diff options
| -rw-r--r-- | numeric.c | 33 |
1 files changed, 20 insertions, 13 deletions
@@ -727,10 +727,6 @@ S_mulexp10(NV value, I32 exponent) if (exponent == 0) return value; - else if (exponent < 0) { - negative = 1; - exponent = -exponent; - } /* On OpenVMS VAX we by default use the D_FLOAT double format, * and that format does not have *easy* capabilities [1] for @@ -743,11 +739,6 @@ S_mulexp10(NV value, I32 exponent) * * [1] Trying to establish a condition handler to trap floating point * exceptions is not a good idea. */ - /* UNICOS fp is similarly non-IEEE. */ -#if ((defined(VMS) && !defined(__IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP) - if ((log10(value) + exponent) >= (NV_MAX_10_EXP)) - return negative ? 0.0 : NV_MAX; -#endif /* In UNICOS and in certain Cray models (such as T90) there is no * IEEE fp, and no way at all from C to catch fp overflows gracefully. @@ -756,12 +747,28 @@ S_mulexp10(NV value, I32 exponent) * disable *all* floating point interrupts, a little bit too large * a hammer. Therefore we need to catch potential overflows before * it's too late. */ -#if defined(_UNICOS) && defined(NV_MAX_10_EXP) - if (!negative && - (log10(value) + exponent) >= NV_MAX_10_EXP) - return NV_MAX; + +#if ((defined(VMS) && !defined(__IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP) + STMT_START { + NV exp_v = log10(value); + if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP) + return NV_MAX; + if (exponent < 0) { + if (-(exponent + exp_v) >= NV_MAX_10_EXP) + return 0.0; + while (-exponent >= NV_MAX_10_EXP) { + /* combination does not overflow, but 10^(-exponent) does */ + value /= 10; + ++exponent; + } + } + } STMT_END; #endif + if (exponent < 0) { + negative = 1; + exponent = -exponent; + } for (bit = 1; exponent; bit <<= 1) { if (exponent & bit) { exponent ^= bit; |