FS#10943, optimized division and clz routines to replace libgcc routines for ARM. Replaces libgcc support functions for unsigned and signed 32-bit division on ARMv4 and up, and leading-zero count on ARMv4.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24432 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
parent
40a3e80697
commit
bff5a35c3c
5 changed files with 703 additions and 1 deletions
|
@ -8,6 +8,7 @@ mdct_lookup.c
|
|||
mdct_arm.S
|
||||
setjmp_arm.S
|
||||
udiv32_arm.S
|
||||
../../../firmware/target/arm/support-arm.S
|
||||
#endif
|
||||
|
||||
#ifdef CPU_COLDFIRE
|
||||
|
|
|
@ -65,7 +65,7 @@ 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);
|
||||
|
||||
#ifdef CPU_ARM
|
||||
#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)
|
||||
|
|
|
@ -30,6 +30,7 @@ profile_plugin.c
|
|||
#endif
|
||||
#ifdef HAVE_LCD_BITMAP
|
||||
#ifdef CPU_ARM
|
||||
../../../firmware/target/arm/support-arm.S
|
||||
pluginlib_jpeg_idct_arm.S
|
||||
#endif
|
||||
pluginlib_jpeg_mem.c
|
||||
|
|
|
@ -375,6 +375,7 @@ target/coldfire/i2c-coldfire.c
|
|||
|
||||
#elif defined(CPU_PP) || defined(CPU_ARM)
|
||||
/* CPU_PP => CPU_ARM, CPU_ARM !=> CPU_PP */
|
||||
target/arm/support-arm.S
|
||||
target/arm/memcpy-arm.S
|
||||
target/arm/memmove-arm.S
|
||||
common/strlen.c
|
||||
|
|
699
firmware/target/arm/support-arm.S
Normal file
699
firmware/target/arm/support-arm.S
Normal file
|
@ -0,0 +1,699 @@
|
|||
/***************************************************************************
|
||||
* __________ __ ___.
|
||||
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
||||
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
||||
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
||||
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
||||
* \/ \/ \/ \/ \/
|
||||
* $Id$
|
||||
*
|
||||
* Copyright (C) 2008 by Jens Arnold
|
||||
* Copyright (C) 2009 by Andrew Mahone
|
||||
*
|
||||
* Optimised replacements for libgcc functions
|
||||
*
|
||||
* 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>
|
||||
|
||||
.macro ARM_SDIV32_PRE numerator, divisor, sign
|
||||
/* sign[31] = divisor sign */
|
||||
ands \sign, \divisor, #1<<31
|
||||
rsbeq \divisor, \divisor, #0
|
||||
/* sign[31] = result sign, sign[0:30], C = numerator sign */
|
||||
eors \sign, \sign, \numerator, asr #32
|
||||
rsbcs \numerator, \numerator, #0
|
||||
.endm
|
||||
|
||||
.macro ARM_SDIV32_POST quotient, remainder, sign
|
||||
movs \sign, \sign, lsl #1
|
||||
.ifnc "", "\quotient"
|
||||
rsbcs \quotient, \quotient, #0
|
||||
.endif
|
||||
.ifnc "", "\remainder"
|
||||
rsbmi \remainder, \remainder, #0
|
||||
.endif
|
||||
.endm
|
||||
|
||||
#if ARM_ARCH < 5
|
||||
.macro ARMV4_UDIV32_BODY numerator, divisor, quotient, remainder, tmp, bits, div0label, return
|
||||
.ifnc "", "\div0label"
|
||||
rsbs \divisor, \divisor, #0
|
||||
beq \div0label
|
||||
.else
|
||||
rsb \divisor, \divisor, #0
|
||||
.endif
|
||||
/* This SWAR divider requires a numerator less than 1<<31, because it must
|
||||
be able to shift the remainder left at each step without shifting out
|
||||
topmost bit. Since a shift might be needed for the aligned remainder to
|
