Tremolo (an ARM optimised version of the Tremor library for doing Ogg Vorbis decompression)
diff --git a/Tremolo/dpen.s b/Tremolo/dpen.s
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+@ Tremolo library
+@ Copyright (C) 2009 Robin Watts for Pinknoise Productions Ltd
+
+ .text
+
+ .global decode_packed_entry_number
+ .global decode_packed_entry_number_REALSTART
+ .global decode_map
+ .global vorbis_book_decodevv_add
+ .global _checksum
+
+ .extern oggpack_adv
+ .extern oggpack_look
+ .extern oggpack_eop
+ .extern crc_lookup
+
+decode_packed_entry_number_REALSTART:
+dpen_nobits:
+ MOV r0,r5 @ r0 = b
+ MOV r1,#1 @ r1 = 1
+ BL oggpack_adv @ oggpack_adv(b,1) /* Force eop */
+duff:
+ MVN r0,#0 @ return -1
+ LDMFD r13!,{r4-r8,r10,PC}
+
+dpen_readfailed:
+ SUBS r4,r4,#1 @ r4 = --read
+ BEQ dpen_nobits
+ MOV r0,r5 @ r0 = b
+ MOV r1,r4 @ r1 = read
+ ADR r14,dpen_read_return
+ B oggpack_look
+
+decode_packed_entry_number:
+ @ r0 = codebook *book
+ @ r1 = oggpack_buffer *b
+ STMFD r13!,{r4-r8,r10,r14}
+
+ LDMIA r0,{r4,r6,r7} @ r4 = read = book->max_length
+ @ r6 = book->dec_table
+ @ r7 = book->dec_method
+ MOV r5,r1 @ r5 = b
+
+ MOV r0,r5 @ r0 = b
+ MOV r1,r4 @ r1 = read
+ BL oggpack_look
+dpen_read_return:
+ CMP r0,#0
+ BLT dpen_readfailed
+
+ @ r0 = lok
+ @ r4 = read
+ @ r5 = b
+ @ r6 = dec_table
+ @ r7 = dec_method
+
+ CMP r7, #3
+ BGT meth4
+ BEQ meth3
+ CMP r7, #1
+ BGT meth2
+ BEQ meth1
+meth0:
+ RSB r1, r4, #0 @ r1 = i-read = 0-read
+ MOV r7, #0 @ r7 = chase
+m0_loop:
+ MOVS r0, r0, LSR #1 @ r0 = lok>>1 C = bottom bit
+ ADC r2, r6, r7, LSL #1 @ r8 = &t[chase*2+C]
+ LDRB r7, [r2]
+ ADDS r1, r1, #1 @ r1 = i-read++ (i-read<0 => i<read)
+ @ stall Xscale
+ CMPLT r7, #0x80
+ BLT m0_loop
+ AND r7, r7, #0x7F @ r7 = chase
+ CMP r1, #0 @ if (i-read >= 0) === (i >= read)
+ MVNGT r7, #0 @ if (i >= read) value to return = -1
+ ADD r1, r1, r4 @ r1 = i-read+read+1 = i +1
+ MOV r0, r5 @ r0 = b
+ BL oggpack_adv @ oggpack_adv(b, i+1);
+ MOV r0, r7 @ return chase
+ LDMFD r13!,{r4-r8,r10,PC}
+
+meth1:
+ @ r0 = lok
+ @ r4 = read
+ @ r5 = b
+ @ r6 = dec_table
+ RSB r1, r4, #0 @ r1 = i = -read
+ MOV r10,#0 @ r10= next = 0
+m1_loop:
+ MOV r7, r10 @ r7 = chase=next
+ MOVS r0, r0, LSR #1 @ r0 = lok>>1 C = bottom bit
+ ADC r8, r6, r7 @ r8 = t+chase+bit
+ LDRB r10,[r8], -r6 @ r10= next=t[chase+bit] r8=chase+bit
