ref: 0ee525d6deff6f047bc152119dd74a0149b815f3
dir: /vp8/decoder/arm/detokenize.asm/
;
; Copyright (c) 2010 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_decode_mb_tokens_v6|
AREA |.text|, CODE, READONLY ; name this block of code
INCLUDE vpx_asm_offsets.asm
l_qcoeff EQU 0
l_i EQU 4
l_type EQU 8
l_stop EQU 12
l_c EQU 16
l_l_ptr EQU 20
l_a_ptr EQU 24
l_bc EQU 28
l_coef_ptr EQU 32
l_stacksize EQU 64
;; constant offsets -- these should be created at build time
c_block2above_offset EQU 25
c_entropy_nodes EQU 11
c_dct_eob_token EQU 11
|vp8_decode_mb_tokens_v6| PROC
stmdb sp!, {r4 - r11, lr}
sub sp, sp, #l_stacksize
mov r7, r1 ; type
mov r9, r0 ; detoken
ldr r1, [r9, #detok_current_bc]
ldr r0, [r9, #detok_qcoeff_start_ptr]
mov r11, #0 ; i
mov r3, #16 ; stop
cmp r7, #1 ; type ?= 1
addeq r11, r11, #24 ; i = 24
addeq r3, r3, #8 ; stop = 24
addeq r0, r0, #3, 24 ; qcoefptr += 24*16
str r0, [sp, #l_qcoeff]
str r11, [sp, #l_i]
str r7, [sp, #l_type]
str r3, [sp, #l_stop]
str r1, [sp, #l_bc]
add lr, r9, r7, lsl #2 ; detoken + type*4
ldr r8, [r1, #bool_decoder_user_buffer]
ldr r10, [lr, #detok_coef_probs]
ldr r5, [r1, #bool_decoder_count]
ldr r6, [r1, #bool_decoder_range]
ldr r4, [r1, #bool_decoder_value]
str r10, [sp, #l_coef_ptr]
BLOCK_LOOP
ldr r3, [r9, #detok_ptr_block2leftabove]
ldr r1, [r9, #detok_L]
ldr r2, [r9, #detok_A]
ldrb r12, [r3, r11]! ; block2left[i]
ldrb r3, [r3, #c_block2above_offset]; block2above[i]
cmp r7, #0 ; c = !type
moveq r7, #1
movne r7, #0
ldrb r0, [r1, r12]! ; *(L += block2left[i])
ldrb r3, [r2, r3]! ; *(A += block2above[i])
mov lr, #c_entropy_nodes ; ENTROPY_NODES = 11
; VP8_COMBINEENTROPYCONTETEXTS(t, *a, *l) => t = ((*a) != 0) + ((*l) !=0)
cmp r0, #0 ; *l ?= 0
movne r0, #1
cmp r3, #0 ; *a ?= 0
addne r0, r0, #1 ; t
str r1, [sp, #l_l_ptr] ; save &l
str r2, [sp, #l_a_ptr] ; save &a
smlabb r0, r0, lr, r10 ; Prob = coef_probs + (t * ENTROPY_NODES)
mov r1, #0 ; t = 0
str r7, [sp, #l_c]
;align 4
COEFF_LOOP
ldr r3, [r9, #detok_ptr_coef_bands_x]
ldr lr, [r9, #detok_coef_tree_ptr]
;STALL
ldrb r3, [r3, r7] ; coef_bands_x[c]
;STALL
;STALL
add r0, r0, r3 ; Prob += coef_bands_x[c]
get_token_loop
ldrb r2, [r0, +r1, asr #1] ; Prob[t >> 1]
mov r3, r6, lsl #8 ; range << 8
sub r3, r3, #256 ; (range << 8) - (1 << 8)
mov r10, #1 ; 1
smlawb r2, r3, r2, r10 ; split = 1 + (((range-1) * probability) >> 8)
ldrb r12, [r8] ; load cx data byte in stall slot : r8 = bufptr
;++
subs r3, r4, r2, lsl #24 ; value-(split<<24): used later to calculate shift for NORMALIZE
