Annotation of OpenXM/src/kan96xx/gmp-2.0.2-ssh-2/mpn/power/submul_1.s, Revision 1.1
1.1 ! takayama 1: # IBM POWER __mpn_submul_1 -- Multiply a limb vector with a limb and subtract
! 2: # the result from 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_submul_1[PR]
! 42: .align 2
! 43: .globl __mpn_submul_1
! 44: .globl .__mpn_submul_1
! 45: .csect __mpn_submul_1[DS]
! 46: __mpn_submul_1:
! 47: .long .__mpn_submul_1[PR], TOC[tc0], 0
! 48: .csect .__mpn_submul_1[PR]
! 49: .__mpn_submul_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 11
! 59: cax 9,9,7
! 60: l 7,4(3)
! 61: sf 8,11,7 # add res_limb
! 62: a 11,8,11 # invert cy (r11 is junk)
! 63: blt Lneg
! 64: Lpos: bdz Lend
! 65:
! 66: Lploop: lu 0,4(4)
! 67: stu 8,4(3)
! 68: cmpi 0,0,0
! 69: mul 10,0,6
! 70: mfmq 0
! 71: ae 11,0,9 # low limb + old_cy_limb + old cy
! 72: l 7,4(3)
! 73: aze 10,10 # propagate cy to new cy_limb
! 74: sf 8,11,7 # add res_limb
! 75: a 11,8,11 # invert cy (r11 is junk)
! 76: bge Lp0
! 77: cax 10,10,6 # adjust high limb for negative limb from s1
! 78: Lp0: bdz Lend0
! 79: lu 0,4(4)
! 80: stu 8,4(3)
! 81: cmpi 0,0,0
! 82: mul 9,0,6
! 83: mfmq 0
! 84: ae 11,0,10
! 85: l 7,4(3)
! 86: aze 9,9
! 87: sf 8,11,7
! 88: a 11,8,11 # invert cy (r11 is junk)
! 89: bge Lp1
! 90: cax 9,9,6 # adjust high limb for negative limb from s1
! 91: Lp1: bdn Lploop
! 92:
! 93: b Lend
! 94:
! 95: Lneg: cax 9,9,0
! 96: bdz Lend
! 97: Lnloop: lu 0,4(4)
! 98: stu 8,4(3)
! 99: cmpi 0,0,0
! 100: mul 10,0,6
! 101: mfmq 7
! 102: ae 11,7,9
! 103: l 7,4(3)
! 104: ae 10,10,0 # propagate cy to new cy_limb
! 105: sf 8,11,7 # add res_limb
! 106: a 11,8,11 # invert cy (r11 is junk)
! 107: bge Ln0
! 108: cax 10,10,6 # adjust high limb for negative limb from s1
! 109: Ln0: bdz Lend0
! 110: lu 0,4(4)
! 111: stu 8,4(3)
! 112: cmpi 0,0,0
! 113: mul 9,0,6
! 114: mfmq 7
! 115: ae 11,7,10
! 116: l 7,4(3)
! 117: ae 9,9,0 # propagate cy to new cy_limb
! 118: sf 8,11,7 # add res_limb
! 119: a 11,8,11 # invert cy (r11 is junk)
! 120: bge Ln1
! 121: cax 9,9,6 # adjust high limb for negative limb from s1
! 122: Ln1: bdn Lnloop
! 123: b Lend
! 124:
! 125: Lend0: cal 9,0(10)
! 126: Lend: st 8,4(3)
! 127: aze 3,9
! 128: br
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