1 dnl PowerPC-32 mpn_sublsh1_n -- rp[] = up[] - (vp[] << 1)
3 dnl Copyright 2003, 2005, 2007 Free Software Foundation, Inc.
5 dnl This file is part of the GNU MP Library.
7 dnl The GNU MP Library is free software; you can redistribute it and/or modify
8 dnl it under the terms of the GNU Lesser General Public License as published
9 dnl by the Free Software Foundation; either version 3 of the License, or (at
10 dnl your option) any later version.
12 dnl The GNU MP Library is distributed in the hope that it will be useful, but
13 dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15 dnl License for more details.
17 dnl You should have received a copy of the GNU Lesser General Public License
18 dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
20 include(`../config.m4')
27 C 744x,745x (G4+): 5.0
48 PROLOGUE(mpn_sublsh1_n)
49 mtctr r6 C copy n in ctr
51 lwz v0, 0(vp) C load v limb
52 lwz u0, 0(up) C load u limb
53 addic up, up, -4 C update up; set cy
54 addi rp, rp, -4 C update rp
56 bdz L(end) C If done, skip loop
59 lwz v1, 4(vp) C load v limb
60 subfe s1, s1, u0 C add limbs with cy, set cy
61 srwi s0, v0, 31 C shift down previous v limb
62 stw s1, 4(rp) C store result limb
63 lwzu u0, 8(up) C load u limb and update up
64 rlwimi s0, v1, 1, 0,30 C left shift v limb and merge with prev v limb
66 bdz L(exit) C decrement ctr and exit if done
68 lwzu v0, 8(vp) C load v limb and update vp
69 subfe s0, s0, u0 C add limbs with cy, set cy
70 srwi s1, v1, 31 C shift down previous v limb
71 stwu s0, 8(rp) C store result limb and update rp
72 lwz u0, 4(up) C load u limb
73 rlwimi s1, v0, 1, 0,30 C left shift v limb and merge with prev v limb
75 bdnz L(loop) C decrement ctr and loop back
77 L(end): subfe r7, s1, u0
79 stw r7, 4(rp) C store last result limb
86 stw r7, 8(rp) C store last result limb