86 lines
3.2 KiB
C
86 lines
3.2 KiB
C
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/*
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(c) Copyright 2017 Michael R. Neilly
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the names of the copyright holders nor the names of their
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contributors may be used to endorse or promote products derived from
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this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <fenv.h>
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/* This implementation is intended to comply with the following
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* specification:
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*
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* http://pubs.opengroup.org/onlinepubs/009695399/functions/feraiseexcept.html
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* Referred to as 'feraiseexcept.html below.
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*
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* "The feraiseexcept() function shall attempt to raise the supported
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* floating-point exceptions represented by the excepts argument. The
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* order in which these floating-point exceptions are raised is
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* unspecified, except that if the excepts argument represents IEC
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* 60559 valid coincident floating-point exceptions for atomic
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* operations (namely overflow and inexact, or underflow and inexact),
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* then overflow or underflow shall be raised before inexact. Whether
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* the feraiseexcept() function additionally raises the inexact
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* floating-point exception whenever it raises the overflow or
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* underflow floating-point exception is implementation-defined."
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*/
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int feraiseexcept(int excepts)
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{
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/* Mask excepts to be sure only supported flag bits are set */
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excepts &= FE_ALL_EXCEPT;
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#if __riscv_flen
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/* Set the requested exception flags */
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asm volatile("csrs fflags, %0" : : "r"(excepts));
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/* Per 'feraiseexcept.html:
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* "If the argument is zero or if all the specified exceptions were
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* successfully raised, feraiseexcept() shall return
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* zero. Otherwise, it shall return a non-zero value."
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*/
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/* Per "The RISC-V Instruction Set Manual: Volume I: User-Level ISA:
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* Version 2.1":
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*
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* "As allowed by the standard, we do not support traps on
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* floating-point exceptions in the base ISA, but instead require
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* explicit checks of the flags in software."
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*
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*/
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#endif
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return (excepts != 0);
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}
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