/* (c) Copyright 2017 Michael R. Neilly All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the names of the copyright holders nor the names of their contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include "riscv_math.h" /* This implementation is intended to comply with the following * specification: * * http://pubs.opengroup.org/onlinepubs/009695399/functions/feholdexcept.html * Referred to as 'feholdexcept.html below. * * "The feholdexcept() function shall save the current floating-point * environment in the object pointed to by envp, clear the * floating-point status flags, and then install a non-stop (continue * on floating-point exceptions) mode, if available, for all * floating-point exceptions." */ int feholdexcept(fenv_t *envp) { #ifdef __RISCV_HARD_FLOAT /* Store the current FP environment in envp*/ fenv_t fcsr; asm volatile("frcsr %0" : "=r"(fcsr)); *envp = fcsr; /* Clear all flags */ asm volatile("csrrc zero, fflags, %0" : : "r"(FE_ALL_EXCEPT)); /* RISC-V does not raise FP traps so it is always in a "non-stop" mode */ /* Per 'feholdexcept.html: * * "The feholdexcept() function shall return zero if and only if * non-stop floating-point exception handling was successfully * installed." */ #endif return 0; }