Re: status of gcc4 -ffast-math
Dave Korn wrote: Hans Horn wrote: Do you where this gobble stuff ‘ comes from, btw? GCC is trying to use the appropriate set of internationalized opening and closing single-quote marks. If you "export LC_LANG=C.ASCII", you'll get regular apostrophes. It's -fno-leading-underscore. Have to see whether I can live without it! You can't live *with* it. Seriously, if you're using it in the first place, you are doing something very very wrong indeed (like trying to link to pre-compiled linux binaries) that you should not be doing, because neither it nor anything else will work. You will break every library and just everything. Sorry about that, but the decision to prefix symbols with an underscore or not is part of the win32 ABI, not open to changing according to a user's preferences, and frankly I don't think this option serves any useful purpose except to break things and confuse people by giving them hope that things might work that can in fact never succeed. cheers, DaveK Dave, thx. for the clarification about the apostrophes! As to -fno-leading-underscore: I had this in my cygwin gcc3.* makefiles now for a couple of years (dunno where it originated). Compiles & links fine without! It's gone down the crapper for good... Now I'm one happy gcc4/gfortran guy! Thanks again for your knowlegdable help! H. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: status of gcc4 -ffast-math
Hans Horn wrote: >> >> Do you where this gobble stuff ‘ comes from, btw? GCC is trying to use the appropriate set of internationalized opening and closing single-quote marks. If you "export LC_LANG=C.ASCII", you'll get regular apostrophes. > It's -fno-leading-underscore. > Have to see whether I can live without it! You can't live *with* it. Seriously, if you're using it in the first place, you are doing something very very wrong indeed (like trying to link to pre-compiled linux binaries) that you should not be doing, because neither it nor anything else will work. You will break every library and just everything. Sorry about that, but the decision to prefix symbols with an underscore or not is part of the win32 ABI, not open to changing according to a user's preferences, and frankly I don't think this option serves any useful purpose except to break things and confuse people by giving them hope that things might work that can in fact never succeed. cheers, DaveK -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: status of gcc4 -ffast-math
Hans Horn wrote:
Dave Korn wrote:
Hans Horn wrote:
Folks,
what is the current status of -ffast-math for gcc4 under cygwin.
I tried to use it for some numerical C code and get the following link
errors:
eval.o:eval.c:(.text+0x79c): undefined reference to `_f_pow'
eval.o:eval.c:(.text+0x7d8): undefined reference to `_f_log'
eval.o:eval.c:(.text+0x7f0): undefined reference to `_f_exp'
WJFFM:
$ cat math.c
#include
int main (int argc, const char **argv)
{
float f = atof (argv[1]);
double d = log (f);
return exp (f);
}
ad...@ubik /tmp/math
$ gcc-4 math.c -o math
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math -O2
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math -O3
ad...@ubik /tmp/math
$
Perhaps a few more details about what you're doing, a simple
reproducible
testcase, what kind of command-lines you're using, etc. etc... might
help.
cheers,
DaveK
Dave,
I was just shooting into the dark expecting more like a yes/no wrt use
of -ffast-math. Thx for responding!
I'm linking with gfortran (v4.5 or v4.3.4) (because the C code calls a
lot of fortran under the hood).
This is how I compile & link:
gcc-4 -c -D_XOPEN_SOURCE_EXTENDED=1 -D_ALL_SOURCE -D_POSIX_SOURCE \
-std=c99 -Wall -Wshadow -Wreturn-type -Wunused \
-Wuninitialized -Wformat -Wunused-function -Wunused-macros
-Wunused-label -Wredundant-decls -fno-leading-underscore -O3 \
-fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 -fstrength-reduce -fgcse \
-fgcse-lm -fgcse-sm -funroll-loops -fforce-addr -fomit-frame-pointer \
-ftree-vectorize -mfpmath=sse -msse3 -ffast-math \
-march=pentium4 -pipe -fbounds-check -Wextra -Winit-self \
-DYY_NO_UNISTD_H -o math.o math.c
gfortran -O3 -fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 \
-fstrength-reduce -fgcse -fgcse-lm -fgcse-sm -funroll-loops -fforce-addr
-fomit-frame-pointer -ftree-vectorize -mfpmath=sse \
-msse3 -ffast-math -march=pentium4 -pipe -L. -o math.exe math.o -Xlinker
-\( -O3 -fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 -fstrength-reduce -fgcse
-fgcse-lm -fgcse-sm -funroll-loops -fforce-addr -fomit-frame-pointer \
-ftree-vectorize -mfpmath=sse -msse3 -ffast-math -march=pentium4 -pipe
-lm -lgsl -ly -lfl --enable-auto-import -Xlinker -\)
Compiling/linking your example gives:
math.c: In function ‘main’:
math.c:4: warning: implicit declaration of function ‘atof’
math.c:5: warning: unused variable ‘d’
math.c:3: warning: unused parameter ‘argc’
math.o:math.c:(.text+0x30): undefined reference to `_f_exp'
collect2: ld returned 1 exit status
Do you where this gobble stuff ‘ comes from, btw?
