[llvm-dev] RFC: Constant folding math functions for long double

[Joerg Sonnenberger via llvm-dev]

On Mon, Apr 04, 2016 at 09:49:24AM -0700, Reid Kleckner via llvm-dev wrote:
> An optional MPFR dependency would also be pretty painful. I expect it will
> frequently be missing and will not be exercised by most buildbots.

IMO if constant folding of transcendental functions makes a significant
difference for your program, you likely are doing something strange
already. I don't think it matters much for a lot of use cases, so having
an optional dependency for this seems to be fine. Note that the
non-transcendental functions are quite a different deal, especially
reasonable well behaving functions like log and exp.

Joerg