| dnl PowerPC-32 mpn_sublsh1_n -- rp[] = up[] - (vp[] << 1) |
| |
| dnl Copyright 2003, 2005, 2007 Free Software Foundation, Inc. |
| |
| dnl This file is part of the GNU MP Library. |
| |
| dnl The GNU MP Library is free software; you can redistribute it and/or modify |
| dnl it under the terms of the GNU Lesser General Public License as published |
| dnl by the Free Software Foundation; either version 3 of the License, or (at |
| dnl your option) any later version. |
| |
| dnl The GNU MP Library is distributed in the hope that it will be useful, but |
| dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| dnl License for more details. |
| |
| dnl You should have received a copy of the GNU Lesser General Public License |
| dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. |
| |
| include(`../config.m4') |
| |
| C cycles/limb |
| C 603e: ? |
| C 604e: 4.0 |
| C 75x (G3): 5.0 |
| C 7400,7410 (G4): 5.0 |
| C 744x,745x (G4+): 5.0 |
| C power4/ppc970: 4.25 |
| C power5: 5.0 |
| |
| C INPUT PARAMETERS |
| C rp r3 |
| C up r4 |
| C vp r5 |
| C n r6 |
| |
| define(`rp',`r3') |
| define(`up',`r4') |
| define(`vp',`r5') |
| |
| define(`s0',`r6') |
| define(`s1',`r7') |
| define(`u0',`r8') |
| define(`v0',`r10') |
| define(`v1',`r11') |
| |
| ASM_START() |
| PROLOGUE(mpn_sublsh1_n) |
| mtctr r6 C copy n in ctr |
| |
| lwz v0, 0(vp) C load v limb |
| lwz u0, 0(up) C load u limb |
| addic up, up, -4 C update up; set cy |
| addi rp, rp, -4 C update rp |
| slwi s1, v0, 1 |
| bdz L(end) C If done, skip loop |
| |
| L(loop): |
| lwz v1, 4(vp) C load v limb |
| subfe s1, s1, u0 C add limbs with cy, set cy |
| srwi s0, v0, 31 C shift down previous v limb |
| stw s1, 4(rp) C store result limb |
| lwzu u0, 8(up) C load u limb and update up |
| rlwimi s0, v1, 1, 0,30 C left shift v limb and merge with prev v limb |
| |
| bdz L(exit) C decrement ctr and exit if done |
| |
| lwzu v0, 8(vp) C load v limb and update vp |
| subfe s0, s0, u0 C add limbs with cy, set cy |
| srwi s1, v1, 31 C shift down previous v limb |
| stwu s0, 8(rp) C store result limb and update rp |
| lwz u0, 4(up) C load u limb |
| rlwimi s1, v0, 1, 0,30 C left shift v limb and merge with prev v limb |
| |
| bdnz L(loop) C decrement ctr and loop back |
| |
| L(end): subfe r7, s1, u0 |
| srwi r4, v0, 31 |
| stw r7, 4(rp) C store last result limb |
| subfze r3, r4 |
| neg r3, r3 |
| blr |
| L(exit): |
| subfe r7, s0, u0 |
| srwi r4, v1, 31 |
| stw r7, 8(rp) C store last result limb |
| subfze r3, r4 |
| neg r3, r3 |
| blr |
| EPILOGUE() |
