X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=-2.3 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org To: cygwin AT cygwin DOT com From: Hans Horn Subject: Re: status of gcc4 -ffast-math Date: Thu, 05 Nov 2009 14:57:53 -0800 Lines: 93 Message-ID: References: <4AF3520B DOT 60803 AT gmail DOT com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) In-Reply-To: <4AF3520B.60803@gmail.com> X-IsSubscribed: yes Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com 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); >> } >> >> >> admin AT ubik /tmp/math >> $ gcc-4 math.c -o math >> >> admin AT ubik /tmp/math >> $ gcc-4 math.c -o math -ffast-math >> >> admin AT ubik /tmp/math >> $ gcc-4 math.c -o math -ffast-math -O2 >> >> admin AT ubik /tmp/math >> $ gcc-4 math.c -o math -ffast-math -O3 >> >> admin AT 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=500000 -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=500000 \ -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=500000 -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. -- 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