term_to_binary use all 32 bits of INTEGER_EXT

Earlier, external format INTEGER_EXT was only produced for 28-bit
signed integers. Now full 32-bit signed integers are produced as
INTEGER_EXT to avoid the more costly SMALL_BIG_EXT format. Both old
and new code can read 32-bit INTEGER_EXT.

Also fixed integer encoding bugs in erl_interface erl_encode/erl_decode.
(Thanks to Alexander Demidenko for reporting)

6 files changed, 216 insertions, 124 deletions

diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index f41b61d73d..466165f26f 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -65,11 +65,9 @@
 #  endif
 #endif
 
-/*
- * For backward compatibility reasons, only encode integers that
- * fit in 28 bits (signed) using INTEGER_EXT.
+/* Does Sint fit in Sint32?
  */
-#define IS_SSMALL28(x) (((Uint) (((x) >> (28-1)) + 1)) < 2)
+#define IS_SSMALL32(x) (((Uint) (((x) >> (32-1)) + 1)) < 2)
 
 /*
  *   Valid creations for nodes are 1, 2, or 3. 0 can also be sent
@@ -1571,13 +1569,15 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 
 	case SMALL_DEF:
 	    {
+		/* From R14B we no longer restrict INTEGER_EXT to 28 bits,
+		 * as done earlier for backward compatibility reasons. */
 		Sint val = signed_val(obj);
 
 		if ((Uint)val < 256) {
 		    *ep++ = SMALL_INTEGER_EXT;
 		    put_int8(val, ep);
 		    ep++;
-		} else if (sizeof(Sint) == 4 || IS_SSMALL28(val)) {
+		} else if (sizeof(Sint) == 4 || IS_SSMALL32(val)) {
 		    *ep++ = INTEGER_EXT;
 		    put_int32(val, ep);
 		    ep += 4;
@@ -1599,18 +1599,32 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 	    break;
 
 	case BIG_DEF:
-	    if ((n = big_bytes(obj)) < 256) {
-		*ep++ = SMALL_BIG_EXT;
-		put_int8(n, ep);
-		ep += 1;
-	    }
-	    else {
-		*ep++ = LARGE_BIG_EXT;
-		put_int32(n, ep);
-		ep += 4;
+	    {
+		int sign = big_sign(obj);
+		n = big_bytes(obj);
+		if (sizeof(Sint)==4 && n<=4) {
+		    Uint dig = big_digit(obj,0);		   
+		    Sint val = sign ? -dig : dig;
+		    if ((val<0) == sign) {
+			*ep++ = INTEGER_EXT;
+			put_int32(val, ep);
+			ep += 4;
+			break;
+		    }
+		}
+		if (n < 256) {
+		    *ep++ = SMALL_BIG_EXT;
+		    put_int8(n, ep);
+		    ep += 1;
+		}
+		else {
+		    *ep++ = LARGE_BIG_EXT;
+		    put_int32(n, ep);
+		    ep += 4;
+		}
+		*ep++ = sign;
+		ep = big_to_bytes(obj, ep);
 	    }
-	    *ep++ = big_sign(obj);
-	    ep = big_to_bytes(obj, ep);
 	    break;
 
 	case PID_DEF:
@@ -2687,7 +2701,7 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags)
 
 		if ((Uint)val < 256)
 		    result += 1 + 1;		/* SMALL_INTEGER_EXT */
-		else if (sizeof(Sint) == 4 || IS_SSMALL28(val))
+		else if (sizeof(Sint) == 4 || IS_SSMALL32(val))
 		    result += 1 + 4;		/* INTEGER_EXT */
 		else {
 		    DeclareTmpHeapNoproc(tmp_big,2);
@@ -2699,7 +2713,10 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags)
 	    }
 	    break;
 	case BIG_DEF:
-	    if ((i = big_bytes(obj)) < 256)
+	    i = big_bytes(obj);
+	    if (sizeof(Sint)==4 && i <= 4 && (big_digit(obj,0)-big_sign(obj)) < (1<<31))
+		result += 1 + 4;          /* INTEGER_EXT */
+	    else if (i < 256)
 		result += 1 + 1 + 1 + i;  /* tag,size,sign,digits */
 	    else
 		result += 1 + 4 + 1 + i;  /* tag,size,sign,digits */
diff --git a/erts/emulator/test/hash_SUITE.erl b/erts/emulator/test/hash_SUITE.erl
index 85bdb8bff8..f5d1871bfb 100644
--- a/erts/emulator/test/hash_SUITE.erl
+++ b/erts/emulator/test/hash_SUITE.erl
@@ -480,14 +480,14 @@ otp_5292_test() ->
     S2 = md5([md5(hash_int(S, E, PH)) || {Start, N, Sz} <- d(), 
                                          {S, E} <- int(Start, N, Sz)]),
     ?line Comment = case S1 of 
-                        <<43,186,76,102,87,4,110,245,203,177,206,6,130,69,43,99>> ->
+			<<4,248,208,156,200,131,7,1,173,13,239,173,112,81,16,174>> ->
 			    ?line big = erlang:system_info(endian),
                             "Big endian machine";
-                        <<21,206,139,15,149,28,167,81,98,225,132,254,49,125,174,195>> ->
+                        <<180,28,33,231,239,184,71,125,76,47,227,241,78,184,176,233>> ->
 			    ?line little = erlang:system_info(endian),
                             "Little endian machine"
                     end,
-    ?line <<140,37,79,80,26,242,130,22,20,229,123,240,223,244,43,99>> = S2,
+    ?line <<124,81,198,121,174,233,19,137,10,83,33,80,226,111,238,99>> = S2,
     ?line 2 = erlang:hash(1, (1 bsl 27) -1),
     ?line {'EXIT', _} = (catch erlang:hash(1, (1 bsl 27))),
     {comment, Comment}.
@@ -507,7 +507,7 @@ hash_int(Start, End, F) ->
     {Start, End, md5(HL)}.
 
 md5(T) ->
-    erlang:md5(term_to_binary(T)).
+    erlang:md5(term_to_binary(T)).   
 
 bit_level_binaries() ->
     ?line [3511317,7022633,14044578,28087749,56173436,112344123,90467083|_] =
diff --git a/lib/erl_interface/src/legacy/erl_marshal.c b/lib/erl_interface/src/legacy/erl_marshal.c
index c57c552b90..18315bfbd3 100644
--- a/lib/erl_interface/src/legacy/erl_marshal.c
+++ b/lib/erl_interface/src/legacy/erl_marshal.c
@@ -26,6 +26,7 @@
 #include <ctype.h>
 #include <sys/types.h>
 #include <string.h>
+#include <limits.h>
 
 #include "erl_interface.h"
 #include "erl_marshal.h"
@@ -178,26 +179,14 @@ int erl_encode_it(ETERM *ep, unsigned char **ext, int dist)
 	return 0;
 
     case ERL_INTEGER:
-	i = ep->uval.ival.i;
-	/* ERL_SMALL_BIG */
-	if ((i > ERL_MAX) || (i < ERL_MIN)) { 
-	    *(*ext)++ = ERL_SMALL_BIG_EXT;
-	    *(*ext)++ = 4;		/* four bytes */
-	    if ((*(*ext)++ = ((i>>31) & 0x01))) /* sign byte  */ 
-	      i = -i;
-	    *(*ext)++ = i  & 0xff;	/* LSB first  */
-	    *(*ext)++ = (i >> 8) & 0xff;
-	    *(*ext)++ = (i >> 16) & 0xff;
-	    *(*ext)++ = (i >> 24) & 0x7f; /* Don't include the sign bit */
-	    return 0;
-	} 
+	i = ep->uval.ival.i;	
 	/* SMALL_INTEGER */
 	if ((i < 256) && (i >= 0)) {
 	    *(*ext)++ = ERL_SMALL_INTEGER_EXT;
 	    *(*ext)++ = i & 0xff;
 	    return 0;
 	}
-	/* INTEGER */
+	/* R14B: Use all 32 bits of INTEGER_EXT */
 	*(*ext)++ = ERL_INTEGER_EXT;
 	*(*ext)++ = (i >> 24) & 0xff;
 	*(*ext)++ = (i >> 16) & 0xff;
@@ -208,23 +197,23 @@ int erl_encode_it(ETERM *ep, unsigned char **ext, int dist)
     case ERL_U_INTEGER:
 	u = ep->uval.uival.u;
 	/* ERL_U_SMALL_BIG */
-	if (u > ERL_MAX) {
-	*(*ext)++ = ERL_SMALL_BIG_EXT;
-	*(*ext)++ = 4;		/* four bytes */
-	*(*ext)++ = 0;		/* sign byte  */ 
-	*(*ext)++ = u  & 0xff;	/* LSB first  */
-	*(*ext)++ = (u >> 8) & 0xff;
-	*(*ext)++ = (u >> 16) & 0xff;
-	*(*ext)++ = (u >> 24) & 0xff; 
-	return 0;
+	if ((int)u < 0) {
+	    *(*ext)++ = ERL_SMALL_BIG_EXT;
+	    *(*ext)++ = 4;		/* four bytes */
+	    *(*ext)++ = 0;		/* sign byte  */ 
+	    *(*ext)++ = u  & 0xff;	/* LSB first  */
+	    *(*ext)++ = (u >> 8) & 0xff;
+	    *(*ext)++ = (u >> 16) & 0xff;
+	    *(*ext)++ = (u >> 24) & 0xff; 
+	    return 0;
 	}
 	/* SMALL_INTEGER */
-	if ((u < 256) && (u >= 0)) {
+	if (u < 256) {
 	    *(*ext)++ = ERL_SMALL_INTEGER_EXT;
 	    *(*ext)++ = u & 0xff;
 	    return 0;
 	}
-	/* INTEGER */
+	/* R14B: Use all 32 bits of INTEGER_EXT */
 	*(*ext)++ = ERL_INTEGER_EXT;
 	*(*ext)++ = (u >> 24) & 0xff;
 	*(*ext)++ = (u >> 16) & 0xff;
@@ -234,29 +223,28 @@ int erl_encode_it(ETERM *ep, unsigned char **ext, int dist)
     case ERL_LONGLONG:
 	l = ep->uval.llval.i;
 	/* ERL_SMALL_BIG */
-	if ((l > ((long long) ERL_MAX)) ||
-	    (l < ((long long) ERL_MIN))) { 
-	    *(*ext)++ = ERL_SMALL_BIG_EXT; 
-	    *(*ext)++ = 8;              /* eight bytes */ 
-	    if ((*(*ext)++ = ((l>>63) & 0x01))) /* sign byte  */ 
+	if (l > ((long long) INT_MAX) || l < ((long long) INT_MIN)) {
+	    *(*ext)++ = ERL_SMALL_BIG_EXT;
+	    *(*ext)++ = 8;
+	    if ((*(*ext)++ = (l<0))) /* sign byte  */ 
 	    	l = -l;
-	    *(*ext)++ = l  & 0xff;      /* LSB first  */
+	    *(*ext)++ =  l        & 0xff; /* LSB first  */
 	    *(*ext)++ = (l >>  8) & 0xff;
 	    *(*ext)++ = (l >> 16) & 0xff;
-	    *(*ext)++ = (l >> 24) & 0xff;
-	    *(*ext)++ = (l >> 32) & 0xff;
-	    *(*ext)++ = (l >> 40) & 0xff;
-	    *(*ext)++ = (l >> 48) & 0xff;
-	    *(*ext)++ = (l >> 56) & 0x7f; /* Don't include the sign bit */
+	    *(*ext)++ = (l >> 24) & 0xff; 
+	    *(*ext)++ = (l >> 32) & 0xff; 
+	    *(*ext)++ = (l >> 40) & 0xff; 
+	    *(*ext)++ = (l >> 48) & 0xff; 
+	    *(*ext)++ = (l >> 56) & 0xff; 
 	    return 0;
 	} 
 	/* SMALL_INTEGER */
 	if ((l < 256) && (l >= 0)) {
-	*(*ext)++ = ERL_SMALL_INTEGER_EXT;
-	*(*ext)++ = l & 0xff;
-	return 0;
+	    *(*ext)++ = ERL_SMALL_INTEGER_EXT;
+	    *(*ext)++ = l & 0xff;
+	    return 0;
 	}
-	/* INTEGER */
+	/* R14B: Use all 32 bits of INTEGER_EXT */
 	*(*ext)++ = ERL_INTEGER_EXT;
 	*(*ext)++ = (l >> 24) & 0xff;
 	*(*ext)++ = (l >> 16) & 0xff;
@@ -267,7 +255,7 @@ int erl_encode_it(ETERM *ep, unsigned char **ext, int dist)
     case ERL_U_LONGLONG:
 	ul = ep->uval.ullval.u;
 	/* ERL_U_SMALL_BIG */
-	if (ul > ((unsigned long long) ERL_MAX)) {
+	if (ul > ((unsigned long long) INT_MAX)) {
 	    *(*ext)++ = ERL_SMALL_BIG_EXT;
 	    *(*ext)++ = 8; /* eight bytes */
 	    *(*ext)++ = 0; /* sign byte  */ 
@@ -287,7 +275,7 @@ int erl_encode_it(ETERM *ep, unsigned char **ext, int dist)
 	    *(*ext)++ = ul & 0xff;
 	    return 0;
 	}
-	/* INTEGER */
+	/* R14B: Use all 32 bits of INTEGER_EXT */
 	*(*ext)++ = ERL_INTEGER_EXT;
 	*(*ext)++ = (ul >> 24) & 0xff;
 	*(*ext)++ = (ul >> 16) & 0xff;
@@ -732,11 +720,6 @@ static ETERM *erl_decode_it(unsigned char **ext)
 	if (arity > 8)             
 	    goto big_truncate;
 
