[MLton] Re: MLton codegen combines divison on arm

[Adam Goode]

On 11/11/2010 10:49 AM, Wesley W. Terpstra wrote:
> On Thu, Nov 11, 2010 at 3:15 PM, Matthew Fluet <matthew.fluet at gmail.com> wrote:
>> Were you able to declare success with the ARM floating-point rounding?
> What needs to be done IMO is to turn on the rounding mode support in
> libgcc. It's absurd that something as simple as wiring it to a public
> symbol is considered a roadblock to fixing this problem. I don't have
> the time or energy needed to try and push a change like this through
> the sorts of people who gather around libc development.
> 

It is not this simple.

If you assume VPU (like ARMv7-A), then you just build your gcc, libc, and
full system and it works like other systems with hardware.

If you are using software floating point, then, at a start, you need to hack these files:

http://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/arm/ieee754-df.S;hb=HEAD
http://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/arm/ieee754-sf.S;hb=HEAD

Good luck, this is some tricky and performance-critical asm.


There are other issues involved with the interaction between gcc and libc that then need to be addressed, see:

http://cygwin.ru/ml/libc-ports/2009-04/msg00020.html



Adam

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