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authorAndrew Mahone <andrew.mahone@gmail.com>2010-02-04 05:49:37 +0000
committerAndrew Mahone <andrew.mahone@gmail.com>2010-02-04 05:49:37 +0000
commit8ed7bda64cb98d491431fd130eb754c6320441a0 (patch)
treebe9b6340aaaba3820e87a57c7c3db545c9c2cf15 /apps/codecs/lib
parent7ed87517f734d7d70ab6f294735a77a65bd22e42 (diff)
Move udiv32_arm.S into libdemac, as this divider is specialized for the APE codec and an optimized divider is already provided for general use in codeclib.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24506 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/lib')
-rw-r--r--apps/codecs/lib/SOURCES1
-rw-r--r--apps/codecs/lib/codeclib.h9
-rw-r--r--apps/codecs/lib/udiv32_arm.S300
3 files changed, 0 insertions, 310 deletions
diff --git a/apps/codecs/lib/SOURCES b/apps/codecs/lib/SOURCES
index a8c3feb1aa..42bb1138d1 100644
--- a/apps/codecs/lib/SOURCES
+++ b/apps/codecs/lib/SOURCES
@@ -7,7 +7,6 @@ mdct_lookup.c
#ifdef CPU_ARM
mdct_arm.S
setjmp_arm.S
-udiv32_arm.S
../../../firmware/target/arm/support-arm.S
#endif
diff --git a/apps/codecs/lib/codeclib.h b/apps/codecs/lib/codeclib.h
index 2d34523de5..6dda3e794c 100644
--- a/apps/codecs/lib/codeclib.h
+++ b/apps/codecs/lib/codeclib.h
@@ -65,15 +65,6 @@ void qsort(void *base, size_t nmemb, size_t size, int(*compar)(const void *, con
extern void mdct_backward(int n, int32_t *in, int32_t *out);
-#if defined(CPU_ARM) && (ARM_ARCH < 5 || defined(USE_IRAM))
-/* optimised unsigned integer division for ARMv4, in IRAM */
-unsigned udiv32_arm(unsigned a, unsigned b);
-#define UDIV32(a, b) udiv32_arm(a, b)
-#else
-/* default */
-#define UDIV32(a, b) (a / b)
-#endif
-
#if !defined(CPU_ARM) || ARM_ARCH < 5
/* From libavutil/common.h */
extern const uint8_t bs_log2_tab[256] ICONST_ATTR;
diff --git a/apps/codecs/lib/udiv32_arm.S b/apps/codecs/lib/udiv32_arm.S
deleted file mode 100644
index 4492492d30..0000000000
--- a/apps/codecs/lib/udiv32_arm.S
+++ /dev/null
@@ -1,300 +0,0 @@
-/***************************************************************************
- * __________ __ ___.
- * Open \______ \ ____ ____ | | _\_ |__ _______ ___
- * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
- * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
- * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
- * \/ \/ \/ \/ \/
- * $Id$
- *
- * Copyright (C) 2008 by Jens Arnold
- * Copyright (C) 2009 by Andrew Mahone
- *
- * Optimised unsigned integer division for ARMv4
- *
- * Based on: libgcc routines for ARM cpu, additional algorithms from ARM System
- * Developer's Guide
- * Division routines, written by Richard Earnshaw, (rearnsha@armltd.co.uk)
- * Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005
- * Free Software Foundation, Inc.