addhs r1, r1, #1 ; t += 1
movhs r4, r3 ; value -= bigsplit (split << 24)
subhs r2, r6, r2 ; range -= split
; movlo r6, r2 ; range = split
ldrsb r1, [lr, r1] ; t = onyx_coef_tree_ptr[t]
; NORMALIZE
clz r3, r2 ; vp8dx_bitreader_norm[range] + 24
sub r3, r3, #24 ; vp8dx_bitreader_norm[range]
subs r5, r5, r3 ; count -= shift
mov r6, r2, lsl r3 ; range <<= shift
mov r4, r4, lsl r3 ; value <<= shift
; if count <= 0, += BR_COUNT; value |= *bufptr++ << (BR_COUNT-count); BR_COUNT = 8, but need to upshift values by +16
addle r5, r5, #8 ; count += 8
rsble r3, r5, #24 ; 24 - count
addle r8, r8, #1 ; bufptr++
orrle r4, r4, r12, lsl r3 ; value |= *bufptr << shift + 16
cmp r1, #0 ; t ?= 0
bgt get_token_loop ; while (t > 0)
cmn r1, #c_dct_eob_token ; if(t == -DCT_EOB_TOKEN)
beq END_OF_BLOCK ; break
rsb lr, r1, #0 ; v = -t;
cmp lr, #4 ; if(v > FOUR_TOKEN)
ble SKIP_EXTRABITS
ldr r3, [r9, #detok_teb_base_ptr]
mov r11, #1 ; 1 in split = 1 + ... nope, v+= 1 << bits_count
add r7, r3, lr, lsl #4 ; detok_teb_base_ptr + (v << 4)
ldrsh lr, [r7, #tokenextrabits_min_val] ; v = teb_ptr->min_val
ldrsh r0, [r7, #tokenextrabits_length] ; bits_count = teb_ptr->Length
extrabits_loop
add r3, r0, r7 ; &teb_ptr->Probs[bits_count]
ldrb r2, [r3, #4] ; probability. why +4?
mov r3, r6, lsl #8 ; range << 8
sub r3, r3, #256 ; range << 8 + 1 << 8
smlawb r2, r3, r2, r11 ; split = 1 + (((range-1) * probability) >> 8)
ldrb r12, [r8] ; *bufptr
;++
subs r10, r4, r2, lsl #24 ; value - (split<<24)
movhs r4, r10 ; value = value - (split << 24)
subhs r2, r6, r2 ; range = range - split
addhs lr, lr, r11, lsl r0 ; v += ((UINT16)1<<bits_count)
; NORMALIZE
clz r3, r2 ; shift - leading zeros in split
sub r3, r3, #24 ; don't count first 3 bytes
subs r5, r5, r3 ; count -= shift
mov r6, r2, lsl r3 ; range = range << shift
mov r4, r4, lsl r3 ; value <<= shift
addle r5, r5, #8 ; count += BR_COUNT
addle r8, r8, #1 ; bufptr++
rsble r3, r5, #24 ; BR_COUNT - count
orrle r4, r4, r12, lsl r3 ; value |= *bufptr << (BR_COUNT - count)
subs r0, r0, #1 ; bits_count --
bpl extrabits_loop
SKIP_EXTRABITS
ldr r11, [sp, #l_qcoeff]
ldr r0, [sp, #l_coef_ptr] ; Prob = coef_probs
cmp r1, #0 ; check for nonzero token - if (t)
beq SKIP_EOB_CHECK ; if t is zero, we will skip the eob table chec
add r3, r6, #1 ; range + 1
mov r2, r3, lsr #1 ; split = (range + 1) >> 1
subs r3, r4, r2, lsl #24 ; value - (split<<24)
movhs r4, r3 ; value -= (split << 24)
subhs r2, r6, r2 ; range -= split
mvnhs r3, lr ; -v
addhs lr, r3, #1 ; v = (v ^ -1) + 1
