| |
| /*============================================================================ |
| |
| 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 "softfloat.h" |
| |
| float128_t |
| softfloat_roundPackToF128( |
| bool sign, |
| int_fast32_t exp, |
| uint_fast64_t sig64, |
| uint_fast64_t sig0, |
| uint_fast64_t sigExtra |
| ) |
| { |
| uint_fast8_t roundingMode; |
| bool roundNearEven, doIncrement, isTiny; |
| struct uint128_extra sig128Extra; |
| uint_fast64_t uiZ64, uiZ0; |
| struct uint128 sig128; |
| union ui128_f128 uZ; |
| |
| roundingMode = softfloat_roundingMode; |
| roundNearEven = (roundingMode == softfloat_round_near_even); |
| doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra); |
| if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) { |
| doIncrement = |
| (roundingMode |
| == (sign ? softfloat_round_min : softfloat_round_max)) |
| && sigExtra; |
| } |
| if ( 0x7FFD <= (uint32_t) exp ) { |
| if ( exp < 0 ) { |
| isTiny = |
| (softfloat_detectTininess |
| == softfloat_tininess_beforeRounding) |
| || (exp < -1) |
| || ! doIncrement |
| || softfloat_lt128( |
| sig64, |
| sig0, |
| UINT64_C( 0x0001FFFFFFFFFFFF ), |
| UINT64_C( 0xFFFFFFFFFFFFFFFF ) |
| ); |
| sig128Extra = |
| softfloat_shiftRightJam128Extra( sig64, sig0, sigExtra, -exp ); |
| sig64 = sig128Extra.v.v64; |
| sig0 = sig128Extra.v.v0; |
| sigExtra = sig128Extra.extra; |
| exp = 0; |
| if ( isTiny && sigExtra ) { |
| softfloat_raiseFlags( softfloat_flag_underflow ); |
| } |
| doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra); |
| if ( |
| ! roundNearEven |
| && (roundingMode != softfloat_round_near_maxMag) |
| ) { |
| doIncrement = |
| (roundingMode |
| == (sign ? softfloat_round_min : softfloat_round_max)) |
| && sigExtra; |
| } |
| } else if ( |
| (0x7FFD < exp) |
| || ((exp == 0x7FFD) |
| && softfloat_eq128( |
| sig64, |
| sig0, |
| UINT64_C( 0x0001FFFFFFFFFFFF ), |
| UINT64_C( 0xFFFFFFFFFFFFFFFF ) |
| ) |
| && doIncrement) |
| ) { |
| softfloat_raiseFlags( |
| softfloat_flag_overflow | softfloat_flag_inexact ); |
| if ( |
| roundNearEven |
| || (roundingMode == softfloat_round_near_maxMag) |
| || (roundingMode |
| == (sign ? softfloat_round_min : softfloat_round_max)) |
| ) { |
| uiZ64 = packToF128UI64( sign, 0x7FFF, 0 ); |
| uiZ0 = 0; |
| } else { |
| uiZ64 = |
| packToF128UI64( |
| sign, 0x7FFE, UINT64_C( 0x0000FFFFFFFFFFFF ) ); |
| uiZ0 = UINT64_C( 0xFFFFFFFFFFFFFFFF ); |
| } |
| goto uiZ; |
| } |
| } |
| if ( sigExtra ) softfloat_exceptionFlags |= softfloat_flag_inexact; |
| if ( doIncrement ) { |
| sig128 = softfloat_add128( sig64, sig0, 0, 1 ); |
| sig64 = sig128.v64; |
| sig0 = |
| sig128.v0 |
| & ~(! (sigExtra & UINT64_C( 0x7FFFFFFFFFFFFFFF )) |
| & roundNearEven); |
| } else { |
| if ( ! (sig64 | sig0) ) exp = 0; |
| } |
| uiZ64 = packToF128UI64( sign, exp, sig64 ); |
| uiZ0 = sig0; |
| uiZ: |
| uZ.ui.v64 = uiZ64; |
| uZ.ui.v0 = uiZ0; |
| return uZ.f; |
| |
| } |
| |