1dnl PowerPC-64 mpn_rsh1sub_n -- rp[] = (up[] - vp[]) >> 1 2 3dnl Copyright 2003, 2005 Free Software Foundation, Inc. 4 5dnl This file is part of the GNU MP Library. 6 7dnl The GNU MP Library is free software; you can redistribute it and/or modify 8dnl it under the terms of the GNU Lesser General Public License as published 9dnl by the Free Software Foundation; either version 3 of the License, or (at 10dnl your option) any later version. 11 12dnl The GNU MP Library is distributed in the hope that it will be useful, but 13dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15dnl License for more details. 16 17dnl You should have received a copy of the GNU Lesser General Public License 18dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. 19 20include(`../config.m4') 21 22C cycles/limb 23C POWER3/PPC630: 2 (1.5 c/l should be possible) 24C POWER4/PPC970: 4 (2.0 c/l should be possible) 25 26C INPUT PARAMETERS 27C rp r3 28C up r4 29C vp r5 30C n r6 31 32define(`rp',`r3') 33define(`up',`r4') 34define(`vp',`r5') 35 36define(`s0',`r6') 37define(`s1',`r7') 38define(`x',`r0') 39define(`u0',`r8') 40define(`u1',`r9') 41define(`v0',`r10') 42define(`v1',`r11') 43 44 45ASM_START() 46PROLOGUE(mpn_rsh1sub_n) 47 mtctr r6 C copy size to count register 48 addi rp, rp, -8 49 50 ld u1, 0(up) 51 ld v1, 0(vp) 52 subfc x, v1, u1 53 rldicl r12, x, 0, 63 C return value 54 srdi s1, x, 1 55 56 bdz L(1) 57 58 ld u0, 8(up) 59 ld v0, 8(vp) 60 61 bdz L(end) 62 63L(oop): ldu u1, 16(up) 64 ldu v1, 16(vp) 65 subfe x, v0, u0 66 srdi s0, x, 1 67 rldimi s1, x, 63, 0 68 std s1, 8(rp) 69 70 bdz L(exit) 71 72 ld u0, 8(up) 73 ld v0, 8(vp) 74 subfe x, v1, u1 75 srdi s1, x, 1 76 rldimi s0, x, 63, 0 77 stdu s0, 16(rp) 78 79 bdnz L(oop) 80 81L(end): subfe x, v0, u0 82 srdi s0, x, 1 83 rldimi s1, x, 63, 0 84 std s1, 8(rp) 85 86 subfe x, x, x 87 rldimi s0, x, 63, 0 88 std s0, 16(rp) 89 mr r3, r12 90 blr 91 92L(exit): subfe x, v1, u1 93 srdi s1, x, 1 94 rldimi s0, x, 63, 0 95 stdu s0, 16(rp) 96 97L(1): subfe x, x, x 98 rldimi s1, x, 63, 0 99 std s1, 8(rp) 100 mr r3, r12 101 blr 102EPILOGUE() 103