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Diffstat (limited to 'softfloat/f128_to_ui64.c')
-rw-r--r-- | softfloat/f128_to_ui64.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/softfloat/f128_to_ui64.c b/softfloat/f128_to_ui64.c new file mode 100644 index 0000000..b88d251 --- /dev/null +++ b/softfloat/f128_to_ui64.c @@ -0,0 +1,96 @@ + +/*============================================================================ + +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, 2016, 2017 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" + +uint_fast64_t + f128_to_ui64( float128_t a, uint_fast8_t roundingMode, bool exact ) +{ + union ui128_f128 uA; + uint_fast64_t uiA64, uiA0; + bool sign; + int_fast32_t exp; + uint_fast64_t sig64, sig0; + int_fast32_t shiftDist; + struct uint128 sig128; + struct uint64_extra sigExtra; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA64 = uA.ui.v64; + uiA0 = uA.ui.v0; + sign = signF128UI64( uiA64 ); + exp = expF128UI64( uiA64 ); + sig64 = fracF128UI64( uiA64 ); + sig0 = uiA0; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + shiftDist = 0x402F - exp; + if ( shiftDist <= 0 ) { + /*-------------------------------------------------------------------- + *--------------------------------------------------------------------*/ + if ( shiftDist < -15 ) { + softfloat_raiseFlags( softfloat_flag_invalid ); + return + (exp == 0x7FFF) && (sig64 | sig0) ? ui64_fromNaN + : sign ? ui64_fromNegOverflow : ui64_fromPosOverflow; + } + /*-------------------------------------------------------------------- + *--------------------------------------------------------------------*/ + sig64 |= UINT64_C( 0x0001000000000000 ); + if ( shiftDist ) { + sig128 = softfloat_shortShiftLeft128( sig64, sig0, -shiftDist ); + sig64 = sig128.v64; + sig0 = sig128.v0; + } + } else { + /*-------------------------------------------------------------------- + *--------------------------------------------------------------------*/ + if ( exp ) sig64 |= UINT64_C( 0x0001000000000000 ); + sigExtra = softfloat_shiftRightJam64Extra( sig64, sig0, shiftDist ); + sig64 = sigExtra.v; + sig0 = sigExtra.extra; + } + return softfloat_roundToUI64( sign, sig64, sig0, roundingMode, exact ); + +} + |