From d47fa0fc89a85dcdb704ed60790de461d8a6e068 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Sat, 1 Dec 2012 11:13:45 +0900
Subject: [PATCH] Make the new optimizations optional.

The usual -O :) (no numbers yet, though). Alternatively, -C [no-]optimize
may be used.
---
 tools/qfcc/include/options.h    |  1 +
 tools/qfcc/include/statements.h |  2 ++
 tools/qfcc/source/function.c    | 14 +++++++++-----
 tools/qfcc/source/options.c     |  7 +++++++
 tools/qfcc/source/statements.c  | 26 ++++++++++++++++++++++++++
 5 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/tools/qfcc/include/options.h b/tools/qfcc/include/options.h
index 9c8d10724..14cf8cb8c 100644
--- a/tools/qfcc/include/options.h
+++ b/tools/qfcc/include/options.h
@@ -38,6 +38,7 @@ typedef struct {
 	qboolean	crc;				// Write progsdef.h crc to progs.dat
 	qboolean	debug;				// Generate debug info for the engine
 	qboolean	short_circuit;		// short circuit logic for && and ||
+	qboolean    optimize;			// perform optimizations
 	qboolean	fast_float;			// use floats directly in ifs
 	qboolean    vector_calls;		// use floats instead of vectors for constant function args
 	qboolean    local_merging;		// merge function locals into one block
diff --git a/tools/qfcc/include/statements.h b/tools/qfcc/include/statements.h
index 133e397c1..f401fb909 100644
--- a/tools/qfcc/include/statements.h
+++ b/tools/qfcc/include/statements.h
@@ -122,6 +122,8 @@ sblock_t *statement_get_target (statement_t *s);
 sblock_t **statement_get_targetlist (statement_t *s);
 void sblock_add_statement (sblock_t *sblock, statement_t *statement);
 sblock_t *make_statements (struct expr_s *expr);
+void statements_count_temps (sblock_t *sblock);
+
 void print_statement (statement_t *s);
 void dump_dot_sblock (void *data, const char *fname);
 void print_sblock (sblock_t *sblock, const char *filename);
diff --git a/tools/qfcc/source/function.c b/tools/qfcc/source/function.c
index 99cfa760f..5bdfe6cd7 100644
--- a/tools/qfcc/source/function.c
+++ b/tools/qfcc/source/function.c
@@ -643,11 +643,15 @@ emit_function (function_t *f, expr_t *e)
 	f->code = pr.code->size;
 	lineno_base = f->def->line;
 	f->sblock = make_statements (e);
-	flow_build_vars (f);
-	f->graph = flow_build_graph (f->sblock, f);
-	f->graph->func = f;
-	flow_data_flow (f->graph);
-	f->sblock = flow_generate (f->graph);
+	if (options.code.optimize) {
+		flow_build_vars (f);
+		f->graph = flow_build_graph (f->sblock, f);
+		f->graph->func = f;
+		flow_data_flow (f->graph);
+		f->sblock = flow_generate (f->graph);
+	} else {
+		statements_count_temps (f->sblock);
+	}
 	emit_statements (f->sblock);
 }
 
diff --git a/tools/qfcc/source/options.c b/tools/qfcc/source/options.c
index 448fbb97e..325d3e81f 100644
--- a/tools/qfcc/source/options.c
+++ b/tools/qfcc/source/options.c
@@ -114,6 +114,7 @@ static const char *short_options =
 	"M::"
 	"N:"	// notice options
 	"o:"	// output file
+	"O"		// optimize
 	"P:"	// progs.src name
 	"p:"	// strip path
 	"q"		// quiet
@@ -194,6 +195,7 @@ code_usage (void)
 "    [no-]fast-float         Use float values directly in \"if\" statements.\n"
 "    help                    Display his text.\n"
 "    [no-]local-merging      Merge the local variable blocks into one.\n"
+"    [no-]optimize           Perform various optimizations on the code.\n"
 "    [no-]short-circuit      Generate short circuit code for logical\n"
 "                            operators.\n"
 "    [no-]single-cpp         Convert progs.src to cpp input file.\n"
@@ -354,6 +356,9 @@ DecodeArgs (int argc, char **argv)
 			case 'g':					// debug
 				options.code.debug = true;
 				break;
+			case 'O':					// optimize
+				options.code.optimize = true;
+				break;
 			case OPT_EXTENDED:
 				options.traditional = 1;
 				options.advanced = false;
@@ -446,6 +451,8 @@ DecodeArgs (int argc, char **argv)
 							code_usage ();
 						} else if (!(strcasecmp (temp, "local-merging"))) {
 							options.code.local_merging = flag;
+						} else if (!(strcasecmp (temp, "optimize"))) {
+							options.code.optimize = flag;
 						} else if (!(strcasecmp (temp, "short-circuit"))) {
 							options.code.short_circuit = flag;
 						} else if (!(strcasecmp (temp, "single-cpp"))) {
diff --git a/tools/qfcc/source/statements.c b/tools/qfcc/source/statements.c
index 3d456f0b4..20a08722d 100644
--- a/tools/qfcc/source/statements.c
+++ b/tools/qfcc/source/statements.c
@@ -1526,3 +1526,29 @@ make_statements (expr_t *e)
 
 	return sblock;
 }
+
+static void
+count_temp (operand_t *op)
+{
+	if (!op)
+		return;
+	while (op->op_type == op_alias)
+		op = op->o.alias;
+	if (op->op_type == op_temp)
+		op->o.tempop.users++;
+}
+
+void
+statements_count_temps (sblock_t *sblock)
+{
+	statement_t *st;
+
+	while (sblock) {
+		for (st = sblock->statements; st; st = st->next) {
+			count_temp (st->opa);
+			count_temp (st->opb);
+			count_temp (st->opc);
+		}
+		sblock = sblock->next;
+	}
+}