glibc/sysdeps/powerpc/fpu_control.h

115 lines
3.7 KiB
C

/* FPU control word definitions. PowerPC version.
Copyright (C) 1996-2024 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 _FPU_CONTROL_H
#define _FPU_CONTROL_H
#if defined __SPE__ || (defined __NO_FPRS__ && !defined _SOFT_FLOAT)
# error "SPE/e500 is no longer supported"
#endif
#ifdef _SOFT_FLOAT
# define _FPU_RESERVED 0xffffffff
# define _FPU_DEFAULT 0x00000000 /* Default value. */
typedef unsigned int fpu_control_t;
# define _FPU_GETCW(cw) (cw) = 0
# define _FPU_SETCW(cw) (void) (cw)
extern fpu_control_t __fpu_control;
#else /* PowerPC 6xx floating-point. */
/* rounding control */
# define _FPU_RC_NEAREST 0x00 /* RECOMMENDED */
# define _FPU_RC_DOWN 0x03
# define _FPU_RC_UP 0x02
# define _FPU_RC_ZERO 0x01
# define _FPU_MASK_RC (_FPU_RC_NEAREST|_FPU_RC_DOWN|_FPU_RC_UP|_FPU_RC_ZERO)
# define _FPU_MASK_NI 0x04 /* non-ieee mode */
/* masking of interrupts */
# define _FPU_MASK_ZM 0x10 /* zero divide */
# define _FPU_MASK_OM 0x40 /* overflow */
# define _FPU_MASK_UM 0x20 /* underflow */
# define _FPU_MASK_XM 0x08 /* inexact */
# define _FPU_MASK_IM 0x80 /* invalid operation */
# define _FPU_RESERVED 0xffffff00 /* These bits are reserved are not changed. */
/* The fdlibm code requires no interrupts for exceptions. */
# define _FPU_DEFAULT 0x00000000 /* Default value. */
/* IEEE: same as above, but (some) exceptions;
we leave the 'inexact' exception off.
*/
# define _FPU_IEEE 0x000000f0
/* Type of the control word. */
typedef unsigned int fpu_control_t;
/* Macros for accessing the hardware control word. */
# define _FPU_GETCW(cw) \
({union { double __d; unsigned long long __ll; } __u; \
__asm__ __volatile__("mffs %0" : "=f" (__u.__d)); \
(cw) = (fpu_control_t) __u.__ll; \
(fpu_control_t) __u.__ll; \
})
# define _FPU_GET_RC_ISA300() \
({union { double __d; unsigned long long __ll; } __u; \
__asm__ __volatile__( \
".machine push; .machine \"power9\"; mffsl %0; .machine pop" \
: "=f" (__u.__d)); \
(fpu_control_t) (__u.__ll & _FPU_MASK_RC); \
})
# ifdef _ARCH_PWR9
# define _FPU_GET_RC() _FPU_GET_RC_ISA300()
# elif defined __BUILTIN_CPU_SUPPORTS__
# define _FPU_GET_RC() \
({fpu_control_t __rc; \
__rc = __glibc_likely (__builtin_cpu_supports ("arch_3_00")) \
? _FPU_GET_RC_ISA300 () \
: _FPU_GETCW (__rc) & _FPU_MASK_RC; \
__rc; \
})
# else
# define _FPU_GET_RC() \
({fpu_control_t __rc = _FPU_GETCW (__rc) & _FPU_MASK_RC; \
__rc; \
})
# endif
# define _FPU_SETCW(cw) \
{ union { double __d; unsigned long long __ll; } __u; \
register double __fr; \
__u.__ll = 0xfff80000LL << 32; /* This is a QNaN. */ \
__u.__ll |= (cw) & 0xffffffffLL; \
__fr = __u.__d; \
__asm__ __volatile__("mtfsf 255,%0" : : "f" (__fr)); \
}
/* Default control word set at startup. */
extern fpu_control_t __fpu_control;
#endif /* PowerPC 6xx floating-point. */
#endif /* _FPU_CONTROL_H */