||||
exceed the divisor, the topmost bit must be unset at the start to avoid
|
||||
this overflow case. The original numerator is saved so that the result
|
||||
can be corrected after the reduced division completes. */
|
||||
cmn \numerator, \divisor
|
||||
.ifc "", "\quotient"
|
||||
.ifc "\numerator", "\remainder"
|
||||
.if \return
|
||||
bxcc lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
.else
|
||||
bcc 20f
|
||||
.endif
|
||||
.else
|
||||
bcc 20f
|
||||
.endif
|
||||
movs \tmp, \numerator
|
||||
movmi \numerator, \numerator, lsr #1
|
||||
mov \bits, #30
|
||||
.set shift, 16
|
||||
.rept 5
|
||||
cmn \divisor, \numerator, lsr #shift
|
||||
subcs \bits, \bits, #shift
|
||||
movcs \divisor, \divisor, lsl #shift
|
||||
.set shift, shift >> 1
|
||||
.endr
|
||||
adds \numerator, \numerator, \divisor
|
||||
subcc \numerator, \numerator, \divisor
|
||||
add pc, pc, \bits, lsl #3
|
||||
nop
|
||||
.rept 30
|
||||
adcs \numerator, \divisor, \numerator, lsl #1
|
||||
subcc \numerator, \numerator, \divisor
|
||||
.endr
|
||||
adc \numerator, \numerator, \numerator
|
||||
movs \tmp, \tmp, asr #1
|
||||
rsb \bits, \bits, #31
|
||||
bmi 10f
|
||||
.ifc "", "\quotient"
|
||||
mov \remainder, \numerator, lsr \bits
|
||||
.else
|
||||
.ifc "", "\remainder"
|
||||
mov \divisor, \numerator, lsr \bits
|
||||
eor \quotient, \numerator, \divisor, lsl \bits
|
||||
.else
|
||||
mov \remainder, \numerator, lsr \bits
|
||||
eor \quotient, \numerator, \remainder, lsl \bits
|
||||
.endif
|
||||
.endif
|
||||
.ifne \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
10:
|
||||
mov \tmp, \numerator, lsr \bits
|
||||
eor \numerator, \numerator, \tmp, lsl \bits
|
||||
sub \bits, \bits, #1
|
||||
adc \tmp, \tmp, \tmp
|
||||
adds \tmp, \tmp, \divisor, asr \bits
|
||||
.ifnc "", "\quotient"
|
||||
adc \quotient, \numerator, \numerator
|
||||
.endif
|
||||
.ifnc "", "\remainder"
|
||||
subcc \remainder, \tmp, \divisor, asr \bits
|
||||
movcs \remainder, \tmp
|
||||
.endif
|
||||
.ifne \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
20:
|
||||
.ifnc "", "\remainder"
|
||||
.ifnc "\remainder", "\numerator"
|
||||
mov \remainder, \numerator
|
||||
.endif
|
||||
.endif
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, #0
|
||||
.endif
|
||||
.ifne \return
|
||||
bx lr
|
||||
.else
|
||||
99:
|
||||
.endif
|
||||
.endm
|
||||
|
||||
.macro ARMV4_SDIV32_BODY numerator, divisor, quotient, remainder, bits, sign, div0label, return
|
||||
/* When this is wrapped for signed division, the wrapper code will handle
|
||||
inverting the divisor, and also the zero divisor test. */
|
||||
ARM_SDIV32_PRE \numerator, \divisor, \sign
|
||||
.ifnc "", "\div0label"
|
||||
tst \divisor, \divisor
|
||||
beq \div0label
|
||||
.endif
|
||||
/* This SWAR divider requires a numerator less than 1<<31, because it must
|
||||
be able to shift the remainder left at each step without shifting out
|
||||
topmost bit. With signed inputs, whose absolute value may not exceed
|
||||
1<<31,this may be accomplished simply by subtracting the divisor before
|
||||
beginning division, and adding 1 to the quotient. */
|
||||
adds \numerator, \numerator, \divisor
|
