Merge branch 'sv/serge-new_float_ext' into dev

* sv/serge-new_float_ext:
  Let ei_get_type() return ERL_FLOAT_EXT instead of NEW_FLOAT_EXT
  Fix ei_tmo to restrict dflags to NEW_FLOAT_EXT
  compact IEEE 754 double encoding in external binary format for ei
  fix typo in ei_decode_ei_term documentation

OTP-8684 sv/serge-new_float_ext

compact IEEE 754 double encoding in external binary format for ei

Implement the compact IEEE 754 double encoding in external binary format
for ei. Encoding for ei now always produces the NEW_FLOAT_EXT format.
Decoding and term printing handle both the old ERL_FLOAT_EXT encoding and
the new NEW_FLOAT_EXT encoding. 

Legacy erl_interface code also handles the new encoding, but still produces
the ERL_FLOAT_EXT encoding by default.

Also enable the DFLAG_NEW_FLOATS distribution flag.

ei_get_type() will return ERL_FLOAT_EXT regardless if the external format
is encoded with ERL_FLOAT_EXT or NEW_FLOAT_EXT for doubles.

Reduce the number of copies of the code for encoding and decoding doubles
throughout ei and erl_interface by instead calling the ei encoding and
decoding functions wherever possible.

Restore commented-out float tests in ei_decode_SUITE and ei_encode_SUITE in
lib/erl_interface/test. Modify them to make them match the style of other
tests in the same suites.

These changes are based on an ei float patch from Serge Aleynikov
originally submitted against R12B-2 in July 2008 and reworked by Steve
Vinoski May 2010.

2 files changed, 25 insertions, 16 deletions

diff --git a/lib/erl_interface/src/decode/decode_double.c b/lib/erl_interface/src/decode/decode_double.c
index 66dbe474ec..ed6e39655e 100644
--- a/lib/erl_interface/src/decode/decode_double.c
+++ b/lib/erl_interface/src/decode/decode_double.c
@@ -1,19 +1,19 @@
 /*
  * %CopyrightBegin%
- * 
- * Copyright Ericsson AB 1998-2009. All Rights Reserved.
- * 
+ *
+ * Copyright Ericsson AB 1998-2010. All Rights Reserved.
+ *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
  * compliance with the License. You should have received a copy of the
  * Erlang Public License along with this software. If not, it can be
  * retrieved online at http://www.erlang.org/.
- * 
+ *
  * Software distributed under the License is distributed on an "AS IS"
  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  * the License for the specific language governing rights and limitations
  * under the License.
- * 
+ *
  * %CopyrightEnd%
  */
 #include <stdio.h>
@@ -26,14 +26,22 @@ int ei_decode_double(const char *buf, int *index, double *p)
 {
   const char *s = buf + *index;
   const char *s0 = s;
-  double f;
+  FloatExt f;
 
-  if (get8(s) != ERL_FLOAT_EXT) return -1;
-  
-  if (sscanf(s, "%lf", &f) != 1) return -1;
+  switch (get8(s)) {
+    case ERL_FLOAT_EXT:
+      if (sscanf(s, "%lf", &f.d) != 1) return -1;
+      s += 31;
+      break;
+    case NEW_FLOAT_EXT:
+      /* IEEE 754 format */
+      f.val = get64be(s);
+      break;
+    default:
+      return -1;
+  }
 
-  s += 31;
-  if (p) *p = f;
+  if (p) *p = f.d;
   *index += s-s0; 
   return 0; 
 }
diff --git a/lib/erl_interface/src/decode/decode_skip.c b/lib/erl_interface/src/decode/decode_skip.c
index 316b5bee98..f6c5d861ab 100644
--- a/lib/erl_interface/src/decode/decode_skip.c
+++ b/lib/erl_interface/src/decode/decode_skip.c
@@ -1,19 +1,19 @@
 /*
  * %CopyrightBegin%
- * 
- * Copyright Ericsson AB 2002-2009. All Rights Reserved.
- * 
+ *
+ * Copyright Ericsson AB 2002-2010. All Rights Reserved.
+ *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
  * compliance with the License. You should have received a copy of the
  * Erlang Public License along with this software. If not, it can be
  * retrieved online at http://www.erlang.org/.
- * 
+ *
  * Software distributed under the License is distributed on an "AS IS"
  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  * the License for the specific language governing rights and limitations
  * under the License.
- * 
+ *
  * %CopyrightEnd%
  */
 #include "eidef.h"
@@ -77,6 +77,7 @@ int ei_skip_term(const char* buf, int* index)
 	if (ei_decode_big(buf, index, NULL) < 0) return -1;
 	break;
     case ERL_FLOAT_EXT:
+    case NEW_FLOAT_EXT:
 	if (ei_decode_double(buf, index, NULL) < 0) return -1;
 	break;
     case ERL_FUN_EXT: