ref: 9a62ecbd352edc1a75f2b5c8dbfb9ca60efb812c
dir: /vpx_dsp/arm/sad_media.asm/
;
; Copyright (c) 2011 The WebM project authors. All Rights Reserved.
;
; Use of this source code is governed by a BSD-style license
; that can be found in the LICENSE file in the root of the source
; tree. An additional intellectual property rights grant can be found
; in the file PATENTS. All contributing project authors may
; be found in the AUTHORS file in the root of the source tree.
;
EXPORT |vpx_sad16x16_media|
ARM
REQUIRE8
PRESERVE8
AREA ||.text||, CODE, READONLY, ALIGN=2
; r0 const unsigned char *src_ptr
; r1 int src_stride
; r2 const unsigned char *ref_ptr
; r3 int ref_stride
|vpx_sad16x16_media| PROC
stmfd sp!, {r4-r12, lr}
pld [r0, r1, lsl #0]
pld [r2, r3, lsl #0]
pld [r0, r1, lsl #1]
pld [r2, r3, lsl #1]
mov r4, #0 ; sad = 0;
mov r5, #8 ; loop count
loop
; 1st row
ldr r6, [r0, #0x0] ; load 4 src pixels (1A)
ldr r8, [r2, #0x0] ; load 4 ref pixels (1A)
ldr r7, [r0, #0x4] ; load 4 src pixels (1A)
ldr r9, [r2, #0x4] ; load 4 ref pixels (1A)
ldr r10, [r0, #0x8] ; load 4 src pixels (1B)
ldr r11, [r0, #0xC] ; load 4 src pixels (1B)
usada8 r4, r8, r6, r4 ; calculate sad for 4 pixels
usad8 r8, r7, r9 ; calculate sad for 4 pixels
ldr r12, [r2, #0x8] ; load 4 ref pixels (1B)
ldr lr, [r2, #0xC] ; load 4 ref pixels (1B)
add r0, r0, r1 ; set src pointer to next row
add r2, r2, r3 ; set dst pointer to next row
pld [r0, r1, lsl #1]
pld [r2, r3, lsl #1]
usada8 r4, r10, r12, r4 ; calculate sad for 4 pixels
usada8 r8, r11, lr, r8 ; calculate sad for 4 pixels
ldr r6, [r0, #0x0] ; load 4 src pixels (2A)
ldr r7, [r0, #0x4] ; load 4 src pixels (2A)
add r4, r4, r8 ; add partial sad values
; 2nd row
ldr r8, [r2, #0x0] ; load 4 ref pixels (2A)
ldr r9, [r2, #0x4] ; load 4 ref pixels (2A)
ldr r10, [r0, #0x8] ; load 4 src pixels (2B)
ldr r11, [r0, #0xC] ; load 4 src pixels (2B)
usada8 r4, r6, r8, r4 ; calculate sad for 4 pixels
usad8 r8, r7, r9 ; calculate sad for 4 pixels
ldr r12, [r2, #0x8] ; load 4 ref pixels (2B)
ldr lr, [r2, #0xC] ; load 4 ref pixels (2B)
add r0, r0, r1 ; set src pointer to next row
add r2, r2, r3 ; set dst pointer to next row
usada8 r4, r10, r12, r4 ; calculate sad for 4 pixels
usada8 r8, r11, lr, r8 ; calculate sad for 4 pixels
pld [r0, r1, lsl #1]
pld [r2, r3, lsl #1]
subs r5, r5, #1 ; decrement loop counter
add r4, r4, r8 ; add partial sad values
bne loop
mov r0, r4 ; return sad
ldmfd sp!, {r4-r12, pc}
ENDP
END