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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
commit | f215e02bf85f68d3a6106c2a1f4f7f063f819064 (patch) | |
tree | 6bb5b92c046312c4e95ac2620b10ddf482d3fa8b /src/libs/softfloat-3e/source/extF80_partialRem.c | |
parent | Initial commit. (diff) | |
download | virtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.tar.xz virtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.zip |
Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libs/softfloat-3e/source/extF80_partialRem.c')
-rw-r--r-- | src/libs/softfloat-3e/source/extF80_partialRem.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/src/libs/softfloat-3e/source/extF80_partialRem.c b/src/libs/softfloat-3e/source/extF80_partialRem.c new file mode 100644 index 00000000..abce80bd --- /dev/null +++ b/src/libs/softfloat-3e/source/extF80_partialRem.c @@ -0,0 +1,292 @@ + +/*============================================================================ + +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, 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" +#include <iprt/cdefs.h> /* RT_BIT_64 */ +#include <iprt/x86.h> /* X86_FSW_C? */ +#include <iprt/assert.h> + +/** VBox: Copy of extF80_rem modified to fit FPREM and FPREM1. */ +extFloat80_t extF80_partialRem( extFloat80_t a, extFloat80_t b, uint8_t roundingMode, + uint16_t *pfCxFlags, softfloat_state_t *pState ) +{ + union { struct extFloat80M s; extFloat80_t f; } uA; + uint_fast16_t uiA64; + uint_fast64_t uiA0; + bool signA; + int_fast32_t expA; + uint_fast64_t sigA; + union { struct extFloat80M s; extFloat80_t f; } uB; + uint_fast16_t uiB64; + uint_fast64_t uiB0; + int_fast32_t expB; + uint_fast64_t sigB; + struct exp32_sig64 normExpSig; + int_fast32_t expDiff; + struct uint128 rem, shiftedSigB; + uint_fast32_t q, recip32; + uint_fast64_t q64; + struct uint128 term, altRem, meanRem; + bool signRem; + struct uint128 uiZ; + uint_fast16_t uiZ64; + uint_fast64_t uiZ0; + union { struct extFloat80M s; extFloat80_t f; } uZ; + + *pfCxFlags = 0; /* C2=0 - complete */ /* VBox */ + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA64 = uA.s.signExp; + uiA0 = uA.s.signif; + signA = signExtF80UI64( uiA64 ); + expA = expExtF80UI64( uiA64 ); + sigA = uiA0; + uB.f = b; + uiB64 = uB.s.signExp; + uiB0 = uB.s.signif; + expB = expExtF80UI64( uiB64 ); + sigB = uiB0; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0x7FFF ) { + if ( + (sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF )) /* VBox: NaN or Indefinite */ + || ((expB == 0x7FFF) && (sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ))) /* VBox: NaN or Indefinite */ + ) { + goto propagateNaN; + } + goto invalid; /* VBox: Infinity */ + } + if ( expB == 0x7FFF ) { + if ( sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN; /* VBox: NaN or Indefinite */ + /*-------------------------------------------------------------------- + | Argument b is an infinity. Doubling `expB' is an easy way to ensure + | that `expDiff' later is less than -1, which will result in returning + | a canonicalized version of argument a. + *--------------------------------------------------------------------*/ + expB += expB; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expB ) expB = 1; + if ( ! (sigB & UINT64_C( 0x8000000000000000 )) ) { + if ( ! sigB ) goto invalid; /* VBox: Zero -> /0 -> invalid. */ + normExpSig = softfloat_normSubnormalExtF80Sig( sigB ); + expB += normExpSig.exp; + sigB = normExpSig.sig; + } + if ( ! expA ) expA = 1; + if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) { + if ( ! sigA ) { +#if 0 /* A is zero. VBox: Don't mix denormals and zero returns! */ /* VBox */ + expA = 0; + goto copyA; +#else /* VBox */ + uiZ64 = packToExtF80UI64( signA, 0); /* VBox */ + uiZ0 = 0; /* VBox */ + goto uiZ; /* VBox */ +#endif /* VBox */ + } + normExpSig = softfloat_normSubnormalExtF80Sig( sigA ); + expA += normExpSig.exp; + sigA = normExpSig.sig; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + expDiff = expA - expB; + + /*------------------------------------------------------------------------ VBox + | Do at most 63 rounds. If exponent difference is 64 or higher, return VBox + | a partial remainder. VBox + *------------------------------------------------------------------------*/ /* VBox */ + bool const fPartial = expDiff >= 64; /* VBox */ + if ( fPartial ) { /* VBox */ /* VBox */ + unsigned N = 32 + ((unsigned)expDiff % 32); /* (Amount of work documented by AMD.) */ /* VBox */ + expB = expA - N; /* VBox */ + expDiff = N; /* VBox */ + roundingMode = softfloat_round_minMag; /* VBox */ + } /* VBox */ + + /*------------------------------------------------------------------------ + | The final rounds. + *------------------------------------------------------------------------*/ + if ( expDiff < -1 ) goto copyA; + rem = softfloat_shortShiftLeft128( 0, sigA, 32 ); + shiftedSigB = softfloat_shortShiftLeft128( 0, sigB, 32 ); + uint64_t quotient = 0; /* VBox */ + if ( expDiff < 1 ) { + if ( expDiff ) { + --expB; + shiftedSigB = softfloat_shortShiftLeft128( 0, sigB, 33 ); + q = 0; + } else { + q = (sigB <= sigA); + quotient = q; /* VBox */ + if ( q ) { + rem = + softfloat_sub128( + rem.v64, rem.v0, shiftedSigB.v64, shiftedSigB.v0 ); + } + } + } else { + recip32 = softfloat_approxRecip32_1( sigB>>32 ); + expDiff -= 30; + for (;;) { + q64 = (uint_fast64_t) (uint32_t) (rem.v64>>2) * recip32; + if ( expDiff < 0 ) break; + q = (q64 + 0x80000000)>>32; + quotient = (quotient << 29) + q; /* VBox */ + rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 29 ); + term = softfloat_mul64ByShifted32To128( sigB, 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, shiftedSigB.v64, shiftedSigB.v0 ); + quotient--; /* VBox */ + } + expDiff -= 29; + } + /*-------------------------------------------------------------------- + | (`expDiff' cannot be less than -29 here.) + *--------------------------------------------------------------------*/ + q = (uint32_t) (q64>>32)>>(~expDiff & 31); + quotient = (quotient << (expDiff + 30)) + q; /* VBox */ + rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, expDiff + 30 ); + term = softfloat_mul64ByShifted32To128( sigB, 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, shiftedSigB.v64, shiftedSigB.v0 ); + goto selectRem; + } + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + do { + altRem = rem; + ++q; + quotient++; /* VBox */ + rem = + softfloat_sub128( + rem.v64, rem.v0, shiftedSigB.v64, shiftedSigB.v0 ); + } while ( ! (rem.v64 & UINT64_C( 0x8000000000000000 )) ); + selectRem: + if (roundingMode == softfloat_round_near_even) { /* VBox */ + 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; + quotient--; /* VBox */ + } + } /* VBox */ + signRem = signA; + if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) { + if (roundingMode != softfloat_round_near_even) { /* VBox */ + rem = altRem; /* VBox */ + quotient--; /* VBox */ + } else { /* VBox */ + signRem = ! signRem; + rem = softfloat_sub128( 0, 0, rem.v64, rem.v0 ); + Assert(!fPartial); /* VBox */ + } /* VBox */ + } else Assert(roundingMode == softfloat_round_near_even); /* VBox */ + + /* VBox: Set pfCxFlags */ /* VBox */ + if ( fPartial ) { /* VBox */ + *pfCxFlags = X86_FSW_C2; /* C2 = 1 - incomplete */ /* VBox */ + } else { /* VBox */ + *pfCxFlags = X86_FSW_CX_FROM_QUOTIENT( quotient ); /* C2 = 0 - complete */ /* VBox */ + } /* VBox */ + + return + softfloat_normRoundPackToExtF80( + signRem, rem.v64 | rem.v0 ? expB + 32 : 0, rem.v64, rem.v0, 80 SOFTFLOAT_STATE_ARG_COMMA ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + propagateNaN: + uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, uiB64, uiB0 SOFTFLOAT_STATE_ARG_COMMA ); + uiZ64 = uiZ.v64; + uiZ0 = uiZ.v0; + goto uiZ; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + invalid: + softfloat_raiseFlags( softfloat_flag_invalid SOFTFLOAT_STATE_ARG_COMMA ); + uiZ64 = defaultNaNExtF80UI64; + uiZ0 = defaultNaNExtF80UI0; + goto uiZ; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + copyA: + if ( expA < 1 ) { +#if 0 /* VBox */ + sigA >>= 1 - expA; + expA = 0; +#else /* VBox */ + Assert(sigA != 0); /* We don't get here for zero values, only denormals. */ /* VBox */ + /* Apply the bias adjust if underflows exceptions aren't masked, unless VBox + the divisor is +/-Infinity. VBox + Note! extB has been tweaked, so don't use if for Inf classification. */ /* VBox */ + if ( (pState->exceptionMask & softfloat_flag_underflow) /* VBox */ + || (expExtF80UI64( b.signExp ) == 0x7fff && !(sigB & (RT_BIT_64( 63 ) - 1))) ) { /* VBox */ + sigA >>= 1 - expA; /* VBox */ + expA = 0; /* VBox */ + } else { /* VBox */ + softfloat_raiseFlags( softfloat_flag_underflow SOFTFLOAT_STATE_ARG_COMMA ); /* VBox */ + expA = (expA + RTFLOAT80U_EXP_BIAS_ADJUST) & RTFLOAT80U_EXP_MAX; /* VBox */ + } /* VBox */ +#endif /* VBox */ + } + uiZ64 = packToExtF80UI64( signA, expA ); + uiZ0 = sigA; + uiZ: + uZ.s.signExp = uiZ64; + uZ.s.signif = uiZ0; + return uZ.f; + +} + |