| |
| /*============================================================================ |
| |
| This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic |
| Package, Release 3d, by John R. Hauser. |
| |
| Copyright 2011, 2012, 2013, 2014, 2015 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 f64_to_f16( float64_t a ) |
| { |
| union ui64_f64 uA; |
| uint_fast64_t uiA; |
| bool sign; |
| int_fast16_t exp; |
| uint_fast64_t frac; |
| struct commonNaN commonNaN; |
| uint_fast16_t uiZ, frac16; |
| union ui16_f16 uZ; |
| |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| uA.f = a; |
| uiA = uA.ui; |
| sign = signF64UI( uiA ); |
| exp = expF64UI( uiA ); |
| frac = fracF64UI( uiA ); |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| if ( exp == 0x7FF ) { |
| if ( frac ) { |
| softfloat_f64UIToCommonNaN( uiA, &commonNaN ); |
| uiZ = softfloat_commonNaNToF16UI( &commonNaN ); |
| } else { |
| uiZ = packToF16UI( sign, 0x1F, 0 ); |
| } |
| goto uiZ; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| frac16 = softfloat_shortShiftRightJam64( frac, 38 ); |
| if ( ! (exp | frac16) ) { |
| uiZ = packToF16UI( sign, 0, 0 ); |
| goto uiZ; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| return softfloat_roundPackToF16( sign, exp - 0x3F1, frac16 | 0x4000 ); |
| uiZ: |
| uZ.ui = uiZ; |
| return uZ.f; |
| |
| } |
| |