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Diffstat (limited to 'src/engine/external/wavpack/arm.S')
| -rw-r--r-- | src/engine/external/wavpack/arm.S | 922 |
1 files changed, 461 insertions, 461 deletions
diff --git a/src/engine/external/wavpack/arm.S b/src/engine/external/wavpack/arm.S index ab882181..4f299892 100644 --- a/src/engine/external/wavpack/arm.S +++ b/src/engine/external/wavpack/arm.S @@ -1,461 +1,461 @@ -//////////////////////////////////////////////////////////////////////////// -// **** WAVPACK **** // -// Hybrid Lossless Wavefile Compressor // -// Copyright (c) 1998 - 2006 Conifer Software. // -// All Rights Reserved. // -// Distributed under the BSD Software License (see license.txt) // -//////////////////////////////////////////////////////////////////////////// - -/* This is an assembly optimized version of the following WavPack function: - * - * void decorr_stereo_pass_cont (struct decorr_pass *dpp, - * long *buffer, long sample_count); - * - * It performs a single pass of stereo decorrelation on the provided buffer. - * Note that this version of the function requires that the 8 previous stereo - * samples are visible and correct. In other words, it ignores the "samples_*" - * fields in the decorr_pass structure and gets the history data directly - * from the buffer. It does, however, return the appropriate history samples - * to the decorr_pass structure before returning. - * - * This is written to work on a ARM7TDMI processor. This version only uses the - * 32-bit multiply-accumulate instruction and so will overflow with 24-bit - * WavPack files. - */ - .text - .align - .global decorr_stereo_pass_cont_arm - -/* - * on entry: - * - * r0 = struct decorr_pass *dpp - * r1 = long *buffer - * r2 = long sample_count - */ - -decorr_stereo_pass_cont_arm: - - stmfd sp!, {r4 - r8, r10, r11, lr} - mov r5, r0 @ r5 = dpp - mov r11, #512 @ r11 = 512 for rounding - ldrsh r6, [r0, #2] @ r6 = dpp->delta - ldrsh r4, [r0, #4] @ r4 = dpp->weight_A - ldrsh r0, [r0, #6] @ r0 = dpp->weight_B - cmp r2, #0 @ exit if no samples to process - beq common_exit - - add r7, r1, r2, asl #3 @ r7 = buffer ending position - ldrsh r2, [r5, #0] @ r2 = dpp->term - cmp r2, #0 - bmi minus_term - - ldr lr, [r1, #-16] @ load 2 sample history from buffer - ldr r10, [r1, #-12] @ for terms 2, 17, and 18 - ldr r8, [r1, #-8] - ldr r3, [r1, #-4] - cmp r2, #17 - beq term_17_loop - cmp r2, #18 - beq term_18_loop - cmp r2, #2 - beq term_2_loop - b term_default_loop @ else handle default (1-8, except 2) - -minus_term: - mov r10, #1024 @ r10 = -1024 for weight clipping - rsb r10, r10, #0 @ (only used for negative terms) - cmn r2, #1 - beq term_minus_1 - cmn r2, #2 - beq term_minus_2 - cmn r2, #3 - beq term_minus_3 - b common_exit - -/* - ****************************************************************************** - * Loop to handle term = 17 condition - * - * r0 = dpp->weight_B r8 = previous left sample - * r1 = bptr r9 = - * r2 = current sample r10 = second previous left sample - * r3 = previous right sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = current decorrelation value - * r5 = dpp sp = - * r6 = dpp->delta lr = second previous right sample - * r7 = eptr pc = - ******************************************************************************* - */ - -term_17_loop: - rsbs ip, lr, r8, asl #1 @ decorr value = (2 * prev) - 2nd prev - mov lr, r8 @ previous becomes 2nd previous - ldr r2, [r1], #4 @ get sample & update pointer - mla r8, ip, r4, r11 @ mult decorr value by weight, round, - add r8, r2, r8, asr #10 @ shift, and add to new sample - strne r8, [r1, #-4] @ if change possible, store sample back - cmpne r2, #0 - beq .L325 - teq ip, r2 