| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) |
| 3 | * |
| 4 | * Floating-point emulation code |
| 5 | * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2, or (at your option) |
| 10 | * any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | /* |
| 22 | * BEGIN_DESC |
| 23 | * |
| 24 | * File: |
| 25 | * @(#) pa/fp/denormal.c $ Revision: $ |
| 26 | * |
| 27 | * Purpose: |
| 28 | * <<please update with a synopsis of the functionality provided by this file>> |
| 29 | * |
| 30 | * External Interfaces: |
| 31 | * <<the following list was autogenerated, please review>> |
| 32 | * dbl_denormalize(dbl_opndp1,dbl_opndp2,inexactflag,rmode) |
| 33 | * sgl_denormalize(sgl_opnd,inexactflag,rmode) |
| 34 | * |
| 35 | * Internal Interfaces: |
| 36 | * <<please update>> |
| 37 | * |
| 38 | * Theory: |
| 39 | * <<please update with a overview of the operation of this file>> |
| 40 | * |
| 41 | * END_DESC |
| 42 | */ |
| 43 | |
| 44 | |
| 45 | |
| 46 | #include "float.h" |
| 47 | #include "sgl_float.h" |
| 48 | #include "dbl_float.h" |
| 49 | #include "hppa.h" |
| 50 | #include <linux/kernel.h> |
| 51 | /* #include <machine/sys/mdep_private.h> */ |
| 52 | |
| 53 | #undef Fpustatus_register |
| 54 | #define Fpustatus_register Fpu_register[0] |
| 55 | |
| 56 | void |
| 57 | sgl_denormalize(unsigned int *sgl_opnd, boolean *inexactflag, int rmode) |
| 58 | { |
| 59 | unsigned int opnd; |
| 60 | int sign, exponent; |
| 61 | boolean guardbit = FALSE, stickybit, inexact; |
| 62 | |
| 63 | opnd = *sgl_opnd; |
| 64 | stickybit = *inexactflag; |
| 65 | exponent = Sgl_exponent(opnd) - SGL_WRAP; |
| 66 | sign = Sgl_sign(opnd); |
| 67 | Sgl_denormalize(opnd,exponent,guardbit,stickybit,inexact); |
| 68 | if (inexact) { |
| 69 | switch (rmode) { |
| 70 | case ROUNDPLUS: |
| 71 | if (sign == 0) { |
| 72 | Sgl_increment(opnd); |
| 73 | } |
| 74 | break; |
| 75 | case ROUNDMINUS: |
| 76 | if (sign != 0) { |
| 77 | Sgl_increment(opnd); |
| 78 | } |
| 79 | break; |
| 80 | case ROUNDNEAREST: |
| 81 | if (guardbit && (stickybit || |
| 82 | Sgl_isone_lowmantissa(opnd))) { |
| 83 | Sgl_increment(opnd); |
| 84 | } |
| 85 | break; |
| 86 | } |
| 87 | } |
| 88 | Sgl_set_sign(opnd,sign); |
| 89 | *sgl_opnd = opnd; |
| 90 | *inexactflag = inexact; |
| 91 | return; |
| 92 | } |
| 93 | |
| 94 | void |
| 95 | dbl_denormalize(unsigned int *dbl_opndp1, |
| 96 | unsigned int * dbl_opndp2, |
| 97 | boolean *inexactflag, |
| 98 | int rmode) |
| 99 | { |
| 100 | unsigned int opndp1, opndp2; |
| 101 | int sign, exponent; |
| 102 | boolean guardbit = FALSE, stickybit, inexact; |
| 103 | |
| 104 | opndp1 = *dbl_opndp1; |
| 105 | opndp2 = *dbl_opndp2; |
| 106 | stickybit = *inexactflag; |
| 107 | exponent = Dbl_exponent(opndp1) - DBL_WRAP; |
| 108 | sign = Dbl_sign(opndp1); |
| 109 | Dbl_denormalize(opndp1,opndp2,exponent,guardbit,stickybit,inexact); |
| 110 | if (inexact) { |
| 111 | switch (rmode) { |
| 112 | case ROUNDPLUS: |
| 113 | if (sign == 0) { |
| 114 | Dbl_increment(opndp1,opndp2); |
| 115 | } |
| 116 | break; |
| 117 | case ROUNDMINUS: |
| 118 | if (sign != 0) { |
| 119 | Dbl_increment(opndp1,opndp2); |
| 120 | } |
| 121 | break; |
| 122 | case ROUNDNEAREST: |
| 123 | if (guardbit && (stickybit || |
| 124 | Dbl_isone_lowmantissap2(opndp2))) { |
| 125 | Dbl_increment(opndp1,opndp2); |
| 126 | } |
| 127 | break; |
| 128 | } |
| 129 | } |
| 130 | Dbl_set_sign(opndp1,sign); |
| 131 | *dbl_opndp1 = opndp1; |
| 132 | *dbl_opndp2 = opndp2; |
| 133 | *inexactflag = inexact; |
| 134 | return; |
| 135 | } |