||||
bcc 20f
|
||||
mov \bits, #30
|
||||
.set shift, 16
|
||||
.rept 5
|
||||
cmn \divisor, \numerator, lsr #shift
|
||||
subcs \bits, \bits, #shift
|
||||
movcs \divisor, \divisor, lsl #shift
|
||||
.set shift, shift >> 1
|
||||
.endr
|
||||
adds \numerator, \numerator, \divisor
|
||||
subcc \numerator, \numerator, \divisor
|
||||
add pc, pc, \bits, lsl #3
|
||||
nop
|
||||
.rept 30
|
||||
adcs \numerator, \divisor, \numerator, lsl #1
|
||||
subcc \numerator, \numerator, \divisor
|
||||
.endr
|
||||
rsb \bits, \bits, #31
|
||||
adc \numerator, \numerator, \numerator
|
||||
.ifc "", "\quotient"
|
||||
mov \remainder, \numerator, lsr \bits
|
||||
.else
|
||||
.ifc "", "\remainder"
|
||||
mov \divisor, \numerator, lsr \bits
|
||||
add \numerator, \numerator, #1
|
||||
sub \quotient, \numerator, \divisor, lsl \bits
|
||||
.else
|
||||
mov \remainder, \numerator, lsr \bits
|
||||
add \numerator, \numerator, #1
|
||||
sub \quotient, \numerator, \remainder, lsl \bits
|
||||
.endif
|
||||
.endif
|
||||
.ifne \return
|
||||
ARM_SDIV32_POST \quotient, \remainder, \sign
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
20:
|
||||
.ifnc "", "\remainder"
|
||||
sub \remainder, \numerator, \divisor
|
||||
.endif
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, #0
|
||||
.endif
|
||||
.ifne \return
|
||||
ARM_SDIV32_POST "", \remainder, \sign
|
||||
bx lr
|
||||
.else
|
||||
99:
|
||||
ARM_SDIV32_POST \quotient, \remainder, \sign
|
||||
.endif
|
||||
.endm
|
||||
|
||||
#else
|
||||
.macro ARMV5_UDIV32_BODY numerator, divisor, quotient, remainder, bits, inv, neg, div0label, return
|
||||
cmp \numerator, \divisor
|
||||
clz \bits, \divisor
|
||||
bcc 30f
|
||||
mov \inv, \divisor, lsl \bits
|
||||
add \neg, pc, \inv, lsr #25
|
||||
/* Test whether divisor is 2^N */
|
||||
cmp \inv, #1<<31
|
||||
/* Load approximate reciprocal */
|
||||
ldrhib \inv, [\neg, #.L_udiv_est_table-.-64]
|
||||
bls 20f
|
||||
subs \bits, \bits, #7
|
||||
rsb \neg, \divisor, #0
|
||||
/* Scale approximate reciprocal, or else branch to large-divisor path */
|
||||
movpl \divisor, \inv, lsl \bits
|
||||
bmi 10f
|
||||
/* Newton-Raphson iteration to improve reciprocal accuracy */
|
||||
mul \inv, \divisor, \neg
|
||||
smlawt \divisor, \divisor, \inv, \divisor
|
||||
mul \inv, \divisor, \neg
|
||||
/* Complete N-R math and produce approximate quotient. Use smmla/smmul on
|
||||
ARMv6. */
|
||||
#if ARM_ARCH >= 6
|
||||
tst \numerator, \numerator
|
||||
smmla \divisor, \divisor, \inv, \divisor
|
||||
/* Branch to large-numerator handler, or else use smmul if sign bit is not
|
||||
set. */
|
||||
bmi 40f
|
||||
smmul \inv, \numerator, \divisor
|
||||
#else
|
||||
/* ARMv5e lacks smmul, so always uses umull. */
|
||||
mov \bits, #0
|
||||
smlal \bits, \divisor, \inv, \divisor
|
||||
umull \bits, \inv, \numerator, \divisor
|
||||
#endif
|
||||
/* Calculate remainder and correct result. */
|
||||
add \numerator, \numerator, \neg
|
||||
.ifnc "", "\remainder"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, \inv
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.else
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
.endif
|
||||
.else
|
||||
mla \divisor, \inv, \neg, \numerator
|
||||
mov \quotient, \inv
|
||||
cmn \divisor, \neg
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.endif
|
||||
.if \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
10:
|
||||
/* Very large divisors can be handled without further improving the
|
||||
reciprocal. First the reciprocal must be reduced to ensure that it
|
||||
underestimates the correct value. */
|
||||
rsb \bits, \bits, #0
|
||||
sub \inv, \inv, #4
|
||||
mov \divisor, \inv, lsr \bits
|
||||
/* Calculate approximate quotient and remainder */
|
||||
umull \bits, \inv, \numerator, \divisor
|
||||
/* Correct quotient and remainder */
|
||||
.ifnc "", "\remainder"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, \inv
|
||||
cmn \neg, \remainder, lsr #1
|
||||
addcs \remainder, \remainder, \neg, lsl #1
|
||||
addcs \quotient, \quotient, #2
|
||||
cmn \neg, \remainder
|
||||
addcs \remainder, \remainder, \neg
|
||||
addcs \quotient, \quotient, #1
|
||||
.else
|
||||
cmn \neg, \remainder, lsr #1
|
||||
addcs \remainder, \remainder, \neg, lsl #1
|
||||
cmn \neg, \remainder
|
||||
addcs \remainder, \remainder, \neg
|
||||
.endif
|
||||
.else
|
||||
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
|
||||
.endif
|
||||
.if \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
20:
|
||||
/* Handle division by powers of two by shifting right. Mod is handled
|
||||
by using divisor-1 as a bitmask. */
|
||||
.ifnc "", "\remainder"
|
||||
.ifnc "", "\div0label"
|
||||
bne \div0label
|
||||
.endif
|
||||
.ifnc "", "\quotient"
|
||||
sub \divisor, \divisor, #1
|
||||
rsb \bits, \bits, #31
|
||||
and \remainder, \numerator, \divisor
|
||||
mov \quotient, \numerator, lsr \bits
|
||||
.else
|
||||
sub \divisor, \divisor, #1
|
||||
and \remainder, \numerator, \divisor
|
||||
.endif
|
||||
.else
|
||||
rsb \bits, \bits, #31
|
||||
.ifnc "", "\div0label"
|
||||
bne \div0label
|
||||
.endif
|
||||
mov \quotient, \numerator, lsr \bits
|
||||
.endif
|
||||
.if \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
30:
|
||||
/* Handle numerator < divisor - quotient is zero, remainder is numerator,
|
||||
which must be restored to its original value on ARMv6. */
|
||||
.ifnc "", "\remainder"
|
||||
mov \remainder, \numerator
|
||||
.endif
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, #0
|
||||
.endif
|
||||
.if \return
|
||||
bx lr
|
||||
.endif
|
||||
#if ARM_ARCH >= 6
|
||||
40:
|
||||
/* Handle large (sign bit set) numerators. Works exactly as the ARMv5e code
|
||||
above 10:. */
|
||||
umull \bits, \inv, \numerator, \divisor
|
||||
add \numerator, \numerator, \neg
|
||||
.ifnc "", "\remainder"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
.ifnc "", "\quotient"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
mov \quotient, \inv
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.else
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
.endif
|
||||
.else
|
||||
mla \divisor, \inv, \neg, \numerator
|
||||
mov \quotient, \inv
|
||||
cmn \divisor, \neg
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.endif
|
||||
.if \return
|
||||
bx lr
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
