ref: 14bc7731996cd27f1d2193d2f841e92ae8fad703
dir: /vp8/encoder/arm/armv6/vp8_fast_quantize_b_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_fast_quantize_b_armv6| INCLUDE vp8_asm_enc_offsets.asm ARM REQUIRE8 PRESERVE8 AREA ||.text||, CODE, READONLY, ALIGN=2 ; r0 BLOCK *b ; r1 BLOCKD *d |vp8_fast_quantize_b_armv6| PROC stmfd sp!, {r1, r4-r11, lr} ldr r3, [r0, #vp8_block_coeff] ; coeff ldr r4, [r0, #vp8_block_quant_fast] ; quant_fast ldr r5, [r0, #vp8_block_round] ; round ldr r6, [r1, #vp8_blockd_qcoeff] ; qcoeff ldr r7, [r1, #vp8_blockd_dqcoeff] ; dqcoeff ldr r8, [r1, #vp8_blockd_dequant] ; dequant ldr r2, loop_count ; loop_count=0x1000000. 'lsls' instruction ; is used to update the counter so that ; it can be used to mark nonzero ; quantized coefficient pairs. mov r1, #0 ; flags for quantized coeffs ; PART 1: quantization and dequantization loop loop ldr r9, [r3], #4 ; [z1 | z0] ldr r10, [r5], #4 ; [r1 | r0] ldr r11, [r4], #4 ; [q1 | q0] ssat16 lr, #1, r9 ; [sz1 | sz0] eor r9, r9, lr ; [z1 ^ sz1 | z0 ^ sz0] ssub16 r9, r9, lr ; x = (z ^ sz) - sz sadd16 r9, r9, r10 ; [x1+r1 | x0+r0] ldr r12, [r3], #4 ; [z3 | z2] smulbb r0, r9, r11 ; [(x0+r0)*q0] smultt r9, r9, r11 ; [(x1+r1)*q1] ldr r10, [r5], #4 ; [r3 | r2] ssat16 r11, #1, r12 ; [sz3 | sz2] eor r12, r12, r11 ; [z3 ^ sz3 | z2 ^ sz2] pkhtb r0, r9, r0, asr #16 ; [y1 | y0] ldr r9, [r4], #4 ; [q3 | q2] ssub16 r12, r12, r11 ; x = (z ^ sz) - sz sadd16 r12, r12, r10 ; [x3+r3 | x2+r2] eor r0, r0, lr ; [(y1 ^ sz1) | (y0 ^ sz0)] smulbb r10, r12, r9 ; [(x2+r2)*q2] smultt r12, r12, r9 ; [(x3+r3)*q3] ssub16 r0, r0, lr ; x = (y ^ sz) - sz cmp r0, #0 ; check if zero orrne r1, r1, r2, lsr #24 ; add flag for nonzero coeffs str r0, [r6], #4 ; *qcoeff++ = x ldr r9, [r8], #4 ; [dq1 | dq0] pkhtb r10, r12, r10, asr #16 ; [y3 | y2] eor r10, r10, r11 ; [(y3 ^ sz3) | (y2 ^ sz2)] ssub16 r10, r10, r11 ; x = (y ^ sz) - sz cmp r10, #0 ; check if zero orrne r1, r1, r2, lsr #23 ; add flag for nonzero coeffs str r10, [r6], #4 ; *qcoeff++ = x ldr r11, [r8], #4 ; [dq3 | dq2] smulbb r12, r0, r9 ; [x0*dq0] smultt r0, r0, r9 ; [x1*dq1] smulbb r9, r10, r11 ; [x2*dq2] smultt r10, r10, r11 ; [x3*dq3] lsls r2, r2, #2 ; update loop counter strh r12, [r7, #0] ; dqcoeff[0] = [x0*dq0] strh r0, [r7, #2] ; dqcoeff[1] = [x1*dq1] strh r9, [r7, #4] ; dqcoeff[2] = [x2*dq2] strh r10, [r7, #6] ; dqcoeff[3] = [x3*dq3] add r7, r7, #8 ; dqcoeff += 8 bne loop ; PART 2: check position for eob... ldr r11, [sp, #0] ; restore BLOCKD pointer mov lr, #0 ; init eob cmp r1, #0 ; coeffs after quantization? ldr r12, [r11, #vp8_blockd_eob] beq end ; skip eob calculations if all zero ldr r0, [r11, #vp8_blockd_qcoeff] ; check shortcut for nonzero qcoeffs tst r1, #0x80 bne quant_coeff_15_14 tst r1, #0x20 bne quant_coeff_13_11 tst r1, #0x8 bne quant_coeff_12_7 tst r1, #0x40 bne quant_coeff_10_9 tst r1, #0x10 bne quant_coeff_8_3 tst r1, #0x2 bne quant_coeff_6_5 tst r1, #0x4 bne quant_coeff_4_2 b quant_coeff_1_0 quant_coeff_15_14 ldrh r2, [r0, #30] ; rc=15, i=15 mov lr, #16 cmp r2, #0 bne end ldrh r3, [r0, #28] ; rc=14, i=14 mov lr, #15 cmp r3, #0 bne end quant_coeff_13_11 ldrh r2, [r0, #22] ; rc=11, i=13 mov lr, #14 cmp r2, #0 bne end quant_coeff_12_7 ldrh r3, [r0, #14] ; rc=7, i=12 mov lr, #13 cmp r3, #0 bne end ldrh r2, [r0, #20] ; rc=10, i=11 mov lr, #12 cmp r2, #0 bne end quant_coeff_10_9 ldrh r3, [r0, #26] ; rc=13, i=10 mov lr, #11 cmp r3, #0 bne end ldrh r2, [r0, #24] ; rc=12, i=9 mov lr, #10 cmp r2, #0 bne end quant_coeff_8_3 ldrh r3, [r0, #18] ; rc=9, i=8 mov lr, #9 cmp r3, #0 bne end ldrh r2, [r0, #12] ; rc=6, i=7 mov lr, #8 cmp r2, #0 bne end quant_coeff_6_5 ldrh r3, [r0, #6] ; rc=3, i=6 mov lr, #7 cmp r3, #0 bne end ldrh r2, [r0, #4] ; rc=2, i=5 mov lr, #6 cmp r2, #0 bne end quant_coeff_4_2 ldrh r3, [r0, #10] ; rc=5, i=4 mov lr, #5 cmp r3, #0 bne end ldrh r2, [r0, #16] ; rc=8, i=3 mov lr, #4 cmp r2, #0 bne end ldrh r3, [r0, #8] ; rc=4, i=2 mov lr, #3 cmp r3, #0 bne end quant_coeff_1_0 ldrh r2, [r0, #2] ; rc=1, i=1 mov lr, #2 cmp r2, #0 bne end mov lr, #1 ; rc=0, i=0 end strb lr, [r12] ldmfd sp!, {r1, r4-r11, pc} ENDP loop_count DCD 0x1000000 END