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - -.L325: rsbs ip, r10, r3, asl #1 @ do same thing for right channel - mov r10, r3 - ldr r2, [r1], #4 - mla r3, ip, r0, r11 - add r3, r2, r3, asr #10 - strne r3, [r1, #-4] - cmpne r2, #0 - beq .L329 - teq ip, r2 - submi r0, r0, r6 - addpl r0, r0, r6 - -.L329: cmp r7, r1 @ loop back if more samples to do - bhi term_17_loop - b store_1718 @ common exit for terms 17 & 18 - -/* - ****************************************************************************** - * Loop to handle term = 18 condition - * - * r0 = dpp->weight_B r8 = previous left sample - * r1 = bptr r9 = - * r2 = current sample r10 = second previous left sample - * r3 = previous right sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = decorrelation value - * r5 = dpp sp = - * r6 = dpp->delta lr = second previous right sample - * r7 = eptr pc = - ******************************************************************************* - */ - -term_18_loop: - sub ip, r8, lr @ decorr value = - mov lr, r8 @ ((3 * prev) - 2nd prev) >> 1 - adds ip, r8, ip, asr #1 - ldr r2, [r1], #4 @ get sample & update pointer - mla r8, ip, r4, r11 @ mult decorr value by weight, round, - add r8, r2, r8, asr #10 @ shift, and add to new sample - strne r8, [r1, #-4] @ if change possible, store sample back - cmpne r2, #0 - beq .L337 - teq ip, r2 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - -.L337: sub ip, r3, r10 @ do same thing for right channel - mov r10, r3 - adds ip, r3, ip, asr #1 - ldr r2, [r1], #4 - mla r3, ip, r0, r11 - add r3, r2, r3, asr #10 - strne r3, [r1, #-4] - cmpne r2, #0 - beq .L341 - teq ip, r2 - submi r0, r0, r6 - addpl r0, r0, r6 - -.L341: cmp r7, r1 @ loop back if more samples to do - bhi term_18_loop - -/* common exit for terms 17 & 18 */ - -store_1718: - str r3, [r5, #40] @ store sample history into struct - str r8, [r5, #8] - str r10, [r5, #44] - str lr, [r5, #12] - b common_exit @ and return - -/* - ****************************************************************************** - * Loop to handle term = 2 condition - * (note that this case can be handled by the default term handler (1-8), but - * this special case is faster because it doesn't have to read memory twice) - * - * r0 = dpp->weight_B r8 = previous left sample - * r1 = bptr r9 = - * r2 = current sample r10 = second previous left sample - * r3 = previous right sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = decorrelation value - * r5 = dpp sp = - * r6 = dpp->delta lr = second previous right sample - * r7 = eptr pc = - ******************************************************************************* - */ - -term_2_loop: - movs ip, lr @ get decorrelation value & test - mov lr, r8 @ previous becomes 2nd previous - ldr r2, [r1], #4 @ get sample & update pointer - mla r8, ip, r4, r11 @ mult decorr value by weight, round, - add r8, r2, r8, asr #10 @ shift, and add to new sample - strne r8, [r1, #-4] @ if change possible, store sample back - cmpne r2, #0 - beq .L225 - teq ip, r2 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - -.L225: movs ip, r10 @ do same thing for right channel - mov r10, r3 - ldr r2, [r1], #4 - mla r3, ip, r0, r11 - add r3, r2, r3, asr #10 - strne r3, [r1, #-4] - cmpne r2, #0 - beq .L229 - teq ip, r2 - submi r0, r0, r6 - addpl r0, r0, r6 - -.L229: cmp r7, r1 @ loop back if more samples to do - bhi term_2_loop - b default_term_exit @ this exit updates all dpp->samples - -/* - ****************************************************************************** - * Loop to handle default term condition - * - * r0 = dpp->weight_B r8 = result accumulator - * r1 = bptr r9 = - * r2 = dpp->term r10 = - * r3 = decorrelation value r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = current