Annotation of OpenXM_contrib/gmp/mpn/power/mul_1.s, Revision 1.1.1.2
1.1.1.2 ! maekawa 1: # IBM POWER __gmpn_mul_1 -- Multiply a limb vector with a limb and store
1.1 maekawa 2: # the result in a second limb vector.
3:
1.1.1.2 ! maekawa 4: # Copyright (C) 1992, 1994, 1999, 2000 Free Software Foundation, Inc.
1.1 maekawa 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
1.1.1.2 ! maekawa 9: # it under the terms of the GNU Lesser General Public License as published by
! 10: # the Free Software Foundation; either version 2.1 of the License, or (at your
1.1 maekawa 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
1.1.1.2 ! maekawa 15: # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
1.1 maekawa 16: # License for more details.
17:
1.1.1.2 ! maekawa 18: # You should have received a copy of the GNU Lesser General Public License
1.1 maekawa 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:
1.1.1.2 ! maekawa 30: # The POWER architecture has no unsigned 32x32->64 bit multiplication
! 31: # instruction. To obtain that operation, we have to use the 32x32->64 signed
! 32: # multiplication instruction, and add the appropriate compensation to the high
! 33: # limb of the result. We add the multiplicand if the multiplier has its most
! 34: # significant bit set, and we add the multiplier if the multiplicand has its
! 35: # most significant bit set. We need to preserve the carry flag between each
1.1 maekawa 36: # iteration, so we have to compute the compensation carefully (the natural,
1.1.1.2 ! maekawa 37: # srai+and doesn't work). Since the POWER architecture has a branch unit we
! 38: # can branch in zero cycles, so that's how we perform the additions.
1.1 maekawa 39:
40: .toc
1.1.1.2 ! maekawa 41: .globl __gmpn_mul_1
! 42: .globl .__gmpn_mul_1
! 43: .csect __gmpn_mul_1[DS]
! 44: __gmpn_mul_1:
! 45: .long .__gmpn_mul_1, TOC[tc0], 0
! 46: .csect .text[PR]
! 47: .align 2
! 48: .__gmpn_mul_1:
1.1 maekawa 49:
50: cal 3,-4(3)
51: l 0,0(4)
52: cmpi 0,6,0
53: mtctr 5
54: mul 9,0,6
55: srai 7,0,31
56: and 7,7,6
57: mfmq 8
58: ai 0,0,0 # reset carry
59: cax 9,9,7
60: blt Lneg
61: Lpos: bdz Lend
62: Lploop: lu 0,4(4)
63: stu 8,4(3)
64: cmpi 0,0,0
65: mul 10,0,6
66: mfmq 0
67: ae 8,0,9
68: bge Lp0
69: cax 10,10,6 # adjust high limb for negative limb from s1
70: Lp0: bdz Lend0
71: lu 0,4(4)
72: stu 8,4(3)
73: cmpi 0,0,0
74: mul 9,0,6
75: mfmq 0
76: ae 8,0,10
77: bge Lp1
78: cax 9,9,6 # adjust high limb for negative limb from s1
79: Lp1: bdn Lploop
80: b Lend
81:
82: Lneg: cax 9,9,0
83: bdz Lend
84: Lnloop: lu 0,4(4)
85: stu 8,4(3)
86: cmpi 0,0,0
87: mul 10,0,6
88: cax 10,10,0 # adjust high limb for negative s2_limb
89: mfmq 0
90: ae 8,0,9
91: bge Ln0
92: cax 10,10,6 # adjust high limb for negative limb from s1
93: Ln0: bdz Lend0
94: lu 0,4(4)
95: stu 8,4(3)
96: cmpi 0,0,0
97: mul 9,0,6
98: cax 9,9,0 # adjust high limb for negative s2_limb
99: mfmq 0
100: ae 8,0,10
101: bge Ln1
102: cax 9,9,6 # adjust high limb for negative limb from s1
103: Ln1: bdn Lnloop
104: b Lend
105:
106: Lend0: cal 9,0(10)
107: Lend: st 8,4(3)
108: aze 3,9
109: br
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