ref: 5cba6516aa020e420106d276bf2dbebc6b517e3f
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