sample - * r5 = dpp sp = - * r6 = dpp->delta lr = - * r7 = eptr pc = - ******************************************************************************* - */ - -term_default_loop: - ldr ip, [r1] @ get original sample - ldr r3, [r1, -r2, asl #3] @ get decorrelation value based on term - mla r8, r3, r4, r11 @ mult decorr value by weight, round, - add r8, ip, r8, asr #10 @ shift and add to new sample - str r8, [r1], #4 @ store update sample - cmp r3, #0 - cmpne ip, #0 - beq .L350 - teq ip, r3 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - -.L350: ldr ip, [r1] @ do the same thing for right channel - ldr r3, [r1, -r2, asl #3] - mla r8, r3, r0, r11 - add r8, ip, r8, asr #10 - str r8, [r1], #4 - cmp r3, #0 - cmpne ip, #0 - beq .L354 - teq ip, r3 - submi r0, r0, r6 - addpl r0, r0, r6 - -.L354: cmp r7, r1 @ loop back if more samples to do - bhi term_default_loop - -/* - * This exit is used by terms 1-8 to store the previous 8 samples into the decorr - * structure (even if they are not all used for the given term) - */ - -default_term_exit: - ldrsh r3, [r5, #0] - sub ip, r3, #1 - mov lr, #7 - -.L358: and r3, ip, #7 - add r3, r5, r3, asl #2 - ldr r2, [r1, #-4] - str r2, [r3, #40] - ldr r2, [r1, #-8]! - str r2, [r3, #8] - sub ip, ip, #1 - sub lr, lr, #1 - cmn lr, #1 - bne .L358 - b common_exit - -/* - ****************************************************************************** - * Loop to handle term = -1 condition - * - * r0 = dpp->weight_B r8 = - * r1 = bptr r9 = - * r2 = intermediate result r10 = -1024 (for clipping) - * r3 = previous right sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = current sample - * r5 = dpp sp = - * r6 = dpp->delta lr = updated left sample - * r7 = eptr pc = - ******************************************************************************* - */ - -term_minus_1: - ldr r3, [r1, #-4] - -term_minus_1_loop: - ldr ip, [r1] @ for left channel the decorrelation value - mla r2, r3, r4, r11 @ is the previous right sample (in r3) - add lr, ip, r2, asr #10 - str lr, [r1], #8 - cmp r3, #0 - cmpne ip, #0 - beq .L361 - teq ip, r3 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - cmp r4, #1024 - movgt r4, #1024 - cmp r4, r10 - movlt r4, r10 - -.L361: ldr r2, [r1, #-4] @ for right channel the decorrelation value - mla r3, lr, r0, r11 @ is the just updated right sample (in lr) - add r3, r2, r3, asr #10 - str r3, [r1, #-4] - cmp lr, #0 - cmpne r2, #0 - beq .L369 - teq r2, lr - submi r0, r0, r6 - addpl r0, r0, r6 - cmp r0, #1024 @ then clip weight to +/-1024 - movgt r0, #1024 - cmp r0, r10 - movlt r0, r10 - -.L369: cmp r7, r1 @ loop back if more samples to do - bhi term_minus_1_loop - - str r3, [r5, #8] @ else store right sample and exit - b common_exit - -/* - ****************************************************************************** - * Loop to handle term = -2 condition - * (note that the channels are processed in the reverse order here) - * - * r0 = dpp->weight_B r8 = - * r1 = bptr r9 = - * r2 = intermediate result r10 = -1024 (for clipping) - * r3 = previous left sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = current sample - * r5 = dpp sp = - * r6 = dpp->delta lr = updated right sample - * r7 = eptr pc = - ******************************************************************************* - */ - -term_minus_2: - ldr r3, [r1, #-8] - -term_minus_2_loop: - ldr ip, [r1, #4] @ for right channel the decorrelation value - mla r2, r3, r0, r11 @ is the previous left sample (in r3) - add lr, ip, r2, asr #10 - str lr, [r1, #4] - cmp r3, #0 - cmpne ip, #0 - beq .L380 - teq ip, r3 @ update weight based on signs - submi r0, r0, r6 - addpl r0, r0, r6 - cmp r0, #1024 @ then clip weight to +/-1024 - movgt r0, #1024 - cmp r0, r10 - movlt r0, r10 - -.L380: ldr r2, [r1, #0] @ for left channel the decorrelation value - mla r3, lr, r4, r11 @ is the just updated left sample (in lr) - add r3, r2, r3, asr #10 - str r3, [r1], #8 - cmp lr, #0 - cmpne r2, #0 - beq .L388 - teq r2, lr - submi r4, r4, r6 - addpl r4, r4, r6 - cmp r4, #1024 - movgt r4, #1024 - cmp r4, r10 - movlt r4, r10 - -.L388: cmp r7, r1 @ loop back if more samples to do - bhi term_minus_2_loop - - str r3, [r5, #40] @ else store left channel and exit - b common_exit - -/* - ****************************************************************************** - * Loop to handle term = -3 condition - * - * r0 = dpp->weight_B r8 = previous left sample - * r1 = bptr r9 = - * r2 = current left sample r10 = -1024 (for clipping) - * r3 = previous right sample r11 = 512 (for rounding) - * r4 = dpp->weight_A ip = intermediate result - * r5 = dpp sp = - * r6 = dpp->delta lr = - * r7 = eptr pc = - ******************************************************************************* - */ - -term_minus_3: - ldr r3, [r1, #-4] @ load previous samples - ldr r8, [r1, #-8] - -term_minus_3_loop: - ldr ip, [r1] - mla r2, r3, r4, r11 - add r2, ip, r2, asr #10 - str r2, [r1], #4 - cmp r3, #0 - cmpne ip, #0 - beq .L399 - teq ip, r3 @ update weight based on signs - submi r4, r4, r6 - addpl r4, r4, r6 - cmp r4, #1024 @ then clip weight to +/-1024 - movgt r4, #1024 - cmp r4, r10 - movlt r4, r10 - -.L399: movs ip, r8 @ ip = previous left we use now - mov r8, r2 @ r8 = current left we use next time - ldr r2, [r1], #4 - mla r3, ip, r0, r11 - add r3, r2, r3, asr #10 - strne r3, [r1, #-4] - cmpne r2, #0 - beq .L407 - teq ip, r2 - submi r0, r0, r6 - addpl r0, r0, r6 - cmp r0, #1024 - movgt r0, #1024 - cmp r0, r10 - movlt r0, r10 - -.L407: cmp r7, r1 @ loop back if more samples to do - bhi term_minus_3_loop - - str r3, [r5, #8] @ else store previous samples & exit - str r8, [r5, #40] - -/* - * Before finally exiting we must store weights back for next time - */ - -common_exit: - strh r4, [r5, #4] - strh r0, [r5, #6] - ldmfd sp!, {r4 - r8, r10, r11, pc} - +//////////////////////////////////////////////////////////////////////////// +// **** WAVPACK **** // +// Hybrid Lossless Wavefile Compressor // +// Copyright (c) 1998 - 2006 Conifer Software. // +// All Rights Reserved. // +// Distributed under the BSD Software License (see license.txt) // +//////////////////////////////////////////////////////////////////////////// + +/* This is an assembly optimized version of the following WavPack function: + * + * void decorr_stereo_pass_cont (struct decorr_pass *dpp, + * long *buffer, long sample_count); + * + * It performs a single pass of stereo decorrelation on the provided buffer. + * Note that this version of the function requires that the 8 previous stereo + * samples are visible and correct. In other words, it ignores the "samples_*" + * fields in the decorr_pass structure and gets the history data directly + * from the buffer. It does, however, return the appropriate history samples + * to the decorr_pass structure before returning. + * + * This is written to work on a ARM7TDMI processor. This version only uses the + * 32-bit multiply-accumulate instruction and so will overflow with 24-bit + * WavPack files. + */ + .text + .align + .global decorr_stereo_pass_cont_arm + +/* + * on entry: + * + * r0 = struct decorr_pass *dpp + * r1 = long *buffer + * r2 = long sample_count + */ + +decorr_stereo_pass_cont_arm: + + stmfd sp!, {r4 - r8, r10, r11, lr} + mov r5, r0 @ r5 = dpp + mov r11, #512 @ r11 = 512 for rounding + ldrsh r6, [r0, #2] @ r6 = dpp->delta + ldrsh r4, [r0, #4] @ r4 = dpp->weight_A + ldrsh r0, [r0, #6] @ r0 = dpp->weight_B + cmp r2, #0 @ exit if no samples to