glibc/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
Zack Weinberg c75772e3f0 Use STRFMON_LDBL_IS_DBL instead of __ldbl_is_dbl.
On platforms where long double used to have the same format as double,
but later switched to a different format (alpha, s390, sparc, and
powerpc), accessing the older behavior is possible and it happens via
__nldbl_* functions (not on the API, but accessible from header
redirection and from compat symbols).  These functions write to the
global flag __ldbl_is_dbl, which tells other functions that long double
variables should be handled as double.  This patch takes the first step
towards removing this global flag and creates __vstrfmon_l_internal,
which takes an explicit flags parameter.

This change arguably makes the generated code slightly worse on
architectures where __ldbl_is_dbl is never true; right now, on those
architectures, it's a compile-time constant; after this change, the
compiler could theoretically prove that __vstrfmon_l_internal was
never called with a nonzero flags argument, but it would probably need
LTO to do it.  This is not performance critical code and I tend to
think that the maintainability benefits of removing action at a
distance are worth it.  However, we _could_ wrap the runtime flag
check with a macro that was defined to ignore its argument and always
return false on architectures where __ldbl_is_dbl is never true, if
people think the codegen benefits are important.

Tested for powerpc and powerpc64le.
2018-11-16 09:21:14 -02:00

118 lines
4.1 KiB
C

/* Prototypes for compatibility double == long double entry points.
Copyright (C) 2006-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@cygnus.com>, 2006.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef __NLDBL_COMPAT_H
#define __NLDBL_COMPAT_H 1
/* Ensure calls to libm functions from libnldbl_nonshared.a call
public names, not libm-internal names. */
#define NO_MATH_REDIRECT
/* Avoid long double prototypes. */
#define __NO_LONG_DOUBLE_MATH 1
#include <stdarg.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <printf.h>
#include <wchar.h>
#include <math.h>
#include <monetary.h>
#include <sys/syslog.h>
/* Declare the __nldbl_NAME function the wrappers call that's in libc.so. */
#define NLDBL_DECL(name) extern __typeof (name) __nldbl_##name
NLDBL_DECL (_IO_vfscanf);
NLDBL_DECL (vfscanf);
NLDBL_DECL (vfwscanf);
NLDBL_DECL (obstack_vprintf);
NLDBL_DECL (vasprintf);
NLDBL_DECL (dprintf);
NLDBL_DECL (vdprintf);
NLDBL_DECL (fprintf);
NLDBL_DECL (vfprintf);
NLDBL_DECL (vfwprintf);
NLDBL_DECL (vsnprintf);
NLDBL_DECL (vsprintf);
NLDBL_DECL (vsscanf);
NLDBL_DECL (vswprintf);
NLDBL_DECL (vswscanf);
NLDBL_DECL (__asprintf);
NLDBL_DECL (asprintf);
NLDBL_DECL (__printf_fp);
NLDBL_DECL (printf_size);
NLDBL_DECL (syslog);
NLDBL_DECL (vsyslog);
NLDBL_DECL (qecvt);
NLDBL_DECL (qfcvt);
NLDBL_DECL (qgcvt);
NLDBL_DECL (__isoc99_scanf);
NLDBL_DECL (__isoc99_fscanf);
NLDBL_DECL (__isoc99_sscanf);
NLDBL_DECL (__isoc99_vscanf);
NLDBL_DECL (__isoc99_vfscanf);
NLDBL_DECL (__isoc99_vsscanf);
NLDBL_DECL (__isoc99_wscanf);
NLDBL_DECL (__isoc99_fwscanf);
NLDBL_DECL (__isoc99_swscanf);
NLDBL_DECL (__isoc99_vwscanf);
NLDBL_DECL (__isoc99_vfwscanf);
NLDBL_DECL (__isoc99_vswscanf);
/* These do not exist in the normal interface, but must exist in the
__nldbl interface so that they can be called from libnldbl. */
extern ssize_t __nldbl___vstrfmon (char *, size_t, const char *, va_list)
__THROW;
extern ssize_t __nldbl___vstrfmon_l (char *, size_t, locale_t, const char *,
va_list)
__THROW;
/* These don't use __typeof because they were not declared by the headers,
since we don't compile with _FORTIFY_SOURCE. */
extern int __nldbl___vfprintf_chk (FILE *__restrict, int,
const char *__restrict, __gnuc_va_list);
extern int __nldbl___vfwprintf_chk (FILE *__restrict, int,
const wchar_t *__restrict, __gnuc_va_list);
extern int __nldbl___vsprintf_chk (char *__restrict, int, size_t,
const char *__restrict, __gnuc_va_list)
__THROW;
extern int __nldbl___vsnprintf_chk (char *__restrict, size_t, int, size_t,
const char *__restrict, __gnuc_va_list)
__THROW;
extern int __nldbl___vswprintf_chk (wchar_t *__restrict, size_t, int, size_t,
const wchar_t *__restrict, __gnuc_va_list)
__THROW;
extern int __nldbl___vasprintf_chk (char **, int, const char *, __gnuc_va_list)
__THROW;
extern int __nldbl___vdprintf_chk (int, int, const char *, __gnuc_va_list);
extern int __nldbl___obstack_vprintf_chk (struct obstack *, int, const char *,
__gnuc_va_list) __THROW;
extern void __nldbl___vsyslog_chk (int, int, const char *, va_list);
/* The original declarations of these were hidden by the including
file. */
extern double __nldbl_daddl (double, double) __THROW;
extern double __nldbl_ddivl (double, double) __THROW;
extern double __nldbl_dmull (double, double) __THROW;
extern double __nldbl_dsubl (double, double) __THROW;
#endif /* __NLDBL_COMPAT_H */