glibc/sysdeps/s390/fpu/math-barriers.h

/* Control when floating-point expressions are evaluated.  s390 version.
   Copyright (C) 2019-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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
   <https://www.gnu.org/licenses/>.  */

#ifndef S390_MATH_BARRIERS_H
#define S390_MATH_BARRIERS_H 1

#ifdef HAVE_S390_VX_GCC_SUPPORT
# define ASM_CONSTRAINT_VR "v"
# ifdef __LONG_DOUBLE_VX__
/* Starting with gcc 11, long double values can also be processed in vector
   registers if build with -march >= z14.  Then GCC defines the
   __LONG_DOUBLE_VX__ macro.  */
#  define ASM_LONG_DOUBLE_IN_VR 1
# else
#  define ASM_LONG_DOUBLE_IN_VR 0
# endif
#else
# define ASM_CONSTRAINT_VR
# define ASM_LONG_DOUBLE_IN_VR 0
#endif

#define math_opt_barrier(x)						\
  ({ __typeof (x) __x = (x);						\
    if (! ASM_LONG_DOUBLE_IN_VR						\
	&& (__builtin_types_compatible_p (__typeof (x), _Float128)	\
	    || __builtin_types_compatible_p (__typeof (x), long double)	\
	    )								\
	)								\
      __asm__ ("# math_opt_barrier_f128 %0" : "+fm" (__x));		\
    else								\
      __asm__ ("# math_opt_barrier %0"					\
	       : "+f" ASM_CONSTRAINT_VR "m" (__x));			\
    __x; })
#define math_force_eval(x)						\
  ({ __typeof (x) __x = (x);						\
    if (! ASM_LONG_DOUBLE_IN_VR						\
	&& (__builtin_types_compatible_p (__typeof (x), _Float128)	\
	    || __builtin_types_compatible_p (__typeof (x), long double) \
	    )								\
	)								\
      __asm__ __volatile__ ("# math_force_eval_f128 %0"			\
			    : : "fm" (__x));				\
    else								\
      __asm__ __volatile__ ("# math_force_eval %0"			\
			    : : "f" ASM_CONSTRAINT_VR "m" (__x));	\
  })

#endif