Home | History | Annotate | Line # | Download | only in quad
__aeabi_ldivmod.S revision 1.1.2.1 
      1 /*-
      2  * Copyright (c) 2012 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to The NetBSD Foundation
      6  * by Matt Thomas of 3am Software Foundry.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include <machine/asm.h>
     31 
     32 RCSID("$NetBSD: __aeabi_ldivmod.S,v 1.1.2.1 2013/06/23 06:26:13 tls Exp $")
     33 
     34 ENTRY(__aeabi_ldivmod)
     35 #if !defined(_KERNEL) && !defined(_STANDALONE)
     36 	orrs	ip, r2, r3
     37 	beq	.Ldivbyzero
     38 #endif
     39 
     40 	push	{r4-r5, sl, lr}
     41 #define	NEG	r5
     42 	mov	NEG, #0
     43 
     44 #ifdef __ARMEB__
     45 #define	ALO	r1	/* incoming numerator, outgoing quotient */
     46 #define	AHI	r0	/* incoming numerator, outgoing quotient */
     47 #define	BLO	r3	/* incoming denominator, outgoing remainder */
     48 #define	BHI	r2	/* incoming denominator, outgoing remainder */
     49 #else
     50 #define	ALO	r0	/* incoming numerator, outgoing quotient */
     51 #define	AHI	r1	/* incoming numerator, outgoing quotient */
     52 #define	BLO	r2	/* incoming denominator, outgoing remainder */
     53 #define	BHI	r3	/* incoming denominator, outgoing remainder */
     54 #endif
     55 
     56 	cmp	BHI, #0
     57 	bge	2f
     58 	eor	NEG, NEG, #1	/* flip quotient sign */
     59 	bl	.Lnegate_b
     60 	bcs	.Lmaxdenom
     61 
     62 2:
     63 	cmp	AHI, #0
     64 	/* bge	3f */
     65 	eorlt	NEG, NEG, #3	/* flip quotient sign, flip remainder sign */
     66 	bllt	.Lnegate_a
     67 3:
     68 	/*
     69 	 * Arguments are setup, allocate some stack for the remainder
     70 	 * and call __qdivrem for the heavy lifting.
     71 	 */
     72 	sub	sp, sp, #16
     73 	add	ip, sp, #8
     74 	str	ip, [sp]
     75 	bl	PLT_SYM(__qdivrem)
     76 	add	sp, sp, #8
     77 
     78 	teq	NEG, #0		/* any signs to flip? */
     79 	/*
     80 	 * The quotient is already in the right place and neither value
     81 	 * needs its sign flipped.
     82 	 */
     83 	popeq	{r2-r5, sl, lr}
     84 	RETc(eq)
     85 
     86 	pop	{r2, r3}
     87 	tst	NEG, #2		/* does remainder need to be negative? */
     88 	blne	.Lnegate_b
     89 	tst	NEG, #1		/* does quotient need to be negative? */
     90 	blne	.Lnegate_a
     91 	pop	{r4-r5, sl, lr}
     92 	RET
     93 
     94 .Lnegate_a:
     95         rsbs	ALO, ALO, #0
     96         rsc	AHI, AHI, #0
     97 	RET
     98 
     99 .Lnegate_b:
    100         rsbs	BLO, BLO, #0
    101         rsc	BHI, BHI, #0
    102 	RET
    103 
    104 .Lmaxdenom:
    105 	/*
    106 	 * We had a carry so the denominator must have INT64_MIN
    107 	 * Also BLO and BHI never changed values so we can use
    108 	 * them to see if the numerator has the same value.  We
    109 	 * don't have to worry about sign.
    110 	 */
    111 	teq	BHI, AHI
    112 	teqeq	BLO, ALO
    113 	bne	1f
    114 
    115 	/*
    116 	 * They were equal, so we return a quotient of 1 and remainder of 0.
    117 	 */
    118 	mov	ALO, #1
    119 	mov	AHI, #0
    120 	mov	BLO, #0
    121 	mov	BHI, #0
    122 	pop	{r4-r5, sl, lr}
    123 	RET
    124 
    125 	/*
    126 	 * Our remainder must be the numerator and our quotient is 0.
    127 	 */
    128 1:	mov	BLO, ALO
    129 	mov	BHI, AHI
    130 	mov	ALO, #0
    131 	mov	AHI, #0
    132 	pop	{r4-r5, sl, lr}
    133 	RET
    134 
    135 #if !defined(_KERNEL) && !defined(_STANDALONE)
    136 .Ldivbyzero:
    137 	push	{r0-r1, ip, lr}
    138 	cmp	AHI, #0
    139 	mvnge	ALO, #0
    140 	movge	AHI, ALO, lsr #1
    141 	movlt	ALO, #0
    142 	andlt	AHI, AHI, #0x800000000
    143 	bl	PLT_SYM(__aeabi_ldiv0)
    144 	pop	{r2-r3, ip, lr}
    145 	RET
    146 #endif
    147 END(__aeabi_ldivmod)
    148