-	if (arity == 8 && ((*ext)[7] & 0x80) && sign) {
-	    /* MSB already occupied ! */
-	    goto big_truncate;
-	}
-
 	if (arity == 4 && ((*ext)[3] & 0x80) && !sign) {
 	    /* It will fit into an unsigned int !! */
 	    u = (((*ext)[3] << 24)|((*ext)[2])<< 16|((*ext)[1]) << 8 |(**ext));
@@ -747,14 +730,10 @@ static ETERM *erl_decode_it(unsigned char **ext)
 	    return ep;
 	} else if (arity == 4 && !((*ext)[3] & 0x80)) {
 	    /* It will fit into an int !! 
-	     * Note: It comes in "one's-complement notation" 
 	     */
-	    if (sign)
-		i = (int) (~(((*ext)[3] << 24) | ((*ext)[2])<< 16 |
-			     ((*ext)[1]) << 8 | (**ext)) | (unsigned int) sign);
-	    else
-		i = (int) (((*ext)[3] << 24) | ((*ext)[2])<< 16 |
-			   ((*ext)[1]) << 8 | (**ext));
+	    i = (int) (((*ext)[3] << 24) | ((*ext)[2])<< 16 |
+		       ((*ext)[1]) << 8 | (**ext));
+	    if (sign) i = -i;
 	    ERL_TYPE(ep) = ERL_INTEGER;
 	    ep->uval.ival.i = i;
 	    *ext += arity;
@@ -780,8 +759,10 @@ static ETERM *erl_decode_it(unsigned char **ext)
 	    for(x = 0 ; x < arity ; x++) {
 		l |= ((long long)(*ext)[x]) << ((long long)(8*x));
 	    }
-
-	    if (sign) l = (long long) (~l | (unsigned long long) sign);
+	    if (sign) {
+		l = -l;
+		if (l > 0) goto big_truncate;
+	    }
 
