PMAXW(%%mm0, %%mm3)
             "add $8, %%"REG_a"			\n\t"
             " js 1b				\n\t"
-            "movq %%mm3, %%mm0			\n\t"
-            "psrlq $32, %%mm3			\n\t"
-	    PMAXW(%%mm0, %%mm3)
-            "movq %%mm3, %%mm0			\n\t"
-            "psrlq $16, %%mm3			\n\t"
-	    PMAXW(%%mm0, %%mm3)
+	    PMAX(%%mm3, %%mm0)
             "movd %%mm3, %%"REG_a"		\n\t"
             "movzb %%al, %%"REG_a"		\n\t" // last_non_zero_p1
 	    : "+a" (last_non_zero_p1)
@@ -170,12 +177,7 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
 	    PMAXW(%%mm0, %%mm3)
             "add $8, %%"REG_a"			\n\t"
             " js 1b				\n\t"
-            "movq %%mm3, %%mm0			\n\t"
-            "psrlq $32, %%mm3			\n\t"
-	    PMAXW(%%mm0, %%mm3)
-            "movq %%mm3, %%mm0			\n\t"
-            "psrlq $16, %%mm3			\n\t"
-	    PMAXW(%%mm0, %%mm3)
+	    PMAX(%%mm3, %%mm0)
             "movd %%mm3, %%"REG_a"		\n\t"
             "movzb %%al, %%"REG_a"		\n\t" // last_non_zero_p1
 	    : "+a" (last_non_zero_p1)