; NORMALIZE
clz r3, r2 ; leading 0s in split
sub r3, r3, #24 ; shift
subs r5, r5, r3 ; count -= shift
mov r6, r2, lsl r3 ; range <<= shift
mov r4, r4, lsl r3 ; value <<= shift
ldrleb r2, [r8], #1 ; *(bufptr++)
addle r5, r5, #8 ; count += 8
rsble r3, r5, #24 ; BR_COUNT - count
orrle r4, r4, r2, lsl r3 ; value |= *bufptr << (BR_COUNT - count)
add r0, r0, #11 ; Prob += ENTROPY_NODES (11)
cmn r1, #1 ; t < -ONE_TOKEN
addlt r0, r0, #11 ; Prob += ENTROPY_NODES (11)
mvn r1, #1 ; t = -1 ???? C is -2
SKIP_EOB_CHECK
ldr r7, [sp, #l_c] ; c
ldr r3, [r9, #detok_scan]
add r1, r1, #2 ; t+= 2
cmp r7, #15 ; c should will be one higher
ldr r3, [r3, +r7, lsl #2] ; scan[c] this needs pre-inc c value
add r7, r7, #1 ; c++
add r3, r11, r3, lsl #1 ; qcoeff + scan[c]
str r7, [sp, #l_c] ; store c
strh lr, [r3] ; qcoef_ptr[scan[c]] = v
blt COEFF_LOOP
sub r7, r7, #1 ; if(t != -DCT_EOB_TOKEN) --c
END_OF_BLOCK
ldr r3, [sp, #l_type] ; type
ldr r10, [sp, #l_coef_ptr] ; coef_ptr
ldr r0, [sp, #l_qcoeff] ; qcoeff
ldr r11, [sp, #l_i] ; i
ldr r12, [sp, #l_stop] ; stop
cmp r3, #0 ; type ?= 0
moveq r1, #1
movne r1, #0
add r3, r11, r9 ; detok + i
cmp r7, r1 ; c ?= !type
strb r7, [r3, #detok_eob] ; eob[i] = c
ldr r7, [sp, #l_l_ptr] ; l
ldr r2, [sp, #l_a_ptr] ; a
movne r3, #1 ; t
moveq r3, #0
add r0, r0, #32 ; qcoeff += 32 (16 * 2?)
add r11, r11, #1 ; i++
strb r3, [r7] ; *l = t
strb r3, [r2] ; *a = t
str r0, [sp, #l_qcoeff] ; qcoeff
str r11, [sp, #l_i] ; i
cmp r11, r12 ; i < stop
ldr r7, [sp, #l_type] ; type
blt BLOCK_LOOP
cmp r11, #25 ; i ?= 25
bne ln2_decode_mb_to
ldr r12, [r9, #detok_qcoeff_start_ptr]
ldr r10, [r9, #detok_coef_probs]
mov r7, #0 ; type/i = 0
mov r3, #16 ; stop = 16
str r12, [sp, #l_qcoeff] ; qcoeff_ptr = qcoeff_start_ptr
str r7, [sp, #l_i]
str r7, [sp, #l_type]
str r3, [sp, #l_stop]
str r10, [sp, #l_coef_ptr] ; coef_probs = coef_probs[type=0]
b BLOCK_LOOP
ln2_decode_mb_to
cmp r11, #16 ; i ?= 16
bne ln1_decode_mb_to
mov r10, #detok_coef_probs
add r10, r10, #2*4 ; coef_probs[type]
ldr r10, [r9, r10] ; detok + detok_coef_probs[type]
mov r7, #2 ; type = 2
mov r3, #24 ; stop = 24
str r7, [sp, #l_type]
str r3, [sp, #l_stop]
str r10, [sp, #l_coef_ptr] ; coef_probs = coef_probs[type]
b BLOCK_LOOP
ln1_decode_mb_to
ldr r2, [sp, #l_bc]
mov r0, #0
nop
str r8, [r2, #bool_decoder_user_buffer]
str r5, [r2, #bool_decoder_count]
str r4, [r2, #bool_decoder_value]
str r6, [r2, #bool_decoder_range]
add sp, sp, #l_stacksize
ldmia sp!, {r4 - r11, pc}
ENDP ; |vp8_decode_mb_tokens_v6|
END