 	    ERL_TYPE(ep) = ERL_LONGLONG;
 	    ep->uval.llval.i = l;
diff --git a/lib/erl_interface/test/ei_decode_SUITE.erl b/lib/erl_interface/test/ei_decode_SUITE.erl
index c6858b45ad..09a37409f2 100644
--- a/lib/erl_interface/test/ei_decode_SUITE.erl
+++ b/lib/erl_interface/test/ei_decode_SUITE.erl
@@ -222,14 +222,16 @@ send_integers(P) ->
     ?line send_term_as_binary(P,256),		% INTEGER_EXT smallest pos (*)
     ?line send_term_as_binary(P,-1),		% INTEGER_EXT largest  neg 
 
-    ?line send_term_as_binary(P, 16#07ffffff),	% INTEGER_EXT largest (28 bits)
-    ?line send_term_as_binary(P,-16#08000000),	% INTEGER_EXT smallest 
-    ?line send_term_as_binary(P, 16#08000000),  % SMALL_BIG_EXT smallest pos(*)
-    ?line send_term_as_binary(P,-16#08000001),	% SMALL_BIG_EXT largest neg (*)
-
-    ?line send_term_as_binary(P, 16#7fffffff),	% SMALL_BIG_EXT largest  i32
-    ?line send_term_as_binary(P,-16#80000000),	% SMALL_BIG_EXT smallest i32
-
+    ?line send_term_as_binary(P, 16#07ffffff),	% INTEGER_EXT old largest (28 bits)
+    ?line send_term_as_binary(P,-16#08000000),	% INTEGER_EXT old smallest
+    ?line send_term_as_binary(P, 16#08000000),  % SMALL_BIG_EXT old smallest pos(*)
+    ?line send_term_as_binary(P,-16#08000001),	% SMALL_BIG_EXT old largest neg (*)
+
+    ?line send_term_as_binary(P, 16#7fffffff),	% INTEGER_EXT new largest (32 bits)
+    ?line send_term_as_binary(P,-16#80000000),	% INTEGER_EXT new smallest (32 bis)
+    ?line send_term_as_binary(P, 16#80000000),  % SMALL_BIG_EXT new smallest pos(*)
+    ?line send_term_as_binary(P,-16#80000001),	% SMALL_BIG_EXT new largest neg (*)
+ 
     case erlang:system_info(wordsize) of
 	4 ->	 
           ?line send_term_as_binary(P, 16#80000000),% SMALL_BIG_EXT u32
@@ -266,15 +268,17 @@ send_integers2(P) ->
     ?line send_term_as_binary(P,255),		% SMALL_INTEGER_EXT largest
     ?line send_term_as_binary(P,256),		% INTEGER_EXT smallest pos (*)
     ?line send_term_as_binary(P,-1),		% INTEGER_EXT largest  neg 
+    
+    ?line send_term_as_binary(P, 16#07ffffff),	% INTEGER_EXT old largest (28 bits)
+    ?line send_term_as_binary(P,-16#08000000),	% INTEGER_EXT old smallest 
+    ?line send_term_as_binary(P, 16#08000000),  % SMALL_BIG_EXT old smallest pos(*)
+    ?line send_term_as_binary(P,-16#08000001),	% SMALL_BIG_EXT old largest neg (*)
 
-    ?line send_term_as_binary(P, 16#07ffffff),	% INTEGER_EXT largest (28 bits)
-    ?line send_term_as_binary(P,-16#08000000),	% INTEGER_EXT smallest 
-    ?line send_term_as_binary(P, 16#08000000),  % SMALL_BIG_EXT smallest pos(*)
-    ?line send_term_as_binary(P,-16#08000001),	% SMALL_BIG_EXT largest neg (*)
+    ?line send_term_as_binary(P, 16#7fffffff),	% INTEGER_EXT new largest (32 bits)
+    ?line send_term_as_binary(P,-16#80000000),	% INTEGER_EXT new smallest
+    ?line send_term_as_binary(P, 16#80000000),  % SMALL_BIG_EXT new smallest pos(*)
+    ?line send_term_as_binary(P,-16#80000001),	% SMALL_BIG_EXT new largest neg (*)
 
