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author | Andrew Waterman <andrew@sifive.com> | 2018-07-11 01:16:28 -0700 |
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committer | Andrew Waterman <andrew@sifive.com> | 2018-07-11 01:16:28 -0700 |
commit | 5cd8d2b93fad2011fdf8f49a263d77697af35b32 (patch) | |
tree | f6fb9cb6d3bef2aa5c9903511b92e5a6e99e9519 /softfloat/f32_sqrt.c | |
parent | 8e69141749065ff957383d2112768f95a33429b6 (diff) | |
download | pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.zip pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.gz pk-5cd8d2b93fad2011fdf8f49a263d77697af35b32.tar.bz2 |
Upgrade to SoftFloat 3e
Diffstat (limited to 'softfloat/f32_sqrt.c')
-rw-r--r--[-rwxr-xr-x] | softfloat/f32_sqrt.c | 195 |
1 files changed, 120 insertions, 75 deletions
diff --git a/softfloat/f32_sqrt.c b/softfloat/f32_sqrt.c index 637f82e..9c6a998 100755..100644 --- a/softfloat/f32_sqrt.c +++ b/softfloat/f32_sqrt.c @@ -1,76 +1,121 @@ -// See LICENSE.SoftFloat for license details. -
-#include <stdbool.h>
-#include <stdint.h>
-#include "platform.h"
-#include "primitives.h"
-#include "internals.h"
-#include "specialize.h"
-#include "softfloat.h"
-
-float32_t f32_sqrt( float32_t a )
-{
- union ui32_f32 uA;
- uint_fast32_t uiA;
- bool signA;
- int_fast16_t expA;
- uint_fast32_t sigA, uiZ;
- struct exp16_sig32 normExpSig;
- int_fast16_t expZ;
- uint_fast32_t sigZ;
- uint_fast64_t term, rem;
- union ui32_f32 uZ;
-
- uA.f = a;
- uiA = uA.ui;
- signA = signF32UI( uiA );
- expA = expF32UI( uiA );
- sigA = fracF32UI( uiA );
- if ( expA == 0xFF ) {
- if ( sigA ) {
- uiZ = softfloat_propagateNaNF32UI( uiA, 0 );
- goto uiZ;
- }
- if ( ! signA ) return a;
- goto invalid;
- }
- if ( signA ) {
- if ( ! ( expA | sigA ) ) return a;
- goto invalid;
- }
- if ( ! expA ) {
- if ( ! sigA ) return a;
- normExpSig = softfloat_normSubnormalF32Sig( sigA );
- expA = normExpSig.exp;
- sigA = normExpSig.sig;
- }
- expZ = ( ( expA - 0x7F )>>1 ) + 0x7E;
- sigA = ( sigA | 0x00800000 )<<8;
- sigZ = softfloat_estimateSqrt32( expA, sigA ) + 2;
- if ( ( sigZ & 0x7F ) <= 5 ) {
- if ( sigZ < 2 ) {
- sigZ = 0x7FFFFFFF;
- goto roundPack;
- }
- sigA >>= expA & 1;
- term = (uint_fast64_t) sigZ * sigZ;
- rem = ( (uint_fast64_t) sigA<<32 ) - term;
- while ( UINT64_C( 0x8000000000000000 ) <= rem ) {
- --sigZ;
- rem += ( (uint_fast64_t) sigZ<<1 ) | 1;
- }
- sigZ |= ( rem != 0 );
- }
- sigZ = softfloat_shortShift32Right1Jam( sigZ );
- roundPack:
- return softfloat_roundPackToF32( 0, expZ, sigZ );
- invalid:
- softfloat_raiseFlags( softfloat_flag_invalid );
- uiZ = defaultNaNF32UI;
- uiZ:
- uZ.ui = uiZ;
- return uZ.f;
-
-}
-
+/*============================================================================ + +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" + +float32_t f32_sqrt( float32_t a ) +{ + union ui32_f32 uA; + uint_fast32_t uiA; + bool signA; + int_fast16_t expA; + uint_fast32_t sigA, uiZ; + struct exp16_sig32 normExpSig; + int_fast16_t expZ; + uint_fast32_t sigZ, shiftedSigZ; + uint32_t negRem; + union ui32_f32 uZ; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + uA.f = a; + uiA = uA.ui; + signA = signF32UI( uiA ); + expA = expF32UI( uiA ); + sigA = fracF32UI( uiA ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( expA == 0xFF ) { + if ( sigA ) { + uiZ = softfloat_propagateNaNF32UI( uiA, 0 ); + goto uiZ; + } + if ( ! signA ) return a; + goto invalid; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( signA ) { + if ( ! (expA | sigA) ) return a; + goto invalid; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( ! expA ) { + if ( ! sigA ) return a; + normExpSig = softfloat_normSubnormalF32Sig( sigA ); + expA = normExpSig.exp; + sigA = normExpSig.sig; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + expZ = ((expA - 0x7F)>>1) + 0x7E; + expA &= 1; + sigA = (sigA | 0x00800000)<<8; + sigZ = + ((uint_fast64_t) sigA * softfloat_approxRecipSqrt32_1( expA, sigA )) + >>32; + if ( expA ) sigZ >>= 1; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + sigZ += 2; + if ( (sigZ & 0x3F) < 2 ) { + shiftedSigZ = sigZ>>2; + negRem = shiftedSigZ * shiftedSigZ; + sigZ &= ~3; + if ( negRem & 0x80000000 ) { + sigZ |= 1; + } else { + if ( negRem ) --sigZ; + } + } + return softfloat_roundPackToF32( 0, expZ, sigZ ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + uiZ = defaultNaNF32UI; + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |