On 03/31/2010 11:25 AM, Vincent Lefevre wrote:
On 2010-03-31 11:04:03 +0200, Marc Glisse wrote:
IMHO this transformation mostly makes sense for the
-ffinite-math-only case where you can replace: "put a constant and
multiply/divide" by "put a constant and add/sub" and never care
about extracting
On Mar 29, 2010, at 16:30, Tim Prince wrote:
> gcc used to have the ability to replace division by a power of 2 by an fscale
> instruction, for appropriate targets (maybe still does).
The problem (again) is that floating point multiplication is
just too damn fast. On x86, even though the latency
On 2010-03-31 11:04:03 +0200, Marc Glisse wrote:
> IMHO this transformation mostly makes sense for the
> -ffinite-math-only case where you can replace: "put a constant and
> multiply/divide" by "put a constant and add/sub" and never care
> about extracting the exponent, overflowing, or anything els
On Wed, 31 Mar 2010, Vincent Lefevre wrote:
On 2010-03-30 20:36:04 +0200, Jeroen Van Der Bossche wrote:
> The if statement is there exactly to address under- and overflow and
> nothing else. It's not because it looks simple that I didn't think
> it through. I know exactly how floating point mult
On 2010-03-30 20:36:04 +0200, Jeroen Van Der Bossche wrote:
> The if statement is there exactly to address under- and overflow and
> nothing else. It's not because it looks simple that I didn't think
> it through. I know exactly how floating point multiplication works,
> and this implementation of
On 29 March 2010 19:51, Geert Bosch wrote:
>
> On Mar 29, 2010, at 13:19, Jeroen Van Der Bossche wrote:
>
>> 've recently written a program where taking the average of 2 floating
>> point numbers was a real bottleneck. I've looked into the assembly
>> generated by gcc -O3 and apparently gcc treats
On 3/29/2010 10:51 AM, Geert Bosch wrote:
On Mar 29, 2010, at 13:19, Jeroen Van Der Bossche wrote:
've recently written a program where taking the average of 2 floating
point numbers was a real bottleneck. I've looked into the assembly
generated by gcc -O3 and apparently gcc treats multipli
On Mar 29, 2010, at 13:19, Jeroen Van Der Bossche wrote:
> 've recently written a program where taking the average of 2 floating
> point numbers was a real bottleneck. I've looked into the assembly
> generated by gcc -O3 and apparently gcc treats multiplication and
> division by a hard-coded 2 li