process + beq common_exit + + add r7, r1, r2, asl #3 @ r7 = buffer ending position + ldrsh r2, [r5, #0] @ r2 = dpp->term + cmp r2, #0 + bmi minus_term + + ldr lr, [r1, #-16] @ load 2 sample history from buffer + ldr r10, [r1, #-12] @ for terms 2, 17, and 18 + ldr r8, [r1, #-8] + ldr r3, [r1, #-4] + cmp r2, #17 + beq term_17_loop + cmp r2, #18 + beq term_18_loop + cmp r2, #2 + beq term_2_loop + b term_default_loop @ else handle default (1-8, except 2) + +minus_term: + mov r10, #1024 @ r10 = -1024 for weight clipping + rsb r10, r10, #0 @ (only used for negative terms) + cmn r2, #1 + beq term_minus_1 + cmn r2, #2 + beq term_minus_2 + cmn r2, #3 + beq term_minus_3 + b common_exit + +/* + ****************************************************************************** + * Loop to handle term = 17 condition + * + * r0 = dpp->weight_B r8 = previous left sample + * r1 = bptr r9 = + * r2 = current sample r10 = second previous left sample + * r3 = previous right sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = current decorrelation value + * r5 = dpp sp = + * r6 = dpp->delta lr = second previous right sample + * r7 = eptr pc = + ******************************************************************************* + */ + +term_17_loop: + rsbs ip, lr, r8, asl #1 @ decorr value = (2 * prev) - 2nd prev + mov lr, r8 @ previous becomes 2nd previous + ldr r2, [r1], #4 @ get sample & update pointer + mla r8, ip, r4, r11 @ mult decorr value by weight, round, + add r8, r2, r8, asr #10 @ shift, and add to new sample + strne r8, [r1, #-4] @ if change possible, store sample back + cmpne r2, #0 + beq .L325 + teq ip, r2 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + +.L325: rsbs ip, r10, r3, asl #1 @ do same thing for right channel + mov r10, r3 + ldr r2, [r1], #4 + mla r3, ip, r0, r11 + add r3, r2, r3, asr #10 + strne r3, [r1, #-4] + cmpne r2, #0 + beq .L329 + teq ip, r2 + submi r0, r0, r6 + addpl r0, r0, r6 + +.L329: cmp r7, r1 @ loop back if more samples to do + bhi term_17_loop + b store_1718 @ common exit for terms 17 & 18 + +/* + ****************************************************************************** + * Loop to handle term = 18 condition + * + * r0 = dpp->weight_B r8 = previous left sample + * r1 = bptr r9 = + * r2 = current sample r10 = second previous left sample + * r3 = previous right sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = decorrelation value + * r5 = dpp sp = + * r6 = dpp->delta lr = second previous right sample + * r7 = eptr pc = + ******************************************************************************* + */ + +term_18_loop: + sub ip, r8, lr @ decorr value = + mov lr, r8 @ ((3 * prev) - 2nd prev) >> 1 + adds ip, r8, ip, asr #1 + ldr r2, [r1], #4 @ get sample & update pointer + mla r8, ip, r4, r11 @ mult decorr value by weight, round, + add r8, r2, r8, asr #10 @ shift, and add to new sample + strne r8, [r1, #-4] @ if change possible, store sample back + cmpne r2, #0 + beq .L337 + teq ip, r2 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + +.L337: sub ip, r3, r10 @ do same thing for right channel + mov r10, r3 + adds ip, r3, ip, asr #1 + ldr r2, [r1], #4 + mla r3, ip, r0, r11 + add r3, r2, r3, asr #10 + strne r3, [r1, #-4] + cmpne r2, #0 + beq .L341 + teq ip, r2 + submi r0, r0, r6 + addpl r0, r0, r6 + +.L341: cmp r7, r1 @ loop back if more samples to do + bhi term_18_loop + +/* common exit for terms 17 & 18 */ + +store_1718: + str r3, [r5, #40] @ store sample history into struct + str r8, [r5, #8] + str r10, [r5, #44] + str lr, [r5, #12] + b common_exit @ and return + +/* + ****************************************************************************** + * Loop to handle term = 2 condition + * (note that this case can be