dnl SPARC v9 mpn_sub_n -- Subtract two limb vectors of the same length > 0 and dnl store difference in a third limb vector. dnl Copyright 2001, 2002 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 2.1 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; 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 Compute carry-out from the most significant bits of u,v, and r, where C r=u-v-carry_in, using logic operations. C This code runs at 4 cycles/limb on UltraSPARC 1 and 2. It has a 4 insn C recurrency, and the UltraSPARC 1 and 2 the IE units are 100% saturated. C Therefore, it seems futile to try to optimize this any further... C INPUT PARAMETERS define(`rp',`%i0') define(`up',`%i1') define(`vp',`%i2') define(`n',`%i3') define(`u0',`%l0') define(`u1',`%l2') define(`u2',`%l4') define(`u3',`%l6') define(`v0',`%l1') define(`v1',`%l3') define(`v2',`%l5') define(`v3',`%l7') define(`cy',`%i4') define(`fanop',`fitod %f0,%f2') dnl A quasi nop running in the FA pipe define(`fmnop',`fmuld %f0,%f0,%f4') dnl A quasi nop running in the FM pipe ASM_START() REGISTER(%g2,#scratch) REGISTER(%g3,#scratch) PROLOGUE(mpn_sub_n) save %sp,-160,%sp fitod %f0,%f0 C make sure f0 contains small, quiet number subcc n,4,%g0 bl,pn %icc,.Loop0 mov 0,cy ldx [up+0],u0 ldx [vp+0],v0 add up,32,up ldx [up-24],u1 ldx [vp+8],v1 add vp,32,vp ldx [up-16],u2 ldx [vp-16],v2 ldx [up-8],u3 ldx [vp-8],v3 subcc n,8,n sub u0,v0,%g1 C main sub sub %g1,cy,%g4 C carry sub orn u0,v0,%g2 bl,pn %icc,.Lend4567 fanop b,a .Loop .align 16 C START MAIN LOOP .Loop: orn %g4,%g2,%g2 andn u0,v0,%g3 ldx [up+0],u0 fanop C -- andn %g2,%g3,%g2 ldx [vp+0],v0 add up,32,up fanop C -- srlx %g2,63,cy sub u1,v1,%g1 stx %g4,[rp+0] fanop C -- sub %g1,cy,%g4 orn u1,v1,%g2 fmnop fanop C -- orn %g4,%g2,%g2 andn u1,v1,%g3 ldx [up-24],u1 fanop C -- andn %g2,%g3,%g2 ldx [vp+8],v1 add vp,32,vp fanop C -- srlx %g2,63,cy sub u2,v2,%g1 stx %g4,[rp+8] fanop C -- sub %g1,cy,%g4 orn u2,v2,%g2 fmnop fanop C -- orn %g4,%g2,%g2 andn u2,v2,%g3 ldx [up-16],u2 fanop C -- andn %g2,%g3,%g2 ldx [vp-16],v2 add rp,32,rp fanop C -- srlx %g2,63,cy sub u3,v3,%g1 stx %g4,[rp-16] fanop C -- sub %g1,cy,%g4 orn u3,v3,%g2 fmnop fanop C -- orn %g4,%g2,%g2 andn u3,v3,%g3 ldx [up-8],u3 fanop C -- andn %g2,%g3,%g2 subcc n,4,n ldx [vp-8],v3 fanop C -- srlx %g2,63,cy sub u0,v0,%g1 stx %g4,[rp-8] fanop C -- sub %g1,cy,%g4 orn u0,v0,%g2 bge,pt %icc,.Loop fanop C END MAIN LOOP .Lend4567: orn %g4,%g2,%g2 andn u0,v0,%g3 andn %g2,%g3,%g2 srlx %g2,63,cy sub u1,v1,%g1 stx %g4,[rp+0] sub %g1,cy,%g4 orn u1,v1,%g2 orn %g4,%g2,%g2 andn u1,v1,%g3 andn %g2,%g3,%g2 srlx %g2,63,cy sub u2,v2,%g1 stx %g4,[rp+8] sub %g1,cy,%g4 orn u2,v2,%g2 orn %g4,%g2,%g2 andn u2,v2,%g3 andn %g2,%g3,%g2 add rp,32,rp srlx %g2,63,cy sub u3,v3,%g1 stx %g4,[rp-16] sub %g1,cy,%g4 orn u3,v3,%g2 orn %g4,%g2,%g2 andn u3,v3,%g3 andn %g2,%g3,%g2 srlx %g2,63,cy stx %g4,[rp-8] addcc n,4,n bz,pn %icc,.Lret fanop .Loop0: ldx [up],u0 add up,8,up ldx [vp],v0 add vp,8,vp add rp,8,rp subcc n,1,n sub u0,v0,%g1 orn u0,v0,%g2 sub %g1,cy,%g4 andn u0,v0,%g3 orn %g4,%g2,%g2 stx %g4,[rp-8] andn %g2,%g3,%g2 bnz,pt %icc,.Loop0 srlx %g2,63,cy .Lret: mov cy,%i0 ret restore EPILOGUE(mpn_sub_n)