1 2/*============================================================================ 3 4This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5Package, Release 3e, by John R. Hauser. 6 7Copyright 2011, 2012, 2013, 2014, 2015 The Regents of the University of 8California. All rights reserved. 9 10Redistribution and use in source and binary forms, with or without 11modification, are permitted provided that the following conditions are met: 12 13 1. Redistributions of source code must retain the above copyright notice, 14 this list of conditions, and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright notice, 17 this list of conditions, and the following disclaimer in the documentation 18 and/or other materials provided with the distribution. 19 20 3. Neither the name of the University nor the names of its contributors may 21 be used to endorse or promote products derived from this software without 22 specific prior written permission. 23 24THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY 25EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 26WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE 27DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 28DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 29(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 31ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 35=============================================================================*/ 36 37#include <stdbool.h> 38#include <stdint.h> 39#include "platform.h" 40#include "internals.h" 41#include "specialize.h" 42#include "softfloat.h" 43 44#ifdef SOFTFLOAT_FAST_INT64 45 46float16_t extF80M_to_f16( const extFloat80_t *aPtr ) 47{ 48 49 return extF80_to_f16( *aPtr ); 50 51} 52 53#else 54 55float16_t extF80M_to_f16( const extFloat80_t *aPtr ) 56{ 57 const struct extFloat80M *aSPtr; 58 uint_fast16_t uiA64; 59 bool sign; 60 int32_t exp; 61 uint64_t sig; 62 struct commonNaN commonNaN; 63 uint16_t uiZ, sig16; 64 union ui16_f16 uZ; 65 66 /*------------------------------------------------------------------------ 67 *------------------------------------------------------------------------*/ 68 aSPtr = (const struct extFloat80M *) aPtr; 69 /*------------------------------------------------------------------------ 70 *------------------------------------------------------------------------*/ 71 uiA64 = aSPtr->signExp; 72 sign = signExtF80UI64( uiA64 ); 73 exp = expExtF80UI64( uiA64 ); 74 sig = aSPtr->signif; 75 /*------------------------------------------------------------------------ 76 *------------------------------------------------------------------------*/ 77 if ( exp == 0x7FFF ) { 78 if ( sig & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { 79 softfloat_extF80MToCommonNaN( aSPtr, &commonNaN ); 80 uiZ = softfloat_commonNaNToF16UI( &commonNaN ); 81 } else { 82 uiZ = packToF16UI( sign, 0x1F, 0 ); 83 } 84 goto uiZ; 85 } 86 /*------------------------------------------------------------------------ 87 *------------------------------------------------------------------------*/ 88 if ( ! (sig & UINT64_C( 0x8000000000000000 )) ) { 89 if ( ! sig ) { 90 uiZ = packToF16UI( sign, 0, 0 ); 91 goto uiZ; 92 } 93 exp += softfloat_normExtF80SigM( &sig ); 94 } 95 /*------------------------------------------------------------------------ 96 *------------------------------------------------------------------------*/ 97 sig16 = softfloat_shortShiftRightJam64( sig, 49 ); 98 exp -= 0x3FF1; 99 if ( sizeof (int_fast16_t) < sizeof (int32_t) ) { 100 if ( exp < -0x40 ) exp = -0x40; 101 } 102 return softfloat_roundPackToF16( sign, exp, sig16 ); 103 /*------------------------------------------------------------------------ 104 *------------------------------------------------------------------------*/ 105 uiZ: 106 uZ.ui = uiZ; 107 return uZ.f; 108 109} 110 111#endif 112 113