1/* $NetBSD: fpu_int.c,v 1.10 2011/07/18 14:11:27 isaki Exp $ */ 2 3/* 4 * Copyright (c) 1995 Ken Nakata 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * @(#)fpu_int.c 29 */ 30 31#include <sys/cdefs.h> 32__KERNEL_RCSID(0, "$NetBSD: fpu_int.c,v 1.10 2011/07/18 14:11:27 isaki Exp $"); 33 34#include <sys/types.h> 35 36#include <machine/reg.h> 37 38#include "fpu_arith.h" 39#include "fpu_emulate.h" 40 41/* FINTRZ - always round to zero */ 42struct fpn * 43fpu_intrz(struct fpemu *fe) 44{ 45 register struct fpn *x = &fe->fe_f2; 46 register int sh, clr, mask, i; 47 48 /* special cases first */ 49 if (x->fp_class != FPC_NUM) { 50 return x; 51 } 52 /* when |x| < 1.0 */ 53 if (x->fp_exp < 0) { 54 x->fp_class = FPC_ZERO; 55 x->fp_mant[0] = x->fp_mant[1] = x->fp_mant[2] = 0; 56 return x; 57 } 58 59 /* real work */ 60 sh = FP_NMANT - 1 - x->fp_exp; 61 if (sh <= 0) { 62 return x; 63 } 64 65 clr = 2 - sh / 32; 66 mask = (0xffffffff << (sh % 32)); 67 68 for (i = 2; i > clr; i--) { 69 x->fp_mant[i] = 0; 70 } 71 x->fp_mant[i] &= mask; 72 73 return x; 74} 75 76/* FINT */ 77struct fpn * 78fpu_int(struct fpemu *fe) 79{ 80 register struct fpn *x = &fe->fe_f2; 81 register int rsh; 82 83 /* special cases first */ 84 if (x->fp_class != FPC_NUM) { 85 return x; 86 } 87 88 rsh = FP_NMANT - 1 - x->fp_exp; 89 if (rsh <= FP_NG) { 90 return x; 91 } 92 93 /* shift to the right */ 94 x->fp_exp = 0; 95 fpu_shr(x, rsh - FP_NG); 96 97 /* round according to FPCR round mode */ 98 fpu_round(fe, x); 99 100 /* shift it back to the left */ 101 x->fp_exp = FP_NMANT - 1; 102 fpu_norm(x); 103 104 return x; 105} 106