- *
- * 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"
-/* Codecs should not normally do this, but we need to check a macro, and
- * codecs.h would confuse the assembler. */
-
-#ifdef USE_IRAM
-#define DIV_RECIP
- .section .icode,"ax",%progbits
-#else
- .text
-#endif
- .align
- .global udiv32_arm
- .type udiv32_arm,%function
-
-#if ARM_ARCH < 5
-/* Adapted from an algorithm given in ARM System Developer's Guide (7.3.1.2)
- for dividing a 30-bit value by a 15-bit value, with two operations per
- iteration by storing quotient and remainder together and adding the previous
- quotient bit during trial subtraction. Modified to work with any dividend
- and divisor both less than 1 << 30, and skipping trials by calculating bits
- in output. */
-.macro ARM_DIV_31_BODY dividend, divisor, result, bits, curbit, quotient, remainder
-
- mov \bits, #1
- /* Shift the divisor left until it aligns with the numerator. If it already
- has the high bit set, this is fine, everything inside .rept will be
- skipped, and the add before and adcs after will set the one-bit result
- to zero. */
- cmn \divisor, \dividend, lsr #16
- movcs \divisor, \divisor, lsl #16
- addcs \bits, \bits, #16
- cmn \divisor, \dividend, lsr #8
- movcs \divisor, \divisor, lsl #8
- addcs \bits, \bits, #8
- cmn \divisor, \dividend, lsr #4
- movcs \divisor, \divisor, lsl #4
- addcs \bits, \bits, #4
- cmn \divisor, \dividend, lsr #2
- movcs \divisor, \divisor, lsl #2
- addcs \bits, \bits, #2
- cmn \divisor, \dividend, lsr #1
- movcs \divisor, \divisor, lsl #1
- addcs \bits, \bits, #1
- adds \result, \dividend, \divisor
- subcc \result, \result, \divisor
- rsb \curbit, \bits, #31
- add pc, pc, \curbit, lsl #3
- nop
- .rept 30
- adcs \result, \divisor, \result, lsl #1
- /* Fix the remainder portion of the result. This must be done because the
- handler for 32-bit numerators needs the remainder. */
- subcc \result, \result, \divisor
- .endr
- /* Shift remainder/quotient left one, add final quotient bit */
- adc \result, \result, \result
- mov \remainder, \result, lsr \bits
- eor \quotient, \result, \remainder, lsl \bits
-.endm
-
-#ifdef CPU_PP
-#if CONFIG_CPU == PP5020
-.set recip_max, 8384
-#elif CONFIG_CPU == PP5002
-.set recip_max, 4608
-#else
-.set recip_max, 16384
-#endif
-#elif CONFIG_CPU == AS3525
-.set recip_max, 42752
-#elif CONFIG_CPU == S5L8701
-.set recip_max, 12800
-#elif CONFIG_CPU == S5L8700
-.set recip_max, 9088
-#endif
-
-udiv32_arm:
-#ifdef DIV_RECIP
- cmp r1, #3
- bcc .L_udiv_tiny
- cmp r1, #recip_max
- bhi .L_udiv
- adr r3, .L_udiv_recip_table-12
- ldr r2, [r3, r1, lsl #2]
- mov r3, r0
- umull ip, r0, r2, r0
- mul r2, r0, r1
- cmp r3, r2
- bxcs lr
- sub r0, r0, #1
- bx lr
-.L_udiv_tiny:
- cmp r1, #1
- movhi r0, r0, lsr #1
- bxcs lr
- b .L_div0
-#endif
-.L_udiv:
- /* Invert divisor. ARM_DIV_31_BODY uses adc to both subtract the divisor
- and add the next bit of the result. The correction code at .L_udiv32
- does not need the divisor inverted, but can be modified to work with it,
- and this allows the zero divisor test to be done early and without an
- explicit comparison. */
- rsbs r1, r1, #0
-#ifndef DIV_RECIP
- beq .L_div0
-#endif
- tst r0, r0
- /* High bit must be unset, otherwise shift numerator right, calculate,
- and correct results. As this case is very uncommon we want to avoid
- any other delays on the main path in handling it, so the long divide
- calls the short divide as a function. */
- bmi .L_udiv32
-.L_udiv31:
- ARM_DIV_31_BODY r0, r1, r2, r3, ip, r0, r1
- bx lr
-.L_udiv32:
- /* store original numerator and divisor, we'll need them to correct the
- result, */
- stmdb sp, { r0, r1, lr }
- /* Call __div0 here if divisor is zero, otherwise it would report the wrong
- address. */
- mov r0, r0, lsr #1
- bl .L_udiv31
- ldmdb sp, { r2, r3, lr }
