mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-27 05:00:15 +00:00
107 lines
2.7 KiB
ArmAsm
107 lines
2.7 KiB
ArmAsm
; mc88100 __mpn_sub -- Subtract two limb vectors of the same length > 0 and
|
|
; store difference in a third limb vector.
|
|
|
|
; Copyright (C) 1992, 1994, 1996 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; see the file COPYING.LIB. If not, write to
|
|
; the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
|
|
; MA 02111-1307, USA.
|
|
|
|
|
|
; INPUT PARAMETERS
|
|
; res_ptr r2
|
|
; s1_ptr r3
|
|
; s2_ptr r4
|
|
; size r5
|
|
|
|
; This code has been optimized to run one instruction per clock, avoiding
|
|
; load stalls and writeback contention. As a result, the instruction
|
|
; order is not always natural.
|
|
|
|
; The speed is about 4.6 clocks/limb + 18 clocks/limb-vector on an 88100,
|
|
; but on the 88110, it seems to run much slower, 6.6 clocks/limb.
|
|
|
|
text
|
|
align 16
|
|
global ___mpn_sub_n
|
|
___mpn_sub_n:
|
|
ld r6,r3,0 ; read first limb from s1_ptr
|
|
extu r10,r5,3
|
|
ld r7,r4,0 ; read first limb from s2_ptr
|
|
|
|
subu r5,r0,r5
|
|
mak r5,r5,3<4>
|
|
bcnd.n eq0,r5,Lzero
|
|
subu.co r0,r0,r0 ; initialize carry
|
|
|
|
or r12,r0,lo16(Lbase)
|
|
or.u r12,r12,hi16(Lbase)
|
|
addu r12,r12,r5 ; r12 is address for entering in loop
|
|
|
|
extu r5,r5,2 ; divide by 4
|
|
subu r2,r2,r5 ; adjust res_ptr
|
|
subu r3,r3,r5 ; adjust s1_ptr
|
|
subu r4,r4,r5 ; adjust s2_ptr
|
|
|
|
or r8,r6,r0
|
|
|
|
jmp.n r12
|
|
or r9,r7,r0
|
|
|
|
Loop: addu r3,r3,32
|
|
st r8,r2,28
|
|
addu r4,r4,32
|
|
ld r6,r3,0
|
|
addu r2,r2,32
|
|
ld r7,r4,0
|
|
Lzero: subu r10,r10,1 ; subtract 0 + 8r limbs (adj loop cnt)
|
|
Lbase: ld r8,r3,4
|
|
subu.cio r6,r6,r7
|
|
ld r9,r4,4
|
|
st r6,r2,0
|
|
ld r6,r3,8 ; subtract 7 + 8r limbs
|
|
subu.cio r8,r8,r9
|
|
ld r7,r4,8
|
|
st r8,r2,4
|
|
ld r8,r3,12 ; subtract 6 + 8r limbs
|
|
subu.cio r6,r6,r7
|
|
ld r9,r4,12
|
|
st r6,r2,8
|
|
ld r6,r3,16 ; subtract 5 + 8r limbs
|
|
subu.cio r8,r8,r9
|
|
ld r7,r4,16
|
|
st r8,r2,12
|
|
ld r8,r3,20 ; subtract 4 + 8r limbs
|
|
subu.cio r6,r6,r7
|
|
ld r9,r4,20
|
|
st r6,r2,16
|
|
ld r6,r3,24 ; subtract 3 + 8r limbs
|
|
subu.cio r8,r8,r9
|
|
ld r7,r4,24
|
|
st r8,r2,20
|
|
ld r8,r3,28 ; subtract 2 + 8r limbs
|
|
subu.cio r6,r6,r7
|
|
ld r9,r4,28
|
|
st r6,r2,24
|
|
bcnd.n ne0,r10,Loop ; subtract 1 + 8r limbs
|
|
subu.cio r8,r8,r9
|
|
|
|
st r8,r2,28 ; store most significant limb
|
|
|
|
addu.ci r2,r0,r0 ; return carry-out from most sign. limb
|
|
jmp.n r1
|
|
xor r2,r2,1
|