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

1 files changed, 165 insertions, 0 deletions

diff --git a/source/extF80_sqrt.c b/source/extF80_sqrt.c
new file mode 100644
index 0000000..f85e3e7
--- /dev/null
+++ b/source/extF80_sqrt.c
@@ -0,0 +1,165 @@
+
+/*============================================================================
+
+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"
+
+extFloat80_t extF80_sqrt( extFloat80_t a )
+{
+    union { struct extFloat80M s; extFloat80_t f; } uA;
+    uint_fast16_t uiA64;
+    uint_fast64_t uiA0;
+    bool signA;
+    int_fast32_t expA;
+    uint_fast64_t sigA;
+    struct uint128 uiZ;
+    uint_fast16_t uiZ64;
+    uint_fast64_t uiZ0;
+    struct exp32_sig64 normExpSig;
+    int_fast32_t expZ;
+    uint_fast32_t sig32A, recipSqrt32, sig32Z;
+    struct uint128 rem;
+    uint_fast64_t q, sigZ, x64;
+    struct uint128 term;
+    uint_fast64_t sigZExtra;
+    union { struct extFloat80M s; extFloat80_t f; } uZ;
+
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uA.f = a;
+    uiA64 = uA.s.signExp;
+    uiA0  = uA.s.signif;
+    signA = signExtF80UI64( uiA64 );
+    expA  = expExtF80UI64( uiA64 );
+    sigA  = uiA0;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( expA == 0x7FFF ) {
+        if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) {
+            uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, 0, 0 );
+            uiZ64 = uiZ.v64;
+            uiZ0  = uiZ.v0;
+            goto uiZ;
+        }
+        if ( ! signA ) return a;
+        goto invalid;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( signA ) {
+        if ( ! sigA ) goto zero;
+        goto invalid;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( ! expA ) expA = 1;
+    if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) {
+        if ( ! sigA ) goto zero;
+        normExpSig = softfloat_normSubnormalExtF80Sig( 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 - 0x3FFF)>>1) + 0x3FFF;
+    expA &= 1;
+    sig32A = sigA>>32;
+    recipSqrt32 = softfloat_approxRecipSqrt32_1( expA, sig32A );
+    sig32Z = ((uint_fast64_t) sig32A * recipSqrt32)>>32;
+    if ( expA ) {
+        sig32Z >>= 1;
+        rem = softfloat_shortShiftLeft128( 0, sigA, 61 );
+    } else {
+        rem = softfloat_shortShiftLeft128( 0, sigA, 62 );
+    }
+    rem.v64 -= (uint_fast64_t) sig32Z * sig32Z;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    q = ((uint_fast64_t) (uint32_t) (rem.v64>>2) * recipSqrt32)>>32;
+    sigZ = ((uint_fast64_t) sig32Z<<32) + (q<<3);
+    x64 = ((uint_fast64_t) sig32Z<<32) + sigZ;
+    term = softfloat_mul64ByShifted32To128( x64, q );
+    rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 29 );
+    rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    q = (((uint_fast64_t) (uint32_t) (rem.v64>>2) * recipSqrt32)>>32) + 2;
+    x64 = sigZ;
+    sigZ = (sigZ<<1) + (q>>25);
+    sigZExtra = (uint64_t) (q<<39);
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( (q & 0xFFFFFF) <= 2 ) {
+        q &= ~0xFFFF;
+        sigZExtra = (uint64_t) (q<<39);
+        term = softfloat_mul64ByShifted32To128( x64 + (q>>27), q );
+        x64 = (uint_fast64_t) (uint32_t) (q<<5) * (uint32_t) q;
+        term = softfloat_add128( term.v64, term.v0, 0, x64 );
+        rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 28 );
+        rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 );
+        if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) {
+            if ( ! sigZExtra ) --sigZ;
+            --sigZExtra;
+        } else {
+            if ( rem.v64 | rem.v0 ) sigZExtra |= 1;
+        }
+    }
+    return
+        softfloat_roundPackToExtF80(
+            0, expZ, sigZ, sigZExtra, extF80_roundingPrecision );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+ invalid:
+    softfloat_raiseFlags( softfloat_flag_invalid );
+    uiZ64 = defaultNaNExtF80UI64;
+    uiZ0  = defaultNaNExtF80UI0;
+    goto uiZ;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+ zero:
+    uiZ64 = packToExtF80UI64( signA, 0 );
+    uiZ0  = 0;
+ uiZ:
+    uZ.s.signExp = uiZ64;
+    uZ.s.signif  = uiZ0;
+    return uZ.f;
+
+}
+