# Alpha 21064 __mpn_mul_1 -- Multiply a limb vector with a limb and store # the result in a second limb vector. # Copyright (C) 1992-2018 Free Software Foundation, Inc. # This file is part of the GNU MP Library. # The GNU MP Library is free software; you can redistribute it and/or modify # it under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation; either version 2.1 of the License, or (at your # option) any later version. # The GNU MP Library is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public # License for more details. # You should have received a copy of the GNU Lesser General Public License # along with the GNU MP Library. If not, see . # INPUT PARAMETERS # res_ptr r16 # s1_ptr r17 # size r18 # s2_limb r19 # This code runs at 42 cycles/limb on the EV4 and 18 cycles/limb on the EV5. # To improve performance for long multiplications, we would use # 'fetch' for S1 and 'fetch_m' for RES. It's not obvious how to use # these instructions without slowing down the general code: 1. We can # only have two prefetches in operation at any time in the Alpha # architecture. 2. There will seldom be any special alignment # between RES_PTR and S1_PTR. Maybe we can simply divide the current # loop into an inner and outer loop, having the inner loop handle # exactly one prefetch block? .set noreorder .set noat .text .align 3 .globl __mpn_mul_1 .ent __mpn_mul_1 2 __mpn_mul_1: .frame $30,0,$26 ldq $2,0($17) # $2 = s1_limb subq $18,1,$18 # size-- mulq $2,$19,$3 # $3 = prod_low bic $31,$31,$4 # clear cy_limb umulh $2,$19,$0 # $0 = prod_high beq $18,Lend1 # jump if size was == 1 ldq $2,8($17) # $2 = s1_limb subq $18,1,$18 # size-- stq $3,0($16) beq $18,Lend2 # jump if size was == 2 .align 3 Loop: mulq $2,$19,$3 # $3 = prod_low addq $4,$0,$0 # cy_limb = cy_limb + 'cy' subq $18,1,$18 # size-- umulh $2,$19,$4 # $4 = cy_limb ldq $2,16($17) # $2 = s1_limb addq $17,8,$17 # s1_ptr++ addq $3,$0,$3 # $3 = cy_limb + prod_low stq $3,8($16) cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low) addq $16,8,$16 # res_ptr++ bne $18,Loop Lend2: mulq $2,$19,$3 # $3 = prod_low addq $4,$0,$0 # cy_limb = cy_limb + 'cy' umulh $2,$19,$4 # $4 = cy_limb addq $3,$0,$3 # $3 = cy_limb + prod_low cmpult $3,$0,$0 # $0 = carry from (cy_limb + prod_low) stq $3,8($16) addq $4,$0,$0 # cy_limb = prod_high + cy ret $31,($26),1 Lend1: stq $3,0($16) ret $31,($26),1 .end __mpn_mul_1