1dnl IA-64 mpn_mod_34lsub1 2 3dnl Contributed to the GNU project by Torbjorn Granlund. 4 5dnl Copyright 2003-2005, 2010 Free Software Foundation, Inc. 6 7dnl This file is part of the GNU MP Library. 8dnl 9dnl The GNU MP Library is free software; you can redistribute it and/or modify 10dnl it under the terms of either: 11dnl 12dnl * the GNU Lesser General Public License as published by the Free 13dnl Software Foundation; either version 3 of the License, or (at your 14dnl option) any later version. 15dnl 16dnl or 17dnl 18dnl * the GNU General Public License as published by the Free Software 19dnl Foundation; either version 2 of the License, or (at your option) any 20dnl later version. 21dnl 22dnl or both in parallel, as here. 23dnl 24dnl The GNU MP Library is distributed in the hope that it will be useful, but 25dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 26dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 27dnl for more details. 28dnl 29dnl You should have received copies of the GNU General Public License and the 30dnl GNU Lesser General Public License along with the GNU MP Library. If not, 31dnl see https://www.gnu.org/licenses/. 32 33include(`../config.m4') 34 35C cycles/limb 36C Itanium: ? 37C Itanium 2: 1 38 39 40C INPUT PARAMETERS 41define(`up', `r32') 42define(`n', `r33') 43 44C Some useful aliases for registers we use 45define(`u0',`r14') define(`u1',`r15') define(`u2',`r16') 46define(`a0',`r17') define(`a1',`r18') define(`a2',`r19') 47define(`c0',`r20') define(`c1',`r21') define(`c2',`r22') 48 49C This is a fairly simple-minded implementation. One could approach 0.67 c/l 50C with a more sophisticated implementation. If we're really crazy, we could 51C super-unroll, storing carries just in predicate registers, then copy them to 52C a general register, and population count them from there. That'd bring us 53C close to 3 insn/limb, for nearly 0.5 c/l. 54 55C Computing n/3 needs 16 cycles, which is a lot of startup overhead. 56C We therefore use a plain while-style loop: 57C add n = -3, n 58C cmp.le p9, p0 = 3, n 59C (p9) br.cond .Loop 60C Alternatively, we could table n/3 for, say, n < 256, and predicate the 61C 16-cycle code. 62 63C The summing-up code at the end was written quickly, and could surely be 64C vastly improved. 65 66ASM_START() 67PROLOGUE(mpn_mod_34lsub1) 68 .prologue 69 .save ar.lc, r2 70 .body 71ifdef(`HAVE_ABI_32',` 72 addp4 up = 0, up C M I 73 nop.m 0 74 zxt4 n = n C I 75 ;; 76') 77 78ifelse(0,1,` 79 movl r14 = 0xAAAAAAAAAAAAAAAB 80 ;; 81 setf.sig f6 = r14 82 setf.sig f7 = r33 83 ;; 84 xmpy.hu f6 = f6, f7 85 ;; 86 getf.sig r8 = f6 87 ;; 88 shr.u r8 = r8, 1 C Loop count 89 ;; 90 mov.i ar.lc = r8 91') 92 93 ld8 u0 = [up], 8 94 cmp.ne p9, p0 = 1, n 95 (p9) br L(gt1) 96 ;; 