- /* Move the low bit of the original numerator to the carry bit */
- movs r2, r2, lsr #1
- /* Shift the remainder left one and add in the carry bit */
- adc r1, r1, r1
- /* Subtract the original divisor from the remainder, setting carry if the
- result is non-negative */
- adds r1, r1, r3
- /* Shift quotient left one and add carry bit */
- adc r0, r0, r0
- bx lr
-.L_div0:
- /* __div0 expects the calling address on the top of the stack */
- stmdb sp!, { lr }
- mov r0, #0
-#if defined(__ARM_EABI__) || !defined(USE_IRAM)
- bl __div0
-#else
- ldr pc, [pc, #-4]
- .word __div0
-#endif
-#ifdef DIV_RECIP
-.L_udiv_recip_table:
- .set div, 3
- .rept recip_max - 2
- .if (div - 1) & div
- .set q, 0x40000000 / div
- .set r, (0x40000000 - (q * div))<<1
- .set q, q << 1
- .if r >= div
- .set q, q + 1
- .set r, r - div
- .endif
- .set r, r << 1
- .set q, q << 1
- .if r >= div
- .set q, q + 1
- .set r, r - div
- .endif
- .set q, q + 1
- .else
- .set q, 0x40000000 / div * 4
- .endif
- .word q
- .set div, div+1
- .endr
-#endif
- .size udiv32_arm, . - udiv32_arm
-
-#else
-.macro ARMV5_UDIV32_BODY numerator, divisor, quotient, bits, inv, neg, div0label
- cmp \numerator, \divisor
- clz \bits, \divisor
- bcc 30f
- mov \inv, \divisor, lsl \bits
- add \neg, pc, \inv, lsr #25
- cmp \inv, #1<<31
- ldrhib \inv, [\neg, #.L_udiv_est_table-.-64]
- bls 20f
- subs \bits, \bits, #7
- rsb \neg, \divisor, #0
- movpl \divisor, \inv, lsl \bits
- bmi 10f
- mul \inv, \divisor, \neg
- smlawt \divisor, \divisor, \inv, \divisor
- mul \inv, \divisor, \neg
- /* This will save a cycle on ARMv6, but does not produce a correct result
- if numerator sign bit is set. This case accounts for about 1 in 10^7 of
- divisions, done by the APE decoder, so we specialize for the more common
- case and handle the uncommon large-numerator separately */
-#if ARM_ARCH >= 6
- tst \numerator, \numerator
- smmla \divisor, \divisor, \inv, \divisor
- bmi 40f
- smmul \inv, \numerator, \divisor
-#else
- mov \bits, #0
- smlal \bits, \divisor, \inv, \divisor
- umull \bits, \inv, \numerator, \divisor
-#endif
- add \numerator, \numerator, \neg
- mla \divisor, \inv, \neg, \numerator
- mov \quotient, \inv
- cmn \divisor, \neg
- addcc \quotient, \quotient, #1
- addpl \quotient, \quotient, #2
- bx lr
-10:
- rsb \bits, \bits, #0
- sub \inv, \inv, #4
- mov \divisor, \inv, lsr \bits
- umull \bits, \inv, \numerator, \divisor
- mla \divisor, \inv, \neg, \numerator
- mov \quotient, \inv
- cmn \neg, \divisor, lsr #1
- addcs \divisor, \divisor, \neg, lsl #1
- addcs \quotient, \quotient, #2
- cmn \neg, \divisor
- addcs \quotient, \quotient, #1
- bx lr
-20:
-.ifnc "", "\div0label"
- rsb \bits, \bits, #31
- bne \div0label
-.endif
- mov \quotient, \numerator, lsr \bits
- bx lr
-30:
- mov \quotient, #0
- bx lr
-#if ARM_ARCH >= 6
-40:
- umull \bits, \inv, \numerator, \divisor
- add \numerator, \numerator, \neg
- mla \divisor, \inv, \neg, \numerator
- mov \quotient, \inv
- cmn \divisor, \neg
- addcc \quotient, \quotient, #1
- addpl \quotient, \quotient, #2
- bx lr
-#endif
-.endm
-
-udiv32_arm:
- ARMV5_UDIV32_BODY r0, r1, r0, r2, r3, ip, .L_div0
-.L_div0:
- /* __div0 expects the calling address on the top of the stack */
- stmdb sp!, { lr }
- mov r0, #0
-#if defined(__ARM_EABI__) || !defined(USE_IRAM)
- bl __div0
-#else
- ldr pc, [pc, #-4]
- .word __div0
-#endif
-.L_udiv_est_table:
- .byte 0xff, 0xfc, 0xf8, 0xf4, 0xf0, 0xed, 0xea, 0xe6
- .byte 0xe3, 0xe0, 0xdd, 0xda, 0xd7, 0xd4, 0xd2, 0xcf
- .byte 0xcc, 0xca, 0xc7, 0xc5, 0xc3, 0xc0, 0xbe, 0xbc
- .byte 0xba, 0xb8, 0xb6, 0xb4, 0xb2, 0xb0, 0xae, 0xac
- .byte 0xaa, 0xa8, 0xa7, 0xa5, 0xa3, 0xa2, 0xa0, 0x9f
- .byte 0x9d, 0x9c, 0x9a, 0x99, 0x97, 0x96, 0x94, 0x93
- .byte 0x92, 0x90, 0x8f, 0x8e, 0x8d, 0x8c, 0x8a, 0x89
- .byte 0x88, 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81
-#endif
- .size udiv32_arm, . - udiv32_arm