kai.ren | 3a9d0de | 2021-01-21 15:53:33 +0800 | [diff] [blame] | 1 | |
| 2 | /*============================================================================ |
| 3 | |
| 4 | This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic |
| 5 | Package, Release 3d, 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 | |
| 40 | #include "internals.h" |
| 41 | #include "platform.h" |
| 42 | #include "softfloat.h" |
| 43 | #include "specialize.h" |
| 44 | |
| 45 | int_fast32_t f16_to_i32( float16_t a, uint_fast8_t roundingMode, bool exact ) |
| 46 | { |
| 47 | union ui16_f16 uA; |
| 48 | uint_fast16_t uiA; |
| 49 | bool sign; |
| 50 | int_fast8_t exp; |
| 51 | uint_fast16_t frac; |
| 52 | int_fast32_t sig32; |
| 53 | int_fast8_t shiftDist; |
| 54 | |
| 55 | /*------------------------------------------------------------------------ |
| 56 | *------------------------------------------------------------------------*/ |
| 57 | uA.f = a; |
| 58 | uiA = uA.ui; |
| 59 | sign = signF16UI( uiA ); |
| 60 | exp = expF16UI( uiA ); |
| 61 | frac = fracF16UI( uiA ); |
| 62 | /*------------------------------------------------------------------------ |
| 63 | *------------------------------------------------------------------------*/ |
| 64 | if ( exp == 0x1F ) { |
| 65 | softfloat_raiseFlags( softfloat_flag_invalid ); |
| 66 | return |
| 67 | frac ? i32_fromNaN |
| 68 | : sign ? i32_fromNegOverflow : i32_fromPosOverflow; |
| 69 | } |
| 70 | /*------------------------------------------------------------------------ |
| 71 | *------------------------------------------------------------------------*/ |
| 72 | sig32 = frac; |
| 73 | if ( exp ) { |
| 74 | sig32 |= 0x0400; |
| 75 | shiftDist = exp - 0x19; |
| 76 | if ( 0 <= shiftDist ) { |
| 77 | sig32 <<= shiftDist; |
| 78 | return sign ? -sig32 : sig32; |
| 79 | } |
| 80 | shiftDist = exp - 0x0D; |
| 81 | if ( 0 < shiftDist ) sig32 <<= shiftDist; |
| 82 | } |
| 83 | return |
| 84 | softfloat_roundToI32( |
| 85 | sign, (uint_fast32_t) sig32, roundingMode, exact ); |
| 86 | |
| 87 | } |
| 88 | |