At present, definitions of float_t and double_t are split among many
bits/mathdef.h headers.
For all but three architectures, these types are float and double.
Furthermore, if you assume __FLT_EVAL_METHOD__ to be defined, that
provides a more generic way of determining the correct values of these
typedefs. Defining these typedefs more generally based on
__FLT_EVAL_METHOD__ was previously proposed by Paul Eggert in
<https://sourceware.org/ml/libc-alpha/2012-02/msg00002.html>.
This patch refactors things in the way I proposed in
<https://sourceware.org/ml/libc-alpha/2016-11/msg00745.html>. A new
header bits/flt-eval-method.h defines a single macro,
__GLIBC_FLT_EVAL_METHOD, which is then used by math.h to define
float_t and double_t. The default is based on __FLT_EVAL_METHOD__
(although actually a default to 0 would have the same effect for
current ports, because ports where values other than 0 or 16 are
possible all have their own headers).
To avoid changing the existing semantics in any case, including for
compilers not defining __FLT_EVAL_METHOD__, architecture-specific
files are then added for m68k, s390, x86 which replicate the existing
semantics. At least with __FLT_EVAL_METHOD__ values possible with
GCC, there should be no change to the choices of float_t and double_t
for any supported configuration.
Architecture maintainer notes:
* m68k: sysdeps/m68k/m680x0/bits/flt-eval-method.h always defines
__GLIBC_FLT_EVAL_METHOD to 2 to replicate the existing logic. But
actually GCC defines __FLT_EVAL_METHOD__ to 0 if TARGET_68040. It
might make sense to make the header prefer to base things on
__FLT_EVAL_METHOD__ if defined, like the x86 version, and so make
the choices of these types more accurate (with a NEWS entry as for
the other changes to these types on particular architectures).
* s390: sysdeps/s390/bits/flt-eval-method.h always defines
__GLIBC_FLT_EVAL_METHOD to 1 to replicate the existing logic. As
previously discussed, it might make sense in coordination with GCC
to eliminate the historic mistake, avoid excess precision in the
-fexcess-precision=standard case and make the typedefs match (with a
NEWS entry, again).
Tested for x86-64 and x86. Also did compilation-only testing with
build-many-glibcs.py.
* bits/flt-eval-method.h: New file.
* sysdeps/m68k/m680x0/bits/flt-eval-method.h: Likewise.
* sysdeps/s390/bits/flt-eval-method.h: Likewise.
* sysdeps/x86/bits/flt-eval-method.h: Likewise.
* math/Makefile (headers): Add bits/flt-eval-method.h.
* math/math.h: Include <bits/flt-eval-method.h>.
[__USE_ISOC99] (float_t): Define based on __GLIBC_FLT_EVAL_METHOD.
[__USE_ISOC99] (double_t): Likewise.
* bits/mathdef.h (float_t): Remove.
(double_t): Likewise.
* sysdeps/aarch64/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/alpha/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/arm/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/hppa/fpu/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/ia64/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/m68k/m680x0/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/mips/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/powerpc/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/s390/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/sh/sh4/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/sparc/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/tile/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* sysdeps/x86/bits/mathdef.h (float_t): Likewise.
(double_t): Likewise.
* math/multc3.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/Makefile
[$(subdir) = math] (libm-routines): Add multc3, divtc3.
* sysdeps/unix/sysv/linux/sparc/sparc32/fpu/Implies: New file.
* sysdeps/sparc/sparc32/fpu/s_fabsl.c: Include math.h and
math_ldbl_opt.h.
(fabsl): Use long_double_symbol instead of weak_alias.
* sysdeps/sparc/sparc32/fpu/s_fabs.c: Include math.h and
math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (fabsl): Add compat_symbol.
2006-01-31 Martin Schwidefsky <schwidefsky@de.ibm.com>
Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/s390/Implies: New file.
* sysdeps/unix/sysv/linux/s390/fpu/Implies: New file.
* sysdeps/unix/sysv/linux/s390/nldbl-abi.h: New file.
* sysdeps/s390/fpu/bits/mathinline.h (signbitl, sqrtl): New inlines.
* sysdeps/s390/bits/mathdef.h: New file.
* sysdeps/s390/fpu/e_sqrtl.c: New file.
* sysdeps/s390/s390-32/bits/wordsize.h (__LONG_DOUBLE_MATH_OPTIONAL,
__NO_LONG_DOUBLE_MATH): Define.
* sysdeps/s390/s390-64/bits/wordsize.h: Likewise.
* sysdeps/s390/Implies: Add ieee754/ldbl-128.
* sysdeps/s390/ldbl2mpn.c: File removed.
* sysdeps/s390/fpu/libm-test-ulps: Updated.
2006-01-31 Roland McGrath <roland@redhat.com>
* sysdeps/alpha/fpu/bits/mathdef.h: Moved to ...
* sysdeps/alpha/bits/mathdef.h: ... here.
* sysdeps/i386/fpu/bits/mathdef.h: Moved to ...
* sysdeps/i386/bits/mathdef.h: ... here.
* sysdeps/mips/fpu/bits/mathdef.h: Moved to ...
* sysdeps/mips/bits/mathdef.h: ... here.
* sysdeps/m68k/fpu/bits/mathdef.h: Moved to ...
* sysdeps/m68k/bits/mathdef.h: ... here.
* sysdeps/powerpc/fpu/bits/mathdef.h: Moved to ...
* sysdeps/powerpc/bits/mathdef.h: ... here.
* sysdeps/sparc/fpu/bits/mathdef.h: Moved to ...
* sysdeps/sparc/bits/mathdef.h: ... here.
* sysdeps/ia64/fpu/bits/mathdef.h: Moved to ...
* sysdeps/ia64/bits/mathdef.h: ... here.
* sysdeps/sh/sh4/fpu/bits/mathdef.h: Moved to ...
* sysdeps/sh/sh4/bits/mathdef.h: ... here.
* sysdeps/x86_64/fpu/bits/mathdef.h: Moved to ...
* sysdeps/x86_64/bits/mathdef.h: ... here.
2006-01-31 Jakub Jelinek <jakub@redhat.com>
