diff options
| -rw-r--r-- | Modules/_math.c | 43 |
1 files changed, 23 insertions, 20 deletions
diff --git a/Modules/_math.c b/Modules/_math.c index d5974e3..2fef481 100644 --- a/Modules/_math.c +++ b/Modules/_math.c @@ -55,7 +55,8 @@ _Py_acosh(double x) else if (x >= two_pow_p28) { /* x > 2**28 */ if (Py_IS_INFINITY(x)) { return x+x; - } else { + } + else { return log(x)+ln2; /* acosh(huge)=log(2x) */ } } @@ -173,15 +174,15 @@ _Py_expm1(double x) */ if (fabs(x) < 0.7) { - double u; - u = exp(x); - if (u == 1.0) - return x; - else - return (u - 1.0) * x / log(u); + double u; + u = exp(x); + if (u == 1.0) + return x; + else + return (u - 1.0) * x / log(u); } else - return exp(x) - 1.0; + return exp(x) - 1.0; } /* log1p(x) = log(1+x). The log1p function is designed to avoid the @@ -213,17 +214,19 @@ _Py_log1p(double x) double y; if (fabs(x) < DBL_EPSILON/2.) { - return x; - } else if (-0.5 <= x && x <= 1.) { - /* WARNING: it's possible than an overeager compiler - will incorrectly optimize the following two lines - to the equivalent of "return log(1.+x)". If this - happens, then results from log1p will be inaccurate - for small x. */ - y = 1.+x; - return log(y)-((y-1.)-x)/y; - } else { - /* NaNs and infinities should end up here */ - return log(1.+x); + return x; + } + else if (-0.5 <= x && x <= 1.) { + /* WARNING: it's possible than an overeager compiler + will incorrectly optimize the following two lines + to the equivalent of "return log(1.+x)". If this + happens, then results from log1p will be inaccurate + for small x. */ + y = 1.+x; + return log(y)-((y-1.)-x)/y; + } + else { + /* NaNs and infinities should end up here */ + return log(1.+x); } } |