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5d96fe8c0d
On s390, the DXC(data-exception-code)-byte in FPC(floating-point-control)-
register contains a code of the last occured exception.
If bits 6 and 7 of DXC-byte are zero, the bits 0-5 correspond to the
ieee-exception flag bits.
The current implementation always uses these bits as ieee-exception flag bits.
fetestexcept() reports any exception after the first usage of a
vector-instruction in a process, because it raises an "vector instruction
exception" with DXC-code 0xFE.
This patch fixes the handling of the DXC-byte. The DXC-Byte is only handled
if bits 6 and 7 are zero.
The #define _FPU_RESERVED is extended by the DXC-Byte.
Otherwise the tests math/test-fpucw-static and math/test-fpucw-ieee-static
fails, because DXC-Byte contains the vector instruction exception when reaching
main(). This exception was triggered by strrchr() call in __init_misc().
__init_misc() is called after __setfpucw () in __libc_init_first().
The field __ieee_instruction_pointer in struct fenv_t is renamed to __unused
because it is a relict from commit "Remove PTRACE_PEEKUSER"
(87b9b50f0d) and isn´t used anymore.
ChangeLog:
[BZ #18610]
* sysdeps/s390/fpu/bits/fenv.h (fenv_t): Rename
__ieee_instruction_pointer to __unused.
* sysdeps/s390/fpu/fesetenv.c (__fesetenv): Remove usage of
__ieee_instruction_pointer.
* sysdeps/s390/fpu/fclrexcpt.c (feclearexcept): Fix dxc-field handling.
* sysdeps/s390/fpu/fgetexcptflg.c (fegetexceptflag): Likewise.
* sysdeps/s390/fpu/fsetexcptflg.c (fesetexceptflag): Likewise.
* sysdeps/s390/fpu/ftestexcept.c (fetestexcept): Likewise.
* sysdeps/s390/fpu/fpu_control.h (_FPU_RESERVED):
Mark dxc-field as reserved.
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/* Copyright (C) 2000-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Denis Joseph Barrow <djbarrow@de.ibm.com>.
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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 bit positions
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of the appropriate bits in the FPU control word. */
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enum
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{
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FE_INVALID =
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#define FE_INVALID 0x80
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FE_INVALID,
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FE_DIVBYZERO =
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#define FE_DIVBYZERO 0x40
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FE_DIVBYZERO,
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FE_OVERFLOW =
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#define FE_OVERFLOW 0x20
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FE_OVERFLOW,
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FE_UNDERFLOW =
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#define FE_UNDERFLOW 0x10
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FE_UNDERFLOW,
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FE_INEXACT =
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#define FE_INEXACT 0x08
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FE_INEXACT
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};
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/* We dont use the y bit of the DXC in the floating point control register
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as glibc has no FE encoding for fe inexact incremented
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or fe inexact truncated.
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We currently use the flag bits in the fpc
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as these are sticky for feholdenv & feupdatenv as it is defined
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in the HP Manpages. */
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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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enum
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{
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FE_TONEAREST =
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#define FE_TONEAREST 0
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FE_TONEAREST,
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FE_DOWNWARD =
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#define FE_DOWNWARD 0x3
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FE_DOWNWARD,
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FE_UPWARD =
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#define FE_UPWARD 0x2
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FE_UPWARD,
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FE_TOWARDZERO =
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#define FE_TOWARDZERO 0x1
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FE_TOWARDZERO
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};
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/* Type representing exception flags. */
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typedef unsigned int fexcept_t; /* size of fpc */
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/* Type representing floating-point environment. This function corresponds
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to the layout of the block written by the `fstenv'. */
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typedef struct
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{
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fexcept_t __fpc;
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void *__unused;
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/* The field __unused (formerly __ieee_instruction_pointer) is a relict from
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commit "Remove PTRACE_PEEKUSER" (87b9b50f0d4b92248905e95a06a13c513dc45e59)
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and isn´t used anymore. */
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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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