; ; 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_variance_halfpixvar16x16_h_media| ARM REQUIRE8 PRESERVE8 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 |vpx_variance_halfpixvar16x16_h_media| PROC stmfd sp!, {r4-r12, lr} pld [r0, r1, lsl #0] pld [r2, r3, lsl #0] mov r8, #0 ; initialize sum = 0 ldr r10, c80808080 mov r11, #0 ; initialize sse = 0 mov r12, #16 ; set loop counter to 16 (=block height) mov lr, #0 ; constant zero loop ; 1st 4 pixels ldr r4, [r0, #0] ; load 4 src pixels ldr r6, [r0, #1] ; load 4 src pixels with 1 byte offset ldr r5, [r2, #0] ; load 4 ref pixels ; bilinear interpolation mvn r6, r6 uhsub8 r4, r4, r6 eor r4, r4, r10 usub8 r6, r4, r5 ; calculate difference pld [r0, r1, lsl #1] sel r7, r6, lr ; select bytes with positive difference usub8 r6, r5, r4 ; calculate difference with reversed operands pld [r2, r3, lsl #1] sel r6, r6, lr ; select bytes with negative difference ; calculate partial sums usad8 r4, r7, lr ; calculate sum of positive differences usad8 r5, r6, lr ; calculate sum of negative differences orr r6, r6, r7 ; differences of all 4 pixels ; calculate total sum adds r8, r8, r4 ; add positive differences to sum subs r8, r8, r5 ; subtract negative differences from sum ; calculate sse uxtb16 r5, r6 ; byte (two pixels) to halfwords uxtb16 r7, r6, ror #8 ; another two pixels to halfwords smlad r11, r5, r5, r11 ; dual signed multiply, add and accumulate (1) ; 2nd 4 pixels ldr r4, [r0, #4] ; load 4 src pixels ldr r6, [r0, #5] ; load 4 src pixels with 1 byte offset ldr r5, [r2, #4] ; load 4 ref pixels ; bilinear interpolation mvn r6, r6 uhsub8 r4, r4, r6 eor r4, r4, r10 smlad r11, r7, r7, r11 ; dual signed multiply, add and accumulate (2) usub8 r6, r4, r5 ; calculate difference sel r7, r6, lr ; select bytes with positive difference usub8 r6, r5, r4 ; calculate difference with reversed operands sel r6, r6, lr ; select bytes with negative difference ; calculate partial sums usad8 r4, r7, lr ; calculate sum of positive differences usad8 r5, r6, lr ; calculate sum of negative differences orr r6, r6, r7 ; differences of all 4 pixels ; calculate total sum add r8, r8, r4 ; add positive differences to sum sub r8, r8, r5 ; subtract negative differences from sum ; calculate sse uxtb16 r5, r6 ; byte (two pixels) to halfwords uxtb16 r7, r6, ror #8 ; another two pixels to halfwords smlad r11, r5, r5, r11 ; dual signed multiply, add and accumulate (1) ; 3rd 4 pixels ldr r4, [r0, #8] ; load 4 src pixels ldr r6, [r0, #9] ; load 4 src pixels with 1 byte offset ldr r5, [r2, #8] ; load 4 ref pixels ; bilinear interpolation mvn r6, r6 uhsub8 r4, r4, r6 eor r4, r4, r10 smlad r11, r7, r7, r11 ; dual signed multiply, add and accumulate (2) usub8 r6, r4, r5 ; calculate difference sel r7, r6, lr ; select bytes with positive difference usub8 r6, r5, r4 ; calculate difference with reversed operands sel r6, r6, lr ; select bytes with negative difference ; calculate partial sums usad8 r4, r7, lr ; calculate sum of positive differences usad8 r5, r6, lr ; calculate sum of negative differences orr r6, r6, r7 ; differences of all 4 pixels ; calculate total sum add r8, r8, r4 ; add positive differences to sum sub r8, r8, r5 ; subtract negative differences from sum ; calculate sse uxtb16 r5, r6 ; byte (two pixels) to halfwords uxtb16 r7, r6, ror #8 ; another two pixels to halfwords smlad r11, r5, r5, r11 ; dual signed multiply, add and accumulate (1) ; 4th 4 pixels ldr r4, [r0, #12] ; load 4 src pixels ldr r6, [r0, #13] ; load 4 src pixels with 1 byte offset ldr r5, [r2, #12] ; load 4 ref pixels ; bilinear interpolation mvn r6, r6 uhsub8 r4, r4, r6 eor r4, r4, r10 smlad r11, r7, r7, r11 ; dual signed multiply, add and accumulate (2) usub8 r6, r4, r5 ; calculate difference add r0, r0, r1 ; set src_ptr to next row sel r7, r6, lr ; select bytes with positive difference usub8 r6, r5, r4 ; calculate difference with reversed operands add r2, r2, r3 ; set dst_ptr to next row sel r6, r6, lr ; select bytes with negative difference ; calculate partial sums usad8 r4, r7, lr ; calculate sum of positive differences usad8 r5, r6, lr ; calculate sum of negative differences orr r6, r6, r7 ; differences of all 4 pixels ; calculate total sum add r8, r8, r4 ; add positive differences to sum sub r8, r8, r5 ; subtract negative differences from sum ; calculate sse uxtb16 r5, r6 ; byte (two pixels) to halfwords uxtb16 r7, r6, ror #8 ; another two pixels to halfwords smlad r11, r5, r5, r11 ; dual signed multiply, add and accumulate (1) smlad r11, r7, r7, r11 ; dual signed multiply, add and accumulate (2) subs r12, r12, #1 bne loop ; return stuff ldr r6, [sp, #40] ; get address of sse mul r0, r8, r8 ; sum * sum str r11, [r6] ; store sse sub r0, r11, r0, lsr #8 ; return (sse - ((sum * sum) >> 8)) ldmfd sp!, {r4-r12, pc} ENDP c80808080 DCD 0x80808080 END