dnl Alpha mpn_submul_1 -- Multiply a limb vector with a limb and subtract
dnl the result from a second limb vector.
dnl Copyright 1992, 1994, 1995, 2000, 2002 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
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 General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C EV4: 42
C EV5: 18
C EV6: 7
C INPUT PARAMETERS
C rp r16
C up r17
C n r18
C limb r19
ASM_START()
PROLOGUE(mpn_submul_1)
ldq r2,0(r17) C r2 = s1_limb
addq r17,8,r17 C s1_ptr++
subq r18,1,r18 C size--
mulq r2,r19,r3 C r3 = prod_low
ldq r5,0(r16) C r5 = *res_ptr
umulh r2,r19,r0 C r0 = prod_high
beq r18,$Lend1 C jump if size was == 1
ldq r2,0(r17) C r2 = s1_limb
addq r17,8,r17 C s1_ptr++
subq r18,1,r18 C size--
subq r5,r3,r3
cmpult r5,r3,r4
stq r3,0(r16)
addq r16,8,r16 C res_ptr++
beq r18,$Lend2 C jump if size was == 2
ALIGN(8)
$Loop: mulq r2,r19,r3 C r3 = prod_low
ldq r5,0(r16) C r5 = *res_ptr
addq r4,r0,r0 C cy_limb = cy_limb + 'cy'
subq r18,1,r18 C size--
umulh r2,r19,r4 C r4 = cy_limb
ldq r2,0(r17) C r2 = s1_limb
addq r17,8,r17 C s1_ptr++
addq r3,r0,r3 C r3 = cy_limb + prod_low
cmpult r3,r0,r0 C r0 = carry from (cy_limb + prod_low)
subq r5,r3,r3
cmpult r5,r3,r5
stq r3,0(r16)
addq r16,8,r16 C res_ptr++
addq r5,r0,r0 C combine carries
bne r18,$Loop
$Lend2: mulq r2,r19,r3 C r3 = prod_low
ldq r5,0(r16) C r5 = *res_ptr
addq r4,r0,r0 C cy_limb = cy_limb + 'cy'
umulh r2,r19,r4 C r4 = cy_limb
addq r3,r0,r3 C r3 = cy_limb + prod_low
cmpult r3,r0,r0 C r0 = carry from (cy_limb + prod_low)
subq r5,r3,r3
cmpult r5,r3,r5
stq r3,0(r16)
addq r5,r0,r0 C combine carries
addq r4,r0,r0 C cy_limb = prod_high + cy
ret r31,(r26),1
$Lend1: subq r5,r3,r3
cmpult r5,r3,r5
stq r3,0(r16)
addq r0,r5,r0
ret r31,(r26),1
EPILOGUE(mpn_submul_1)
ASM_END()