#endif
|
||||
99:
|
||||
.endm
|
||||
|
||||
.macro ARMV5_SDIV32_BODY numerator, divisor, quotient, remainder, bits, inv, neg, sign, div0label, return
|
||||
/* sign[31] = divisor sign */
|
||||
ands \sign, \divisor, #1<<31
|
||||
rsbne \divisor, \divisor, #0
|
||||
/* sign[31] = result sign, sign[0:30], C = numerator sign */
|
||||
eors \sign, \sign, \numerator, asr #32
|
||||
clz \bits, \divisor
|
||||
rsbcs \numerator, \numerator, #0
|
||||
/* On ARMv6, subtract divisor before performing division, which ensures
|
||||
numerator sign bit is clear and smmul may be used in place of umull. The
|
||||
fixup for the results can be fit entirely into existing delay slots on
|
||||
the main division paths. It costs 1c in the num<div path if the
|
||||
the remainder is to be produced in the numerator's register, and 1c in
|
||||
the power-of-2-divisor path only if producing both remainder and
|
||||
quotient. */
|
||||
#if ARM_ARCH >= 6
|
||||
subs \numerator, \numerator, \divisor
|
||||
#else
|
||||
cmp \numerator, \divisor
|
||||
#endif
|
||||
movcs \inv, \divisor, lsl \bits
|
||||
bcc 30f
|
||||
/* Test whether divisor is 2^N */
|
||||
cmp \inv, #1<<31
|
||||
add \inv, pc, \inv, lsr #25
|
||||
bls 20f
|
||||
/* Load approximate reciprocal */
|
||||
ldrb \inv, [\inv, #.L_udiv_est_table-.-64]
|
||||
subs \bits, \bits, #7
|
||||
rsb \neg, \divisor, #0
|
||||
/* Scale approximate reciprocal, or else branch to large-divisor path */
|
||||
movpl \divisor, \inv, lsl \bits
|
||||
bmi 10f
|
||||
/* Newton-Raphson iteration to improve reciprocal accuracy */
|
||||
mul \inv, \divisor, \neg
|
||||
smlawt \divisor, \divisor, \inv, \divisor
|
||||
mul \inv, \divisor, \neg
|
||||
/* Complete N-R math and produce approximate quotient. Use smmla/smmul on
|
||||
ARMv6. */
|
||||
#if ARM_ARCH >= 6
|
||||
smmla \divisor, \divisor, \inv, \divisor
|
||||
smmul \inv, \numerator, \divisor
|
||||
#else
|
||||
mov \bits, #0
|
||||
smlal \bits, \divisor, \inv, \divisor
|
||||
umull \bits, \inv, \numerator, \divisor
|
||||
#endif
|
||||
/* Calculate remainder and correct quotient. */
|
||||
add \numerator, \numerator, \neg
|
||||
.ifnc "", "\remainder"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
.ifnc "", "\quotient"
|
||||
#if ARM_ARCH >= 6
|
||||
add \quotient, \inv, #1
|
||||
#else
|
||||
mov \quotient, \inv
|
||||
#endif
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.else
|
||||
cmn \remainder, \neg
|
||||
subcs \remainder, \remainder, \neg
|
||||
addpl \remainder, \remainder, \neg, lsl #1
|
||||
.endif
|
||||
.else
|
||||
mla \divisor, \inv, \neg, \numerator
|
||||
#if ARM_ARCH >= 6
|
||||
add \quotient, \inv, #1
|
||||
#else
|
||||
mov \quotient, \inv
|
||||
#endif
|
||||
cmn \divisor, \neg
|
||||
addcc \quotient, \quotient, #1
|
||||
addpl \quotient, \quotient, #2
|
||||
.endif
|
||||
ARM_SDIV32_POST \quotient, \remainder, \sign
|
||||
.ifnc "", "\return"
|
||||
\return
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
10:
|
||||
/* Very large divisors can be handled without further improving the
|
||||
reciprocal. First the reciprocal must be reduced to ensure that it
|
||||
underestimates the correct value. */
|
||||
