dnl SPARC mpn_sub_n -- Subtract two limb vectors of the same length > 0 and dnl store difference in a third limb vector. dnl Copyright (C) 1995, 1996, 2000 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 Library General Public License as published dnl by the Free Software Foundation; either version 2 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 Library General Public dnl License for more details. dnl You should have received a copy of the GNU Library General Public License dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write to dnl the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, dnl MA 02111-1307, USA. include(`../config.m4') C INPUT PARAMETERS define(res_ptr,%o0) define(s1_ptr,%o1) define(s2_ptr,%o2) define(n,%o3) ASM_START() PROLOGUE(mpn_sub_n) xor s2_ptr,res_ptr,%g1 andcc %g1,4,%g0 bne L(1) C branch if alignment differs nop C ** V1a ** andcc res_ptr,4,%g0 C res_ptr unaligned? Side effect: cy=0 be L(v1) C if no, branch nop C Add least significant limb separately to align res_ptr and s2_ptr ld [s1_ptr],%g4 add s1_ptr,4,s1_ptr ld [s2_ptr],%g2 add s2_ptr,4,s2_ptr add n,-1,n subcc %g4,%g2,%o4 st %o4,[res_ptr] add res_ptr,4,res_ptr L(v1): addx %g0,%g0,%o4 C save cy in register cmp n,2 C if n < 2 ... bl L(end2) C ... branch to tail code subcc %g0,%o4,%g0 C restore cy ld [s1_ptr+0],%g4 addcc n,-10,n ld [s1_ptr+4],%g1 ldd [s2_ptr+0],%g2 blt L(fin1) subcc %g0,%o4,%g0 C restore cy C Add blocks of 8 limbs until less than 8 limbs remain L(loop1): subxcc %g4,%g2,%o4 ld [s1_ptr+8],%g4 subxcc %g1,%g3,%o5 ld [s1_ptr+12],%g1 ldd [s2_ptr+8],%g2 std %o4,[res_ptr+0] subxcc %g4,%g2,%o4 ld [s1_ptr+16],%g4 subxcc %g1,%g3,%o5 ld [s1_ptr+20],%g1 ldd [s2_ptr+16],%g2 std %o4,[res_ptr+8] subxcc %g4,%g2,%o4 ld [s1_ptr+24],%g4 subxcc %g1,%g3,%o5 ld [s1_ptr+28],%g1 ldd [s2_ptr+24],%g2 std %o4,[res_ptr+16] subxcc %g4,%g2,%o4 ld [s1_ptr+32],%g4 subxcc %g1,%g3,%o5 ld [s1_ptr+36],%g1 ldd [s2_ptr+32],%g2 std %o4,[res_ptr+24] addx %g0,%g0,%o4 C save cy in register addcc n,-8,n add s1_ptr,32,s1_ptr add s2_ptr,32,s2_ptr add res_ptr,32,res_ptr bge L(loop1) subcc %g0,%o4,%g0 C restore cy L(fin1): addcc n,8-2,n blt L(end1) subcc %g0,%o4,%g0 C restore cy C Add blocks of 2 limbs until less than 2 limbs remain L(loope1): subxcc %g4,%g2,%o4 ld [s1_ptr+8],%g4 subxcc %g1,%g3,%o5 ld [s1_ptr+12],%g1 ldd [s2_ptr+8],%g2 std %o4,[res_ptr+0] addx %g0,%g0,%o4 C save cy in register addcc n,-2,n add s1_ptr,8,s1_ptr add s2_ptr,8,s2_ptr add res_ptr,8,res_ptr bge L(loope1) subcc %g0,%o4,%g0 C restore cy L(end1): subxcc %g4,%g2,%o4 subxcc %g1,%g3,%o5 std %o4,[res_ptr+0] addx %g0,%g0,%o4 C save cy in register andcc n,1,%g0 be L(ret1) subcc %g0,%o4,%g0 C restore cy C Add last limb ld [s1_ptr+8],%g4 ld [s2_ptr+8],%g2 subxcc %g4,%g2,%o4 st %o4,[res_ptr+8] L(ret1): retl addx %g0,%g0,%o0 C return carry-out from most sign. limb L(1): xor s1_ptr,res_ptr,%g1 andcc %g1,4,%g0 bne L(2) nop C ** V1b ** andcc res_ptr,4,%g0 C res_ptr unaligned? Side effect: cy=0 be L(v1b) C if no, branch nop C Add least significant limb separately to align res_ptr and s1_ptr ld [s2_ptr],%g4 add s2_ptr,4,s2_ptr ld [s1_ptr],%g2 add s1_ptr,4,s1_ptr add n,-1,n subcc %g2,%g4,%o4 st %o4,[res_ptr] add res_ptr,4,res_ptr L(v1b): addx %g0,%g0,%o4 C save cy in register cmp n,2 C if n < 2 ... bl L(end2) C ... branch to tail code subcc %g0,%o4,%g0 C restore cy ld [s2_ptr+0],%g4 addcc n,-10,n ld [s2_ptr+4],%g1 ldd [s1_ptr+0],%g2 blt L(fin1b) subcc %g0,%o4,%g0 C restore cy C Add blocks of 8 limbs until less than 8 limbs remain L(loop1b): subxcc %g2,%g4,%o4 ld [s2_ptr+8],%g4 subxcc %g3,%g1,%o5 ld [s2_ptr+12],%g1 ldd [s1_ptr+8],%g2 std %o4,[res_ptr+0] subxcc %g2,%g4,%o4 ld [s2_ptr+16],%g4 subxcc %g3,%g1,%o5 ld [s2_ptr+20],%g1 ldd [s1_ptr+16],%g2 std %o4,[res_ptr+8] subxcc %g2,%g4,%o4 ld [s2_ptr+24],%g4 subxcc %g3,%g1,%o5 ld [s2_ptr+28],%g1 ldd [s1_ptr+24],%g2 std %o4,[res_ptr+16] subxcc %g2,%g4,%o4 ld [s2_ptr+32],%g4 subxcc %g3,%g1,%o5 ld [s2_ptr+36],%g1 ldd [s1_ptr+32],%g2 std %o4,[res_ptr+24] addx %g0,%g0,%o4 C save cy in register addcc n,-8,n add s1_ptr,32,s1_ptr add s2_ptr,32,s2_ptr add res_ptr,32,res_ptr bge L(loop1b) subcc %g0,%o4,%g0 C restore cy L(fin1b): addcc n,8-2,n blt L(end1b) subcc %g0,%o4,%g0 C restore cy C Add blocks of 2 limbs until less than 2 limbs remain L(loope1b): subxcc %g2,%g4,%o4 ld [s2_ptr+8],%g4 subxcc %g3,%g1,%o5 ld [s2_ptr+12],%g1 ldd [s1_ptr+8],%g2 std %o4,[res_ptr+0] addx %g0,%g0,%o4 C save cy in register addcc n,-2,n add s1_ptr,8,s1_ptr add s2_ptr,8,s2_ptr add res_ptr,8,res_ptr bge L(loope1b) subcc %g0,%o4,%g0 C restore cy L(end1b): subxcc %g2,%g4,%o4 subxcc %g3,%g1,%o5 std %o4,[res_ptr+0] addx %g0,%g0,%o4 C save cy in register andcc n,1,%g0 be L(ret1b) subcc %g0,%o4,%g0 C restore cy C Add last limb ld [s2_ptr+8],%g4 ld [s1_ptr+8],%g2 subxcc %g2,%g4,%o4 st %o4,[res_ptr+8] L(ret1b): retl addx %g0,%g0,%o0 C return carry-out from most sign. limb C ** V2 ** C If we come here, the alignment of s1_ptr and res_ptr as well as the C alignment of s2_ptr and res_ptr differ. Since there are only two ways C things can be aligned (that we care about) we now know that the alignment C of s1_ptr and s2_ptr are the same. L(2): cmp n,1 be L(jone) nop andcc s1_ptr,4,%g0 C s1_ptr unaligned? Side effect: cy=0 be L(v2) C if no, branch nop C Add least significant limb separately to align s1_ptr and s2_ptr ld [s1_ptr],%g4 add s1_ptr,4,s1_ptr ld [s2_ptr],%g2 add s2_ptr,4,s2_ptr add n,-1,n subcc %g4,%g2,%o4 st %o4,[res_ptr] add res_ptr,4,res_ptr L(v2): addx %g0,%g0,%o4 C save cy in register addcc n,-8,n blt L(fin2) subcc %g0,%o4,%g0 C restore cy C Add blocks of 8 limbs until less than 8 limbs remain L(loop2): ldd [s1_ptr+0],%g2 ldd [s2_ptr+0],%o4 subxcc %g2,%o4,%g2 st %g2,[res_ptr+0] subxcc %g3,%o5,%g3 st %g3,[res_ptr+4] ldd [s1_ptr+8],%g2 ldd [s2_ptr+8],%o4 subxcc %g2,%o4,%g2 st %g2,[res_ptr+8] subxcc %g3,%o5,%g3 st %g3,[res_ptr+12] ldd [s1_ptr+16],%g2 ldd [s2_ptr+16],%o4 subxcc %g2,%o4,%g2 st %g2,[res_ptr+16] subxcc %g3,%o5,%g3 st %g3,[res_ptr+20] ldd [s1_ptr+24],%g2 ldd [s2_ptr+24],%o4 subxcc %g2,%o4,%g2 st %g2,[res_ptr+24] subxcc %g3,%o5,%g3 st %g3,[res_ptr+28] addx %g0,%g0,%o4 C save cy in register addcc n,-8,n add s1_ptr,32,s1_ptr add s2_ptr,32,s2_ptr add res_ptr,32,res_ptr bge L(loop2) subcc %g0,%o4,%g0 C restore cy L(fin2): addcc n,8-2,n blt L(end2) subcc %g0,%o4,%g0 C restore cy L(loope2): ldd [s1_ptr+0],%g2 ldd [s2_ptr+0],%o4 subxcc %g2,%o4,%g2 st %g2,[res_ptr+0] subxcc %g3,%o5,%g3 st %g3,[res_ptr+4] addx %g0,%g0,%o4 C save cy in register addcc n,-2,n add s1_ptr,8,s1_ptr add s2_ptr,8,s2_ptr add res_ptr,8,res_ptr bge L(loope2) subcc %g0,%o4,%g0 C restore cy L(end2): andcc n,1,%g0 be L(ret2) subcc %g0,%o4,%g0 C restore cy C Add last limb L(jone): ld [s1_ptr],%g4 ld [s2_ptr],%g2 subxcc %g4,%g2,%o4 st %o4,[res_ptr] L(ret2): retl addx %g0,%g0,%o0 C return carry-out from most sign. limb EPILOGUE(mpn_sub_n)