handled by the default term handler (1-8), but + * this special case is faster because it doesn't have to read memory twice) + * + * r0 = dpp->weight_B r8 = previous left sample + * r1 = bptr r9 = + * r2 = current sample r10 = second previous left sample + * r3 = previous right sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = decorrelation value + * r5 = dpp sp = + * r6 = dpp->delta lr = second previous right sample + * r7 = eptr pc = + ******************************************************************************* + */ + +term_2_loop: + movs ip, lr @ get decorrelation value & test + mov lr, r8 @ previous becomes 2nd previous + ldr r2, [r1], #4 @ get sample & update pointer + mla r8, ip, r4, r11 @ mult decorr value by weight, round, + add r8, r2, r8, asr #10 @ shift, and add to new sample + strne r8, [r1, #-4] @ if change possible, store sample back + cmpne r2, #0 + beq .L225 + teq ip, r2 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + +.L225: movs ip, r10 @ do same thing for right channel + mov r10, r3 + ldr r2, [r1], #4 + mla r3, ip, r0, r11 + add r3, r2, r3, asr #10 + strne r3, [r1, #-4] + cmpne r2, #0 + beq .L229 + teq ip, r2 + submi r0, r0, r6 + addpl r0, r0, r6 + +.L229: cmp r7, r1 @ loop back if more samples to do + bhi term_2_loop + b default_term_exit @ this exit updates all dpp->samples + +/* + ****************************************************************************** + * Loop to handle default term condition + * + * r0 = dpp->weight_B r8 = result accumulator + * r1 = bptr r9 = + * r2 = dpp->term r10 = + * r3 = decorrelation value r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = current sample + * r5 = dpp sp = + * r6 = dpp->delta lr = + * r7 = eptr pc = + ******************************************************************************* + */ + +term_default_loop: + ldr ip, [r1] @ get original sample + ldr r3, [r1, -r2, asl #3] @ get decorrelation value based on term + mla r8, r3, r4, r11 @ mult decorr value by weight, round, + add r8, ip, r8, asr #10 @ shift and add to new sample + str r8, [r1], #4 @ store update sample + cmp r3, #0 + cmpne ip, #0 + beq .L350 + teq ip, r3 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + +.L350: ldr ip, [r1] @ do the same thing for right channel + ldr r3, [r1, -r2, asl #3] + mla r8, r3, r0, r11 + add r8, ip, r8, asr #10 + str r8, [r1], #4 + cmp r3, #0 + cmpne ip, #0 + beq .L354 + teq ip, r3 + submi r0, r0, r6 + addpl r0, r0, r6 + +.L354: cmp r7, r1 @ loop back if more samples to do + bhi term_default_loop + +/* + * This exit is used by terms 1-8 to store the previous 8 samples into the decorr + * structure (even if they are not all used for the given term) + */ + +default_term_exit: + ldrsh r3, [r5, #0] + sub ip, r3, #1 + mov lr, #7 + +.L358: and r3, ip, #7 + add r3, r5, r3, asl #2 + ldr r2, [r1, #-4] + str r2, [r3, #40] + ldr r2, [r1, #-8]! + str r2, [r3, #8] + sub ip, ip, #1 + sub lr, lr, #1 + cmn lr, #1 + bne .L358 + b common_exit + +/* + ****************************************************************************** + * Loop to handle term = -1 condition + * + * r0 = dpp->weight_B r8 = + * r1 = bptr r9 = + * r2 = intermediate result r10 = -1024 (for clipping) + * r3 = previous right sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = current sample + * r5 = dpp sp = + * r6 = dpp->delta lr = updated left sample + * r7 = eptr pc = + ******************************************************************************* + */ + +term_minus_1: + ldr r3, [r1, #-4] + +term_minus_1_loop: + ldr ip, [r1] @ for left channel the decorrelation value + mla r2, r3, r4, r11 @ is the previous right sample (in r3) + add lr, ip, r2, asr #10 + str lr, [r1], #8 + cmp r3, #0 + cmpne ip, #0 + beq .L361 + teq ip, r3 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + cmp r4, #1024 + movgt r4, #1024 + cmp r4, r10 + movlt r4, r10 + +.L361: ldr r2, [r1, #-4] @ for right channel the decorrelation value + mla r3, lr, r0, r11 @ is the just updated right sample (in lr) + add r3, r2, r3, asr #10 + str r3, [r1, #-4] + cmp lr, #0 + cmpne r2, #0 + beq .L369 + teq r2, lr + submi r0, r0, r6 + addpl r0, r0, r6 + cmp r0, #1024 @ then clip weight to +/-1024 + movgt r0, #1024 + cmp r0, r10 + movlt r0, r10 + +.L369: cmp r7, r1 @ loop back if more samples to do + bhi term_minus_1_loop + + str r3, [r5, #8] @ else store right sample and exit + b common_exit + +/* + ****************************************************************************** + * Loop to handle term = -2 condition + * (note that the channels are processed in the reverse order here) + * + * r0 = dpp->weight_B r8 = + * r1 = bptr r9 = + * r2 = intermediate result r10 = -1024 (for clipping) + * r3 = previous left sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = current sample + * r5 = dpp sp = + * r6 = dpp->delta lr = updated right sample + * r7 = eptr pc = + ******************************************************************************* + */ + +term_minus_2: + ldr r3, [r1, #-8] + +term_minus_2_loop: + ldr ip, [r1, #4] @ for right channel the decorrelation value + mla r2, r3, r0, r11 @ is the previous left sample (in r3) + add lr, ip, r2, asr #10 + str lr, [r1, #4] + cmp r3, #0 + cmpne ip, #0 + beq .L380 + teq ip, r3 @ update weight based on signs + submi r0, r0, r6 + addpl r0, r0, r6 + cmp r0, #1024 @ then clip weight to +/-1024 + movgt r0, #1024 + cmp r0, r10 + movlt r0, r10 + +.L380: ldr r2, [r1, #0] @ for left channel the decorrelation value + mla r3, lr, r4, r11 @ is the just updated left sample (in lr) + add r3, r2, r3, asr #10 + str r3, [r1], #8 + cmp lr, #0 + cmpne r2, #0 + beq .L388 + teq r2, lr + submi r4, r4, r6 + addpl r4, r4, r6 + cmp r4, #1024 + movgt r4, #1024 + cmp r4, r10 + movlt r4, r10 + +.L388: cmp r7, r1 @ loop back if more samples to do + bhi term_minus_2_loop + + str r3, [r5, #40] @ else store left channel and exit + b common_exit + +/* + ****************************************************************************** + * Loop to handle term = -3 condition + * + * r0 = dpp->weight_B r8 = previous left sample + * r1 = bptr r9 = + * r2 = current left sample r10 = -1024 (for clipping) + * r3 = previous right sample r11 = 512 (for rounding) + * r4 = dpp->weight_A ip = intermediate result + * r5 = dpp sp = + * r6 = dpp->delta lr = + * r7 = eptr pc = + ******************************************************************************* + */ + +term_minus_3: + ldr r3, [r1, #-4] @ load previous samples + ldr r8, [r1, #-8] + +term_minus_3_loop: + ldr ip, [r1] + mla r2, r3, r4, r11 + add r2, ip, r2, asr #10 + str r2, [r1], #4 + cmp r3, #0 + cmpne ip, #0 + beq .L399 + teq ip, r3 @ update weight based on signs + submi r4, r4, r6 + addpl r4, r4, r6 + cmp r4, #1024 @ then clip weight to +/-1024 + movgt r4, #1024 + cmp r4, r10 + movlt r4, r10 + +.L399: movs ip, r8 @ ip = previous left we use now + mov r8, r2 @ r8 = current left we use next time + ldr r2, [r1], #4 + mla r3, ip, r0, r11 + add r3, r2, r3, asr #10 + strne r3, [r1, #-4] + cmpne r2, #0 + beq .L407 + teq ip, r2 + submi r0, r0, r6 + addpl r0, r0, r6 + cmp r0, #1024 + movgt r0, #1024 + cmp r0, r10 + movlt r0, r10 + +.L407: cmp r7, r1 @ loop back if more samples to do + bhi term_minus_3_loop + + str r3, [r5, #8] @ else store previous samples & exit + str r8, [r5, #40] + +/* + * Before finally exiting we must store weights back for next time + */ + +common_exit: + strh r4, [r5, #4] + strh r0, [r5, #6] + ldmfd sp!, {r4 - r8, r10, r11, pc} + |