+ ADDS r1, r1, #1 @ r1 = i++
+ @ stall Xscale
+ CMPLT r10,#0x80 @ if (next & 0x80) == 0
+ BLT m1_loop
+
+ ADD r1, r1, r4 @ r1 = i+read
+ MOV r0, r5 @ r0 = b
+ BL oggpack_adv @ oggpack_adv(b, i)
+
+ CMP r10,#0x80
+ BLT duff
+
+ CMP r8, r7 @ if bit==0 (chase+bit==chase) (sets C)
+ LDRNEB r14,[r6, r7] @ r14= t[chase]
+ MOVEQ r14,#128
+ ADC r12,r8, r6 @ r12= chase+bit+1+t
+ LDRB r14,[r12,r14,LSR #7] @ r14= t[chase+bit+1+(!bit || t[chase]0x0x80)]
+ BIC r10,r10,#0x80 @ r3 = next &= ~0x80
+ @ stall Xscale
+ ORR r0, r14,r10,LSL #8 @ r7 = chase = (next<<8) | r14
+
+ LDMFD r13!,{r4-r8,r10,PC}
+
+
+meth2:
+ RSB r1, r4, #0 @ r1 = i-read = 0-read
+ MOV r7, #0 @ r7 = chase
+ MOV r6, r6, LSR #1
+m2_loop:
+ MOVS r0, r0, LSR #1 @ r0 = lok>>1 C = bottom bit
+ ADC r2, r6, r7, LSL #1 @ r8 = &t[chase*2+C]
+ LDRH r7, [r2, r2]
+ ADDS r1, r1, #1 @ r1 = i-read++ (i-read<0 => i<read)
+ @ stall Xscale
+ CMPLT r7, #0x8000
+ BLT m2_loop
+ BIC r7, r7, #0x8000 @ r7 = chase
+ CMP r1, #0 @ if (i-read >= 0) === (i >= read)
+ MVNGT r7, #0 @ if (i >= read) value to return = -1
+ ADD r1, r1, r4 @ r1 = i-read+read+1 = i +1
+ MOV r0, r5 @ r0 = b
+ BL oggpack_adv @ oggpack_adv(b, i+1);
+ MOV r0, r7 @ return chase
+ LDMFD r13!,{r4-r8,r10,PC}
+
+meth3:
+ @ r0 = lok
+ @ r4 = read
+ @ r5 = b
+ @ r6 = dec_table
+ RSB r1, r4, #0 @ r1 = i = -read
+ MOV r10,#0 @ r10= next = 0
+m3_loop:
+ MOV r7, r10 @ r7 = chase=next
+ MOVS r0, r0, LSR #1 @ r0 = lok>>1 C = bottom bit
+ ADC r8, r7, #0 @ r8 = chase+bit
+ MOV r8, r8, LSL #1 @ r8 = (chase+bit)<<1
+ LDRH r10,[r6, r8] @ r10= next=t[chase+bit]
+ ADDS r1, r1, #1 @ r1 = i++
+ @ stall Xscale
+ CMPLT r10,#0x8000 @ if (next & 0x8000) == 0
+ BLT m3_loop
+
+ ADD r1, r1, r4 @ r1 = i+read
+ MOV r0, r5 @ r0 = b
+ BL oggpack_adv @ oggpack_adv(b, i)
+
+ CMP r10,#0x8000
+ BLT duff
+
+ MOV r7, r7, LSL #1
+ CMP r8, r7 @ if bit==0 (chase+bit==chase) sets C
+ LDRNEH r14,[r6, r7] @ r14= t[chase]
+ MOVEQ r14,#0x8000
+ ADC r12,r8, r14,LSR #15 @ r12= 1+((chase+bit)<<1)+(!bit || t[chase]0x0x8000)
+ ADC r12,r12,r14,LSR #15 @ r12= t + (1+chase+bit+(!bit || t[chase]0x0x8000))<<1
+ LDRH r14,[r6, r12] @ r14= t[chase+bit+1
+ BIC r10,r10,#0x8000 @ r3 = next &= ~0x8000
+ @ stall Xscale
+ ORR r0, r14,r10,LSL #16 @ r7 = chase = (next<<16) | r14
+
+ LDMFD r13!,{r4-r8,r10,PC}