rsb \bits, \bits, #0
|
||||
sub \inv, \inv, #4
|
||||
mov \divisor, \inv, lsr \bits
|
||||
/* Calculate approximate quotient and remainder */
|
||||
#if ARM_ARCH >= 6
|
||||
smmul \inv, \numerator, \divisor
|
||||
#else
|
||||
umull \bits, \inv, \numerator, \divisor
|
||||
#endif
|
||||
/* Correct quotient and remainder */
|
||||
.ifnc "", "\remainder"
|
||||
mla \remainder, \inv, \neg, \numerator
|
||||
.ifnc "", "\quotient"
|
||||
#if ARM_ARCH >= 6
|
||||
add \quotient, \inv, #1
|
||||
#else
|
||||
mov \quotient, \inv
|
||||
#endif
|
||||
cmn \neg, \remainder, lsr #1
|
||||
addcs \remainder, \remainder, \neg, lsl #1
|
||||
addcs \quotient, \quotient, #2
|
||||
cmn \neg, \remainder
|
||||
addcs \remainder, \remainder, \neg
|
||||
addcs \quotient, \quotient, #1
|
||||
.else
|
||||
cmn \neg, \remainder, lsr #1
|
||||
addcs \remainder, \remainder, \neg, lsl #1
|
||||
cmn \neg, \remainder
|
||||
addcs \remainder, \remainder, \neg
|
||||
.endif
|
||||
.else
|
||||
mla \divisor, \inv, \neg, \numerator
|
||||
#if ARM_ARCH >= 6
|
||||
add \quotient, \inv, #1
|
||||
#else
|
||||
mov \quotient, \inv
|
||||
#endif
|
||||
cmn \neg, \divisor, lsr #1
|
||||
addcs \divisor, \divisor, \neg, lsl #1
|
||||
addcs \quotient, \quotient, #2
|
||||
cmn \neg, \divisor
|
||||
addcs \quotient, \quotient, #1
|
||||
.endif
|
||||
ARM_SDIV32_POST \quotient, \remainder, \sign
|
||||
.ifnc "", "\return"
|
||||
\return
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
20:
|
||||
/* Handle division by powers of two by shifting right. Mod is handled
|
||||
by using divisor-1 as a bitmask. */
|
||||
.ifnc "", "\div0label"
|
||||
bne \div0label
|
||||
.endif
|
||||
.ifnc "", "\remainder"
|
||||
.ifnc "", "\quotient"
|
||||
rsb \bits, \bits, #31
|
||||
#if ARM_ARCH >= 6
|
||||
add \numerator, \numerator, \divisor
|
||||
#endif
|
||||
sub \divisor, \divisor, #1
|
||||
and \remainder, \numerator, \divisor
|
||||
mov \quotient, \numerator, lsr \bits
|
||||
.else
|
||||
sub \divisor, \divisor, #1
|
||||
and \remainder, \numerator, \divisor
|
||||
.endif
|
||||
.else
|
||||
rsb \bits, \bits, #31
|
||||
#if ARM_ARCH >= 6
|
||||
add \numerator, \numerator, \divisor
|
||||
#endif
|
||||
mov \quotient, \numerator, lsr \bits
|
||||
.endif
|
||||
ARM_SDIV32_POST \quotient, \remainder, \sign
|
||||
.ifnc "", "\return"
|
||||
\return
|
||||
.else
|
||||
b 99f
|
||||
.endif
|
||||
30:
|
||||
/* Handle numerator < divisor - quotient is zero, remainder is numerator,
|
||||
which must be restored to its original value on ARMv6. */
|
||||
.ifnc "", "\remainder"
|
||||
#if ARM_ARCH >= 6
|
||||
add \remainder, \numerator, \divisor
|
||||
#else
|
||||
.ifnc "\remainder", "\numerator"
|
||||
mov \remainder, \numerator
|
||||
.endif
|
||||
#endif
|
||||
.endif
|
||||
.ifnc "", "\quotient"
|
||||
mov \quotient, #0
|
||||
.endif
|
||||
ARM_SDIV32_POST "", \remainder, \sign
|
||||
.ifnc "", "\return"
|
||||
\return
|
||||
.endif
|
||||
99:
|
||||
.endm
|
||||
#endif
|
||||
|
||||
.section .text
|
||||
|
||||
__div0_wrap_s:
|
||||
sub sp, sp, #4
|
||||
mov r0, #0
|
||||
b __div0
|
||||
.size __div0_wrap_s, . - __div0_wrap_s
|
||||
|
||||
__div0_wrap:
|
||||
str lr, [sp, #-4]!
