properFraction implemented with modf primitive?
I need a fast 'fraction' function for Double. I can use 'properFraction', but its Double instance uses 'decodeFloat', which is rather slow. It's also clumsy to use, because I have to provide an Integral type, although I'm not interested in the integral part. I can use (x - int2Double (double2Int x)) but this fails for x beyond the Int number range, and it is hard to fix that for an unknown implementation of Double.
What about a 'modf' primitive which either calls 'modf' from standard C library or invokes an appropriate FPU command? If Double is in IEEE format the 'fraction' command could also be implemented quite efficiently by some bit masking without the FPU.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.8.2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | ghc@henning-thielemann.de |
| Operating system | Multiple |
| Architecture | Multiple |