22083 – [3.4/4.0 Regression] TARGET_C99_FUNCTIONS is wrongly defined on AIX 5.1 (original) (raw)

| Description Lev Makhlis 2005-06-15 20:56:09 UTC gcc/config/rs6000/aix51.h and gcc/config/rs6000/aix52.h both define TARGET_C99_FUNCTIONS. This seems to be wrong for AIX 5.1: it has xxxl functions, but not xxxf ones. Source code: === CUT === extern double sqrt(double); float f(float x) { return sqrt(x); } int main() { return f(1.0f) != 1.0f; } === CUT === "gcc -v" output: === CUT === Reading specs from /bmc/moe/lib/gcc/powerpc-ibm-aix5.1.0.0/3.4.3/specs Configured with: /depot/gnu/gcc-3.4.3/configure --prefix=/bmc/moe --srcdir=/depot/gnu/gcc-3.4.3 --exec-prefix=/bmc/moe --with-local-prefix=/bmc/moe --enable-shared --with-as=/usr/bin/as --with-ld=/usr/bin/ld --enable-threads=posix --with-x --enable-java-awt=xlib --disable-nls Thread model: aix gcc version 3.4.3 === CUT === "oslevel -r" output: 5100-04 "lslpp -l bos.adt.libm" output: === CUT === Fileset Level State Description ---------------------------------------------------------------------------- Path: /usr/lib/objrepos bos.adt.libm 5.1.0.25 COMMITTED Base Application Development Math Library === CUT === "gcc -O -lm" output: ld: 0711-317 ERROR: Undefined symbol: .sqrtf ld: 0711-345 Use the -bloadmap or -bnoquiet option to obtain more information. collect2: ld returned 8 exit status The problem becomes even worse for C++ code: libstdc++ correctly detects that (e.g.) sqrtf() is missing, and generates a stub that calls sqrt(). But the compiler converts that sqrt() call back into sqrtf(), resulting in infinite recursion! The following example triggers this: === CUT === #include int main() { return std::sqrt(1.0f) != 1.0f; } === CUT === Comment 1 David Edelsohn 2005-06-17 13:56:51 UTC The macro was defined for AIX 5.1 by Roger Sayle: 2003-07-04 Roger Sayle <roger@eyesopen.com> * config/rs6000/aix51.h (TARGET_C99_FUNCTIONS): Define. * config/rs6000/aix52.h (TARGET_C99_FUNCTIONS): Likewise. Comment 3 roger 2005-06-17 17:22:06 UTC Unfortunately, the AIX 5.1 machine that was loaned to OpenEye by IBM has had to be returned since this patch was submitted/applied in 2003. So my only guess is that this may have been a patch level issue with bos.adt.libm as I'm fairly confident that our 5.1 machine had sqrtf and friends when the patch was developed. We do still have a 5.2 machine, and that certainly has sqrtf. Could this be related to the version(s) of IBM's Visual Age C/C++, that was installed on the machine? Unfortunately, without access to a 5.1 box I'm unable to properly test the obvious trivial change to config/rs6000/aix51.h. Clearly, if there are flavors of AIX 5.1 out there without sqrtf, it unsafe to define TARGET_C99_FUNCTIONS in aix51.h. Fortunately, such a change won't negatively affect users of AIX 5.2 or later. Dave, I'm happy to post an untested patch to gcc-patches if that's appropriate. Alternatively, Lev could you try removing the five lines I added to aix51.h and confirm that that resolves the issues you're seeing. Many thanks in advance. Sorry for any inconvenience. Comment 4 Lev Makhlis 2005-06-17 19:01:31 UTC It might be an issue with the patch level of libm -- I was testing on 5.1 ML04, which was released in 2002 -- but I've found another machine at ML05 (released in Oct 2003), and it still doesn't have sqrtf and friends in libm. I don't have access to anything newer than that right now. I doubt it's related to Visual Age. VAC's implementation of the standard C++ library, /usr/lib/libC.a, does have sqrtf and friends -- but I'm not linking with it when using GCC. Before submitting the bug report, I tried removing the macro definition in aix51.h, and it does solve the problem. There is a related C++-specific problem that still isn't solved, but maybe that merits a separate PR. The problem is: If you have C++ code that uses std::sqrt(float) and build a dynamically linked executable on AIX 5.1, then bring it over to AIX 5.2, it won't run, because sqrtf() is now in libm, but not in libstdc++. This doesn't seem to be a problem on other platforms (for example, a program compiled on Solaris 8, against sqrtf() in libstdc++, runs fine on Solaris 10, with sqrtf() in libm), but on AIX the dynamic loader looks for a symbol only in a specific library. I am guessing it's a difference between COFF and ELF? As a side point, TARGET_C99_FUNCTION isn't defined on any Solaris platforms. I think it's okay to define it on Solaris 9 and up? Comment 5 Drea Pinski 2005-06-17 19:05:16 UTC (In reply to comment #4) > If you have C++ code that uses std::sqrt(float) and build a dynamically linked > executable on AIX 5.1, then bring it over to AIX 5.2, it won't run, because > sqrtf() is now in libm, but not in libstdc++. This doesn't seem to be a problem > on other platforms (for example, a program compiled on Solaris 8, against > sqrtf() in libstdc++, runs fine on Solaris 10, with sqrtf() in libm), but on AIX > the dynamic loader looks for a symbol only in a specific library. I am guessing > it's a difference between COFF and ELF? That is not a bug, you cannot do that as libstdc++ is not forward compatiable, this is also happens on Darwin (Mac OS X). Comment 6 Eric Botcazou 2005-06-17 19:13:12 UTC > As a side point, TARGET_C99_FUNCTION isn't defined on any Solaris platforms. I > think it's okay to define it on Solaris 9 and up? Only Solaris 10 has full C99 math support out of the box (and after a bit of tweaking to make it usable for GCC). Comment 7 Lev Makhlis 2005-06-17 19:32:25 UTC Andrew: I am trying to run older (5.1) programs on a newer (5.2) system, not vice versa -- why would that require forward (rather than backward) compatibility? Comment 9 Drea Pinski 2005-06-30 21:54:43 UTC *** Bug 22261 has been marked as a duplicate of this bug. *** Comment 10 Mark Mitchell 2005-07-06 16:28:34 UTC Reset target milestone to 4.0.2. (Gaby and I have a standing agreement that the more current release branch gets the target milestone.) Patch OK for 4.0.2. Comment 13 David Edelsohn 2005-07-08 18:35:04 UTC Patch applied to gcc-4.0 and gcc-3.4 branches. | | | 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