Upgrade to SoftFloat 3e

1 files changed, 89 insertions, 23 deletions

diff --git a/softfloat/f64_div.c b/softfloat/f64_div.c
index c8eede9..7f5eddd 100755..100644
--- a/softfloat/f64_div.c
+++ b/softfloat/f64_div.c
@@ -1,10 +1,42 @@
-// See LICENSE.SoftFloat for license details.
 
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3e, 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 "primitives.h"
 #include "internals.h"
 #include "specialize.h"
 #include "softfloat.h"
@@ -24,22 +56,28 @@ float64_t f64_div( float64_t a, float64_t b )
     bool signZ;
     struct exp16_sig64 normExpSig;
     int_fast16_t expZ;
+    uint32_t recip32, sig32Z, doubleTerm;
+    uint_fast64_t rem;
+    uint32_t q;
     uint_fast64_t sigZ;
-    struct uint128 term, rem;
     uint_fast64_t uiZ;
     union ui64_f64 uZ;
 
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
     uA.f = a;
     uiA = uA.ui;
     signA = signF64UI( uiA );
-    expA = expF64UI( uiA );
-    sigA = fracF64UI( uiA );
+    expA  = expF64UI( uiA );
+    sigA  = fracF64UI( uiA );
     uB.f = b;
     uiB = uB.ui;
     signB = signF64UI( uiB );
-    expB = expF64UI( uiB );
-    sigB = fracF64UI( uiB );
+    expB  = expF64UI( uiB );
+    sigB  = fracF64UI( uiB );
     signZ = signA ^ signB;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
     if ( expA == 0x7FF ) {
         if ( sigA ) goto propagateNaN;
         if ( expB == 0x7FF ) {
@@ -52,10 +90,12 @@ float64_t f64_div( float64_t a, float64_t b )
         if ( sigB ) goto propagateNaN;
         goto zero;
     }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
     if ( ! expB ) {
         if ( ! sigB ) {
-            if ( ! ( expA | sigA ) ) goto invalid;
-            softfloat_raiseFlags( softfloat_flag_infinity );
+            if ( ! (expA | sigA) ) goto invalid;
+            softfloat_raiseFlags( softfloat_flag_infinite );
             goto infinity;
         }
         normExpSig = softfloat_normSubnormalF64Sig( sigB );
@@ -68,34 +108,60 @@ float64_t f64_div( float64_t a, float64_t b )
         expA = normExpSig.exp;
         sigA = normExpSig.sig;
     }
-    expZ = expA - expB + 0x3FD;
-    sigA = ( sigA | UINT64_C( 0x0010000000000000 ) )<<10;
-    sigB = ( sigB | UINT64_C( 0x0010000000000000 ) )<<11;
-    if ( sigB <= ( sigA + sigA ) ) {
-        ++expZ;
-        sigA >>= 1;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    expZ = expA - expB + 0x3FE;
+    sigA |= UINT64_C( 0x0010000000000000 );
+    sigB |= UINT64_C( 0x0010000000000000 );
+    if ( sigA < sigB ) {
+        --expZ;
+        sigA <<= 11;
+    } else {
+        sigA <<= 10;
     }
-    sigZ = softfloat_estimateDiv128To64( sigA, 0, sigB );
-    if ( ( sigZ & 0x1FF ) <= 2 ) {
-        term = softfloat_mul64To128( sigB, sigZ );
-        rem = softfloat_sub128( sigA, 0, term.v64, term.v0 );
-        while ( UINT64_C( 0x8000000000000000 ) <= rem.v64 ) {
-            --sigZ;
-            rem = softfloat_add128( rem.v64, rem.v0, 0, sigB );
+    sigB <<= 11;
+    recip32 = softfloat_approxRecip32_1( sigB>>32 ) - 2;
+    sig32Z = ((uint32_t) (sigA>>32) * (uint_fast64_t) recip32)>>32;
+    doubleTerm = sig32Z<<1;
+    rem =
+        ((sigA - (uint_fast64_t) doubleTerm * (uint32_t) (sigB>>32))<<28)
+            - (uint_fast64_t) doubleTerm * ((uint32_t) sigB>>4);
+    q = (((uint32_t) (rem>>32) * (uint_fast64_t) recip32)>>32) + 4;
+    sigZ = ((uint_fast64_t) sig32Z<<32) + ((uint_fast64_t) q<<4);
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( (sigZ & 0x1FF) < 4<<4 ) {
+        q &= ~7;
+        sigZ &= ~(uint_fast64_t) 0x7F;
+        doubleTerm = q<<1;
+        rem =
+            ((rem - (uint_fast64_t) doubleTerm * (uint32_t) (sigB>>32))<<28)
+                - (uint_fast64_t) doubleTerm * ((uint32_t) sigB>>4);
+        if ( rem & UINT64_C( 0x8000000000000000 ) ) {
+            sigZ -= 1<<7;
+        } else {
+            if ( rem ) sigZ |= 1;
         }
-        sigZ |= ( rem.v0 != 0 );
     }
     return softfloat_roundPackToF64( signZ, expZ, sigZ );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
  propagateNaN:
     uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
     goto uiZ;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
  invalid:
     softfloat_raiseFlags( softfloat_flag_invalid );
     uiZ = defaultNaNF64UI;
     goto uiZ;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
  infinity:
     uiZ = packToF64UI( signZ, 0x7FF, 0 );
     goto uiZ;
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
  zero:
     uiZ = packToF64UI( signZ, 0, 0 );
  uiZ: