Merge branch 'bjorn/erts/use-const'

* bjorn/erts/use-const:
  beam_makeops: Save some memory by making loader tables 'const'
  beam_makeops: Separate static information from counters
  make_preload: Save some memory by making preloaded code 'const'

6 files changed, 30 insertions, 20 deletions

diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 0c2743beb2..4ca2c6a13f 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -4860,7 +4860,7 @@ transform_engine(LoaderState* st)
 {
     Uint op;
     int ap;			/* Current argument. */
-    Uint* restart;		/* Where to restart if current match fails. */
+    const Uint* restart; /* Where to restart if current match fails. */
     GenOpArg var[TE_MAX_VARS];	/* Buffer for variables. */
     GenOpArg* rest_args = NULL;
     int num_rest_args = 0;
@@ -4869,7 +4869,7 @@ transform_engine(LoaderState* st)
     GenOp* instr;
     GenOp* first = st->genop;
     GenOp* keep = NULL;
-    Uint* pc;
+    const Uint* pc;
     static Uint restart_fail[1] = {TOP_fail};
 
     ASSERT(gen_opc[first->op].transform != -1);
diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h
index fd2dd97fee..92a9abddbf 100644
--- a/erts/emulator/beam/beam_load.h
+++ b/erts/emulator/beam/beam_load.h
@@ -35,7 +35,7 @@ typedef struct gen_op_entry {
    int transform;
 } GenOpEntry;
 
-extern GenOpEntry gen_opc[];
+extern const GenOpEntry gen_opc[];
 
 #ifdef NO_JUMP_TABLE 
 #define BeamOp(Op) (Op)
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 3fb866733c..e5d3f38ce4 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2394,7 +2394,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 							     ERTS_ATOM_ENC_LATIN1,
 							     1),
 					       erts_bld_uint(hpp, hszp,
-							     opc[i].count)),
+							     erts_instr_count[i])),
 				res);
 	}
 
diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h
index f97716d030..60c2349f36 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -146,11 +146,12 @@ typedef struct op_entry {
    int sz;			/* Number of loaded words. */
    char* pack;			/* Instructions for packing engine. */
    char* sign;			/* Signature string. */
-   unsigned count;		/* Number of times executed. */
 } OpEntry;
 
-extern OpEntry opc[];		/* Description of all instructions. */
-extern int num_instructions;	/* Number of instruction in opc[]. */
+extern const OpEntry opc[];	/* Description of all instructions. */
+extern const int num_instructions; /* Number of instruction in opc[]. */
+
+extern Uint erts_instr_count[];
 
 /* some constants for various table sizes etc */
 
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index 4407f7e289..9813142585 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -475,7 +475,7 @@ sub emulator_output {
     print '#include "beam_load.h"', "\n";
     print "\n";
 
-    print "char tag_to_letter[] = {\n  ";
+    print "const char tag_to_letter[] = {\n  ";
     for ($i = 0; $i < length($genop_types); $i++) {
 	print "'$tag_type[$i]', ";
     }
@@ -489,7 +489,7 @@ sub emulator_output {
     # Generate code for specific ops.
     #
     my($spec_opnum) = 0;
-    print "OpEntry opc[] = {\n";
+    print "const OpEntry opc[] = {\n";
     foreach $key (sort keys %specific_op) {
 	$gen_to_spec{$key} = $spec_opnum;
 	$num_specific{$key} = @{$specific_op{$key}};
@@ -566,13 +566,22 @@ sub emulator_output {
 		$sep = ",";
 	    }
 	    $init .= "}";
-	    init_item($print_name, $init, $involves_r, $size, $pack, $sign, 0);
+	    init_item($print_name, $init, $involves_r, $size, $pack, $sign);
 	    $op_to_name[$spec_opnum] = $instr;
 	    $spec_opnum++;
 	}
     }
     print "};\n\n";
-    print "int num_instructions = $spec_opnum;\n\n";
+    print "const int num_instructions = $spec_opnum;\n\n";
+
+    #
+    # Print the array for instruction counts.
+    #
+
+    print "#ifdef ERTS_OPCODE_COUNTER_SUPPORT\n";
+    print "Uint erts_instr_count[$spec_opnum];\n";
+    print "#endif\n";
+    print "\n";
 
     #
     # Generate transformations.
@@ -584,7 +593,7 @@ sub emulator_output {
     # Print the generic instruction table.
     #
 
-    print "GenOpEntry gen_opc[] = {\n";
+    print "const GenOpEntry gen_opc[] = {\n";
     for ($i = 0; $i < @gen_opname; $i++) {
 	if ($i == $num_file_opcodes) {
 	    print "\n/*\n * Internal generic instructions.\n */\n\n";
@@ -678,8 +687,8 @@ sub emulator_output {
     print "#define TE_MAX_VARS $te_max_vars\n";
     print "\n";
 
-    print "extern char tag_to_letter[];\n";
-    print "extern Uint op_transform[];\n";
+    print "extern const char tag_to_letter[];\n";
+    print "extern const Uint op_transform[];\n";
     print "\n";
 
     for ($i = 0; $i < @op_to_name; $i++) {
@@ -708,7 +717,7 @@ sub emulator_output {
     print "#define DEFINE_COUNTING_LABELS";
     for ($i = 0; $i < @op_to_name; $i++) {
 	my($name) = $op_to_name[$i];
-	print " \\\nCountCase($name): opc[$i].count++; goto lb_$name;";
+	print " \\\nCountCase($name): erts_instr_count[$i]++; goto lb_$name;";
     }
     print "\n\n";
 
@@ -1417,7 +1426,7 @@ sub tr_gen {
     # Print the generated transformation engine.
     #
     my($offset) = 0;
-    print "Uint op_transform[] = {\n";
+    print "const Uint op_transform[] = {\n";
     foreach $key (sort keys %gen_transform) {
 	$gen_transform_offset{$key} = $offset;
 	my @instr = @{$gen_transform{$key}};
diff --git a/erts/emulator/utils/make_preload b/erts/emulator/utils/make_preload
index f489bc2a39..8b629d9517 100755
--- a/erts/emulator/utils/make_preload
+++ b/erts/emulator/utils/make_preload
@@ -94,8 +94,8 @@ foreach $file (@ARGV) {
 	close(FILE);
 	
 	push(@modules, "  {\"$module\", " . length($_) . ", preloaded_$module},\n");
-	print "unsigned preloaded_size_$module = ", length($_), ";\n";
-	print "unsigned char preloaded_$module", "[] = {\n";
+	print "const unsigned preloaded_size_$module = ", length($_), ";\n";
+	print "const unsigned char preloaded_$module", "[] = {\n";
 	for ($i = 0; $i < length($_); $i++) {
 	    if ($i % 8 == 0 && $comment ne '') {
 		$comment =~ s@/\*@..@g; # Comment start -- avoid warning.
@@ -125,10 +125,10 @@ if ($gen_rc) {
     print @modules;
     print "END\n";
 } elsif ($gen_old) {
-    print "struct {\n";
+    print "const struct {\n";
     print "   char* name;\n";
     print "   int size;\n";
-    print "   unsigned char* code;\n";
+    print "   const unsigned char* code;\n";
     print "} pre_loaded[] = {\n";
     foreach (@modules) {
 	print;