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 32RCSID("$NetBSD: __aeabi_ldivmod.S,v 1.12 2013/08/19 03:27:34 matt Exp $") 33 34#ifdef __ARMEB__ 35#define ALO r1 /* incoming numerator, outgoing quotient */ 36#define AHI r0 /* incoming numerator, outgoing quotient */ 37#define BLO r3 /* incoming denominator, outgoing remainder */ 38#define BHI r2 /* incoming denominator, outgoing remainder */ 39#else 40#define ALO r0 /* incoming numerator, outgoing quotient */ 41#define AHI r1 /* incoming numerator, outgoing quotient */ 42#define BLO r2 /* incoming denominator, outgoing remainder */ 43#define BHI r3 /* incoming denominator, outgoing remainder */ 44#endif 45 46ENTRY(__aeabi_ldivmod) 47#ifdef __ARM_EABI__ 48 .fnstart 49 .cfi_startproc 50#endif 51#if !defined(_KERNEL) && !defined(_STANDALONE) 52#if !defined(__thumb__) 53 orrs ip, BLO, BHI 54 beq .Ldivbyzero 55#elif defined(_ARM_ARCH_T2) 56 cbnz BLO, 1f 57 cbz BHI, .Ldivbyzero 58#else 59 cmp BLO, #0 60 bne 1f 61 cmp BHI, #0 62 beq .Ldivbyzero 63#endif 641: 65#endif 66 67 push {r4-r6, lr} 68#ifdef __ARM_EABI__ 69 .cfi_def_cfa_offset 16 70 .cfi_offset 14, -4 71 .cfi_offset 6, -8 72 .cfi_offset 5, -12 73 .cfi_offset 4, -16 74#endif 75#define NEG r5 76 movs NEG, #0 77 78 cmp BHI, #0 79 bge 2f 80 movs NEG, #1 /* flip quotient sign */ 81 bl .Lnegate_b 82 bcs .Lmaxdenom 83 842: 85 cmp AHI, #0 86#ifdef __thumb__ 87 bge 3f 88 movs r4, #3 89 eors NEG, NEG, r4 /* flip quotient sign, flip remainder sign */ 90 bl .Lnegate_a 913: 92#else 93 eorlt NEG, NEG, #3 /* flip quotient sign, flip remainder sign */ 94 bllt .Lnegate_a 95#endif 96 97 /* 98 * Arguments are setup, allocate some stack for the remainder 99 * and call __qdivrem for the heavy lifting. 100 */ 101#ifdef __ARM_EABI__ 102 .cfi_def_cfa_offset 32 103#endif 104 sub sp, sp, #16 105#if !defined(__thumb__) || defined(_ARM_ARCH_T2) 106 adds r4, sp, #8 107#else 108 mov r4, sp 109 adds r4, r4, #8 110#endif 111 str r4, [sp] 112 bl PLT_SYM(__qdivrem) 113 add sp, sp, #8 114#ifdef __ARM_EABI__ 115 .cfi_def_cfa_offset 24 116 .cfi_offset 3, -20 117 .cfi_offset 2, -24 118#endif 119 120 /* 121 * The quotient is already in the right place and neither value 122 * needs its sign flipped. 123 */ 124#if defined(__thumb__) && defined(_ARM_ARCH_T2) 125 cbz NEG, .Lnegate_neither 126#else 127 cmp NEG, #0 /* any signs to flip? */ 128 beq .Lnegate_neither 129#endif 130 131 cmp NEG, #2 /* does remainder need to be negative? */ 132 beq .Lnegate_b_only /* 2 means b only */ 133 bgt .Lnegate_both /* 3 means both */ 134.Lnegate_a_only: 135 bl .Lnegate_a /* 1 means a only */ 136.Lnegate_neither: 137 pop {r2-r6, pc} /* grab b from stack */ 138.Lnegate_both: 139 bl .Lnegate_a 140.Lnegate_b_only: 141 pop {r2-r3} /* get remainder */ 142#ifdef __ARM_EABI__ 143 .cfi_def_cfa_offset 16 144#endif 145 bl .Lnegate_b /* negate it */ 146 pop {r4-r6, pc} 147 148 .align 0 149.Lnegate_a: 150#ifdef __thumb__ 151 movs r4, AHI 152 movs AHI, #0 153 negs ALO, ALO 154 sbcs AHI, AHI, r4 155#else 156 negs ALO, ALO 157 rsc AHI, AHI, #0 158#endif 159 RET 160 161 .align 0 162.Lnegate_b: 163#ifdef __thumb__ 164 movs r4, BHI 165 movs BHI, #0 166 negs BLO, BLO 167 sbcs BHI, BHI, r4 168#else 169 negs BLO, BLO 170 rsc BHI, BHI, #0 171#endif 172 RET 173 174 .align 0 175.Lmaxdenom: 176 /* 177 * We had a carry so the denominator must have INT64_MIN 178 * Also BLO and BHI never changed values so we can use 179 * them to see if the numerator has the same value. We 180 * don't have to worry about sign. 181 */ 182 cmp BHI, AHI 183#ifdef __thumb__ 184 bne 1f 185 cmp BLO, ALO 186#else 187 cmpeq BLO, ALO 188#endif 189 bne 1f 190 191 /* 192 * They were equal, so we return a quotient of 1 and remainder of 0. 193 */ 194 movs ALO, #1 195 movs AHI, #0 196 movs BLO, #0 197 movs BHI, #0 198 pop {r4-r6, pc} 199 200 /* 201 * Our remainder must be the numerator and our quotient is 0. 202 */ 203 .align 0 2041: movs BLO, ALO 205 movs BHI, AHI 206 movs ALO, #0 207 movs AHI, #0 208 pop {r4-r6, pc} 209 210#if !defined(_KERNEL) && !defined(_STANDALONE) 211 .align 0 212.Ldivbyzero: 213 push {r0-r1,r4,lr} 214#ifdef __ARM_EABI__ 215 .save {r0-r1,r4,lr} 216 .cfi_def_cfa_offset 16 217 .cfi_offset 14, -4 218 .cfi_offset 4, -8 219#endif 220 cmp AHI, #0 221#if !defined(__thumb__) || defined(_ARM_ARCH_T2) 222#ifdef __thumb__ 223 ittee ge 224#endif 225 mvnge ALO, #0 226 mvnge AHI, #0x80000000 227 movlt ALO, #0 228 movlt AHI, #0x80000000 229#else 230 blt 1f 231 movs ALO, #0 232 mvns ALO, ALO 233 mov AHI, ALO 234 lsrs AHI, AHI, #1 235 b 2f 2361: 237 movs ALO, #0 238 movs AHI, #1 239 lsls AHI, AHI, #31 2402: 241#endif /* __thumb__ && !_ARM_ARCH_T2 */ 242 bl PLT_SYM(__aeabi_ldiv0) 243 pop {r2-r4, pc} 244#endif /* !_KERNEL && !_STANDALONE */ 245#ifdef __ARM_EABI__ 246 .cfi_endproc 247 .fnend 248#endif 249END(__aeabi_ldivmod) 250