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authorAndrew Waterman <waterman@cs.berkeley.edu>2016-03-01 16:24:05 -0800
committerAndrew Waterman <waterman@cs.berkeley.edu>2016-03-01 16:24:44 -0800
commita95b44df9d142a49f3e1bfe4a60d259ed41ca247 (patch)
tree49f59c903609e5b0de05d5b0c7f7bd23de8c4f13 /softfloat/f32_sqrt.c
parentbea283531abfd013811e83c75ff6189a0d9b3075 (diff)
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Upgrade to latest SoftFloat
Diffstat (limited to 'softfloat/f32_sqrt.c')
-rw-r--r--[-rwxr-xr-x]softfloat/f32_sqrt.c195
1 files changed, 121 insertions, 74 deletions
diff --git a/softfloat/f32_sqrt.c b/softfloat/f32_sqrt.c
index c9eb907..d0b489c 100755..100644
--- a/softfloat/f32_sqrt.c
+++ b/softfloat/f32_sqrt.c
@@ -1,74 +1,121 @@
-
-#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 3a, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014 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 = shiftedSigZ<<2;
+ 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;
+
+}
+