diff options
| author | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2018-06-20 14:08:37 +0000 |
|---|---|---|
| committer | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2018-06-20 14:08:37 +0000 |
| commit | 673568cc583d7a0a1b7103ecefedab0f1bda1aa7 (patch) | |
| tree | 81897488deefed4a47d66e99570b0d7885a2c47f /src/get_d64.c | |
| parent | 582755d986f8cf92d80611cd564abd31de400f46 (diff) | |
| download | mpfr-673568cc583d7a0a1b7103ecefedab0f1bda1aa7.tar.gz | |
[get_d64.c] added comments and simplified code
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@12794 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'src/get_d64.c')
| -rw-r--r-- | src/get_d64.c | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/src/get_d64.c b/src/get_d64.c index fa2c307eb..c54cbf6a3 100644 --- a/src/get_d64.c +++ b/src/get_d64.c @@ -154,7 +154,9 @@ get_decimal64_zero (int negative) return y.d64; } -/* construct the decimal64 smallest non-zero with given sign */ +/* construct the decimal64 smallest non-zero with given sign: + it is 10^emin * 10^(1-p). Since emax = 384, emin = 1-emax = -383, + and p = 16, we get 10^(-398) */ static _Decimal64 get_decimal64_min (int negative) { @@ -303,11 +305,8 @@ string_to_Decimal64 (char *s) char m[17]; long n = 0; /* mantissa length */ char *endptr[1]; - _Decimal64 x = 0.0; + _Decimal64 x = 0; int sign = 0; -#ifdef DPD_FORMAT - unsigned int G, d1, d2, d3, d4, d5; -#endif /* read sign */ if (*s == '-') @@ -318,16 +317,14 @@ string_to_Decimal64 (char *s) /* read mantissa */ while (ISDIGIT (*s)) m[n++] = *s++; - exp = n; /* as constructed in mpfr_get_decimal64, s cannot have any '.' separator */ - /* we have exp digits before decimal point, and a total of n digits */ - exp -= n; /* we will consider an integer mantissa */ + /* we will consider an integer mantissa m*10^exp */ MPFR_ASSERTN(n <= 16); - /* s always have an exponent separator 'E' */ + /* s always has an exponent separator 'E' */ MPFR_ASSERTN(*s == 'E'); - exp += strtol (s + 1, endptr, 10); + exp = strtol (s + 1, endptr, 10); MPFR_ASSERTN(**endptr == '\0'); MPFR_ASSERTN(-398 <= exp && exp <= (long) (385 - n)); while (n < 16) @@ -521,7 +518,7 @@ mpfr_get_decimal64 (mpfr_srcptr src, mpfr_rnd_t rnd_mode) else /* RNDA: return the smallest non-zero number */ return get_decimal64_min (negative); } - /* the largest decimal64 number is just below 10^(385) < 2^1279 */ + /* the largest decimal64 number is just below 10^385 < 2^1279 */ else if (MPFR_UNLIKELY (e > 1279)) /* then src >= 2^1279 */ { if (rnd_mode == MPFR_RNDZ) |