Annotation of OpenXM/src/kan96xx/gmp-2.0.2-ssh-2/mpn/power/sub_n.s, Revision 1.1.1.1
1.1 takayama 1: # IBM POWER __mpn_sub_n -- Subtract two limb vectors of equal, non-zero length.
2:
3: # Copyright (C) 1992, 1994, 1995, 1996 Free Software Foundation, Inc.
4:
5: # This file is part of the GNU MP Library.
6:
7: # The GNU MP Library is free software; you can redistribute it and/or modify
8: # it under the terms of the GNU Library General Public License as published by
9: # the Free Software Foundation; either version 2 of the License, or (at your
10: # option) any later version.
11:
12: # The GNU MP Library is distributed in the hope that it will be useful, but
13: # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14: # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
15: # License for more details.
16:
17: # You should have received a copy of the GNU Library General Public License
18: # along with the GNU MP Library; see the file COPYING.LIB. If not, write to
19: # the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
20: # MA 02111-1307, USA.
21:
22:
23: # INPUT PARAMETERS
24: # res_ptr r3
25: # s1_ptr r4
26: # s2_ptr r5
27: # size r6
28:
29: .toc
30: .extern __mpn_sub_n[DS]
31: .extern .__mpn_sub_n
32: .csect [PR]
33: .align 2
34: .globl __mpn_sub_n
35: .globl .__mpn_sub_n
36: .csect __mpn_sub_n[DS]
37: __mpn_sub_n:
38: .long .__mpn_sub_n, TOC[tc0], 0
39: .csect [PR]
40: .__mpn_sub_n:
41: andil. 10,6,1 # odd or even number of limbs?
42: l 8,0(4) # load least significant s1 limb
43: l 0,0(5) # load least significant s2 limb
44: cal 3,-4(3) # offset res_ptr, it's updated before it's used
45: sri 10,6,1 # count for unrolled loop
46: sf 7,0,8 # subtract least significant limbs, set cy
47: mtctr 10 # copy count into CTR
48: beq 0,Leven # branch if even # of limbs (# of limbs >= 2)
49:
50: # We have an odd # of limbs. Add the first limbs separately.
51: cmpi 1,10,0 # is count for unrolled loop zero?
52: bne 1,L1 # branch if not
53: st 7,4(3)
54: sfe 3,0,0 # load !cy into ...
55: sfi 3,3,0 # ... return value register
56: br # return
57:
58: # We added least significant limbs. Now reload the next limbs to enter loop.
59: L1: lu 8,4(4) # load s1 limb and update s1_ptr
60: lu 0,4(5) # load s2 limb and update s2_ptr
61: stu 7,4(3)
62: sfe 7,0,8 # subtract limbs, set cy
63: Leven: lu 9,4(4) # load s1 limb and update s1_ptr
64: lu 10,4(5) # load s2 limb and update s2_ptr
65: bdz Lend # If done, skip loop
66:
67: Loop: lu 8,4(4) # load s1 limb and update s1_ptr
68: lu 0,4(5) # load s2 limb and update s2_ptr
69: sfe 11,10,9 # subtract previous limbs with cy, set cy
70: stu 7,4(3) #
71: lu 9,4(4) # load s1 limb and update s1_ptr
72: lu 10,4(5) # load s2 limb and update s2_ptr
73: sfe 7,0,8 # subtract previous limbs with cy, set cy
74: stu 11,4(3) #
75: bdn Loop # decrement CTR and loop back
76:
77: Lend: sfe 11,10,9 # subtract limbs with cy, set cy
78: st 7,4(3) #
79: st 11,8(3) #
80: sfe 3,0,0 # load !cy into ...
81: sfi 3,3,0 # ... return value register
82: br
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