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Re: [MiNT] Strange FPU Stuff
Hello!
> http://gcc.gnu.org/ml/gcc-bugs/1999-03n/msg00897.html
>
> Here is some interesting results similar to the bug he described:
The same as in the above message described, but what do you want to know?
> root@washi:/root/fputest>gcc -m68020-60 -m68881 -msoft-float -o fptest
The last entry (-msoft-float) disable the FPU code generation and use the
software emulation.
> root@washi:/root/fputest>gcc -m68020-60 -m68881 -o fptest fptest.c
Enables output for 68881 instructions.
> root@washi:/root/fputest>gcc -m68060 -o fptest fptest.c
Enables output for 68060 FPU only.
> root@washi:/root/fputest>gcc -m68060 -m68881 -o fptest fptest.c
Enables output for 68881 instructions.
> Can anyone make sense of these results? Note the sample code and read
> the post it describes a possible 060 bug so this may not be relevant as
> to whether or not my 060 is okay. But check this out. This is an fpu
> test program.
Following the message it's a software problem, not a hardware problem.
> This is the only way this fpu test program works at all, the -DINTRIG
> uses internal routines for all floating point functions (defined in the
> .c).
Which test program do you refer here?
> Mint soft-float bug?
It's definitly not FreeMiNT related. It's most probably a compiler problem
(and the math-68881.h is related to mintlib).
Btw. if you specify -m68020-60 -m68881 you overwrite the optimized code
generation of -m68020-60 for the FPU.
-m68020-60 enables optimized code that run well on 68020/68881, 68040 and
68060 *and* don't use a instruction that is not available on the 040 or
060.
Ciao
...Frank
--
ATARI FALCON 040 // MILAN 060
-----------------------------------------
http://www.cs.uni-magdeburg.de/~fnaumann/
e-Mail: fnaumann@freemint.de