ceph/src/civetweb/src/third_party/duktape-1.8.0/src-separate/duk_replacements.c

   1 /*
   2  *  Replacements for missing platform functions.
   3  *
   4  *  Unlike the originals, fpclassify() and signbit() replacements don't
   5  *  work on any floating point types, only doubles.  The C typing here
   6  *  mimics the standard prototypes.
   7  */
   8
   9 #include "duk_internal.h"
  10
  11 #if defined(DUK_USE_COMPUTED_NAN)
  12 DUK_INTERNAL double duk_computed_nan;
  13 #endif
  14
  15 #if defined(DUK_USE_COMPUTED_INFINITY)
  16 DUK_INTERNAL double duk_computed_infinity;
  17 #endif
  18
  19 #if defined(DUK_USE_REPL_FPCLASSIFY)
  20 DUK_INTERNAL int duk_repl_fpclassify(double x) {
  21         duk_double_union u;
  22         duk_uint_fast16_t expt;
  23         duk_small_int_t mzero;
  24
  25         u.d = x;
  26         expt = (duk_uint_fast16_t) (u.us[DUK_DBL_IDX_US0] & 0x7ff0UL);
  27         if (expt > 0x0000UL && expt < 0x7ff0UL) {
  28                 /* expt values [0x001,0x7fe] = normal */
  29                 return DUK_FP_NORMAL;
  30         }
  31
  32         mzero = (u.ui[DUK_DBL_IDX_UI1] == 0 && (u.ui[DUK_DBL_IDX_UI0] & 0x000fffffUL) == 0);
  33         if (expt == 0x0000UL) {
  34                 /* expt 0x000 is zero/subnormal */
  35                 if (mzero) {
  36                         return DUK_FP_ZERO;
  37                 } else {
  38                         return DUK_FP_SUBNORMAL;
  39                 }
  40         } else {
  41                 /* expt 0xfff is infinite/nan */
  42                 if (mzero) {
  43                         return DUK_FP_INFINITE;
  44                 } else {
  45                         return DUK_FP_NAN;
  46                 }
  47         }
  48 }
  49 #endif
  50
  51 #if defined(DUK_USE_REPL_SIGNBIT)
  52 DUK_INTERNAL int duk_repl_signbit(double x) {
  53         duk_double_union u;
  54         u.d = x;
  55         return (int) (u.uc[DUK_DBL_IDX_UC0] & 0x80UL);
  56 }
  57 #endif
  58
  59 #if defined(DUK_USE_REPL_ISFINITE)
  60 DUK_INTERNAL int duk_repl_isfinite(double x) {
  61         int c = DUK_FPCLASSIFY(x);
  62         if (c == DUK_FP_NAN || c == DUK_FP_INFINITE) {
  63                 return 0;
  64         } else {
  65                 return 1;
  66         }
  67 }
  68 #endif
  69
  70 #if defined(DUK_USE_REPL_ISNAN)
  71 DUK_INTERNAL int duk_repl_isnan(double x) {
  72         int c = DUK_FPCLASSIFY(x);
  73         return (c == DUK_FP_NAN);
  74 }
  75 #endif
  76
  77 #if defined(DUK_USE_REPL_ISINF)
  78 DUK_INTERNAL int duk_repl_isinf(double x) {
  79         int c = DUK_FPCLASSIFY(x);
  80         return (c == DUK_FP_INFINITE);
  81 }
  82 #endif