First draft of RC for Release 3, to start review process.

1 files changed, 130 insertions, 0 deletions

diff --git a/source/f64_sqrt.c b/source/f64_sqrt.c
new file mode 100644
index 0000000..b1821a2
--- /dev/null
+++ b/source/f64_sqrt.c
@@ -0,0 +1,130 @@
+
+/*============================================================================
+
+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"
+
+float64_t f64_sqrt( float64_t a )
+{
+    union ui64_f64 uA;
+    uint_fast64_t uiA;
+    bool signA;
+    int_fast16_t expA;
+    uint_fast64_t sigA, uiZ;
+    struct exp16_sig64 normExpSig;
+    int_fast16_t expZ;
+    uint32_t sig32A, recipSqrt32, sig32Z;
+    uint_fast64_t rem;
+    uint32_t q;
+    uint_fast64_t sigZ, shiftedSigZ;
+    union ui64_f64 uZ;
+
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uA.f = a;
+    uiA = uA.ui;
+    signA = signF64UI( uiA );
+    expA  = expF64UI( uiA );
+    sigA  = fracF64UI( uiA );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( expA == 0x7FF ) {
+        if ( sigA ) {
+            uiZ = softfloat_propagateNaNF64UI( 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_normSubnormalF64Sig( sigA );
+        expA = normExpSig.exp;
+        sigA = normExpSig.sig;
+    }
+    /*------------------------------------------------------------------------
+    | (`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 - 0x3FF)>>1) + 0x3FE;
+    expA &= 1;
+    sigA |= UINT64_C( 0x0010000000000000 );
+    sig32A = sigA>>21;
+    recipSqrt32 = softfloat_approxRecipSqrt32_1( expA, sig32A );
+    sig32Z = ((uint_fast64_t) sig32A * recipSqrt32)>>32;
+    if ( expA ) {
+        sigA <<= 8;
+        sig32Z >>= 1;
+    } else {
+        sigA <<= 9;
+    }
+    rem = sigA - (uint_fast64_t) sig32Z * sig32Z;
+    q = ((uint32_t) (rem>>2) * (uint_fast64_t) recipSqrt32)>>32;
+    sigZ = ((uint_fast64_t) sig32Z<<32 | 1<<5) + ((uint_fast64_t) q<<3);
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( (sigZ & 0x1FF) < 1<<5 ) {
+        sigZ &= ~(uint_fast64_t) 0x3F;
+        shiftedSigZ = sigZ>>6;
+        rem = (sigA<<52) - shiftedSigZ * shiftedSigZ;
+        if ( rem & UINT64_C( 0x8000000000000000 ) ) {
+            --sigZ;
+        } else {
+            if ( rem ) sigZ |= 1;
+        }
+    }
+    return softfloat_roundPackToF64( 0, expZ, sigZ );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+ invalid:
+    softfloat_raiseFlags( softfloat_flag_invalid );
+    uiZ = defaultNaNF64UI;
+ uiZ:
+    uZ.ui = uiZ;
+    return uZ.f;
+
+}
+