-    ?line send_term_as_binary(P, 16#7fffffff),	% SMALL_BIG_EXT largest  i32
-    ?line send_term_as_binary(P,-16#80000000),	% SMALL_BIG_EXT smallest i32
-    ?line send_term_as_binary(P, 16#80000000),% SMALL_BIG_EXT u32
     ?line send_term_as_binary(P, 16#ffffffff),% SMALL_BIG_EXT largest u32
 
     ?line send_term_as_binary(P, 16#7fffffffffff), % largest  i48
diff --git a/lib/erl_interface/test/ei_decode_SUITE_data/ei_decode_test.c b/lib/erl_interface/test/ei_decode_SUITE_data/ei_decode_test.c
index 5447e2deb3..b349138ae9 100644
--- a/lib/erl_interface/test/ei_decode_SUITE_data/ei_decode_test.c
+++ b/lib/erl_interface/test/ei_decode_SUITE_data/ei_decode_test.c
@@ -246,13 +246,23 @@ TESTCASE(test_ei_decode_long)
     EI_DECODE_2     (decode_long,  5, long, 256);
     EI_DECODE_2     (decode_long,  5, long, -1);
 
+    /* Old 28 bit limits for INTEGER_EXT */
     EI_DECODE_2     (decode_long,  5, long,  0x07ffffff);
     EI_DECODE_2     (decode_long,  5, long, -0x08000000);
-    EI_DECODE_2     (decode_long,  7, long,  0x08000000);
-    EI_DECODE_2     (decode_long,  7, long, -0x08000001);
+    EI_DECODE_2     (decode_long,  5, long,  0x08000000);  
+    EI_DECODE_2     (decode_long,  5, long, -0x08000001);
 
-    EI_DECODE_2     (decode_long,  7, long,  0x7fffffff);
-    EI_DECODE_2     (decode_long,  7, long, -ll(0x80000000)); /* Strange :-( */
+    /* New 32 bit limits for INTEGER_EXT */
+    EI_DECODE_2     (decode_long,  5, long,     0x7fffffff);
+    EI_DECODE_2     (decode_long,  5, long, -ll(0x80000000)); /* Strange :-( */
+    if (sizeof(long) > 4) {
+	EI_DECODE_2(decode_long,  7, long,     0x80000000);
+	EI_DECODE_2(decode_long,  7, long, -ll(0x80000001));
+    }
+    else {
+	EI_DECODE_2_FAIL(decode_long,  7, long,     0x80000000);
+	EI_DECODE_2_FAIL(decode_long,  7, long, -ll(0x80000001));       
+    }
 
     EI_DECODE_2_FAIL(decode_long,  7, long,  0x80000000);
     EI_DECODE_2_FAIL(decode_long,  7, long,  0xffffffff);
@@ -280,11 +290,13 @@ TESTCASE(test_ei_decode_ulong)
 
     EI_DECODE_2     (decode_ulong,  5, unsigned long,  0x07ffffff);
     EI_DECODE_2_FAIL(decode_ulong,  5, unsigned long, -0x08000000);
-    EI_DECODE_2     (decode_ulong,  7, unsigned long,  0x08000000);
-    EI_DECODE_2_FAIL(decode_ulong,  7, unsigned long, -0x08000001);
+    EI_DECODE_2     (decode_ulong,  5, unsigned long,  0x08000000);
+    EI_DECODE_2_FAIL(decode_ulong,  5, unsigned long, -0x08000001);
 
