Store pointers to heap data in 32-bit words

Store Erlang terms in 32-bit entities on the heap, expanding the
pointers to 64-bit when needed. This works because all terms are stored
on addresses in the 32-bit address range (the 32 most significant bits
of pointers to term data are always 0).

Introduce a new datatype called UWord (along with its companion SWord),
which is an integer having the exact same size as the machine word
(a void *), but might be larger than Eterm/Uint.

Store code as machine words, as the instructions are pointers to
executable code which might reside outside the 32-bit address range.

Continuation pointers are stored on the 32-bit stack and hence must
point to addresses in the low range, which means that loaded beam code
much be placed in the low 32-bit address range (but, as said earlier,
the instructions themselves are full words).

No Erlang term data can be stored on C stacks (enforced by an
earlier commit).

This version gives a prompt, but test cases still fail (and dump core).

The loader (and emulator loop) has instruction packing disabled.

The main issues has been in rewriting loader and actual virtual
machine. Subsystems (like distribution) does not work yet.

1 files changed, 16 insertions, 24 deletions

diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index f98d5ee522..eb61c72e90 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -1182,7 +1182,7 @@ seq_trace_output_generic(Eterm token, Eterm msg, Uint type,
  * or   {trace, Pid, return_to, {Mod, Func, Arity}}
  */
 void 
-erts_trace_return_to(Process *p, Uint *pc)
+erts_trace_return_to(Process *p, UWord *pc)
 {
 #define LOCAL_HEAP_SIZE (4+5+5)
     Eterm* hp;
@@ -1190,7 +1190,7 @@ erts_trace_return_to(Process *p, Uint *pc)
     Eterm mess;
     DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 
-    Eterm *code_ptr = find_function_from_pc(pc);
+    UWord *code_ptr = find_function_from_pc(pc);
 
 
     UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
@@ -1249,7 +1249,7 @@ erts_trace_return_to(Process *p, Uint *pc)
  * or   {trace, Pid, return_from, {Mod, Name, Arity}, Retval}
  */
 void
-erts_trace_return(Process* p, Eterm* fi, Eterm retval, Eterm *tracer_pid)
+erts_trace_return(Process* p, UWord* fi, Eterm retval, Eterm *tracer_pid)
 {
     Eterm* hp;
     Eterm mfa;
@@ -1380,7 +1380,7 @@ erts_trace_return(Process* p, Eterm* fi, Eterm retval, Eterm *tracer_pid)
  * Where Class is atomic but Value is any term.
  */
 void
-erts_trace_exception(Process* p, Eterm mfa[3], Eterm class, Eterm value, 
+erts_trace_exception(Process* p, UWord mfa[3], Eterm class, Eterm value,
 		     Eterm *tracer_pid)
 {
     Eterm* hp;
@@ -1439,7 +1439,7 @@ erts_trace_exception(Process* p, Eterm mfa[3], Eterm class, Eterm value,
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 	hp = local_heap;
-	mfa_tuple = TUPLE3(hp, mfa[0], mfa[1], make_small(mfa[2]));
+	mfa_tuple = TUPLE3(hp, (Eterm) mfa[0], (Eterm) mfa[1], make_small((Eterm)mfa[2]));
 	hp += 4;
 	cv = TUPLE2(hp, class, value);
 	hp += 3;
@@ -1485,7 +1485,7 @@ erts_trace_exception(Process* p, Eterm mfa[3], Eterm class, Eterm value,
 	 * Build the trace tuple and put it into receive queue of the tracer process.
 	 */
 	