|
||||
mov r0, #0
|
||||
b __div0
|
||||
.size __div0_wrap, . - __div0_wrap
|
||||
|
||||
#ifndef __ARM_EABI__
|
||||
.global __divsi3
|
||||
.type __divsi3,%function
|
||||
.global __udivsi3
|
||||
.type __udivsi3,%function
|
||||
.global __udivsi3
|
||||
.type __udivsi3,%function
|
||||
#else
|
||||
/* The div+mod averagess a fraction of a cycle worse for signed values, and
|
||||
slightly better for unsigned, so just alias div to divmod. */
|
||||
.global __aeabi_uidivmod
|
||||
.type __aeabi_uidivmod,%function
|
||||
.global __aeabi_uidiv
|
||||
.type __aeabi_uidiv,%function
|
||||
.set __aeabi_uidiv,__aeabi_uidivmod
|
||||
.global __aeabi_idivmod
|
||||
.type __aeabi_idivmod,%function
|
||||
.global __aeabi_idiv
|
||||
.type __aeabi_idiv,%function
|
||||
.set __aeabi_idiv,__aeabi_idivmod
|
||||
#endif
|
||||
|
||||
|
||||
#if ARM_ARCH < 5
|
||||
.global __clzsi2
|
||||
.type __clzsi2, %function
|
||||
|
||||
__clzsi2:
|
||||
orr r0, r0, r0, lsr #8
|
||||
orr r0, r0, r0, lsr #4
|
||||
orr r0, r0, r0, lsr #2
|
||||
orr r0, r0, r0, lsr #1
|
||||
bic r0, r0, r0, lsr #16
|
||||
rsb r0, r0, r0, lsl #14
|
||||
rsb r0, r0, r0, lsl #11
|
||||
rsb r0, r0, r0, lsl #9
|
||||
ldrb r0, [pc, r0, lsr #26]
|
||||
bx lr
|
||||
.byte 32, 20, 19, 0, 0, 18, 0, 7, 10, 17, 0, 0, 14, 0, 6, 0
|
||||
.byte 0, 9, 0, 16, 0, 0, 1, 26, 0, 13, 0, 0, 24, 5, 0, 0
|
||||
.byte 0, 21, 0, 8, 11, 0, 15, 0, 0, 0, 0, 2, 27, 0, 25, 0
|
||||
.byte 22, 0, 12, 0, 0, 3, 28, 0, 23, 0, 4, 29, 0, 0, 30, 31
|
||||
.size __clzsi2, .-__clzsi2
|
||||
|
||||
#ifndef __ARM_EABI__
|
||||
__udivsi3:
|
||||
ARMV4_UDIV32_BODY r0, r1, r0, "", r2, r3, __div0_wrap, 1
|
||||
.size __udivsi3, . - __udivsi3
|
||||
|
||||
__divsi3:
|
||||
ARMV4_SDIV32_BODY r0, r1, r0, "", r2, r3, __div0_wrap, 1
|
||||
.size __divsi3, . - __divsi3
|
||||
|
||||
#else
|
||||
__aeabi_uidivmod:
|
||||
ARMV4_UDIV32_BODY r0, r1, r0, r1, r2, r3, __div0_wrap, 1
|
||||
.size __aeabi_uidivmod, . - __aeabi_uidivmo
|
||||
|
||||
__aeabi_idivmod
|
||||
ARMV4_SDIV32_BODY r0, r1, r0, r1, r2, r3, __div0_wrap, 1
|
||||
.size __aeabi_idivmod, . - __aeabi_idivmod
|
||||
#endif
|
||||
|
||||
#else
|
||||
#ifndef __ARM_EABI__
|
||||
__udivsi3:
|
||||
ARMV5_UDIV32_BODY r0, r1, r0, "", r2, r3, ip, __div0_wrap, 1
|
||||
.size __udivsi3, . - __udivsi3
|
||||
|
||||
__divsi3:
|
||||
ARMV5_SDIV32_BODY r0, r1, r0, "", r2, lr, ip, r3, __div0_wrap_s, "ldr pc, [sp, #-4]"
|
||||
.size __divsi3, . - __divsi3
|
||||
|
||||
#else
|
||||
__aeabi_uidivmod:
|
||||
ARMV5_UDIV32_BODY r0, r1, r0, r1, r2, r3, ip, __div0_wrap, 1
|
||||
.size __aeabi_uidivmod, . - __aeabi_uidivmo
|
||||
|
||||
__aeabi_idivmod
|
||||
ARMV5_SDIV32_BODY r0, r1, r0, r1, r2, lr, ip, r3, __div0_wrap_s, "ldr pc, [sp, #-4]"
|
||||
.size __aeabi_idivmod, . - __aeabi_idivmod
|
||||
#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
|
Loading…
Reference in a new issue