mulww.f
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:2k
- c Helper for mpn_mul_1, mpn_addmul_1, and mpn_submul_1 for Cray PVP.
- c Copyright 1996, 2000 Free Software Foundation, Inc.
- c This file is part of the GNU MP Library.
- c The GNU MP Library is free software; you can redistribute it and/or
- c modify it under the terms of the GNU Lesser General Public License as
- c published by the Free Software Foundation; either version 3 of the
- c License, or (at your option) any later version.
- c The GNU MP Library is distributed in the hope that it will be useful,
- c but WITHOUT ANY WARRANTY; without even the implied warranty of
- c MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- c Lesser General Public License for more details.
- c You should have received a copy of the GNU Lesser General Public License
- c along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
- c p1[] = hi(a[]*s); the upper limbs of each product
- c p0[] = low(a[]*s); the corresponding lower limbs
- c n is number of limbs in the vectors
- subroutine gmpn_mulww(p1,p0,a,n,s)
- integer*8 p1(0:*),p0(0:*),a(0:*),s
- integer n
- integer*8 a0,a1,a2,s0,s1,s2,c
- integer*8 ai,t0,t1,t2,t3,t4
- s0 = shiftl(and(s,4194303),24)
- s1 = shiftl(and(shiftr(s,22),4194303),24)
- s2 = shiftl(and(shiftr(s,44),4194303),24)
- do i = 0,n-1
- ai = a(i)
- a0 = shiftl(and(ai,4194303),24)
- a1 = shiftl(and(shiftr(ai,22),4194303),24)
- a2 = shiftl(and(shiftr(ai,44),4194303),24)
- t0 = i24mult(a0,s0)
- t1 = i24mult(a0,s1)+i24mult(a1,s0)
- t2 = i24mult(a0,s2)+i24mult(a1,s1)+i24mult(a2,s0)
- t3 = i24mult(a1,s2)+i24mult(a2,s1)
- t4 = i24mult(a2,s2)
- p0(i)=shiftl(t2,44)+shiftl(t1,22)+t0
- c=shiftr(shiftr(t0,22)+and(t1,4398046511103)+
- $ shiftl(and(t2,1048575),22),42)
- p1(i)=shiftl(t4,24)+shiftl(t3,2)+shiftr(t2,20)+shiftr(t1,42)+c
- end do
- end