-	mfa_tuple = TUPLE3(hp, mfa[0], mfa[1], make_small(mfa[2]));
+	mfa_tuple = TUPLE3(hp, (Eterm) mfa[0], (Eterm) mfa[1], make_small((Eterm) mfa[2]));
 	hp += 4;
 	value = copy_struct(value, value_size, &hp, off_heap);
 	cv = TUPLE2(hp, class, value);
@@ -1522,7 +1522,7 @@ erts_trace_exception(Process* p, Eterm mfa[3], Eterm class, Eterm value,
  * if it is a pid or port we do a meta trace.
  */
 Uint32
-erts_call_trace(Process* p, Eterm mfa[3], Binary *match_spec, 
+erts_call_trace(Process* p, UWord mfa[3], Binary *match_spec,
 		Eterm* args, int local, Eterm *tracer_pid)
 {
     Eterm* hp;
@@ -1589,7 +1589,7 @@ erts_call_trace(Process* p, Eterm mfa[3], Binary *match_spec,
      * such as size_object() and copy_struct(), we must make sure that we
      * temporarily convert any match contexts to sub binaries.
      */
-    arity = mfa[2];
+    arity = (Eterm) mfa[2];
     UseTmpHeap(ERL_SUB_BIN_SIZE,p);
 #ifdef DEBUG
     sub_bin_heap->thing_word = 0;
@@ -1725,7 +1725,7 @@ erts_call_trace(Process* p, Eterm mfa[3], Binary *match_spec,
 		hp += 2;
 	    }
 	}
-	mfa_tuple = TUPLE3(hp, mfa[0], mfa[1], mfa_tuple);
+	mfa_tuple = TUPLE3(hp, (Eterm) mfa[0], (Eterm) mfa[1], mfa_tuple);
 	hp += 4;
 	
 	/*
@@ -1888,7 +1888,7 @@ erts_call_trace(Process* p, Eterm mfa[3], Binary *match_spec,
 		hp += 2;
 	    }
 	}
-	mfa_tuple = TUPLE3(hp, mfa[0], mfa[1], mfa_tuple);
+	mfa_tuple = TUPLE3(hp, (Eterm) mfa[0], (Eterm) mfa[1], mfa_tuple);
 	hp += 4;
 	
 	/*
@@ -2092,7 +2092,7 @@ void save_calls(Process *p, Export *e)
  */
 Eterm
 erts_bif_trace(int bif_index, Process* p, 
-	       Eterm arg1, Eterm arg2, Eterm arg3, Uint *I)
+	       Eterm arg1, Eterm arg2, Eterm arg3, UWord *I)
 {
     Eterm result;
     int meta = !!(erts_bif_trace_flags[bif_index] & BIF_TRACE_AS_META);
@@ -2106,10 +2106,10 @@ erts_bif_trace(int bif_index, Process* p,
 	 * no tracing will occur. Doing the whole else branch will 
 	 * also do nothing, only slower.
 	 */
-	Eterm (*func)(Process*, Eterm, Eterm, Eterm, Uint*) = bif_table[bif_index].f;
+	Eterm (*func)(Process*, Eterm, Eterm, Eterm, UWord*) = bif_table[bif_index].f;
 	result = func(p, arg1, arg2, arg3, I);
     } else {
-	Eterm (*func)(Process*, Eterm, Eterm, Eterm, Uint*);
+	Eterm (*func)(Process*, Eterm, Eterm, Eterm, UWord*);
 	Export* ep = bif_export[bif_index];
 	Uint32 flags = 0, flags_meta = 0;
 	int global = !!(erts_bif_trace_flags[bif_index] & BIF_TRACE_AS_GLOBAL);
@@ -2118,16 +2118,9 @@ erts_bif_trace(int bif_index, Process* p,
 	int applying = (I == &(ep->code[3])); /* Yup, the apply code for a bif
 					       * is actually in the 
 					       * export entry */
-	Eterm *cp = p->cp;
+	UWord *cp = p->cp;
 	
-#ifndef _OSE_
 	Eterm args[3] = {arg1, arg2, arg3};
-#else
-	Eterm args[3];
-	args[0] = arg1;
-	args[1] = arg2;
-	args[2] = arg3;
-#endif
 	
 	/* 
 	 * Make continuation pointer OK, it is not during direct BIF calls,
@@ -2157,12 +2150,11 @@ erts_bif_trace(int bif_index, Process* p,
 	    Eterm *cpp;
 	    /* Maybe advance cp to skip trace stack frames */
 	    for (cpp = p->stop;  ;  cp = cp_val(*cpp++)) {
-		ASSERT(is_CP((Eterm) cp));
-		if (*cp_val((Eterm) cp) == i_return_trace) {
+		if (*cp == i_return_trace) {
 		    /* Skip stack frame variables */
 		    while (is_not_CP(*cpp)) cpp++;
 		    cpp += 2; /* Skip return_trace parameters */
-		} else if (*cp_val((Eterm) cp) == i_return_to_trace) {
+		} else if (*cp == i_return_to_trace) {
 		    /* A return_to trace message is going to be generated
 		     * by normal means, so we do not have to.
 		     */