+
+meth4:
+ RSB r1, r4, #0 @ r1 = i-read = 0-read
+ MOV r7, #0 @ r7 = chase
+m4_loop:
+ MOVS r0, r0, LSR #1 @ r0 = lok>>1 C = bottom bit
+ ADC r2, r7, r7 @ r8 = chase*2+C
+ LDR r7, [r6, r2, LSL #2]
+ ADDS r1, r1, #1 @ r1 = i-read++ (i-read<0 => i<read)
+ @ stall Xscale
+ CMPLT r7, #0x80000000
+ BLT m4_loop
+ BIC r7, r7, #0x80000000 @ r7 = chase
+ CMP r1, #0 @ if (i-read >= 0) === (i >= read)
+ MVNGT r7, #0 @ if (i >= read) value to return = -1
+ ADD r1, r1, r4 @ r1 = i-read+read+1 = i +1
+ MOV r0, r5 @ r0 = b
+ BL oggpack_adv @ oggpack_adv(b, i+1);
+ MOV r0, r7 @ return chase
+ LDMFD r13!,{r4-r8,r10,PC}
+
+decode_map:
+ @ r0 = codebook *s
+ @ r1 = oggpack_buffer *b
+ @ r2 = int v
+ @ r3 = int point
+ STMFD r13!,{r4-r11,r14}
+
+ MOV r4, r0 @ r4 = s
+ MOV r5, r1 @ r5 = b
+ MOV r6, r2 @ r6 = v
+ MOV r7, r3 @ r7 = point
+ BL decode_packed_entry_number
+ MOV r8, r0
+
+ MOV r0, r5
+ BL oggpack_eop
+ CMP r0, #0
+ BNE dm_duff
+
+ @ r4 = s
+ @ r5 = b
+ @ r6 = v
+ @ r7 = point
+ @ r8 = entry
+
+ LDR r1, [r4,#12] @ r1 = s->dec_type
+ LDR r2, [r4,#16] @ r2 = s->q_bits
+ LDR r3, [r4,#20] @ r3 = s->dim
+ LDR r5, [r4,#24] @ r5 = s->q_delp
+ LDR r11,[r4,#28] @ r11= s->q_minp
+ LDR r12,[r4,#32] @ r12= s->q_del = mul
+ LDR r14,[r4,#36] @ r14= s->q_min
+ SUBS r11,r7, r11 @ r11= add = point - s->q_minp
+
+ MOVGT r14,r14,ASR r11 @ r14= add = s->q_min >> add (if add >0)
+ RSBLT r11,r11,#0
+ MOVLT r14,r14,LSL r11 @ r14= add = s->q_min << -add (if add < 0)
+
+ SUBS r5, r7, r5 @ r5 = shiftM = point - s->q_delp
+ LDR r7, [r4,#40] @ r7 = s->q_seq
+ RSBLT r5, r5, #0 @ if (shiftM<0) r5 =-shiftM
+ MOVLT r12,r12,LSL r5 @ r12=mul<<-shiftM
+ MOVLT r5, #0 @ r5 =shiftM = 0
+ MOVGT r14,r14,LSL r5 @ add <<= shiftM
+
+ CMP r7,#0 @ seqMask = (s->q_seq?-1:0)
+ MVNNE r7,#0
+
+ CMP r1, #2
+ BEQ dm2
+ BGT dm3
+ CMP r1,#0 @ probably never happens
+ BLE dm_duff
+dm1:
+ @ r1 = s->dec_type
+ @ r2 = s->q_bits
+ @ r3 = s->dim
+ @ r5 = shiftM
+ @ r6 = v
+ @ r7 = seqMask
+ @ r8 = entry
+ @ r12= mul
+ @ r14= add
+ MOV r0, #1
+ RSB r0, r0, r0, LSL r2 @ r0 = mask = (1<<s->q_bits)-1
+ MOV r11,#0 @ r11= prev = 0
+dm1_loop:
+ AND r1, r8, r0 @ r1 = v = entry & mask
+ MLA r1, r12, r1, r14 @ r1 = (add + mul*v)
+ MOV r8, r8, LSR r2 @ r8 = entry>>s->q_bits
+ SUBS r3, r3, #1
+ ADD r1, r11,r1, ASR r5 @ r1 = v = prev+((add+mul*v)>>shiftM)
