1dnl PowerPC-64 mpn_invert_limb -- Invert a normalized limb. 2 3dnl Copyright 2004-2006, 2008, 2010, 2013 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 33C cycles/limb (approximate) 34C POWER3/PPC630 80 35C POWER4/PPC970 86 36C POWER5 86 37C POWER6 170 38C POWER7 66 39 40ASM_START() 41PROLOGUE(mpn_invert_limb,toc) 42 LEAL( r12, approx_tab) 43 srdi r9, r3, 32 44 rlwinm r9, r9, 10, 23, 30 C (d >> 55) & 0x1fe 45 srdi r10, r3, 24 C d >> 24 46 lis r11, 0x1000 47 rldicl r8, r3, 0, 63 C d mod 2 48 addi r10, r10, 1 C d40 49 sldi r11, r11, 32 C 2^60 50 srdi r7, r3, 1 C d/2 51 add r7, r7, r8 C d63 = ceil(d/2) 52 neg r8, r8 C mask = -(d mod 2) 53 lhzx r0, r9, r12 54 mullw r9, r0, r0 C v0*v0 55 sldi r6, r0, 11 C v0 << 11 56 addi r0, r6, -1 C (v0 << 11) - 1 57 mulld r9, r9, r10 C v0*v0*d40 58 srdi r9, r9, 40 C v0*v0*d40 >> 40 59 subf r9, r9, r0 C v1 = (v0 << 11) - (v0*v0*d40 >> 40) - 1 60 mulld r0, r9, r10 C v1*d40 61 sldi r6, r9, 13 C v1 << 13 62 subf r0, r0, r11 C 2^60 - v1*d40 63 mulld r0, r0, r9 C v1 * (2^60 - v1*d40) 64 srdi r0, r0, 47 C v1 * (2^60 - v1*d40) >> 47 65 add r0, r0, r6 C v2 = (v1 << 13) + (v1 * (2^60 - v1*d40) >> 47) 66 mulld r11, r0, r7 C v2 * d63 67 srdi r10, r0, 1 C v2 >> 1 68 sldi r9, r0, 31 C v2 << 31 69 and r8, r10, r8 C (v2 >> 1) & mask 70 subf r8, r11, r8 C ((v2 >> 1) & mask) - v2 * d63 71 mulhdu r0, r8, r0 C p1 = v2 * (((v2 >> 1) & mask) - v2 * d63) 72 srdi r0, r0, 1 C p1 >> 1 73 add r0, r0, r9 C v3 = (v2 << 31) + (p1 >> 1) 74 nop 75 mulld r11, r0, r3 76 mulhdu r9, r0, r3 77 addc r10, r11, r3 78 adde r3, r9, r3 79 subf r3, r3, r0 80 blr 81EPILOGUE() 82 83DEF_OBJECT(approx_tab) 84forloop(i,256,512-1,dnl 85` .short eval(0x7fd00/i) 86')dnl 87END_OBJECT(approx_tab) 88ASM_END() 89