97 shr.u r8 = u0, 48 98 dep.z r27 = u0, 0, 48 99 ;; 100 add r8 = r8, r27 101 br.ret.sptk.many b0 102 103 104L(gt1): 105 {.mmi; nop.m 0 106 mov a0 = 0 107 add n = -2, n 108}{.mmi; mov c0 = 0 109 mov c1 = 0 110 mov c2 = 0 111 ;; 112}{.mmi; ld8 u1 = [up], 8 113 mov a1 = 0 114 cmp.ltu p6, p0 = r0, r0 C clear p6 115}{.mmb; cmp.gt p9, p0 = 3, n 116 mov a2 = 0 117 (p9) br.cond.dptk L(end) 118 ;; 119} 120 ALIGN(32) 121L(top): 122 {.mmi; ld8 u2 = [up], 8 123 (p6) add c0 = 1, c0 124 cmp.ltu p7, p0 = a0, u0 125}{.mmb; sub a0 = a0, u0 126 add n = -3, n 127 nop.b 0 128 ;; 129}{.mmi; ld8 u0 = [up], 8 130 (p7) add c1 = 1, c1 131 cmp.ltu p8, p0 = a1, u1 132}{.mmb; sub a1 = a1, u1 133 cmp.le p9, p0 = 3, n 134 nop.b 0 135 ;; 136}{.mmi; ld8 u1 = [up], 8 137 (p8) add c2 = 1, c2 138 cmp.ltu p6, p0 = a2, u2 139}{.mmb; sub a2 = a2, u2 140 nop.m 0 141dnl br.cloop.dptk L(top) 142 (p9) br.cond.dptk L(top) 143 ;; 144} 145L(end): 146 cmp.eq p10, p0 = 0, n 147 cmp.eq p11, p0 = 1, n 148 (p10) br L(0) 149 150L(2): 151 {.mmi; ld8 u2 = [up], 8 152 (p6) add c0 = 1, c0 153 cmp.ltu p7, p0 = a0, u0 154}{.mmb; sub a0 = a0, u0 155 nop.m 0 156 (p11) br L(1) 157 ;; 158} ld8 u0 = [up], 8 159 (p7) add c1 = 1, c1 160 cmp.ltu p8, p0 = a1, u1 161 sub a1 = a1, u1 162 ;; 163 (p8) add c2 = 1, c2 164 cmp.ltu p6, p0 = a2, u2 165 sub a2 = a2, u2 166 ;; 167 (p6) add c0 = 1, c0 168 cmp.ltu p7, p0 = a0, u0 169 sub a0 = a0, u0 170 ;; 171 (p7) add c1 = 1, c1 172 br L(com) 173 174 175L(1): 176 (p7) add c1 = 1, c1 177 cmp.ltu p8, p0 = a1, u1 178 sub a1 = a1, u1 179 ;; 180 (p8) add c2 = 1, c2 181 cmp.ltu p6, p0 = a2, u2 182 sub a2 = a2, u2 183 ;; 184 (p6) add c0 = 1, c0 185 br L(com) 186 187 188L(0): 189 (p6) add c0 = 1, c0 190 cmp.ltu p7, p0 = a0, u0 191 sub a0 = a0, u0 192 ;; 193 (p7) add c1 = 1, c1 194 cmp.ltu p8, p0 = a1, u1 195 sub a1 = a1, u1 196 ;; 197 (p8) add c2 = 1, c2 198 199L(com): 200C | a2 | a1 | a0 | 201C | | | | | 202 shr.u r24 = a0, 48 C 16 bits 203 shr.u r25 = a1, 32 C 32 bits 204 shr.u r26 = a2, 16 C 48 bits 205 ;; 206 shr.u r10 = c0, 48 C 16 bits, always zero 207 shr.u r11 = c1, 32 C 32 bits 208 shr.u r30 = c2, 16 C 48 bits 209 ;; 210 dep.z r27 = a0, 0, 48 C 48 bits 211 dep.z r28 = a1, 16, 32 C 48 bits 212 dep.z r29 = a2, 32, 16 C 48 bits 213 dep.z r31 = c0, 0, 48 C 48 bits 214 dep.z r14 = c1, 16, 32 C 48 bits 215 dep.z r15 = c2, 32, 16 C 48 bits 216 ;; 217 {.mmi; add r24 = r24, r25 218 add r26 = r26, r27 219 add r28 = r28, r29 220}{.mmi; add r10 = r10, r11 221 add r30 = r30, r31 222 add r14 = r14, r15 223 ;; 224} 225 movl r8 = 0xffffffffffff0 226 add r24 = r24, r26 227 add r10 = r10, r30 228 ;; 229 add r24 = r24, r28 230 add r10 = r10, r14 231 ;; 232 sub r8 = r8, r24 233 ;; 234 add r8 = r8, r10 235 br.ret.sptk.many b0 236EPILOGUE() 237ASM_END() 238