Reporting bugs: there is nothing to gain in frustrating reporters
Robert Dewar
dewar@adacore.com
Sat Jun 18 21:37:00 GMT 2005
Laurent GUERBY wrote:
> On Sat, 2005-06-18 at 16:45 -0400, Robert Dewar wrote:
>
>>Mattias Karlsson wrote:
>>
>>
>>>Since the "gcc-is-buggy" solution of changing x87 rounding modes will:
>>>1) Be a lot of work.
>>>2) Cause a lot of regressions.
>>
>>To this you can add
>>
>> 3) generate less efficient code
>
>
> Changing the default rounding of the processor will make code less
> efficient?
>
> Laurent
Yes, if you have to change it backwards and forwards for float and
double ... and if you insist on getting the range right as well as
the precision, then you have to do extra stores. Changing the
rounding mode alone does not give what people call IEEE behavior.
More information about the Gcc
mailing list