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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/f16_roundToInt.c | |
parent | 8e69141749065ff957383d2112768f95a33429b6 (diff) | |
download | pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.zip pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.gz pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.bz2 |
Upgrade to SoftFloat 3e
Diffstat (limited to 'softfloat/f16_roundToInt.c')
-rw-r--r-- | softfloat/f16_roundToInt.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/softfloat/f16_roundToInt.c b/softfloat/f16_roundToInt.c new file mode 100644 index 0000000..721d4ec --- /dev/null +++ b/softfloat/f16_roundToInt.c @@ -0,0 +1,120 @@ + +/*============================================================================ + +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 "specialize.h" +#include "softfloat.h" + +float16_t f16_roundToInt( float16_t a, uint_fast8_t roundingMode, bool exact ) +{ + union ui16_f16 uA; + uint_fast16_t uiA; + int_fast8_t exp; + uint_fast16_t uiZ, lastBitMask, roundBitsMask; + union ui16_f16 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA = uA.ui; + exp = expF16UI( uiA ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( exp <= 0xE ) { + if ( !(uint16_t) (uiA<<1) ) return a; + if ( exact ) softfloat_raiseFlags( softfloat_flag_inexact ); + uiZ = uiA & packToF16UI( 1, 0, 0 ); + switch ( roundingMode ) { + case softfloat_round_near_even: + if ( !fracF16UI( uiA ) ) break; + case softfloat_round_near_maxMag: + if ( exp == 0xE ) uiZ |= packToF16UI( 0, 0xF, 0 ); + break; + case softfloat_round_min: + if ( uiZ ) uiZ = packToF16UI( 1, 0xF, 0 ); + break; + case softfloat_round_max: + if ( !uiZ ) uiZ = packToF16UI( 0, 0xF, 0 ); + break; +#ifdef SOFTFLOAT_ROUND_ODD + case softfloat_round_odd: + uiZ |= packToF16UI( 0, 0xF, 0 ); + break; +#endif + } + goto uiZ; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( 0x19 <= exp ) { + if ( (exp == 0x1F) && fracF16UI( uiA ) ) { + uiZ = softfloat_propagateNaNF16UI( uiA, 0 ); + goto uiZ; + } + return a; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uiZ = uiA; + lastBitMask = (uint_fast16_t) 1<<(0x19 - exp); + roundBitsMask = lastBitMask - 1; + if ( roundingMode == softfloat_round_near_maxMag ) { + uiZ += lastBitMask>>1; + } else if ( roundingMode == softfloat_round_near_even ) { + uiZ += lastBitMask>>1; + if ( !(uiZ & roundBitsMask) ) uiZ &= ~lastBitMask; + } else if ( + roundingMode + == (signF16UI( uiZ ) ? softfloat_round_min : softfloat_round_max) + ) { + uiZ += roundBitsMask; + } + uiZ &= ~roundBitsMask; + if ( uiZ != uiA ) { +#ifdef SOFTFLOAT_ROUND_ODD + if ( roundingMode == softfloat_round_odd ) uiZ |= lastBitMask; +#endif + if ( exact ) softfloat_raiseFlags( softfloat_flag_inexact ); + } + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |