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author | Andrew Waterman <andrew@sifive.com> | 2018-07-11 01:16:28 -0700 |
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committer | Andrew Waterman <andrew@sifive.com> | 2018-07-11 01:16:28 -0700 |
commit | 5cd8d2b93fad2011fdf8f49a263d77697af35b32 (patch) | |
tree | f6fb9cb6d3bef2aa5c9903511b92e5a6e99e9519 /softfloat/s_roundPackToF128.c | |
parent | 8e69141749065ff957383d2112768f95a33429b6 (diff) | |
download | riscv-pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.zip riscv-pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.gz riscv-pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.bz2 |
Upgrade to SoftFloat 3e
Diffstat (limited to 'softfloat/s_roundPackToF128.c')
-rw-r--r-- | softfloat/s_roundPackToF128.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/softfloat/s_roundPackToF128.c b/softfloat/s_roundPackToF128.c new file mode 100644 index 0000000..ade5092 --- /dev/null +++ b/softfloat/s_roundPackToF128.c @@ -0,0 +1,171 @@ + +/*============================================================================ + +This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3e, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014, 2015, 2017 The Regents of the University of +California. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions, and the following disclaimer. + + 2. 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. + + 3. Neither the name of the University nor the names of its contributors may + be used to endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <stdbool.h> +#include <stdint.h> +#include "platform.h" +#include "internals.h" +#include "softfloat.h" + +float128_t + softfloat_roundPackToF128( + bool sign, + int_fast32_t exp, + uint_fast64_t sig64, + uint_fast64_t sig0, + uint_fast64_t sigExtra + ) +{ + uint_fast8_t roundingMode; + bool roundNearEven, doIncrement, isTiny; + struct uint128_extra sig128Extra; + uint_fast64_t uiZ64, uiZ0; + struct uint128 sig128; + union ui128_f128 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + roundingMode = softfloat_roundingMode; + roundNearEven = (roundingMode == softfloat_round_near_even); + doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra); + if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) { + doIncrement = + (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + && sigExtra; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( 0x7FFD <= (uint32_t) exp ) { + if ( exp < 0 ) { + /*---------------------------------------------------------------- + *----------------------------------------------------------------*/ + isTiny = + (softfloat_detectTininess + == softfloat_tininess_beforeRounding) + || (exp < -1) + || ! doIncrement + || softfloat_lt128( + sig64, + sig0, + UINT64_C( 0x0001FFFFFFFFFFFF ), + UINT64_C( 0xFFFFFFFFFFFFFFFF ) + ); + sig128Extra = + softfloat_shiftRightJam128Extra( sig64, sig0, sigExtra, -exp ); + sig64 = sig128Extra.v.v64; + sig0 = sig128Extra.v.v0; + sigExtra = sig128Extra.extra; + exp = 0; + if ( isTiny && sigExtra ) { + softfloat_raiseFlags( softfloat_flag_underflow ); + } + doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra); + if ( + ! roundNearEven + && (roundingMode != softfloat_round_near_maxMag) + ) { + doIncrement = + (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + && sigExtra; + } + } else if ( + (0x7FFD < exp) + || ((exp == 0x7FFD) + && softfloat_eq128( + sig64, + sig0, + UINT64_C( 0x0001FFFFFFFFFFFF ), + UINT64_C( 0xFFFFFFFFFFFFFFFF ) + ) + && doIncrement) + ) { + /*---------------------------------------------------------------- + *----------------------------------------------------------------*/ + softfloat_raiseFlags( + softfloat_flag_overflow | softfloat_flag_inexact ); + if ( + roundNearEven + || (roundingMode == softfloat_round_near_maxMag) + || (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + ) { + uiZ64 = packToF128UI64( sign, 0x7FFF, 0 ); + uiZ0 = 0; + } else { + uiZ64 = + packToF128UI64( + sign, 0x7FFE, UINT64_C( 0x0000FFFFFFFFFFFF ) ); + uiZ0 = UINT64_C( 0xFFFFFFFFFFFFFFFF ); + } + goto uiZ; + } + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( sigExtra ) { + softfloat_raiseFlags( softfloat_flag_inexact ); +#ifdef SOFTFLOAT_ROUND_ODD + if ( roundingMode == softfloat_round_odd ) { + sig0 |= 1; + goto packReturn; + } +#endif + } + if ( doIncrement ) { + sig128 = softfloat_add128( sig64, sig0, 0, 1 ); + sig64 = sig128.v64; + sig0 = + sig128.v0 + & ~(uint64_t) + (! (sigExtra & UINT64_C( 0x7FFFFFFFFFFFFFFF )) + & roundNearEven); + } else { + if ( ! (sig64 | sig0) ) exp = 0; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + packReturn: + uiZ64 = packToF128UI64( sign, exp, sig64 ); + uiZ0 = sig0; + uiZ: + uZ.ui.v64 = uiZ64; + uZ.ui.v0 = uiZ0; + return uZ.f; + +} + |