H.
Dave,
I just found the culprit!
It's -fno-leading-underscore.
Have to see whether I can live without it!
Thx. again
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Re: status of gcc4 -ffast-math
Dave Korn wrote:
Hans Horn wrote:
Folks,
what is the current status of -ffast-math for gcc4 under cygwin.
I tried to use it for some numerical C code and get the following link
errors:
eval.o:eval.c:(.text+0x79c): undefined reference to `_f_pow'
eval.o:eval.c:(.text+0x7d8): undefined reference to `_f_log'
eval.o:eval.c:(.text+0x7f0): undefined reference to `_f_exp'
WJFFM:
$ cat math.c
#include
int main (int argc, const char **argv)
{
float f = atof (argv[1]);
double d = log (f);
return exp (f);
}
ad...@ubik /tmp/math
$ gcc-4 math.c -o math
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math -O2
ad...@ubik /tmp/math
$ gcc-4 math.c -o math -ffast-math -O3
ad...@ubik /tmp/math
$
Perhaps a few more details about what you're doing, a simple reproducible
testcase, what kind of command-lines you're using, etc. etc... might help.
cheers,
DaveK
Dave,
I was just shooting into the dark expecting more like a yes/no wrt use
of -ffast-math. Thx for responding!
I'm linking with gfortran (v4.5 or v4.3.4) (because the C code calls a
lot of fortran under the hood).
This is how I compile & link:
gcc-4 -c -D_XOPEN_SOURCE_EXTENDED=1 -D_ALL_SOURCE -D_POSIX_SOURCE \
-std=c99 -Wall -Wshadow -Wreturn-type -Wunused \
-Wuninitialized -Wformat -Wunused-function -Wunused-macros
-Wunused-label -Wredundant-decls -fno-leading-underscore -O3 \
-fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 -fstrength-reduce -fgcse \
-fgcse-lm -fgcse-sm -funroll-loops -fforce-addr -fomit-frame-pointer \
-ftree-vectorize -mfpmath=sse -msse3 -ffast-math \
-march=pentium4 -pipe -fbounds-check -Wextra -Winit-self \
-DYY_NO_UNISTD_H -o math.o math.c
gfortran -O3 -fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 \
-fstrength-reduce -fgcse -fgcse-lm -fgcse-sm -funroll-loops -fforce-addr
-fomit-frame-pointer -ftree-vectorize -mfpmath=sse \
-msse3 -ffast-math -march=pentium4 -pipe -L. -o math.exe math.o -Xlinker
-\( -O3 -fno-strict-aliasing -Winline -fexpensive-optimizations \
-finline-functions -finline-limit=50 -fstrength-reduce -fgcse
-fgcse-lm -fgcse-sm -funroll-loops -fforce-addr -fomit-frame-pointer \
-ftree-vectorize -mfpmath=sse -msse3 -ffast-math -march=pentium4 -pipe
-lm -lgsl -ly -lfl --enable-auto-import -Xlinker -\)
Compiling/linking your example gives:
math.c: In function ‘main’:
math.c:4: warning: implicit declaration of function ‘atof’
math.c:5: warning: unused variable ‘d’
math.c:3: warning: unused parameter ‘argc’
math.o:math.c:(.text+0x30): undefined reference to `_f_exp'
collect2: ld returned 1 exit status
Do you where this gobble stuff ‘ comes from, btw?
H.
--
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Re: status of gcc4 -ffast-math
Hans Horn wrote:
> Folks,
>
> what is the current status of -ffast-math for gcc4 under cygwin.
>
> I tried to use it for some numerical C code and get the following link
> errors:
>
> eval.o:eval.c:(.text+0x79c): undefined reference to `_f_pow'
> eval.o:eval.c:(.text+0x7d8): undefined reference to `_f_log'
> eval.o:eval.c:(.text+0x7f0): undefined reference to `_f_exp'
WJFFM:
> $ cat math.c
>
> #include
>
> int main (int argc, const char **argv)
> {
>
> float f = atof (argv[1]);
> double d = log (f);
> return exp (f);
> }
>
>
> ad...@ubik /tmp/math
> $ gcc-4 math.c -o math
>
> ad...@ubik /tmp/math
> $ gcc-4 math.c -o math -ffast-math
>
> ad...@ubik /tmp/math
> $ gcc-4 math.c -o math -ffast-math -O2
>
> ad...@ubik /tmp/math
> $ gcc-4 math.c -o math -ffast-math -O3
>
> ad...@ubik /tmp/math
> $
Perhaps a few more details about what you're doing, a simple reproducible
testcase, what kind of command-lines you're using, etc. etc... might help.
cheers,
DaveK
--
Problem reports: http://cygwin.com/problems.html
FAQ: http://cygwin.com/faq/
Documentation: http://cygwin.com/docs.html
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