| |
| /*============================================================================ |
| |
| This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic |
| Package, Release 3, by John R. Hauser. |
| |
| Copyright 2011, 2012, 2013, 2014 The Regents of the University of California |
| (Regents). All Rights Reserved. Redistribution and use in source and binary |
| forms, with or without modification, are permitted provided that the following |
| conditions are met: |
| |
| Redistributions of source code must retain the above copyright notice, |
| this list of conditions, and the following two paragraphs of disclaimer. |
| Redistributions in binary form must reproduce the above copyright notice, |
| this list of conditions, and the following two paragraphs of disclaimer in the |
| documentation and/or other materials provided with the distribution. Neither |
| the name of the Regents nor the names of its contributors may be used to |
| endorse or promote products derived from this software without specific prior |
| written permission. |
| |
| IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, |
| SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING |
| OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS |
| BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED |
| TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED |
| HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE |
| MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
| |
| =============================================================================*/ |
| |
| #include <stdbool.h> |
| #include <stdint.h> |
| #include "platform.h" |
| #include "internals.h" |
| #include "specialize.h" |
| #include "softfloat.h" |
| |
| float64_t f128_to_f64( float128_t a ) |
| { |
| union ui128_f128 uA; |
| uint_fast64_t uiA64, uiA0; |
| bool sign; |
| int_fast32_t exp; |
| uint_fast64_t sig64, sig0; |
| struct commonNaN commonNaN; |
| uint_fast64_t uiZ; |
| struct uint128 sig128; |
| union ui64_f64 uZ; |
| |
| uA.f = a; |
| uiA64 = uA.ui.v64; |
| uiA0 = uA.ui.v0; |
| sign = signF128UI64( uiA64 ); |
| exp = expF128UI64( uiA64 ); |
| sig64 = fracF128UI64( uiA64 ); |
| sig0 = uiA0; |
| if ( exp == 0x7FFF ) { |
| if ( sig64 | sig0 ) { |
| softfloat_f128UIToCommonNaN( uiA64, uiA0, &commonNaN ); |
| uiZ = softfloat_commonNaNToF64UI( &commonNaN ); |
| } else { |
| uiZ = packToF64UI( sign, 0x7FF, 0 ); |
| } |
| goto uiZ; |
| } |
| sig128 = softfloat_shortShiftLeft128( sig64, sig0, 14 ); |
| sig64 = sig128.v64 | (sig128.v0 != 0); |
| if ( ! (exp | sig64) ) { |
| uiZ = packToF64UI( sign, 0, 0 ); |
| goto uiZ; |
| } |
| exp -= 0x3C01; |
| if ( sizeof (int_fast16_t) < sizeof (int_fast32_t) ) { |
| if ( exp < -0x1000 ) exp = -0x1000; |
| } |
| return |
| softfloat_roundPackToF64( |
| sign, exp, sig64 | UINT64_C( 0x4000000000000000 ) ); |
| uiZ: |
| uZ.ui = uiZ; |
| return uZ.f; |
| |
| } |
| |