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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:49:04 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:49:04 +0000 |
commit | 16f504a9dca3fe3b70568f67b7d41241ae485288 (patch) | |
tree | c60f36ada0496ba928b7161059ba5ab1ab224f9d /src/libs/softfloat-3e/source/f64_rem.c | |
parent | Initial commit. (diff) | |
download | virtualbox-upstream.tar.xz virtualbox-upstream.zip |
Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/libs/softfloat-3e/source/f64_rem.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/libs/softfloat-3e/source/f64_rem.c b/src/libs/softfloat-3e/source/f64_rem.c new file mode 100644 index 00000000..a944a1c5 --- /dev/null +++ b/src/libs/softfloat-3e/source/f64_rem.c @@ -0,0 +1,189 @@ + +/*============================================================================ + +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 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" + +float64_t f64_rem( float64_t a, float64_t b SOFTFLOAT_STATE_DECL_COMMA ) +{ + union ui64_f64 uA; + uint_fast64_t uiA; + bool signA; + int_fast16_t expA; + uint_fast64_t sigA; + union ui64_f64 uB; + uint_fast64_t uiB; + int_fast16_t expB; + uint_fast64_t sigB; + struct exp16_sig64 normExpSig; + uint64_t rem; + int_fast16_t expDiff; + uint32_t q, recip32; + uint_fast64_t q64; + uint64_t altRem, meanRem; + bool signRem; + uint_fast64_t uiZ; + union ui64_f64 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA = uA.ui; + signA = signF64UI( uiA ); + expA = expF64UI( uiA ); + sigA = fracF64UI( uiA ); + uB.f = b; + uiB = uB.ui; + expB = expF64UI( uiB ); + sigB = fracF64UI( uiB ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0x7FF ) { + if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN; + goto invalid; + } + if ( expB == 0x7FF ) { + if ( sigB ) goto propagateNaN; + return a; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA < expB - 1 ) return a; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expB ) { + if ( ! sigB ) goto invalid; + normExpSig = softfloat_normSubnormalF64Sig( sigB ); + expB = normExpSig.exp; + sigB = normExpSig.sig; + } + if ( ! expA ) { + if ( ! sigA ) return a; + normExpSig = softfloat_normSubnormalF64Sig( sigA ); + expA = normExpSig.exp; + sigA = normExpSig.sig; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + rem = sigA | UINT64_C( 0x0010000000000000 ); + sigB |= UINT64_C( 0x0010000000000000 ); + expDiff = expA - expB; + if ( expDiff < 1 ) { + if ( expDiff < -1 ) return a; + sigB <<= 9; + if ( expDiff ) { + rem <<= 8; + q = 0; + } else { + rem <<= 9; + q = (sigB <= rem); + if ( q ) rem -= sigB; + } + } else { + recip32 = softfloat_approxRecip32_1( sigB>>21 ); + /*-------------------------------------------------------------------- + | Changing the shift of `rem' here requires also changing the initial + | subtraction from `expDiff'. + *--------------------------------------------------------------------*/ + rem <<= 9; + expDiff -= 30; + /*-------------------------------------------------------------------- + | The scale of `sigB' affects how many bits are obtained during each + | cycle of the loop. Currently this is 29 bits per loop iteration, + | the maximum possible. + *--------------------------------------------------------------------*/ + sigB <<= 9; + for (;;) { + q64 = (uint32_t) (rem>>32) * (uint_fast64_t) recip32; + if ( expDiff < 0 ) break; + q = (q64 + 0x80000000)>>32; +#ifdef SOFTFLOAT_FAST_INT64 + rem <<= 29; +#else + rem = (uint_fast64_t) (uint32_t) (rem>>3)<<32; +#endif + rem -= q * (uint64_t) sigB; + if ( rem & UINT64_C( 0x8000000000000000 ) ) rem += sigB; + expDiff -= 29; + } + /*-------------------------------------------------------------------- + | (`expDiff' cannot be less than -29 here.) + *--------------------------------------------------------------------*/ + q = (uint32_t) (q64>>32)>>(~expDiff & 31); + rem = (rem<<(expDiff + 30)) - q * (uint64_t) sigB; + if ( rem & UINT64_C( 0x8000000000000000 ) ) { + altRem = rem + sigB; + goto selectRem; + } + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + do { + altRem = rem; + ++q; + rem -= sigB; + } while ( ! (rem & UINT64_C( 0x8000000000000000 )) ); + selectRem: + meanRem = rem + altRem; + if ( + (meanRem & UINT64_C( 0x8000000000000000 )) || (! meanRem && (q & 1)) + ) { + rem = altRem; + } + signRem = signA; + if ( rem & UINT64_C( 0x8000000000000000 ) ) { + signRem = ! signRem; + rem = -rem; + } + return softfloat_normRoundPackToF64( signRem, expB, rem SOFTFLOAT_STATE_ARG_COMMA ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + propagateNaN: + uiZ = softfloat_propagateNaNF64UI( uiA, uiB SOFTFLOAT_STATE_ARG_COMMA ); + goto uiZ; + invalid: + softfloat_raiseFlags( softfloat_flag_invalid SOFTFLOAT_STATE_ARG_COMMA ); + uiZ = defaultNaNF64UI; + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |