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Re: Possible Issue in ieeefp.h
On 11/21/2016 11:38 AM, Joel Sherrill wrote:
float.h is generally assumed to be supplied by the compiler, in a fashion
similar to stdarg.h, as it contains compiler-specific sizes. (I just took a
look at the GCC 4.1.1 PowerPC cross compiler's float.h, and they pretty much
just turn their internal defines into the C-required names.) Probably the
--with-fortran option is messing things up. Could you perhaps build without it
just to get the right float.h, and then use that as a bootstrap of sorts to make
the --with-fortran build work? (Any way of finding the right float.h for your
GCC version should work.)
On 11/21/2016 10:26 AM, Craig Howland wrote:
On 11/21/2016 11:08 AM, Joel Sherrill wrote:
An RTEMS user has tried to build GNU FORTRAN. It used to build
and test OK. I am copying his report and my suggestion. I think
the constants tested in ieeefp.h do NOT match those predefined
by GCC. I need someone more knowledgable to confirm.
On Mon, Nov 21, 2016 at 9:24 AM, Ricardo Derbes <email@example.com> wrote:
I'm trying to build rtems toolchain for i386 using
rtems-source-builder with fortran support (--with-fortran option).
The RSB I'm using has been dowloaded from git, commit
534332f22a66f16b4022e87ae50c11ff20c98dcb from Sep 12 2016.
As for my application I need fortran support, how can I fix this problem?
As long I can see, all symbols that the compiler claims as undeclared
are indeed declared and accessible in file
May be it's missing a symbol, e.g a proper value for LDBL_MANT_DIG ?
I see that GCC predefines these symbols:
#define __FLT_MANT_DIG__ 24
#define __DEC64_MANT_DIG__ 16
#define __LDBL_MANT_DIG__ 53
#define __DBL_MANT_DIG__ 53
#define __DEC32_MANT_DIG__ 7
#define __DEC128_MANT_DIG__ 34
And ieeefp.h in newlib has this:
#elif LDBL_MANT_DIG == 53
/* This happens when doubles are 32-bits and long doubles are 64-bits. */
#define EXT_EXPBITS 11
#define EXT_FRACHBITS 20
#define EXT_FRACLBITS 32
#define __ieee_ext_field_type unsigned long
I am suspicious that the ifdef should use __LDBL_MANT_DIG__ not LDBL_MANT_DIG.
ieeefp.h is definitely intending to use LDBL_MANT_DIG. This is the C-standard
defined name which is supposed to be defined in float.h, and which ieeefp.h
directly states it is relying on. Apparently the float.h being used is not
properly defined/set up, and this is what needs to be corrected.
I have never poked in this area before. Where is this generated?
Help on where to look and what could be broken is appreciated.