Improve handling of temp aliases

This makes all tests pass when not optimizing. More work needs to be
done in dags.

tools/qfcc/include/flow.h

@@ -46,6 +46,7 @@ typedef struct flowvar_s {
 	struct set_s *define;		///< set of statements that define this var
 	struct operand_s *op;		///< an operand using this var
 	int         number;			///< number of variable in func's ref list
+	int         flowaddr;		///< psuedo address for local and temp vars
 } flowvar_t;
 
 typedef struct flowloop_s {

tools/qfcc/include/function.h

@@ -94,6 +94,7 @@ typedef struct function_s {
 	struct set_s       *global_vars;///< set indicating which vars are global
 	struct statement_s **statements;
 	int                 num_statements;
+	int                 tmpaddr;	///< tmp var "address" for flow analysis
 } function_t;
 
 extern function_t *current_func;

tools/qfcc/include/statements.h

@@ -49,6 +49,7 @@ typedef struct {
 	struct operand_s *alias;
 	struct operand_s *alias_ops;
 	int         users;
+	int         flowaddr;		///< "address" of temp in flow analysis, != 0
 } tempop_t;
 
 typedef struct operand_s {

tools/qfcc/source/constfold.c

@@ -1478,7 +1478,7 @@ fold_constants (expr_t *e)
 		}
 
 		op = e->e.expr.op;
-		if (op == 'i' || op == 'n' || op == 'c' || op == 's') {
+		if (op == 'A' || op == 'i' || op == 'n' || op == 'c' || op == 's') {
 			return e;
 		}
 

tools/qfcc/source/dags.c

@@ -158,8 +158,8 @@ operand_label (dag_t *dag, operand_t *op)
 		return 0;
 
 	if (op->op_type == op_temp) {
-		while (op->o.tempop.alias)
-			op = op->o.tempop.alias;
+		//while (op->o.tempop.alias)
+		//	op = op->o.tempop.alias;
 		if (op->o.tempop.daglabel)
 			return op->o.tempop.daglabel;
 		label = new_label (dag);

tools/qfcc/source/emit.c

@@ -91,10 +91,18 @@ get_operand_def (expr_t *expr, operand_t *op)
 			zero_def.type = &type_short;
 			return &zero_def;	//FIXME
 		case op_temp:
-			while (op->o.tempop.alias)
-				op = op->o.tempop.alias;
-			if (!op->o.tempop.def)
+			if (op->o.tempop.def) {
+				return op->o.tempop.def;
+			}
+			if (op->o.tempop.alias) {
+				def_t      *tdef = get_operand_def (expr, op->o.tempop.alias);
+				int         offset = op->o.tempop.offset;
+				type_t     *type = ev_types[op->type];
+				op->o.tempop.def = alias_def (tdef, type, offset);
+			}
+			if (!op->o.tempop.def) {
 				op->o.tempop.def = temp_def (op->type, op->size);
+			}
 			return op->o.tempop.def;
 		case op_alias:
 			return get_operand_def (expr, op->o.alias);

tools/qfcc/source/flow.c

@@ -204,6 +204,12 @@ flowvar_is_param (flowvar_t *var)
 		return 0;
 	return 1;
 }
+
+static int
+flowvar_is_local (flowvar_t *var)
+{
+	return !(flowvar_is_global (var) || flowvar_is_param (var));
+}
 #if 0
 static int
 flowvar_is_initialized (flowvar_t *var)
@@ -263,6 +269,24 @@ count_operand (operand_t *op)
 	return 0;
 }
 
+static int
+get_temp_address (function_t *func, operand_t *op)
+{
+	operand_t  *top = op;
+	if (op->o.tempop.flowaddr) {
+		return op->o.tempop.flowaddr;
+	}
+	while (top->o.tempop.alias) {
+		top = top->o.tempop.alias;
+	}
+	if (!top->o.tempop.flowaddr) {
+		top->o.tempop.flowaddr = func->tmpaddr;
+		func->tmpaddr += top->size;
+	}
+	op->o.tempop.flowaddr = top->o.tempop.flowaddr + op->o.tempop.offset;
+	return op->o.tempop.flowaddr;
+}
+
 static void
 add_operand (function_t *func, operand_t *op)
 {
@@ -280,6 +304,11 @@ add_operand (function_t *func, operand_t *op)
 		var->number = func->num_vars++;
 		var->op = op;
 		func->vars[var->number] = var;
+		if (op->op_type == op_temp) {
+			var->flowaddr = get_temp_address (func, op);
+		} else if (flowvar_is_local (var)) {
+			var->flowaddr = func->num_statements + def_offset (var->op->o.def);
+		}
 	}
 }
 
@@ -348,6 +377,9 @@ flow_build_vars (function_t *func)
 	stuse = set_new ();
 	stdef = set_new ();
 
+	// set up pseudo address space for temp vars so accessing tmp vars
+	// though aliases analyses correctly
+	func->tmpaddr = func->num_statements + func->symtab->space->size;
 	func->num_vars = 0;	// incremented by add_operand
 	// first, add .return and .param_[0-7] as they are always needed
 	for (i = 0; i < num_flow_params; i++)
@@ -382,27 +414,18 @@ flow_build_vars (function_t *func)
 	//     ([num_statements ... num_statements+localsize])
 	// with a set element for each def used in the local space
 	//
-	// temporary vars add their var number to the size of the local space
-	// before adding the number of statements in the function:
-	//     ([num_statements+localsize ... num_vars])
-	// temporary vars are always accessed as a full var, so only one set
-	// element per temporary var is needed. This can lead to holes in the
-	// temporary var set element space, but it does keep things simple
+	// temporary vars are pseudo allocated and their addresses are added as for
+	// locals
+	// add_operand takes care of setting flowaddr for both locals and temps
 	for (i = 0; i < func->num_vars; i++) {
-		int         offset, size;
 		int         j;
 
 		var = func->vars[i];
-		if (flowvar_is_global (var) || flowvar_is_param (var))
+		if (flowvar_is_global (var) || flowvar_is_param (var)) {
 			continue;
-		if (var->op->op_type == op_temp) {
-			j = func->symtab->space->size + var->number;
-			set_add (var->define, func->num_statements + j);
-		} else {
-			offset = def_offset (var->op->o.def);
-			size = def_size (var->op->o.def);
-			for (j = offset; j < offset + size; j++)
-				set_add (var->define, func->num_statements + j);
+		}
+		for (j = 0; j < var->op->size; j++) {
+			set_add (var->define, var->flowaddr + j);
 		}
 	}
 

tools/qfcc/source/statements.c

@@ -126,10 +126,11 @@ operand_string (operand_t *op)
 			return op->o.label->name;
 		case op_temp:
 			if (op->o.tempop.alias)
-				return va ("<tmp %s %p:%d:%p:%d>",
+				return va ("<tmp %s %p:%d:%p:%d:%d>",
 						   pr_type_name[op->type],
 						   op, op->o.tempop.users,
 						   op->o.tempop.alias,
+						   op->o.tempop.offset,
 						   op->o.tempop.alias->o.tempop.users);
 			return va ("<tmp %s %p:%d>", pr_type_name[op->o.tempop.type->type],
 					   op, op->o.tempop.users);
@@ -307,6 +308,7 @@ def_operand (def_t *def, type_t *type)
 		type = def->type;
 	op = new_operand (op_def);
 	op->type = low_level_type (type);
+	op->size = type_size (type);
 	op->o.def = def;
 	return op;
 }
@@ -830,6 +832,8 @@ expr_alias (sblock_t *sblock, expr_t *e, operand_t **op)
 			aop = aop->o.tempop.alias;
 			if (aop->op_type != op_temp)
 				internal_error (e, "temp alias of non-temp var");
+			if (aop->o.tempop.alias)
+				bug (e, "aliased temp alias");
 		}
 		for (top = aop->o.tempop.alias_ops; top; top = top->next) {
 			if (top->type == type && top->o.tempop.offset == offset) {
@@ -839,6 +843,7 @@ expr_alias (sblock_t *sblock, expr_t *e, operand_t **op)
 		if (!top) {
 			top = new_operand (op_temp);
 			top->type = type;
+			top->size = pr_type_size[type];
 			top->o.tempop.alias = aop;
 			top->o.tempop.offset = offset;
 			top->next = aop->o.tempop.alias_ops;