ref: 14bc7731996cd27f1d2193d2f841e92ae8fad703
dir: /vp8/encoder/arm/armv6/vp8_mse16x16_armv6.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 |vp8_mse16x16_armv6| ARM AREA ||.text||, CODE, READONLY, ALIGN=2 ; r0 unsigned char *src_ptr ; r1 int source_stride ; r2 unsigned char *ref_ptr ; r3 int recon_stride ; stack unsigned int *sse ; ;note: Based on vp8_variance16x16_armv6. In this function, sum is never used. ; So, we can remove this part of calculation. |vp8_mse16x16_armv6| PROC push {r4-r9, lr} pld [r0, r1, lsl #0] pld [r2, r3, lsl #0] mov r12, #16 ; set loop counter to 16 (=block height) mov r4, #0 ; initialize sse = 0 loop ; 1st 4 pixels ldr r5, [r0, #0x0] ; load 4 src pixels ldr r6, [r2, #0x0] ; load 4 ref pixels mov lr, #0 ; constant zero usub8 r8, r5, r6 ; calculate difference pld [r0, r1, lsl #1] sel r7, r8, lr ; select bytes with positive difference usub8 r9, r6, r5 ; calculate difference with reversed operands pld [r2, r3, lsl #1] sel r8, r9, lr ; select bytes with negative difference ; calculate partial sums usad8 r5, r7, lr ; calculate sum of positive differences usad8 r6, r8, lr ; calculate sum of negative differences orr r8, r8, r7 ; differences of all 4 pixels ldr r5, [r0, #0x4] ; load 4 src pixels ; calculate sse uxtb16 r6, r8 ; byte (two pixels) to halfwords uxtb16 r7, r8, ror #8 ; another two pixels to halfwords smlad r4, r6, r6, r4 ; dual signed multiply, add and accumulate (1) ; 2nd 4 pixels ldr r6, [r2, #0x4] ; load 4 ref pixels smlad r4, r7, r7, r4 ; dual signed multiply, add and accumulate (2) usub8 r8, r5, r6 ; calculate difference sel r7, r8, lr ; select bytes with positive difference usub8 r9, r6, r5 ; calculate difference with reversed operands sel r8, r9, lr ; select bytes with negative difference ; calculate partial sums usad8 r5, r7, lr ; calculate sum of positive differences usad8 r6, r8, lr ; calculate sum of negative differences orr r8, r8, r7 ; differences of all 4 pixels ldr r5, [r0, #0x8] ; load 4 src pixels ; calculate sse uxtb16 r6, r8 ; byte (two pixels) to halfwords uxtb16 r7, r8, ror #8 ; another two pixels to halfwords smlad r4, r6, r6, r4 ; dual signed multiply, add and accumulate (1) ; 3rd 4 pixels ldr r6, [r2, #0x8] ; load 4 ref pixels smlad r4, r7, r7, r4 ; dual signed multiply, add and accumulate (2) usub8 r8, r5, r6 ; calculate difference sel r7, r8, lr ; select bytes with positive difference usub8 r9, r6, r5 ; calculate difference with reversed operands sel r8, r9, lr ; select bytes with negative difference ; calculate partial sums usad8 r5, r7, lr ; calculate sum of positive differences usad8 r6, r8, lr ; calculate sum of negative differences orr r8, r8, r7 ; differences of all 4 pixels ldr r5, [r0, #0xc] ; load 4 src pixels ; calculate sse uxtb16 r6, r8 ; byte (two pixels) to halfwords uxtb16 r7, r8, ror #8 ; another two pixels to halfwords smlad r4, r6, r6, r4 ; dual signed multiply, add and accumulate (1) ; 4th 4 pixels ldr r6, [r2, #0xc] ; load 4 ref pixels smlad r4, r7, r7, r4 ; dual signed multiply, add and accumulate (2) usub8 r8, r5, r6 ; calculate difference add r0, r0, r1 ; set src_ptr to next row sel r7, r8, lr ; select bytes with positive difference usub8 r9, r6, r5 ; calculate difference with reversed operands add r2, r2, r3 ; set dst_ptr to next row sel r8, r9, lr ; select bytes with negative difference ; calculate partial sums usad8 r5, r7, lr ; calculate sum of positive differences usad8 r6, r8, lr ; calculate sum of negative differences orr r8, r8, r7 ; differences of all 4 pixels subs r12, r12, #1 ; next row ; calculate sse uxtb16 r6, r8 ; byte (two pixels) to halfwords uxtb16 r7, r8, ror #8 ; another two pixels to halfwords smlad r4, r6, r6, r4 ; dual signed multiply, add and accumulate (1) smlad r4, r7, r7, r4 ; dual signed multiply, add and accumulate (2) bne loop ; return stuff ldr r1, [sp, #28] ; get address of sse mov r0, r4 ; return sse str r4, [r1] ; store sse pop {r4-r9, pc} ENDP END