-\r
-#include <stdbool.h>\r
-#include <stdint.h>\r
-#include "platform.h"\r
-#include "primitives.h"\r
-#include "internals.h"\r
-#include "specialize.h"\r
-#include "softfloat.h"\r
-\r
-float32_t f32_sqrt( float32_t a )\r
-{\r
- union ui32_f32 uA;\r
- uint_fast32_t uiA;\r
- bool signA;\r
- int_fast16_t expA;\r
- uint_fast32_t sigA, uiZ;\r
- struct exp16_sig32 normExpSig;\r
- int_fast16_t expZ;\r
- uint_fast32_t sigZ;\r
- uint_fast64_t term, rem;\r
- union ui32_f32 uZ;\r
-\r
- uA.f = a;\r
- uiA = uA.ui;\r
- signA = signF32UI( uiA );\r
- expA = expF32UI( uiA );\r
- sigA = fracF32UI( uiA );\r
- if ( expA == 0xFF ) {\r
- if ( sigA ) {\r
- uiZ = softfloat_propagateNaNF32UI( uiA, 0 );\r
- goto uiZ;\r
- }\r
- if ( ! signA ) return a;\r
- goto invalid;\r
- }\r
- if ( signA ) {\r
- if ( ! ( expA | sigA ) ) return a;\r
- goto invalid;\r
- }\r
- if ( ! expA ) {\r
- if ( ! sigA ) return a;\r
- normExpSig = softfloat_normSubnormalF32Sig( sigA );\r
- expA = normExpSig.exp;\r
- sigA = normExpSig.sig;\r
- }\r
- expZ = ( ( expA - 0x7F )>>1 ) + 0x7E;\r
- sigA = ( sigA | 0x00800000 )<<8;\r
- sigZ = softfloat_estimateSqrt32( expA, sigA ) + 2;\r
- if ( ( sigZ & 0x7F ) <= 5 ) {\r
- if ( sigZ < 2 ) {\r
- sigZ = 0x7FFFFFFF;\r
- goto roundPack;\r
- }\r
- sigA >>= expA & 1;\r
- term = (uint_fast64_t) sigZ * sigZ;\r
- rem = ( (uint_fast64_t) sigA<<32 ) - term;\r
- while ( UINT64_C( 0x8000000000000000 ) <= rem ) {\r
- --sigZ;\r
- rem += ( (uint_fast64_t) sigZ<<1 ) | 1;\r
- }\r
- sigZ |= ( rem != 0 );\r
- }\r
- sigZ = softfloat_shortShift32Right1Jam( sigZ );\r
- roundPack:\r
- return softfloat_roundPackToF32( 0, expZ, sigZ );\r
- invalid:\r
- softfloat_raiseFlags( softfloat_flag_invalid );\r
- uiZ = defaultNaNF32UI;\r
- uiZ:\r
- uZ.ui = uiZ;\r
- return uZ.f;\r
-\r
-}\r
-\r
+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3d, 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;
+
+}
+
projects / riscv-isa-sim.git / blobdiff