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Diffstat (limited to 'softfloat/extF80M_sqrt.c')
| -rw-r--r-- | softfloat/extF80M_sqrt.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/softfloat/extF80M_sqrt.c b/softfloat/extF80M_sqrt.c new file mode 100644 index 0000000..21c15da --- /dev/null +++ b/softfloat/extF80M_sqrt.c @@ -0,0 +1,180 @@ + +/*============================================================================ + +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, 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" + +#ifdef SOFTFLOAT_FAST_INT64 + +void extF80M_sqrt( const extFloat80_t *aPtr, extFloat80_t *zPtr ) +{ + + *zPtr = extF80_sqrt( *aPtr ); + +} + +#else + +void extF80M_sqrt( const extFloat80_t *aPtr, extFloat80_t *zPtr ) +{ + const struct extFloat80M *aSPtr; + struct extFloat80M *zSPtr; + uint_fast16_t uiA64, signUI64; + int32_t expA; + uint64_t rem64; + int32_t expZ; + uint32_t rem96[3], sig32A, recipSqrt32, sig32Z, q; + uint64_t sig64Z, x64; + uint32_t rem32, term[4], rem[4], extSigZ[3]; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + aSPtr = (const struct extFloat80M *) aPtr; + zSPtr = (struct extFloat80M *) zPtr; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uiA64 = aSPtr->signExp; + signUI64 = uiA64 & packToExtF80UI64( 1, 0 ); + expA = expExtF80UI64( uiA64 ); + rem64 = aSPtr->signif; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0x7FFF ) { + if ( rem64 & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { + softfloat_propagateNaNExtF80M( aSPtr, 0, zSPtr ); + return; + } + if ( signUI64 ) goto invalid; + rem64 = UINT64_C( 0x8000000000000000 ); + goto copyA; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expA ) expA = 1; + if ( ! (rem64 & UINT64_C( 0x8000000000000000 )) ) { + if ( ! rem64 ) { + uiA64 = signUI64; + goto copyA; + } + expA += softfloat_normExtF80SigM( &rem64 ); + } + if ( signUI64 ) goto invalid; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + expZ = ((expA - 0x3FFF)>>1) + 0x3FFF; + expA &= 1; + softfloat_shortShiftLeft64To96M( rem64, 30 - expA, rem96 ); + sig32A = rem64>>32; + recipSqrt32 = softfloat_approxRecipSqrt32_1( expA, sig32A ); + sig32Z = ((uint64_t) sig32A * recipSqrt32)>>32; + if ( expA ) sig32Z >>= 1; + rem64 = + ((uint64_t) rem96[indexWord( 3, 2 )]<<32 | rem96[indexWord( 3, 1 )]) + - (uint64_t) sig32Z * sig32Z; + rem96[indexWord( 3, 2 )] = rem64>>32; + rem96[indexWord( 3, 1 )] = rem64; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + q = ((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32; + sig64Z = ((uint64_t) sig32Z<<32) + ((uint64_t) q<<3); + term[indexWord( 3, 2 )] = 0; + /*------------------------------------------------------------------------ + | (Repeating this loop is a rare occurrence.) + *------------------------------------------------------------------------*/ + for (;;) { + x64 = ((uint64_t) sig32Z<<32) + sig64Z; + term[indexWord( 3, 1 )] = x64>>32; + term[indexWord( 3, 0 )] = x64; + softfloat_remStep96MBy32( + rem96, 29, term, q, &rem[indexMultiwordHi( 4, 3 )] ); + rem32 = rem[indexWord( 4, 3 )]; + if ( ! (rem32 & 0x80000000) ) break; + --q; + sig64Z -= 1<<3; + } + rem64 = (uint64_t) rem32<<32 | rem[indexWord( 4, 2 )]; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + q = (((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32) + 2; + if ( rem64>>34 ) q += recipSqrt32; + x64 = (uint64_t) q<<7; + extSigZ[indexWord( 3, 0 )] = x64; + x64 = (sig64Z<<1) + (x64>>32); + extSigZ[indexWord( 3, 2 )] = x64>>32; + extSigZ[indexWord( 3, 1 )] = x64; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( (q & 0xFFFFFF) <= 2 ) { + q &= ~(uint32_t) 0xFFFF; + extSigZ[indexWordLo( 3 )] = q<<7; + x64 = sig64Z + (q>>27); + term[indexWord( 4, 3 )] = 0; + term[indexWord( 4, 2 )] = x64>>32; + term[indexWord( 4, 1 )] = x64; + term[indexWord( 4, 0 )] = q<<5; + rem[indexWord( 4, 0 )] = 0; + softfloat_remStep128MBy32( rem, 28, term, q, rem ); + q = rem[indexWordHi( 4 )]; + if ( q & 0x80000000 ) { + softfloat_sub1X96M( extSigZ ); + } else { + if ( q || rem[indexWord( 4, 1 )] || rem[indexWord( 4, 2 )] ) { + extSigZ[indexWordLo( 3 )] |= 1; + } + } + } + softfloat_roundPackMToExtF80M( + 0, expZ, extSigZ, extF80_roundingPrecision, zSPtr ); + return; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + invalid: + softfloat_invalidExtF80M( zSPtr ); + return; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + copyA: + zSPtr->signExp = uiA64; + zSPtr->signif = rem64; + +} + +#endif + |