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@********************************************************************
@* *
@* THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
@* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
@* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
@* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
@* *
@* THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2010 *
@* *
@********************************************************************
@
@ function:
@ last mod: $Id$
@
@********************************************************************
.text; .p2align 2
.global oc_pack_read_arm
.global oc_pack_read1_arm
.global oc_huff_token_decode_arm
.type oc_pack_read1_arm, %function; oc_pack_read1_arm: @ PROC
@ r0 = oc_pack_buf *_b
ADD r12,r0,#8
LDMIA r12,{r2,r3} @ r2 = window
@ Stall... ; r3 = available
@ Stall...
SUBS r3,r3,#1 @ r3 = available-1, available<1 => LT
BLT oc_pack_read1_refill
MOV r0,r2,LSR #31 @ r0 = window>>31
MOV r2,r2,LSL #1 @ r2 = window<<=1
STMIA r12,{r2,r3} @ window = r2
@ available = r3
MOV PC,r14
.size oc_pack_read1_arm, .-oc_pack_read1_arm @ ENDP
.type oc_pack_read_arm, %function; oc_pack_read_arm: @ PROC
@ r0 = oc_pack_buf *_b
@ r1 = int _bits
ADD r12,r0,#8
LDMIA r12,{r2,r3} @ r2 = window
@ Stall... ; r3 = available
@ Stall...
SUBS r3,r3,r1 @ r3 = available-_bits, available<_bits => LT
BLT oc_pack_read_refill
RSB r0,r1,#32 @ r0 = 32-_bits
MOV r0,r2,LSR r0 @ r0 = window>>32-_bits
MOV r2,r2,LSL r1 @ r2 = window<<=_bits
STMIA r12,{r2,r3} @ window = r2
@ available = r3
MOV PC,r14
@ We need to refill window.
oc_pack_read1_refill:
MOV r1,#1
oc_pack_read_refill:
STMFD r13!,{r10,r11,r14}
LDMIA r0,{r10,r11} @ r10 = stop
@ r11 = ptr
RSB r0,r1,#32 @ r0 = 32-_bits
RSB r3,r3,r0 @ r3 = 32-available
@ We can use unsigned compares for both the pointers and for available
@ (allowing us to chain condition codes) because available will never be
@ larger than 32 (or we wouldn't be here), and thus 32-available will never be
@ negative.
CMP r10,r11 @ ptr<stop => HI
CMPHI r3,#7 @ available<=24 => HI
LDRBHI r14,[r11],#1 @ r14 = *ptr++
SUBHI r3,#8 @ available += 8
@ (HI) Stall...
ORRHI r2,r2,r14,LSL r3 @ r2 = window|=r14<<32-available
CMPHI r10,r11 @ ptr<stop => HI
CMPHI r3,#7 @ available<=24 => HI
LDRBHI r14,[r11],#1 @ r14 = *ptr++
SUBHI r3,#8 @ available += 8
@ (HI) Stall...
ORRHI r2,r2,r14,LSL r3 @ r2 = window|=r14<<32-available
CMPHI r10,r11 @ ptr<stop => HI
CMPHI r3,#7 @ available<=24 => HI
LDRBHI r14,[r11],#1 @ r14 = *ptr++
SUBHI r3,#8 @ available += 8
@ (HI) Stall...
ORRHI r2,r2,r14,LSL r3 @ r2 = window|=r14<<32-available
CMPHI r10,r11 @ ptr<stop => HI
CMPHI r3,#7 @ available<=24 => HI
LDRBHI r14,[r11],#1 @ r14 = *ptr++
SUBHI r3,#8 @ available += 8
@ (HI) Stall...
ORRHI r2,r2,r14,LSL r3 @ r2 = window|=r14<<32-available
SUBS r3,r0,r3 @ r3 = available-=_bits, available<bits => GT
BLT oc_pack_read_refill_last
MOV r0,r2,LSR r0 @ r0 = window>>32-_bits
MOV r2,r2,LSL r1 @ r2 = window<<=_bits
STR r11,[r12,#-4] @ ptr = r11
STMIA r12,{r2,r3} @ window = r2
@ available = r3
LDMFD r13!,{r10,r11,PC}
@ Either we wanted to read more than 24 bits and didn't have enough room to
@ stuff the last byte into the window, or we hit the end of the packet.
oc_pack_read_refill_last:
CMP r11,r10 @ ptr<stop => LO
@ If we didn't hit the end of the packet, then pull enough of the next byte to
@ to fill up the window.
LDRBLO r14,[r11] @ (LO) r14 = *ptr
@ Otherwise, set the EOF flag and pretend we have lots of available bits.
MOVHS r14,#1 @ (HS) r14 = 1
ADDLO r10,r3,r1 @ (LO) r10 = available
STRHS r14,[r12,#8] @ (HS) eof = 1
ANDLO r10,r10,#7 @ (LO) r10 = available0x7
MOVHS r3,#1<<30 @ (HS) available = OC_LOTS_OF_BITS
ORRLO r2,r2,r14,LSL r10 @ (LO) r2 = window|=*ptr>>(available0x7)
MOV r0,r2,LSR r0 @ r0 = window>>32-_bits
MOV r2,r2,LSL r1 @ r2 = window<<=_bits
STR r11,[r12,#-4] @ ptr = r11
STMIA r12,{r2,r3} @ window = r2
@ available = r3
LDMFD r13!,{r10,r11,PC}
.size oc_pack_read_arm, .-oc_pack_read_arm @ ENDP
.type oc_huff_token_decode_arm, %function; oc_huff_token_decode_arm: @ PROC
@ r0 = oc_pack_buf *_b
@ r1 = const ogg_int16_t *_tree
STMFD r13!,{r4,r5,r10,r14}
LDRSH r10,[r1] @ r10 = n=_tree[0]
LDMIA r0,{r2-r5} @ r2 = stop
@ Stall... ; r3 = ptr
@ Stall... ; r4 = window
@ r5 = available
CMP r10,r5 @ n>available => GT
BGT oc_huff_token_decode_refill0
RSB r14,r10,#32 @ r14 = 32-n
MOV r14,r4,LSR r14 @ r14 = bits=window>>32-n
ADD r14,r1,r14,LSL #1 @ r14 = _tree+bits
LDRSH r12,[r14,#2] @ r12 = node=_tree[1+bits]
@ Stall...
@ Stall...
RSBS r14,r12,#0 @ r14 = -node, node>0 => MI
BMI oc_huff_token_decode_continue
MOV r10,r14,LSR #8 @ r10 = n=node>>8
MOV r4,r4,LSL r10 @ r4 = window<<=n
SUB r5,r10 @ r5 = available-=n
STMIB r0,{r3-r5} @ ptr = r3
@ window = r4
@ available = r5
AND r0,r14,#255 @ r0 = node0x255
LDMFD r13!,{r4,r5,r10,pc}
@ The first tree node wasn't enough to reach a leaf, read another
oc_huff_token_decode_continue:
ADD r12,r1,r12,LSL #1 @ r12 = _tree+node
MOV r4,r4,LSL r10 @ r4 = window<<=n
SUB r5,r5,r10 @ r5 = available-=n
LDRSH r10,[r12],#2 @ r10 = n=_tree[node]
@ Stall... ; r12 = _tree+node+1
@ Stall...
CMP r10,r5 @ n>available => GT
BGT oc_huff_token_decode_refill
RSB r14,r10,#32 @ r14 = 32-n
MOV r14,r4,LSR r14 @ r14 = bits=window>>32-n
ADD r12,r12,r14 @
LDRSH r12,[r12,r14] @ r12 = node=_tree[node+1+bits]
@ Stall...
@ Stall...
RSBS r14,r12,#0 @ r14 = -node, node>0 => MI
BMI oc_huff_token_decode_continue
MOV r10,r14,LSR #8 @ r10 = n=node>>8
MOV r4,r4,LSL r10 @ r4 = window<<=n
SUB r5,r10 @ r5 = available-=n
STMIB r0,{r3-r5} @ ptr = r3
@ window = r4
@ available = r5
AND r0,r14,#255 @ r0 = node0x255
LDMFD r13!,{r4,r5,r10,pc}
oc_huff_token_decode_refill0:
ADD r12,r1,#2 @ r12 = _tree+1
oc_huff_token_decode_refill:
@ We can't possibly need more than 15 bits, so available must be <= 15.
@ Therefore we can load at least two bytes without checking it.
CMP r2,r3 @ ptr<stop => HI
LDRBHI r14,[r3],#1 @ r14 = *ptr++
RSBHI r5,r5,#24 @ (HI) available = 32-(available+=8)
RSBLS r5,r5,#32 @ (LS) r5 = 32-available
ORRHI r4,r4,r14,LSL r5 @ r4 = window|=r14<<32-available
CMPHI r2,r3 @ ptr<stop => HI
LDRBHI r14,[r3],#1 @ r14 = *ptr++
SUBHI r5,#8 @ available += 8
@ (HI) Stall...
ORRHI r4,r4,r14,LSL r5 @ r4 = window|=r14<<32-available
@ We can use unsigned compares for both the pointers and for available
@ (allowing us to chain condition codes) because available will never be
@ larger than 32 (or we wouldn't be here), and thus 32-available will never be
@ negative.
CMPHI r2,r3 @ ptr<stop => HI
CMPHI r5,#7 @ available<=24 => HI
LDRBHI r14,[r3],#1 @ r14 = *ptr++
SUBHI r5,#8 @ available += 8
@ (HI) Stall...
ORRHI r4,r4,r14,LSL r5 @ r4 = window|=r14<<32-available
CMP r2,r3 @ ptr<stop => HI
MOVLS r5,#-1<<30 @ (LS) available = OC_LOTS_OF_BITS+32
CMPHI r5,#7 @ (HI) available<=24 => HI
LDRBHI r14,[r3],#1 @ (HI) r14 = *ptr++
SUBHI r5,#8 @ (HI) available += 8
@ (HI) Stall...
ORRHI r4,r4,r14,LSL r5 @ (HI) r4 = window|=r14<<32-available
RSB r14,r10,#32 @ r14 = 32-n
MOV r14,r4,LSR r14 @ r14 = bits=window>>32-n
ADD r12,r12,r14 @
LDRSH r12,[r12,r14] @ r12 = node=_tree[node+1+bits]
RSB r5,r5,#32 @ r5 = available
@ Stall...
RSBS r14,r12,#0 @ r14 = -node, node>0 => MI
BMI oc_huff_token_decode_continue
MOV r10,r14,LSR #8 @ r10 = n=node>>8
MOV r4,r4,LSL r10 @ r4 = window<<=n
SUB r5,r10 @ r5 = available-=n
STMIB r0,{r3-r5} @ ptr = r3
@ window = r4
@ available = r5
AND r0,r14,#255 @ r0 = node0x255
LDMFD r13!,{r4,r5,r10,pc}
.size oc_huff_token_decode_arm, .-oc_huff_token_decode_arm @ ENDP
@ END
.section .note.GNU-stack,"",%progbits