nest-open-source / nest-learning-thermostat / 5.1.8 / libgcrypt / refs/heads/master / . / libgcrypt-1.4.6 / mpi / power / mpih-mul1.S

/* IBM POWER mul_1 -- Multiply a limb vector with a limb and store | |

* the result in a second limb vector. | |

* | |

* Copyright (C) 1992, 1994, 1999, 2002 Free Software Foundation, Inc. | |

* | |

* This file is part of Libgcrypt. | |

* | |

* Libgcrypt 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. | |

* | |

* Libgcrypt 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 this program; if not, write to the Free Software | |

* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA | |

*/ | |

#include "sysdep.h" | |

#include "asm-syntax.h" | |

/* | |

# INPUT PARAMETERS | |

# res_ptr r3 | |

# s1_ptr r4 | |

# size r5 | |

# s2_limb r6 | |

# The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To | |

# obtain that operation, we have to use the 32x32->64 signed multiplication | |

# instruction, and add the appropriate compensation to the high limb of the | |

# result. We add the multiplicand if the multiplier has its most significant | |

# bit set, and we add the multiplier if the multiplicand has its most | |

# significant bit set. We need to preserve the carry flag between each | |

# iteration, so we have to compute the compensation carefully (the natural, | |

# srai+and doesn't work). Since the POWER architecture has a branch unit | |

# we can branch in zero cycles, so that's how we perform the additions. | |

*/ | |

.toc | |

.csect ._gcry_mpih_mul_1[PR] | |

.align 2 | |

.globl _gcry_mpih_mul_1 | |

.globl ._gcry_mpih_mul_1 | |

.csect _gcry_mpih_mul_1[DS] | |

_gcry_mpih_mul_1: | |

.long ._gcry_mpih_mul_1[PR], TOC[tc0], 0 | |

.csect ._gcry_mpih_mul_1[PR] | |

._gcry_mpih_mul_1: | |

cal 3,-4(3) | |

l 0,0(4) | |

cmpi 0,6,0 | |

mtctr 5 | |

mul 9,0,6 | |

srai 7,0,31 | |

and 7,7,6 | |

mfmq 8 | |

ai 0,0,0 # reset carry | |

cax 9,9,7 | |

blt Lneg | |

Lpos: bdz Lend | |

Lploop: lu 0,4(4) | |

stu 8,4(3) | |

cmpi 0,0,0 | |

mul 10,0,6 | |

mfmq 0 | |

ae 8,0,9 | |

bge Lp0 | |

cax 10,10,6 # adjust high limb for negative limb from s1 | |

Lp0: bdz Lend0 | |

lu 0,4(4) | |

stu 8,4(3) | |

cmpi 0,0,0 | |

mul 9,0,6 | |

mfmq 0 | |

ae 8,0,10 | |

bge Lp1 | |

cax 9,9,6 # adjust high limb for negative limb from s1 | |

Lp1: bdn Lploop | |

b Lend | |

Lneg: cax 9,9,0 | |

bdz Lend | |

Lnloop: lu 0,4(4) | |

stu 8,4(3) | |

cmpi 0,0,0 | |

mul 10,0,6 | |

cax 10,10,0 # adjust high limb for negative s2_limb | |

mfmq 0 | |

ae 8,0,9 | |

bge Ln0 | |

cax 10,10,6 # adjust high limb for negative limb from s1 | |

Ln0: bdz Lend0 | |

lu 0,4(4) | |

stu 8,4(3) | |

cmpi 0,0,0 | |

mul 9,0,6 | |

cax 9,9,0 # adjust high limb for negative s2_limb | |

mfmq 0 | |

ae 8,0,10 | |

bge Ln1 | |

cax 9,9,6 # adjust high limb for negative limb from s1 | |

Ln1: bdn Lnloop | |

b Lend | |

Lend0: cal 9,0(10) | |

Lend: st 8,4(3) | |

aze 3,9 | |

br | |