diff options
Diffstat (limited to 'apps/eq_arm.S')
| -rw-r--r-- | apps/eq_arm.S | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/apps/eq_arm.S b/apps/eq_arm.S deleted file mode 100644 index b0e1771..0000000 --- a/apps/eq_arm.S +++ /dev/null @@ -1,89 +0,0 @@ -/*************************************************************************** - * __________ __ ___. - * Open \______ \ ____ ____ | | _\_ |__ _______ ___ - * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / - * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < - * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ - * \/ \/ \/ \/ \/ - * $Id$ - * - * Copyright (C) 2006-2007 Thom Johansen - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY - * KIND, either express or implied. - * - ****************************************************************************/ - -#include "config.h" - -/* uncomment this to make filtering calculate lower bits after shifting. - * without this, "shift" of the lower bits will be lost here. - */ -/* #define HIGH_PRECISION */ - -/* - * void eq_filter(int32_t **x, struct eqfilter *f, unsigned num, - * unsigned channels, unsigned shift) - */ -#if CONFIG_CPU == PP5002 - .section .icode,"ax",%progbits -#else - .text -#endif - .global eq_filter -eq_filter: - ldr r12, [sp] @ get shift parameter - stmdb sp!, { r0-r11, lr } @ save all params and clobbered regs - ldmia r1!, { r4-r8 } @ load coefs - mov r10, r1 @ loop prelude expects filter struct addr in r10 - -.filterloop: - ldr r9, [sp] @ get pointer to this channels data - add r0, r9, #4 - str r0, [sp] @ save back pointer to next channels data - ldr r9, [r9] @ r9 = x[] - ldr r14, [sp, #8] @ r14 = numsamples - ldmia r10, { r0-r3 } @ load history, r10 should be filter struct addr - str r10, [sp, #4] @ save it for loop end - - /* r0-r3 = history, r4-r8 = coefs, r9 = x[], r10..r11 = accumulator, - * r12 = shift amount, r14 = number of samples. - */ -.loop: - /* Direct form 1 filtering code. - * y[n] = b0*x[i] + b1*x[i - 1] + b2*x[i - 2] + a1*y[i - 1] + a2*y[i - 2], - * where y[] is output and x[] is input. This is performed out of order to - * reuse registers, we're pretty short on regs. - */ - smull r10, r11, r6, r1 @ acc = b2*x[i - 2] - mov r1, r0 @ fix input history - smlal r10, r11, r5, r0 @ acc += b1*x[i - 1] - ldr r0, [r9] @ load input and fix history in same operation - smlal r10, r11, r7, r2 @ acc += a1*y[i - 1] - smlal r10, r11, r8, r3 @ acc += a2*y[i - 2] - smlal r10, r11, r4, r0 @ acc += b0*x[i] /* avoid stall on arm9*/ - mov r3, r2 @ fix output history - mov r2, r11, asl r12 @ get upper part of result and shift left -#ifdef HIGH_PRECISION - rsb r11, r12, #32 @ get shift amount for lower part - orr r2, r2, r10, lsr r11 @ then mix in correctly shifted lower part -#endif - str r2, [r9], #4 @ save result - subs r14, r14, #1 @ are we done with this channel? - bne .loop - - ldr r10, [sp, #4] @ load filter struct pointer - stmia r10!, { r0-r3 } @ save back history - ldr r11, [sp, #12] @ load number of channels - subs r11, r11, #1 @ all channels processed? - strne r11, [sp, #12] - bne .filterloop - - add sp, sp, #16 @ compensate for temp storage - ldmpc regs=r4-r11 - |