[x265] [PATCH] asm: assembly code for pixel_sad_12x16

[chen]

+%macro PROCESS_SAD_12x4 0
+    movu    m1,  [r2]
+    movu    m2,  [r0]
+    pand    m1,  m4
+    pand    m2,  m4
+    psadbw  m1,  m2
+    paddd   m0,  m1
+    lea     r2,  [r2 + r3]
+    lea     r0,  [r0 + r1]
+    movu    m1,  [r2]
+    movu    m2,  [r0]
+    pand    m1,  m4
+    pand    m2,  m4
+    psadbw  m1,  m2
+    paddd   m0,  m1
>>+    lea     r2,  [r2 + r3]
>>+    lea     r0,  [r0 + r1]
>>+    movu    m1,  [r2]
>>+    movu    m2,  [r0]


we don't need to load address every time when we are adding stride to it. we should try to calculate address first using multiply by 1, 2, 4, or 8 if it not the case then we should load it.
 like above four instruction can be replaced with these two only.


movu    m1,  [r2 + 2 * r3]
movu    m2,  [r0 + 2 * r1]


+    pand    m1,  m4
+    pand    m2,  m4
+    psadbw  m1,  m2
+    paddd   m0,  m1
+    lea     r2,  [r2 + r3]
+    lea     r0,  [r0 + r1]
+    movu    m1,  [r2]
+    movu    m2,  [r0]
+    pand    m1,  m4
+    pand    m2,  m4
+    psadbw  m1,  m2
+    paddd   m0,  m1
+%endmacro
+
 %macro PROCESS_SAD_16x4 0
     movu    m1,  [r2]
     movu    m2,  [r2 + r3]
@@ -1007,6 +1041,29 @@
     movd    eax, m0
     RET

+;-----------------------------------------------------------------------------
+; int pixel_sad_12x16( uint8_t *, intptr_t, uint8_t *, intptr_t )
+;-----------------------------------------------------------------------------
+cglobal pixel_sad_12x16, 4,4,4
+    mova  m4,  [MSK]
+    pxor  m0,  m0
+
+    PROCESS_SAD_12x4
+    lea         r2,  [r2 + r3]
+    lea         r0,  [r0 + r1]
+    PROCESS_SAD_12x4
+    lea         r2,  [r2 + r3]
+    lea         r0,  [r0 + r1]
+    PROCESS_SAD_12x4
+    lea         r2,  [r2 + r3]
+    lea         r0,  [r0 + r1]
+    PROCESS_SAD_12x4
+
+    movhlps m1,  m0
+    paddd   m0,  m1
+    movd    eax, m0
+    RET
+
 %endmacro


overuse of lea  instruction please eliminate them, use available registers to save loads operations.

Excuse me, I forgot something, for 12xN, use MOVQ+MOVD is better than MOVU+PAND
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