Annotation of OpenXM/src/kan96xx/gmp-2.0.2-ssh-2/mpn/power/mul_1.s, Revision 1.1.1.1
1.1 takayama 1: # IBM POWER __mpn_mul_1 -- Multiply a limb vector with a limb and store
2: # the result in a second limb vector.
3:
4: # Copyright (C) 1992, 1994 Free Software Foundation, Inc.
5:
6: # This file is part of the GNU MP Library.
7:
8: # The GNU MP Library is free software; you can redistribute it and/or modify
9: # it under the terms of the GNU Library General Public License as published by
10: # the Free Software Foundation; either version 2 of the License, or (at your
11: # option) any later version.
12:
13: # The GNU MP Library is distributed in the hope that it will be useful, but
14: # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15: # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
16: # License for more details.
17:
18: # You should have received a copy of the GNU Library General Public License
19: # along with the GNU MP Library; see the file COPYING.LIB. If not, write to
20: # the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
21: # MA 02111-1307, USA.
22:
23:
24: # INPUT PARAMETERS
25: # res_ptr r3
26: # s1_ptr r4
27: # size r5
28: # s2_limb r6
29:
30: # The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To
31: # obtain that operation, we have to use the 32x32->64 signed multiplication
32: # instruction, and add the appropriate compensation to the high limb of the
33: # result. We add the multiplicand if the multiplier has its most significant
34: # bit set, and we add the multiplier if the multiplicand has its most
35: # significant bit set. We need to preserve the carry flag between each
36: # iteration, so we have to compute the compensation carefully (the natural,
37: # srai+and doesn't work). Since the POWER architecture has a branch unit
38: # we can branch in zero cycles, so that's how we perform the additions.
39:
40: .toc
41: .csect .__mpn_mul_1[PR]
42: .align 2
43: .globl __mpn_mul_1
44: .globl .__mpn_mul_1
45: .csect __mpn_mul_1[DS]
46: __mpn_mul_1:
47: .long .__mpn_mul_1[PR], TOC[tc0], 0
48: .csect .__mpn_mul_1[PR]
49: .__mpn_mul_1:
50:
51: cal 3,-4(3)
52: l 0,0(4)
53: cmpi 0,6,0
54: mtctr 5
55: mul 9,0,6
56: srai 7,0,31
57: and 7,7,6
58: mfmq 8
59: ai 0,0,0 # reset carry
60: cax 9,9,7
61: blt Lneg
62: Lpos: bdz Lend
63: Lploop: lu 0,4(4)
64: stu 8,4(3)
65: cmpi 0,0,0
66: mul 10,0,6
67: mfmq 0
68: ae 8,0,9
69: bge Lp0
70: cax 10,10,6 # adjust high limb for negative limb from s1
71: Lp0: bdz Lend0
72: lu 0,4(4)
73: stu 8,4(3)
74: cmpi 0,0,0
75: mul 9,0,6
76: mfmq 0
77: ae 8,0,10
78: bge Lp1
79: cax 9,9,6 # adjust high limb for negative limb from s1
80: Lp1: bdn Lploop
81: b Lend
82:
83: Lneg: cax 9,9,0
84: bdz Lend
85: Lnloop: lu 0,4(4)
86: stu 8,4(3)
87: cmpi 0,0,0
88: mul 10,0,6
89: cax 10,10,0 # adjust high limb for negative s2_limb
90: mfmq 0
91: ae 8,0,9
92: bge Ln0
93: cax 10,10,6 # adjust high limb for negative limb from s1
94: Ln0: bdz Lend0
95: lu 0,4(4)
96: stu 8,4(3)
97: cmpi 0,0,0
98: mul 9,0,6
99: cax 9,9,0 # adjust high limb for negative s2_limb
100: mfmq 0
101: ae 8,0,10
102: bge Ln1
103: cax 9,9,6 # adjust high limb for negative limb from s1
104: Ln1: bdn Lnloop
105: b Lend
106:
107: Lend0: cal 9,0(10)
108: Lend: st 8,4(3)
109: aze 3,9
110: br
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