beam_makeops: Save some memory by making loader tables 'const'

Before:

$ size bin/x86_64-unknown-linux-gnu/beam.smp
   text	   data	    bss	    dec	    hex	filename
3080982	 188369	 158472	3427823	 344def	bin/x86_64-unknown-linux-gnu/beam.smp

After:

$ size bin/x86_64-unknown-linux-gnu/beam.smp
   text	   data	    bss	    dec	    hex	filename
3164694	 104657	 158472	3427823	 344def	bin/x86_64-unknown-linux-gnu/beam.smp

4 files changed, 12 insertions, 12 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_vm.h b/erts/emulator/beam/erl_vm.h
index 22c8e8ee12..60c2349f36 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -148,8 +148,8 @@ typedef struct op_entry {
    char* sign;			/* Signature string. */
 } 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[];
 
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index acc0084145..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}};
@@ -572,7 +572,7 @@ sub emulator_output {
 	}
     }
     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.
@@ -593,7 +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";
@@ -687,8 +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; $i++) {
@@ -1426,7 +1426,7 @@ sub tr_gen {
     # Print the generated transformation engine.
     #
     my($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}};