From 460ee50de054396cc9791ff4cfdc2f5029fb923d Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 26 Mar 2020 11:00:56 -0300 Subject: x86_64: Add SSE sfp-exceptions The exported x86_64 fenv.h functions operate on both i387 and SSE (since they should work on both float, double, and long double) while the internal libc_fe* set either SSE (float, double, and float128) or i387 (long double). The libgcc __sfp_handle_exceptions (used on float128 implementation), however, will set either SEE or i387 exception depending of the exception to raise. This broke the internal assumption of float128 where only SSE operations will be used. This patch reimplements the libgcc __sfp_handle_exceptions to use only SSE operations and sets libgcc to use it instead of its own implementation. And I think we should fix libgcc in a similar manner, since checking on config/i386/64/sfp-machine.h it already only supports SSE rounding mode and x86_64 ABI also expectes float128 to use SSE registers [1] (although it is not clear on how future implementation might implement it). Checked on x86_64-linux-gnu. [1] https://github.com/hjl-tools/x86-psABI/wiki/X86-psABI --- sysdeps/x86/fpu/sfp-exceptions.c | 57 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 sysdeps/x86/fpu/sfp-exceptions.c (limited to 'sysdeps/x86/fpu') diff --git a/sysdeps/x86/fpu/sfp-exceptions.c b/sysdeps/x86/fpu/sfp-exceptions.c new file mode 100644 index 0000000000..74ce0716e2 --- /dev/null +++ b/sysdeps/x86/fpu/sfp-exceptions.c @@ -0,0 +1,57 @@ +/* x86_64 soft-fp exception handling for _Float128. + Copyright (C) 2020 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 + . */ + +#include +#include +#include +#include + +void +__sfp_handle_exceptions (int _fex) +{ + if (_fex & FP_EX_INVALID) + { + float f = 0.0f; + math_force_eval (f / f); + } + if (_fex & FP_EX_DENORM) + { + float f = FLT_MIN, g = 2.0f; + math_force_eval (f / g); + } + if (_fex & FP_EX_DIVZERO) + { + float f = 1.0f, g = 0.0f; + math_force_eval (f / g); + } + if (_fex & FP_EX_OVERFLOW) + { + float force_underflow = FLT_MAX * FLT_MAX; + math_force_eval (force_underflow); + } + if (_fex & FP_EX_UNDERFLOW) + { + float force_overflow = FLT_MIN * FLT_MIN; + math_force_eval (force_overflow); + } + if (_fex & FP_EX_INEXACT) + { + float f = 1.0f, g = 3.0f; + math_force_eval (f / g); + } +} -- cgit 1.4.1