On Sun, Oct 3, 2010 at 6:56 PM, Nanakos Chrysostomos <nanakos@xxxxxxxxxxxx> wrote: > Hi all, > I have the above C code snippet. I am trying to get a resonable result in a fixed form with printf for > a long double value but with no luck. What am I doing wrong? > > Thanks in advance. > > long.c > ------------------------------------------------------------- > #include <stdio.h> > #include <math.h> > > int main(void) > { > long double c = powl(10.0L,30.0L); > > printf("%llf %lle\n",c,c); > I think you want %llg instead of %llf. g is for double-precision, f is for single. > > return 0; > } > > ------------------------------------------------------------ > > # gcc -DDOUBLE -msse2 -mfpmath=sse -m64 -m128bit-long-double long.c -lm > #./a.out > > 1000000000000000000024696061952.000000 1.000000e+30 > > The second result is right but how can I get a fixed right result for the first one? > The fixed precision should be a lot bigger than this according to the IEEE-754 standard. > I am using a 64-bit machine with Debian Squeeze x86-64 version. > ----------------------------------------------------------------------------------------- > Using built-in specs. > Target: x86_64-linux-gnu > Configured with: ../src/configure -v --with-pkgversion='Debian 4.4.4-8' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --with-arch-32=i586 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu > Thread model: posix > gcc version 4.4.5 20100728 (prerelease) (Debian 4.4.4-8) > ----------------------------------------------------------------------------------------- > # gcc -dM -E -xc /dev/null | grep __LDBL_MAX__ > #define __LDBL_MAX__ 1.18973149535723176502e+4932L > > -- > To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html