OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libgcc/] [config/] [libbid/] [bid64_scalb.c] - Blame information for rev 734

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 734 jeremybenn
/* Copyright (C) 2007, 2009  Free Software Foundation, Inc.
2
 
3
This file is part of GCC.
4
 
5
GCC is free software; you can redistribute it and/or modify it under
6
the terms of the GNU General Public License as published by the Free
7
Software Foundation; either version 3, or (at your option) any later
8
version.
9
 
10
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
11
WARRANTY; without even the implied warranty of MERCHANTABILITY or
12
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13
for more details.
14
 
15
Under Section 7 of GPL version 3, you are granted additional
16
permissions described in the GCC Runtime Library Exception, version
17
3.1, as published by the Free Software Foundation.
18
 
19
You should have received a copy of the GNU General Public License and
20
a copy of the GCC Runtime Library Exception along with this program;
21
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
22
<http://www.gnu.org/licenses/>.  */
23
 
24
#include "bid_internal.h"
25
 
26
#define MAX_FORMAT_DIGITS     16
27
#define DECIMAL_EXPONENT_BIAS 398
28
#define MAX_DECIMAL_EXPONENT  767
29
 
30
#if DECIMAL_CALL_BY_REFERENCE
31
 
32
void
33
bid64_scalb (UINT64 * pres, UINT64 * px,
34
             int *pn _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
35
             _EXC_INFO_PARAM) {
36
  UINT64 x;
37
  int n;
38
#else
39
 
40
UINT64
41
bid64_scalb (UINT64 x,
42
             int n _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
43
             _EXC_INFO_PARAM) {
44
#endif
45
  UINT64 sign_x, coefficient_x, res;
46
  SINT64 exp64;
47
  int exponent_x, rmode;
48
 
49
#if DECIMAL_CALL_BY_REFERENCE
50
#if !DECIMAL_GLOBAL_ROUNDING
51
  _IDEC_round rnd_mode = *prnd_mode;
52
#endif
53
  x = *px;
54
  n = *pn;
55
#endif
56
 
57
  // unpack arguments, check for NaN or Infinity
58
  if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) {
59
    // x is Inf. or NaN or 0
60
#ifdef SET_STATUS_FLAGS
61
    if ((x & SNAN_MASK64) == SNAN_MASK64)       // y is sNaN
62
      __set_status_flags (pfpsf, INVALID_EXCEPTION);
63
#endif
64
    if (coefficient_x)
65
      res = coefficient_x & QUIET_MASK64;
66
        else {
67
       exp64 = (SINT64) exponent_x + (SINT64) n;
68
           if(exp64<0) exp64=0;
69
           if(exp64>MAX_DECIMAL_EXPONENT) exp64=MAX_DECIMAL_EXPONENT;
70
       exponent_x = exp64;
71
      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);    // 0
72
        }
73
    BID_RETURN (res);
74
  }
75
 
76
  exp64 = (SINT64) exponent_x + (SINT64) n;
77
  exponent_x = exp64;
78
 
79
  if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT) {
80
    res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
81
    BID_RETURN (res);
82
  }
83
  // check for overflow
84
  if (exp64 > MAX_DECIMAL_EXPONENT) {
85
    // try to normalize coefficient
86
    while ((coefficient_x < 1000000000000000ull)
87
           && (exp64 > MAX_DECIMAL_EXPONENT)) {
88
      // coefficient_x < 10^15, scale by 10
89
      coefficient_x = (coefficient_x << 1) + (coefficient_x << 3);
90
      exponent_x--;
91
      exp64--;
92
    }
93
    if (exp64 <= MAX_DECIMAL_EXPONENT) {
94
      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
95
      BID_RETURN (res);
96
    } else
97
      exponent_x = 0x7fffffff;  // overflow
98
  }
99
  // exponent < 0
100
  // the BID pack routine will round the coefficient
101
  rmode = rnd_mode;
102
  res = get_BID64 (sign_x, exponent_x, coefficient_x, rmode, pfpsf);
103
  BID_RETURN (res);
104
 
105
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.