diff options
Diffstat (limited to 'contrib/gdtoa/README')
| -rw-r--r-- | contrib/gdtoa/README | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/contrib/gdtoa/README b/contrib/gdtoa/README index 95a40aa..ce8be55 100644 --- a/contrib/gdtoa/README +++ b/contrib/gdtoa/README @@ -56,7 +56,9 @@ two letters: whose sum is the desired value For decimal -> binary conversions, there are three families of -helper routines: one for round-nearest: +helper routines: one for round-nearest (or the current rounding +mode on IEEE-arithmetic systems that provide the C99 fegetround() +function, if compiled with -DHonor_FLT_ROUNDS): strtof strtod @@ -191,6 +193,9 @@ in the buffer, if the buffer was long enough, or 0. Other forms of conversion are easily done with the help of gdtoa(), such as %e or %f style and conversions with direction of rounding specified (so that, if desired, the decimal value is either >= or <= the binary value). +On IEEE-arithmetic systems that provide the C99 fegetround() function, +if compiled with -DHonor_FLT_ROUNDS, these routines honor the current +rounding mode. For an example of more general conversions based on dtoa(), see netlib's "printf.c from ampl/solvers". @@ -342,5 +347,11 @@ standard says it should -- when Honor_FLT_ROUNDS is #defined, the current rounding mode is obtained from fegetround() rather than from FLT_ROUNDS, unless Trust_FLT_ROUNDS is also #defined. +Compile with -DUSE_LOCALE to use the current locale; otherwise +decimal points are assumed to be '.'. With -DUSE_LOCALE, unless +you also compile with -DNO_LOCALE_CACHE, the details about the +current "decimal point" character string are cached and assumed not +to change during the program's execution. + Please send comments to David M. Gay (dmg at acm dot org, with " at " changed at "@" and " dot " changed to "."). |
