| |
| /*============================================================================ |
| |
| 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, 2015 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 "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 rem[4], sig32A, recipSqrt32, sig32Z, q; |
| uint64_t sig64Z, x64; |
| uint32_t term[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, &rem[indexMultiwordHi( 4, 3 )] ); |
| sig32A = rem64>>32; |
| recipSqrt32 = softfloat_approxRecipSqrt32_1( expA, sig32A ); |
| sig32Z = ((uint64_t) sig32A * recipSqrt32)>>32; |
| if ( expA ) sig32Z >>= 1; |
| rem64 = |
| ((uint64_t) rem[indexWord( 4, 3 )]<<32 | rem[indexWord( 4, 2 )]) |
| - (uint64_t) sig32Z * sig32Z; |
| rem[indexWord( 4, 3 )] = rem64>>32; |
| rem[indexWord( 4, 2 )] = rem64; |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| q = ((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32; |
| sig64Z = ((uint64_t) sig32Z<<32) + ((uint64_t) q<<3); |
| x64 = ((uint64_t) sig32Z<<32) + sig64Z; |
| term[indexWord( 3, 2 )] = 0; |
| term[indexWord( 3, 1 )] = x64>>32; |
| term[indexWord( 3, 0 )] = x64; |
| softfloat_remStep96MBy32( |
| &rem[indexMultiwordHi( 4, 3 )], |
| 29, |
| term, |
| q, |
| &rem[indexMultiwordHi( 4, 3 )] |
| ); |
| rem64 = (uint64_t) rem[indexWord( 4, 3 )]<<32 | rem[indexWord( 4, 2 )]; |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| q = (((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32) + 2; |
| 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 |
| |