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Re: Support for non-default rounding modes in the softfloat layer

A lot of scientific software uses non-default rounding modes as
optimisation short cut. but then this is software which runs on high
end hardware a la SPARC T5, SPARC64, NEC SX9 or the very latest
IA32/AMD64 hardware.


On Tue, Apr 30, 2013 at 12:17 PM, Joerg Sonnenberger
<> wrote:
> Hi all,
> one major difference between the existing softfloat support in libc and
> compiler-rt's softfloat implementation is the (non)support for
> rounding modes. libc supports some global variables for that, which is
> of limited usefulness in a multi-threaded world. Making them fully
> thread-local on the other hand is quite expensive. A discussion with the
> responsible developer of the compiler-rt code and some LLVM folks
> resulting in the suggestion of providing an alternative set of entry
> points, where the float environment is an explicit argument, if this
> feature is really desirable. Long story short, does anyone use
> non-default rounding modes on platforms with softfloat?
> Joerg

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