Re: [boost] [boostcon][proto] Suggestion for LIAW session: fixed-pointnumbers

Subject: Re: [boost] [boostcon][proto] Suggestion for LIAW session: fixed-pointnumbers
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2011-03-16 09:27:17

On 16/03/2011 02:45, Gruenke, Matt wrote:

> One area in which I spent a fair amount of time was fast conversion to/from IEEE floating-point.  In trying to use the rounding-by-adding trick, I got slightly burned by differences in FPU configuration of Linux vs. Windows.  With x87 arithmetic, the default FPU configuration keeps different amounts of intermediate precision.

What do you mean?

MSVC doesn't specify whether floating point instructions use x87 or SSE 
(it is free to use either).

GCC allows to choose whether you use exclusively x87 (32-bit default), 
SSE (64-bit default) or any (experimental).