1 2 /*============================================================================ 3 4 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5 Package, Release 3e, by John R. Hauser. 6 7 Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017 The Regents of the 8 University of California. All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, 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 24 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY 25 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 26 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE 27 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 28 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 29 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 31 ON 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 33 SOFTWARE, 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 int_fast64_t softfloat_roundToI64(bool sign,uint_fast64_t sig,uint_fast64_t sigExtra,uint_fast8_t roundingMode,bool exact)45 softfloat_roundToI64( 46 bool sign, 47 uint_fast64_t sig, 48 uint_fast64_t sigExtra, 49 uint_fast8_t roundingMode, 50 bool exact 51 ) 52 { 53 union { uint64_t ui; int64_t i; } uZ; 54 int_fast64_t z; 55 56 /*------------------------------------------------------------------------ 57 *------------------------------------------------------------------------*/ 58 if ( 59 (roundingMode == softfloat_round_near_maxMag) 60 || (roundingMode == softfloat_round_near_even) 61 ) { 62 if ( UINT64_C( 0x8000000000000000 ) <= sigExtra ) goto increment; 63 } else { 64 if ( 65 sigExtra 66 && (sign 67 ? (roundingMode == softfloat_round_min) 68 #ifdef SOFTFLOAT_ROUND_ODD 69 || (roundingMode == softfloat_round_odd) 70 #endif 71 : (roundingMode == softfloat_round_max)) 72 ) { 73 increment: 74 ++sig; 75 if ( !sig ) goto invalid; 76 if ( 77 (sigExtra == UINT64_C( 0x8000000000000000 )) 78 && (roundingMode == softfloat_round_near_even) 79 ) { 80 sig &= ~(uint_fast64_t) 1; 81 } 82 } 83 } 84 uZ.ui = sign ? -sig : sig; 85 z = uZ.i; 86 if ( z && ((z < 0) ^ sign) ) goto invalid; 87 if ( sigExtra ) { 88 #ifdef SOFTFLOAT_ROUND_ODD 89 if ( roundingMode == softfloat_round_odd ) z |= 1; 90 #endif 91 if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; 92 } 93 return z; 94 /*------------------------------------------------------------------------ 95 *------------------------------------------------------------------------*/ 96 invalid: 97 softfloat_raiseFlags( softfloat_flag_invalid ); 98 return sign ? i64_fromNegOverflow : i64_fromPosOverflow; 99 100 } 101 102