[newlib] libm with ieeelib.c from torbjorn

Christian Walter wolti@sil.at
Mon Apr 17 18:46:00 GMT 2006


Hello,

I am currently using newlib 1.14 with gcc-3.4.6 on an m68k-elf target with code 
compiled for mcpu32. I tried to integrate the ieeelib patches from torbjorn 
which give me a speedup of about 25% in a simple test using some multiply and 
divide operations.
The basic results look okay and the results from the floating point executions 
are correct when using only operations like *,/,+,-,... If I use the newlib 
functions from libm targeted for my cpu I get wrong results. For example with 
pow, powf, ... If I switch back to the floating point implementation fp-bit from 
gcc the functions work as expected. Are there any more dependencies except 
beeing IEEE compliant?

The patch I used is based on the initial message from Torbjorn Granlund 
(http://gcc.gnu.org/ml/gcc/1999-07n/msg00553.html) with two patches applied from 
[1] and [2].

[1] fix float comparision problem: http://gcc.gnu.org/ml/gcc/2003-06/msg02495.html
[2] updates for new gcc:
http://gcc.gnu.org/ml/gcc/2005-11/msg01373.html

I would really be grateful for any hints to point me into the right direction. 
Or should I better redirect my question on the gcc list?

Regards,
	Christian Walter

--
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \\\\\\ \\ \
Christian Walter Bakk. techn.\ Friends don't let friends drink and su(1)
email: wolti@sil.at          \               -- Kevin Harris




More information about the Newlib mailing list