lib/libc/gen/fixunstfsi_ieee754.c

   1 /*      $NetBSD: fixunstfsi_ieee754.c,v 1.2 2012/08/05 04:28:58 matt Exp $      */
   2 /*-
   3  * Copyright (c) 2011 The NetBSD Foundation, Inc.
   4  * All rights reserved.
   5  *
   6  * This code is derived from software contributed to The NetBSD Foundation
   7  * by Matt Thomas of 3am Software Foundry.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 __RCSID("$NetBSD: fixunstfsi_ieee754.c,v 1.2 2012/08/05 04:28:58 matt Exp $");
  35 #endif /* LIBC_SCCS and not lint */
  36
  37 #include <stdbool.h>
  38 #include <stdint.h>
  39 #include <float.h>
  40 #include <machine/ieee.h>
  41
  42 #ifdef SOFTFLOAT
  43 #include "softfloat/softfloat-for-gcc.h"
  44 #endif
  45
  46 #if defined(__x86_64__) || defined(__i486__)
  47 #define FIXUNS  __fixunsxfsi
  48 #else
  49 #define FIXUNS  __fixunstfsi
  50 #endif
  51
  52 uint32_t __fixunsgen32(int, bool, size_t, size_t, const uint32_t *);
  53
  54 uint32_t FIXUNS(long double);
  55
  56 /*
  57  * Convert long double to (unsigned) int.  All operations are done module 2^32.
  58  */
  59 uint32_t
  60 FIXUNS(long double x)
  61 {
  62         const union ieee_ext_u extu = { .extu_ld = x };
  63         uint32_t frac[(EXT_FRACBITS + 31)/32 + 1];
  64
  65         frac[0] = 0;
  66
  67         EXT_TO_ARRAY32(extu, &frac[1]);
  68
  69         return __fixunsgen32(
  70                 extu.extu_ext.ext_exp - EXT_EXP_BIAS,
  71                 extu.extu_ext.ext_sign != 0,
  72                 LDBL_MANT_DIG,
  73                 EXT_FRACHBITS,
  74                 &frac[__arraycount(frac)-1]);
  75 }