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Diffstat (limited to 'softfloat/f128_rem.c')
| -rw-r--r-- | softfloat/f128_rem.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/softfloat/f128_rem.c b/softfloat/f128_rem.c new file mode 100644 index 0000000..28d3df6 --- /dev/null +++ b/softfloat/f128_rem.c @@ -0,0 +1,190 @@ + +/*============================================================================ + +This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3e, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014, 2015, 2016 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" + +float128_t f128_rem( float128_t a, float128_t b ) +{ + union ui128_f128 uA; + uint_fast64_t uiA64, uiA0; + bool signA; + int_fast32_t expA; + struct uint128 sigA; + union ui128_f128 uB; + uint_fast64_t uiB64, uiB0; + int_fast32_t expB; + struct uint128 sigB; + struct exp32_sig128 normExpSig; + struct uint128 rem; + int_fast32_t expDiff; + uint_fast32_t q, recip32; + uint_fast64_t q64; + struct uint128 term, altRem, meanRem; + bool signRem; + struct uint128 uiZ; + union ui128_f128 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA64 = uA.ui.v64; + uiA0 = uA.ui.v0; + signA = signF128UI64( uiA64 ); + expA = expF128UI64( uiA64 ); + sigA.v64 = fracF128UI64( uiA64 ); + sigA.v0 = uiA0; + uB.f = b; + uiB64 = uB.ui.v64; + uiB0 = uB.ui.v0; + expB = expF128UI64( uiB64 ); + sigB.v64 = fracF128UI64( uiB64 ); + sigB.v0 = uiB0; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0x7FFF ) { + if ( + (sigA.v64 | sigA.v0) || ((expB == 0x7FFF) && (sigB.v64 | sigB.v0)) + ) { + goto propagateNaN; + } + goto invalid; + } + if ( expB == 0x7FFF ) { + if ( sigB.v64 | sigB.v0 ) goto propagateNaN; + return a; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expB ) { + if ( ! (sigB.v64 | sigB.v0) ) goto invalid; + normExpSig = softfloat_normSubnormalF128Sig( sigB.v64, sigB.v0 ); + expB = normExpSig.exp; + sigB = normExpSig.sig; + } + if ( ! expA ) { + if ( ! (sigA.v64 | sigA.v0) ) return a; + normExpSig = softfloat_normSubnormalF128Sig( sigA.v64, sigA.v0 ); + expA = normExpSig.exp; + sigA = normExpSig.sig; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + sigA.v64 |= UINT64_C( 0x0001000000000000 ); + sigB.v64 |= UINT64_C( 0x0001000000000000 ); + rem = sigA; + expDiff = expA - expB; + if ( expDiff < 1 ) { + if ( expDiff < -1 ) return a; + if ( expDiff ) { + --expB; + sigB = softfloat_add128( sigB.v64, sigB.v0, sigB.v64, sigB.v0 ); + q = 0; + } else { + q = softfloat_le128( sigB.v64, sigB.v0, rem.v64, rem.v0 ); + if ( q ) { + rem = softfloat_sub128( rem.v64, rem.v0, sigB.v64, sigB.v0 ); + } + } + } else { + recip32 = softfloat_approxRecip32_1( sigB.v64>>17 ); + expDiff -= 30; + for (;;) { + q64 = (uint_fast64_t) (uint32_t) (rem.v64>>19) * recip32; + if ( expDiff < 0 ) break; + q = (q64 + 0x80000000)>>32; + rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 29 ); + term = softfloat_mul128By32( sigB.v64, sigB.v0, q ); + rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 ); + if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) { + rem = softfloat_add128( rem.v64, rem.v0, sigB.v64, sigB.v0 ); + } + expDiff -= 29; + } + /*-------------------------------------------------------------------- + | (`expDiff' cannot be less than -29 here.) + *--------------------------------------------------------------------*/ + q = (uint32_t) (q64>>32)>>(~expDiff & 31); + rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, expDiff + 30 ); + term = softfloat_mul128By32( sigB.v64, sigB.v0, q ); + rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 ); + if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) { + altRem = softfloat_add128( rem.v64, rem.v0, sigB.v64, sigB.v0 ); + goto selectRem; + } + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + do { + altRem = rem; + ++q; + rem = softfloat_sub128( rem.v64, rem.v0, sigB.v64, sigB.v0 ); + } while ( ! (rem.v64 & UINT64_C( 0x8000000000000000 )) ); + selectRem: + meanRem = softfloat_add128( rem.v64, rem.v0, altRem.v64, altRem.v0 ); + if ( + (meanRem.v64 & UINT64_C( 0x8000000000000000 )) + || (! (meanRem.v64 | meanRem.v0) && (q & 1)) + ) { + rem = altRem; + } + signRem = signA; + if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) { + signRem = ! signRem; + rem = softfloat_sub128( 0, 0, rem.v64, rem.v0 ); + } + return softfloat_normRoundPackToF128( signRem, expB - 1, rem.v64, rem.v0 ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + propagateNaN: + uiZ = softfloat_propagateNaNF128UI( uiA64, uiA0, uiB64, uiB0 ); + goto uiZ; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + uiZ.v64 = defaultNaNF128UI64; + uiZ.v0 = defaultNaNF128UI0; + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |