On Mon, Sep 13, 2021 at 06:32:56PM +0200, Tobias Burnus wrote: > On 13.09.21 17:56, Gerald Pfeifer wrote: > > This broke bootstrap on i586-unknown-freebsd11: > > > > In file included from > > .../GCC-HEAD/libgfortran/runtime/ISO_Fortran_binding.c:30: > > .../GCC-HEAD/libgfortran/ISO_Fortran_binding.h:255:2: > > error: #error "Can't determine kind of long double" > > 255 | #error "Can't determine kind of long double" > > | ^~~~~ > > > > Does this work on i586-*-linux? > > > > > > % egrep -r '#define.*LDBL_(MANT_DIG|MIN_EXP|MAX_EXP)' /usr/include/ > > /usr/include/x86/float.h:#define LDBL_MANT_DIG 64 > > /usr/include/x86/float.h:#define LDBL_MIN_EXP (-16381) > > /usr/include/x86/float.h:#define LDBL_MAX_EXP 16384 > > > > This looks like it matches existing Linux case already in place? > > Can you run 'echo | cpp -E -g3|grep DBL' to (or in the build dir: echo | > ./gcc/cc1 -E -g3 -dD|grep DBL) to check what's the output? > > It might be that /usr/include/x86/float.h is not used; e.g. there is > $(gcc-src)/ginclude/float.h which undef's the LDBL_MAX_EXP to replace it > by a #define using __LDBL_MAX_EXP. Thus, if those are different from the > values under /usr/include, it might be the reason for the fail? > > I think it works under Linux, at least the "x86-64 -m32" > libgfortran.{so,a} build and the -m32 testsuite runs do work.
Wouldn't it be better to use the __LDBL_* macros anyway and not rely on float.h? The header doesn't want to test what float.h tells about the long double type, but what the compiler knows about it. Jakub