+ AND r11,r1, r7 @ r11= prev = seqMask & v
+ STR r1, [r6], #4 @ *v++ = v
+ BGT dm1_loop
+
+ MOV r0, #0
+ LDMFD r13!,{r4-r11,PC}
+dm2:
+ @ r1 = s->dec_type
+ @ r2 = s->q_bits
+ @ r3 = s->dim
+ @ r4 = s
+ @ r5 = shiftM
+ @ r6 = v
+ @ r7 = seqMask
+ @ r8 = entry
+ @ r12= mul
+ @ r14= add
+ LDR r1, [r4,#44] @ r1 = s->q_pack
+ LDR r4, [r4,#48] @ r4 = s->q_val
+ MOV r11,#0 @ r11= prev
+ MOV r0, #1
+ RSB r0, r0, r0, LSL r1 @ r8 = mask = (1<<s->q_pack)-1
+ CMP r2,#8
+ BGT dm2_hword
+dm2_loop:
+ AND r2, r8, r0 @ r2 = entry & mask
+ LDRB r2, [r4, r2] @ r2 = v = q->val[entry & mask]
+ MOV r8, r8, LSR r1 @ r8 = entry>>q_pack
+ MLA r2, r12,r2, r14 @ r2 = (add+mul*v)
+ SUBS r3, r3, #1
+ ADD r2, r11,r2, ASR r5 @ r2 = v = prev+(add+mul*v)>>shiftM
+ AND r11,r2, r7 @ r11= prev = seqMask & v
+ STR r2, [r6], #4 @ *v++ = v
+ BGT dm2_loop
+ MOV r0, #0
+ LDMFD r13!,{r4-r11,PC}
+
+dm2_hword:
+ AND r2, r8, r0 @ r2 = entry & mask
+ MOV r2, r2, LSL #1 @ r2 = 2*r2
+ LDRH r2, [r4, r2] @ r2 = v = q->val[entry & mask]
+ MOV r8, r8, LSR r1 @ r8 = entry>>q_pack
+ MLA r2, r12,r2, r14 @ r2 = (add+mul*v)
+ SUBS r3, r3, #1
+ ADD r2, r11,r2, ASR r5 @ r2 = v = prev+(add+mul*v)>>shiftM
+ AND r11,r2, r7 @ r11= prev = seqMask & v
+ STR r2, [r6], #4 @ *v++ = v
+ BGT dm2_hword
+ MOV r0, #0
+ LDMFD r13!,{r4-r11,PC}
+
+dm3:
+ @ r1 = s->dec_type
+ @ r2 = s->q_bits
+ @ r3 = s->dim
+ @ r4 = s
+ @ r5 = shiftM
+ @ r6 = v
+ @ r7 = seqMask
+ @ r8 = entry
+ @ r12= mul
+ @ r14= add
+ LDR r1, [r4,#44] @ r1 = s->q_pack
+ LDR r4, [r4,#52] @ r4 = s->q_val
+ CMP r2,#8
+ MOV r11,#0 @ r11= prev
+ MLA r4,r1,r8,r4 @ r4 = ptr = s->q_val+entry*s->q_pack
+
+ BGT dm3_hword
+dm3_loop:
+ LDRB r2, [r4], #1 @ r2 = v = *ptr++
+ SUBS r3, r3, #1
+ MLA r2, r12,r2, r14 @ r2 = (add+mul*v)
+ ADD r2, r11,r2, ASR r5 @ r2 = v = prev+(add+mul*v)>>shiftM
+ AND r11,r2, r7 @ r11= prev = seqMask & v
+ STR r2, [r6], #4 @ *v++ = v
+ BGT dm3_loop
+ MOV r0, #0
+ LDMFD r13!,{r4-r11,PC}
+
+dm3_hword:
+ LDRH r2, [r4], #2 @ r2 = *ptr++
+ SUBS r3, r3, #1
+ MLA r2, r12,r2, r14 @ r2 = (add+mul*v)
+ ADD r2, r11,r2, ASR r5 @ r2 = v = prev+(add+mul*v)>>shiftM
+ AND r11,r2, r7 @ r11= prev = seqMask & v
+ STR r2, [r6], #4 @ *v++ = v
+ BGT dm3_hword
+ MOV r0, #0
+ LDMFD r13!,{r4-r11,PC}
+
+dm_duff:
+ MVN r0,#0
+ LDMFD r13!,{r4-r11,PC}
+
