1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 
  27 /*
  28  * Copyright 2019 Joyent, Inc.
  29  */
  30 
  31 #include "lint.h"
  32 #include <sys/types.h>
  33 #include "base_conversion.h"
  34 #include <sys/isa_defs.h>
  35 
  36 /*
  37  * Miscellaneous support routines used in base conversion
  38  */
  39 
  40 static const union {
  41         unsigned int    u[2];
  42         double          d;
  43 } C[] = {
  44 #ifdef _LITTLE_ENDIAN
  45         { 0x00000000u, 0x00100000u },
  46         { 0x00000001u, 0x7ff00000u }
  47 #else
  48         { 0x00100000u, 0x00000000u },
  49         { 0x7ff00000u, 0x00000001u }
  50 #endif
  51 };
  52 
  53 #define minnormal       C[0].d
  54 #define signalingnan    C[1].d
  55 
  56 /* raise the floating point exceptions indicated by ef */
  57 void
  58 __base_conversion_set_exception(fp_exception_field_type ef)
  59 {
  60         double  t;
  61         volatile double tstored __unused;
  62 
  63         if (ef == (1 << fp_inexact)) {
  64                 t = 9.999999962747097015E-1;
  65                 /*
  66                  * 28 sig bits so product isn't inexact in extended
  67                  * accumulator, causing two inexact traps.
  68                  */
  69         } else if ((ef & (1 << fp_invalid)) != 0) {
  70                 t = signalingnan;
  71         } else if ((ef & (1 << fp_overflow)) != 0) {
  72                 t = 4.149515553422842866E+180;
  73                 /*
  74                  * 28 sig bits so product isn't inexact in extended
  75                  * accumulator, causing inexact trap prior to overflow trap
  76                  * on store.
  77                  */
  78         } else if ((ef & (1 << fp_underflow)) != 0) {
  79                 t = minnormal;
  80         } else
  81                 return;
  82 
  83         /* Storage forces exception */
  84         tstored = t * t;
  85 #if defined(__lint)
  86         tstored = tstored;
  87 #endif
  88 }
  89 
  90 /*
  91  * The following routine is no longer used in libc, but we have
  92  * to leave it for now because it's still used by Sun's old Fortran
  93  * runtime libraries.  Today this is a bug; in the days of SunOS 4.x,
  94  * when the relevant design decisions were made, it was a feature.
  95  *
  96  * Regardless, on 32-bit, 'quadruple' under GCC is not 128 bits, so it
  97  * uses uninitialized memory...
  98  */
  99 #pragma GCC diagnostic ignored "-Wuninitialized"
 100 enum fp_class_type
 101 __class_quadruple(quadruple *x)
 102 {
 103         quadruple_equivalence kluge;
 104 
 105         kluge.x = *x;
 106         if (kluge.f.msw.exponent == 0) {        /* 0 or sub */
 107                 if ((kluge.f.msw.significand == 0) &&
 108                     (kluge.f.significand2 == 0) &&
 109                     (kluge.f.significand3 == 0) &&
 110                     (kluge.f.significand4 == 0))
 111                         return (fp_zero);
 112                 else
 113                         return (fp_subnormal);
 114         } else if (kluge.f.msw.exponent == 0x7fff) {    /* inf or nan */
 115                 if ((kluge.f.msw.significand == 0) &&
 116                     (kluge.f.significand2 == 0) &&
 117                     (kluge.f.significand3 == 0) &&
 118                     (kluge.f.significand4 == 0))
 119                         return (fp_infinity);
 120                 else if ((kluge.f.msw.significand & 0xffff) >=
 121                     (unsigned int)0x8000)
 122                         return (fp_quiet);
 123                 else
 124                         return (fp_signaling);
 125         } else
 126                 return (fp_normal);
 127 }