-    EI_DECODE_2     (decode_ulong,  7, unsigned long,  0x7fffffff);
-    EI_DECODE_2_FAIL(decode_ulong,  7, unsigned long, -ll(0x80000000));
+    EI_DECODE_2     (decode_ulong,  5, unsigned long,     0x7fffffff);
+    EI_DECODE_2_FAIL(decode_ulong,  5, unsigned long, -ll(0x80000000));
+    EI_DECODE_2     (decode_ulong,  7, unsigned long,     0x80000000);
+    EI_DECODE_2_FAIL(decode_ulong,  7, unsigned long, -ll(0x80000001));
 
     if (sizeof(long) > 4) {
       EI_DECODE_2     (decode_ulong,  11, unsigned long,  ll(0x8000000000000000));
@@ -319,13 +331,14 @@ TESTCASE(test_ei_decode_longlong)
 
     EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG,  0x07ffffff);
     EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG, -0x08000000);
-    EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG,  0x08000000);
-    EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG, -0x08000001);
-
-    EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG,  0x7fffffff);
-    EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG, -ll(0x80000000));
+    EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG,  0x08000000);
+    EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG, -0x08000001);
 
+    EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG,  0x7fffffff);
+    EI_DECODE_2     (decode_longlong,  5, EI_LONGLONG, -ll(0x80000000));
     EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG,  0x80000000);
+    EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG, -ll(0x80000001));
+
     EI_DECODE_2     (decode_longlong,  7, EI_LONGLONG,  0xffffffff);
 
     EI_DECODE_2     (decode_longlong,  9, EI_LONGLONG,  ll(0x7fffffffffff));
@@ -352,13 +365,14 @@ TESTCASE(test_ei_decode_ulonglong)
 
     EI_DECODE_2     (decode_ulonglong, 5, EI_ULONGLONG,  0x07ffffff);
     EI_DECODE_2_FAIL(decode_ulonglong, 5, EI_ULONGLONG, -0x08000000);
-    EI_DECODE_2     (decode_ulonglong, 7, EI_ULONGLONG,  0x08000000);
-    EI_DECODE_2_FAIL(decode_ulonglong, 7, EI_ULONGLONG, -0x08000001);
-
-    EI_DECODE_2     (decode_ulonglong, 7, EI_ULONGLONG,  0x7fffffff);
-    EI_DECODE_2_FAIL(decode_ulonglong, 7, EI_ULONGLONG, -ll(0x80000000));
+    EI_DECODE_2     (decode_ulonglong, 5, EI_ULONGLONG,  0x08000000);
+    EI_DECODE_2_FAIL(decode_ulonglong, 5, EI_ULONGLONG, -0x08000001);
 
+    EI_DECODE_2     (decode_ulonglong, 5, EI_ULONGLONG,  0x7fffffff);
+    EI_DECODE_2_FAIL(decode_ulonglong, 5, EI_ULONGLONG, -ll(0x80000000));
     EI_DECODE_2     (decode_ulonglong, 7, EI_ULONGLONG,  0x80000000);
+    EI_DECODE_2_FAIL(decode_ulonglong, 7, EI_ULONGLONG, -0x80000001);
+
     EI_DECODE_2     (decode_ulonglong, 7, EI_ULONGLONG,  0xffffffff);
 
     EI_DECODE_2     (decode_ulonglong, 9, EI_ULONGLONG,  ll(0x7fffffffffff));
diff --git a/lib/erl_interface/test/erl_eterm_SUITE_data/eterm_test.c b/lib/erl_interface/test/erl_eterm_SUITE_data/eterm_test.c
index 6b2ec8f766..f273efd532 100644
--- a/lib/erl_interface/test/erl_eterm_SUITE_data/eterm_test.c
+++ b/lib/erl_interface/test/erl_eterm_SUITE_data/eterm_test.c
@@ -63,32 +63,108 @@ TESTCASE(build_terms)
     report(1);
 }
 