+vorbis_book_decodevv_add:
+ @ r0 = codebook *book
+ @ r1 = ogg_int32_t **a
+ @ r2 = long offset
+ @ r3 = int ch
+ @ <> = b
+ @ <> = n
+ @ <> = point
+ STMFD r13!,{r4-r11,R14}
+ LDR r7, [r0, #13*4] @ r7 = used_entries
+ MOV r9, r0 @ r9 = book
+ MOV r10,r1 @ r10= 0xa[chptr] chptr=0
+ MOV r6, r3 @ r6 = ch
+ ADD r8, r10,r3, LSL #2 @ r8 = 0xa[ch]
+ MOV r11,r2 @ r11= offset
+ CMP r7, #0 @ if (used_entries <= 0)
+ BLE vbdvva_exit @ exit
+ LDR r5, [r13,#10*4] @ r5 = n
+vbdvva_loop1:
+ @ r5 = n
+ @ r6 = ch
+ @ r8 = 0xa[ch]
+ @ r9 = book
+ @ r10= 0xa[chptr]
+ @ r11= offset
+ MOV r0, r9 @ r0 = book
+ LDR r1, [r13,# 9*4] @ r1 = b
+ LDR r2, [r9, #14*4] @ r2 = v = dec_buf
+ LDR r3, [r13,#11*4] @ r3 = point
+ BL decode_map
+ CMP r0, #0
+ BNE vbdvva_fail
+
+ LDR r0, [r9, # 5*4] @ r0 = book->dim
+ LDR r1, [r9, #14*4] @ r1 = v = dec_buf
+vbdvva_loop2:
+ LDR r2, [r10],#4 @ r2 = a[chptr++]
+ LDR r12,[r1], #4 @ r1 = v[j++]
+ CMP r10,r8 @ if (chptr == ch)
+ SUBEQ r10,r10,r6, LSL #2 @ chptr = 0
+ LDR r14,[r2, r11,LSL #2]! @ r2 = 0xa[chptr++][i] r14=[r12]
+ ADDEQ r11,r11,#1 @ i++
+ SUBEQ r5, r5, #1 @ n--
+ SUBS r0, r0, #1 @ r0--
+ ADD r12,r12,r14 @ r12= a[chptr++][i]+ v[j]
+ STR r12,[r2] @ r12= a[chptr++][i]+=v[j]
+ BGT vbdvva_loop2
+ CMP r5,#0
+ BGT vbdvva_loop1
+vbdvva_exit:
+ MOV r0, #0 @ return 0
+ LDMFD r13!,{r4-r11,PC}
+vbdvva_fail:
+ MVN r0, #0 @ return -1
+ LDMFD r13!,{r4-r11,PC}
+
+_checksum:
+ @ r0 = ogg_reference *or
+ @ r1 = bytes
+ STMFD r13!,{r5-r6,r14}
+
+ LDR r5,=crc_lookup
+ MOV r14,#0 @ r14= crc_reg = 0
+ MOVS r12,r0
+ BEQ _cs_end
+_cs_loop1:
+ LDMIA r12,{r0,r2,r3,r12} @ r0 = or->buffer
+ @ r2 = or->begin
+ @ r3 = or->length
+ @ r12= or->next
+ LDR r0,[r0] @ r0 = or->buffer->data
+ CMP r1,r3 @ r3 = post = (bytes < or->length ?
+ MOVLT r3,r1 @ bytes : or->length)
+ MOVS r6,r3 @ r6 = j = post
+ BEQ _cs_no_bytes
+ ADD r0,r0,r2 @ r0 = or->buffer->data + or->begin
+_cs_loop2:
+ LDRB r2, [r0],#1 @ r2 = data[j]
+ @ stall
+ @ stall Xscale
+ EOR r2, r2, r14,LSR #24 @ r2 = (crc_reg>>24)^data[j]
+ LDR r2, [r5, r2, LSL #2] @ r2 = crc_lkp[(crc_reg>>24)^data[j]]
+ SUBS r6, r6, #1 @ j--
+ @ stall Xscale
+ EOR r14,r2, r14,LSL #8 @ r14= crc_reg = (crc_reg<<8)^r2
+ BGT _cs_loop2
+_cs_no_bytes:
+ SUBS r1, r1, r3
+ CMPNE r12,#0
+ BNE _cs_loop1
+_cs_end:
+ MOV r0,r14
+ LDMFD r13!,{r5-r6,PC}
+
+ @ END