1dnl Intel P5 mpn_mod_34lsub1 -- mpn remainder modulo 2**24-1. 2 3dnl Copyright 2000-2002 Free Software Foundation, Inc. 4 5dnl This file is part of the GNU MP Library. 6dnl 7dnl The GNU MP Library is free software; you can redistribute it and/or modify 8dnl it under the terms of either: 9dnl 10dnl * the GNU Lesser General Public License as published by the Free 11dnl Software Foundation; either version 3 of the License, or (at your 12dnl option) any later version. 13dnl 14dnl or 15dnl 16dnl * the GNU General Public License as published by the Free Software 17dnl Foundation; either version 2 of the License, or (at your option) any 18dnl later version. 19dnl 20dnl or both in parallel, as here. 21dnl 22dnl The GNU MP Library is distributed in the hope that it will be useful, but 23dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 24dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 25dnl for more details. 26dnl 27dnl You should have received copies of the GNU General Public License and the 28dnl GNU Lesser General Public License along with the GNU MP Library. If not, 29dnl see https://www.gnu.org/licenses/. 30 31include(`../config.m4') 32 33 34C P5: 1.66 cycles/limb 35 36 37C mp_limb_t mpn_mod_34lsub1 (mp_srcptr src, mp_size_t size) 38C 39 40defframe(PARAM_SIZE, 8) 41defframe(PARAM_SRC, 4) 42 43 TEXT 44 ALIGN(16) 45PROLOGUE(mpn_mod_34lsub1) 46deflit(`FRAME',0) 47 48 movl PARAM_SIZE, %ecx 49 movl PARAM_SRC, %edx 50 51 subl $2, %ecx 52 ja L(three_or_more) 53 54 movl (%edx), %eax 55 jne L(one) 56 57 58 movl 4(%edx), %ecx 59 movl %eax, %edx 60 61 shrl $24, %edx 62 andl $0xFFFFFF, %eax 63 64 addl %edx, %eax 65 movl %ecx, %edx 66 67 shrl $16, %ecx 68 andl $0xFFFF, %edx 69 70 shll $8, %edx 71 addl %ecx, %eax 72 73 addl %edx, %eax 74 75L(one): 76 ret 77 78 79L(three_or_more): 80 C eax 81 C ebx 82 C ecx size-2 83 C edx src 84 C esi 85 C edi 86 C ebp 87 88 pushl %ebx FRAME_pushl() 89 pushl %esi FRAME_pushl() 90 91 pushl %edi FRAME_pushl() 92 pushl %ebp FRAME_pushl() 93 94 xorl %esi, %esi C 0mod3 95 xorl %edi, %edi C 1mod3 96 97 xorl %ebp, %ebp C 2mod3, and clear carry 98 99L(top): 100 C eax scratch 101 C ebx scratch 102 C ecx counter, limbs 103 C edx src 104 C esi 0mod3 105 C edi 1mod3 106 C ebp 2mod3 107 108 movl (%edx), %eax 109 movl 4(%edx), %ebx 110 111 adcl %eax, %esi 112 movl 8(%edx), %eax 113 114 adcl %ebx, %edi 115 leal 12(%edx), %edx 116 117 adcl %eax, %ebp 118 leal -2(%ecx), %ecx 119 120 decl %ecx 121 jg L(top) 122 123 124 C ecx is -2, -1 or 0, representing 0, 1 or 2 more limbs, respectively 125 126 movl $0xFFFFFFFF, %ebx C mask 127 incl %ecx 128 129 js L(combine) C 0 more 130 131 movl (%edx), %eax 132 movl $0xFFFFFF00, %ebx 133 134 adcl %eax, %esi 135 decl %ecx 136 137 js L(combine) C 1 more 138 139 movl 4(%edx), %eax 140 movl $0xFFFF0000, %ebx 141 142 adcl %eax, %edi 143 144 145 146L(combine): 147 C eax 148 C ebx mask 149 C ecx 150 C edx 151 C esi 0mod3 152 C edi 1mod3 153 C ebp 2mod3 154 155 sbbl %ecx, %ecx C carry 156 movl %esi, %eax C 0mod3 157 158 andl %ebx, %ecx C masked for position 159 andl $0xFFFFFF, %eax C 0mod3 low 160 161 shrl $24, %esi C 0mod3 high 162 subl %ecx, %eax C apply carry 163 164 addl %esi, %eax C apply 0mod3 165 movl %edi, %ebx C 1mod3 166 167 shrl $16, %edi C 1mod3 high 168 andl $0x0000FFFF, %ebx 169 170 shll $8, %ebx C 1mod3 low 171 addl %edi, %eax C apply 1mod3 high 172 173 addl %ebx, %eax C apply 1mod3 low 174 movl %ebp, %ebx C 2mod3 175 176 shrl $8, %ebp C 2mod3 high 177 andl $0xFF, %ebx 178 179 shll $16, %ebx C 2mod3 low 180 addl %ebp, %eax C apply 2mod3 high 181 182 addl %ebx, %eax C apply 2mod3 low 183 184 popl %ebp 185 popl %edi 186 187 popl %esi 188 popl %ebx 189 190 ret 191 192EPILOGUE() 193