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ec94343f59
TS 18661-1 defines a type femode_t to represent the set of dynamic floating-point control modes (such as the rounding mode and trap enablement modes), and functions fegetmode and fesetmode to manipulate those modes (without affecting other state such as the raised exception flags) and a corresponding macro FE_DFL_MODE. This patch series implements those interfaces for glibc. This first patch adds the architecture-independent pieces, the x86 and x86_64 implementations, and the <bits/fenv.h> and ABI baseline updates for all architectures so glibc keeps building and passing the ABI tests on all architectures. Subsequent patches add the fegetmode and fesetmode implementations for other architectures. femode_t is generally an integer type - the same type as fenv_t, or as the single element of fenv_t where fenv_t is a structure containing a single integer (or the single relevant element, where it has elements for both status and control registers) - except where architecture properties or consistency with the fenv_t implementation indicate otherwise. FE_DFL_MODE follows FE_DFL_ENV in whether it's a magic pointer value (-1 cast to const femode_t *), a value that can be distinguished from valid pointers by its high bits but otherwise contains a representation of the desired register contents, or a pointer to a constant variable (the powerpc case; __fe_dfl_mode is added as an exported constant object, an alias to __fe_dfl_env). Note that where architectures (that share a register between control and status bits) gain definitions of new floating-point control or status bits in future, the implementations of fesetmode for those architectures may need updating (depending on whether the new bits are control or status bits and what the implementation does with previously unknown bits), just like existing implementations of <fenv.h> functions that take care not to touch reserved bits may need updating when the set of reserved bits changes. (As any new bits are outside the scope of ISO C, that's just a quality-of-implementation issue for supporting them, not a conformance issue.) As with fenv_t, femode_t should properly include any software DFP rounding mode (and for both fenv_t and femode_t I'd consider that fragment of DFP support appropriate for inclusion in glibc even in the absence of the rest of libdfp; hardware DFP rounding modes should already be included if the definitions of which bits are status / control bits are correct). Tested for x86_64, x86, mips64 (hard float, and soft float to test the fallback version), arm (hard float) and powerpc (hard float, soft float and e500). Other architecture versions are untested. * math/fegetmode.c: New file. * math/fesetmode.c: Likewise. * sysdeps/i386/fpu/fegetmode.c: Likewise. * sysdeps/i386/fpu/fesetmode.c: Likewise. * sysdeps/x86_64/fpu/fegetmode.c: Likewise. * sysdeps/x86_64/fpu/fesetmode.c: Likewise. * math/fenv.h: Update comment on inclusion of <bits/fenv.h>. [__GLIBC_USE (IEC_60559_BFP_EXT)] (fegetmode): New function declaration. [__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetmode): Likewise. * bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/aarch64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/alpha/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/arm/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/hppa/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/ia64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/m68k/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/microblaze/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/mips/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/nios2/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/powerpc/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (__fe_dfl_mode): New variable declaration. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/s390/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/sh/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/sparc/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/tile/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * sysdeps/x86/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New typedef. [__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro. * manual/arith.texi (FE_DFL_MODE): Document macro. (fegetmode): Document function. (fesetmode): Likewise. * math/Versions (fegetmode): New libm symbol at version GLIBC_2.25. (fesetmode): Likewise. * math/Makefile (libm-support): Add fegetmode and fesetmode. (tests): Add test-femode and test-femode-traps. * math/test-femode-traps.c: New file. * math/test-femode.c: Likewise. * sysdeps/powerpc/fpu/fenv_const.c (__fe_dfl_mode): Declare as alias for __fe_dfl_env. * sysdeps/powerpc/nofpu/fenv_const.c (__fe_dfl_mode): Likewise. * sysdeps/powerpc/powerpc32/e500/nofpu/fenv_const.c (__fe_dfl_mode): Likewise. * sysdeps/powerpc/Versions (__fe_dfl_mode): New libm symbol at version GLIBC_2.25. * sysdeps/nacl/libm.abilist: Update. * sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
100 lines
3.1 KiB
C
100 lines
3.1 KiB
C
/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by David Huggins-Daines <dhd@debian.org>
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _FENV_H
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# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
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#endif
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/* Define bits representing the exception. We use the values of the
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appropriate enable bits in the FPU status word (which,
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coincidentally, are the same as the flag bits, but shifted right by
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27 bits). */
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enum
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{
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FE_INVALID =
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#define FE_INVALID (1<<4) /* V */
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FE_INVALID,
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FE_DIVBYZERO =
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#define FE_DIVBYZERO (1<<3) /* Z */
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FE_DIVBYZERO,
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FE_OVERFLOW =
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#define FE_OVERFLOW (1<<2) /* O */
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FE_OVERFLOW,
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FE_UNDERFLOW =
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#define FE_UNDERFLOW (1<<1) /* U */
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FE_UNDERFLOW,
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FE_INEXACT =
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#define FE_INEXACT (1<<0) /* I */
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FE_INEXACT,
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};
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#define FE_ALL_EXCEPT \
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(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
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/* The PA-RISC FPU supports all of the four defined rounding modes.
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We use the values of the RM field in the floating point status
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register for the appropriate macros. */
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enum
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{
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FE_TONEAREST =
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#define FE_TONEAREST (0 << 9)
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FE_TONEAREST,
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FE_TOWARDZERO =
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#define FE_TOWARDZERO (1 << 9)
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FE_TOWARDZERO,
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FE_UPWARD =
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#define FE_UPWARD (2 << 9)
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FE_UPWARD,
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FE_DOWNWARD =
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#define FE_DOWNWARD (3 << 9)
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FE_DOWNWARD,
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};
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/* Type representing exception flags. */
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typedef unsigned int fexcept_t;
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/* Type representing floating-point environment. This structure
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corresponds to the layout of the status and exception words in the
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register file. The exception registers are never saved/stored by
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userspace. This structure is also not correctly aligned ever, in
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an ABI error we left out __aligned(8) and subsequently all of our
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fenv functions must accept unaligned input, align the input, and
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then use assembly to store fr0. This is a performance hit, but
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means the ABI is stable. */
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typedef struct
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{
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unsigned int __status_word;
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unsigned int __exception[7];
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} fenv_t;
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/* If the default argument is used we use this value. */
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#define FE_DFL_ENV ((const fenv_t *) -1)
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#ifdef __USE_GNU
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/* Floating-point environment where none of the exceptions are masked. */
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# define FE_NOMASK_ENV ((const fenv_t *) -2)
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#endif
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#if __GLIBC_USE (IEC_60559_BFP_EXT)
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/* Type representing floating-point control modes. */
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typedef unsigned int femode_t;
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/* Default floating-point control modes. */
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# define FE_DFL_MODE ((const femode_t *) -1L)
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#endif
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