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+
+/*============================================================================
+
+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 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 f128M_sqrt( const float128_t *aPtr, float128_t *zPtr )
+{
+
+ *zPtr = f128_sqrt( *aPtr );
+
+}
+
+#else
+
+void f128M_sqrt( const float128_t *aPtr, float128_t *zPtr )
+{
+ const uint32_t *aWPtr;
+ uint32_t *zWPtr;
+ uint32_t uiA96;
+ bool signA;
+ int32_t rawExpA;
+ uint32_t rem[6];
+ int32_t expA, expZ;
+ uint64_t rem64;
+ uint32_t sig32A, recipSqrt32, sig32Z, qs[3], q;
+ uint64_t sig64Z, x64;
+ uint32_t term[5], y[5], rem32;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ aWPtr = (const uint32_t *) aPtr;
+ zWPtr = (uint32_t *) zPtr;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uiA96 = aWPtr[indexWordHi( 4 )];
+ signA = signF128UI96( uiA96 );
+ rawExpA = expF128UI96( uiA96 );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( rawExpA == 0x7FFF ) {
+ if (
+ fracF128UI96( uiA96 )
+ || (aWPtr[indexWord( 4, 2 )] | aWPtr[indexWord( 4, 1 )]
+ | aWPtr[indexWord( 4, 0 )])
+ ) {
+ softfloat_propagateNaNF128M( aWPtr, 0, zWPtr );
+ return;
+ }
+ if ( ! signA ) goto copyA;
+ goto invalid;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ expA = softfloat_shiftNormSigF128M( aWPtr, 13 - (rawExpA & 1), rem );
+ if ( expA == -128 ) goto copyA;
+ if ( signA ) goto invalid;
+ /*------------------------------------------------------------------------
+ | (`sig32Z' is guaranteed to be a lower bound on the square root of
+ | `sig32A', which makes `sig32Z' also a lower bound on the square root of
+ | `sigA'.)
+ *------------------------------------------------------------------------*/
+ expZ = ((expA - 0x3FFF)>>1) + 0x3FFE;
+ expA &= 1;
+ rem64 = (uint64_t) rem[indexWord( 4, 3 )]<<32 | rem[indexWord( 4, 2 )];
+ if ( expA ) {
+ if ( ! rawExpA ) {
+ softfloat_shortShiftRight128M( rem, 1, rem );
+ rem64 >>= 1;
+ }
+ sig32A = rem64>>29;
+ } else {
+ sig32A = rem64>>30;
+ }
+ recipSqrt32 = softfloat_approxRecipSqrt32_1( expA, sig32A );
+ sig32Z = ((uint64_t) sig32A * recipSqrt32)>>32;
+ if ( expA ) sig32Z >>= 1;
+ qs[2] = sig32Z;
+ rem64 -= (uint64_t) sig32Z * sig32Z;
+ rem[indexWord( 4, 3 )] = rem64>>32;
+ rem[indexWord( 4, 2 )] = rem64;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ q = ((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32;
+ qs[1] = q;
+ sig64Z = ((uint64_t) sig32Z<<32) + ((uint64_t) q<<3);
+ x64 = ((uint64_t) sig32Z<<32) + sig64Z;
+ term[indexWord( 4, 3 )] = 0;
+ term[indexWord( 4, 2 )] = x64>>32;
+ term[indexWord( 4, 1 )] = x64;
+ term[indexWord( 4, 0 )] = 0;
+ softfloat_remStep128MBy32( rem, 29, term, q, y );
+ rem64 = (uint64_t) y[indexWord( 4, 3 )]<<32 | y[indexWord( 4, 2 )];
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ q = ((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32;
+ sig64Z <<= 1;
+ /*------------------------------------------------------------------------
+ | (Repeating this loop is a rare occurrence.)
+ *------------------------------------------------------------------------*/
+ for (;;) {
+ x64 = sig64Z + (q>>26);
+ term[indexWord( 4, 2 )] = x64>>32;
+ term[indexWord( 4, 1 )] = x64;
+ term[indexWord( 4, 0 )] = q<<6;
+ term[indexWord( 4, 3 )] = 0;
+ softfloat_remStep128MBy32(
+ y, 29, term, q, &rem[indexMultiwordHi( 6, 4 )] );
+ rem32 = rem[indexWordHi( 6 )];
+ if ( ! (rem32 & 0x80000000) ) break;
+ --q;
+ }
+ qs[0] = q;
+ rem64 = (uint64_t) rem32<<32 | rem[indexWord( 6, 4 )];
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ q = (((uint32_t) (rem64>>2) * (uint64_t) recipSqrt32)>>32) + 2;
+ x64 = (uint64_t) q<<27;
+ y[indexWord( 5, 0 )] = x64;
+ x64 = ((uint64_t) qs[0]<<24) + (x64>>32);
+ y[indexWord( 5, 1 )] = x64;
+ x64 = ((uint64_t) qs[1]<<21) + (x64>>32);
+ y[indexWord( 5, 2 )] = x64;
+ x64 = ((uint64_t) qs[2]<<18) + (x64>>32);
+ y[indexWord( 5, 3 )] = x64;
+ y[indexWord( 5, 4 )] = x64>>32;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( (q & 0xF) <= 2 ) {
+ q &= ~3;
+ y[indexWordLo( 5 )] = q<<27;
+ term[indexWord( 5, 4 )] = 0;
+ term[indexWord( 5, 3 )] = 0;
+ term[indexWord( 5, 2 )] = 0;
+ term[indexWord( 5, 1 )] = q>>6;
+ term[indexWord( 5, 0 )] = q<<26;
+ softfloat_sub160M( y, term, term );
+ rem[indexWord( 6, 1 )] = 0;
+ rem[indexWord( 6, 0 )] = 0;
+ softfloat_remStep160MBy32(
+ &rem[indexMultiwordLo( 6, 5 )],
+ 14,
+ term,
+ q,
+ &rem[indexMultiwordLo( 6, 5 )]
+ );
+ rem32 = rem[indexWord( 6, 4 )];
+ if ( rem32 & 0x80000000 ) {
+ softfloat_sub1X160M( y );
+ } else {
+ if (
+ rem32 || rem[indexWord( 6, 0 )] || rem[indexWord( 6, 1 )]
+ || (rem[indexWord( 6, 3 )] | rem[indexWord( 6, 2 )])
+ ) {
+ y[indexWordLo( 5 )] |= 1;
+ }
+ }
+ }
+ softfloat_roundPackMToF128M( 0, expZ, y, zWPtr );
+ return;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ invalid:
+ softfloat_invalidF128M( zWPtr );
+ return;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ copyA:
+ zWPtr[indexWordHi( 4 )] = uiA96;
+ zWPtr[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )];
+ zWPtr[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )];
+ zWPtr[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )];
+
+}
+
+#endif
+
generated by cgit v1.1 at 2024-08-16 00:18:16 +0000