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/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <machine/asm.h>
#ifdef __ARMEB__
#define ALO r1 /* incoming numerator, outgoing quotient */
#define AHI r0 /* incoming numerator, outgoing quotient */
#define BLO r3 /* incoming denominator, outgoing remainder */
#define BHI r2 /* incoming denominator, outgoing remainder */
#else
#define ALO r0 /* incoming numerator, outgoing quotient */
#define AHI r1 /* incoming numerator, outgoing quotient */
#define BLO r2 /* incoming denominator, outgoing remainder */
#define BHI r3 /* incoming denominator, outgoing remainder */
#endif
ENTRY(__aeabi_ldivmod)
push {r4-r6, lr}
#define NEG r5
movs NEG, #0
cmp BHI, #0
bge 2f
movs NEG, #1 /* flip quotient sign */
bl .Lnegate_b
bcs .Lmaxdenom
2:
cmp AHI, #0
eorlt NEG, NEG, #3 /* flip quotient sign, flip remainder sign */
bllt .Lnegate_a
/*
* Arguments are setup, allocate some stack for the remainder
* and call __qdivrem for the heavy lifting.
*/
sub sp, sp, #16
adds r4, sp, #8
str r4, [sp]
bl __qdivrem
add sp, sp, #8
/*
* The quotient is already in the right place and neither value
* needs its sign flipped.
*/
cmp NEG, #0 /* any signs to flip? */
beq .Lnegate_neither
cmp NEG, #2 /* does remainder need to be negative? */
beq .Lnegate_b_only /* 2 means b only */
bgt .Lnegate_both /* 3 means both */
.Lnegate_a_only:
bl .Lnegate_a /* 1 means a only */
.Lnegate_neither:
pop {r2-r6, pc} /* grab b from stack */
.Lnegate_both:
bl .Lnegate_a
.Lnegate_b_only:
pop {r2-r3} /* get remainder */
bl .Lnegate_b /* negate it */
pop {r4-r6, pc}
.align 0
.Lnegate_a:
negs ALO, ALO
rsc AHI, AHI, #0
mov pc, lr
.align 0
.Lnegate_b:
negs BLO, BLO
rsc BHI, BHI, #0
mov pc, lr
.align 0
.Lmaxdenom:
/*
* We had a carry so the denominator must have INT64_MIN
* Also BLO and BHI never changed values so we can use
* them to see if the numerator has the same value. We
* don't have to worry about sign.
*/
cmp BHI, AHI
cmpeq BLO, ALO
bne 1f
/*
* They were equal, so we return a quotient of 1 and remainder of 0.
*/
movs ALO, #1
movs AHI, #0
movs BLO, #0
movs BHI, #0
pop {r4-r6, pc}
/*
* Our remainder must be the numerator and our quotient is 0.
*/
.align 0
1: movs BLO, ALO
movs BHI, AHI
movs ALO, #0
movs AHI, #0
pop {r4-r6, pc}
END(__aeabi_ldivmod)
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