+static int abs_and_sign(ETERM* v, unsigned long long* av, int* sign)
+{
+    long long sv;
+    switch (ERL_TYPE(v)) {
+    case ERL_INTEGER: sv = ERL_INT_VALUE(v); break;
+    case ERL_U_INTEGER: *av = ERL_INT_UVALUE(v); *sign = 0; return 1;
+    case ERL_LONGLONG: sv = ERL_LL_VALUE(v); break;
+    case ERL_U_LONGLONG: *av = ERL_LL_UVALUE(v); *sign = 0; return 1;
+    default: return 0;
+    }
+    if (sv < 0) {
+	*av = -sv;
+	*sign = 1;
+    }
+    else {
+	*av = sv;
+	*sign = 0;
+    }
+    return 1;
+}
+
+/* Shouldn't erl_match() cope with this?
+*/
+static int eq_ints(ETERM* a, ETERM* b)
+{
+    unsigned long long a_abs, b_abs;
+    int a_sign, b_sign;
+    return abs_and_sign(a, &a_abs, &a_sign) && abs_and_sign(b, &b_abs, &b_sign)
+           && (a_abs == b_abs) && (a_sign == b_sign);
+}
+
+static void encode_decode(ETERM* original, const char* text)
+{
+    static unsigned char encoded[16*1024];
+    ETERM* new_terms;
+    int bytes = erl_encode(original, encoded);
+
+    if (bytes == 0) {
+	fail("failed to encode terms");
+    } 
+    else if (bytes > sizeof(encoded)) {
+	fail("encoded terms buffer overflow");
+    }
+    else if ((new_terms = erl_decode(encoded)) == NULL) {
+	fail("failed to decode terms");
+    }
+    else if (!erl_match(original, new_terms) && !eq_ints(original, new_terms)) {
+	erl_print_term(stderr, original);
+	fprintf(stderr, "(%i) != (%i)", ERL_TYPE(original), ERL_TYPE(new_terms));
+	erl_print_term(stderr, new_terms);
+	fprintf(stderr, " [%s]\r\n", text);
+	fail("decoded terms didn't match original");
+    }
+    erl_free_term(original);
+    erl_free_term(new_terms);
+}
 /*
  * Converts an Erlang term to the external term format and back again.
  */
 
 TESTCASE(round_trip_conversion)
 {
-    ETERM* original;
-    ETERM* new_terms;
-    char encoded[16*1024];
-    int n;
+    int n, i;
 
     erl_init(NULL, 0);
-    original = all_types();
-    if (erl_encode(original, encoded) == 0) 
+    encode_decode(all_types(), "ALL");
+
     {
-	fail("failed to encode terms");
-    } else if ((new_terms = erl_decode(encoded)) == NULL)
+	int v;
+	for (v = 8; v; v <<= 1) {
+	    for (i=-4; i<4; i++) {
+		encode_decode(erl_mk_int(v+i), "INT");
+		encode_decode(erl_mk_int(-(v+i)), "NEG INT");
+	    }
+	}
+    }
     {
-	fail("failed to decode terms");
-    } else if (!erl_match(original, new_terms))
+	unsigned int v;
+	for (v = 8; v; v <<= 1) {
+	    for (i=-4; i<4; i++) {
+		encode_decode(erl_mk_uint(v+i), "UINT");
+	    }
+	}
+    }
     {
-	fail("decoded terms didn't match original");
+	long long v;
+	for (v = 8; v; v <<= 1) {
+	    for (i=-4; i<4; i++) {
+		encode_decode(erl_mk_longlong(v+i), "LONGLONG");
+		encode_decode(erl_mk_longlong(-(v+i)), "NEG LONGLONG");
+	    }
+	}
+    }
+    {
+	unsigned long long v;
+	for (v = 8; v; v <<= 1) {
+	    for (i=-4; i<4; i++) {
+		encode_decode(erl_mk_ulonglong(v+i), "ULONGLONG");
+	    }
+	}
     }
 
-    erl_free_term(original);
-    erl_free_term(new_terms);
     report(1);
 }