Move to separate function, don't perform it in main

Author: nielsdos

Zend/Optimizer/dfa_pass.c

@@ -1066,6 +1066,55 @@ static bool zend_dfa_try_to_replace_result(zend_op_array *op_array, zend_ssa *ss
 	return 0;
 }
 
+/* Sets a flag on SEND ops when a copy can be a avoided. */
+static void zend_dfa_optimize_send_copies(zend_op_array *op_array, zend_ssa *ssa)
+{
+	for (int v = 0; v < ssa->vars_count; v++) {
+		int var = ssa->vars[v].var;
+		if (var >= op_array->last_var) {
+			continue;
+		}
+
+		uint32_t type = ssa->var_info[v].type;
+		if (!(type & (MAY_BE_ANY-(MAY_BE_RC1|MAY_BE_ARRAY|MAY_BE_ARRAY_OF_ANY|MAY_BE_STRING|MAY_BE_NULL)))) {
+			continue;
+		}
+
+#if 0
+		fprintf(stderr, "cv %d: ", v);
+		zend_dump_var(op_array, IS_CV, v);
+		fprintf(stderr, "\n");
+		fprintf(stderr, "type %x\n", type);
+#endif
+
+		int use = ssa->vars[v].use_chain;
+		if (use >= 0
+			&& op_array->opcodes[use].opcode == ZEND_SEND_VAR
+			&& op_array->opcodes[use].op2_type == IS_UNUSED) {
+			int next_use = zend_ssa_next_use(ssa->ops, v, use);
+#if 0
+			if (next_use >= 0 && op_array->opcodes[next_use].opcode == ZEND_ASSIGN) {
+				fprintf(stderr, "v=%d next_use %d (%d, %d, %d, %d)\n", v, next_use, ssa->ops[next_use].result_def, ssa->ops[next_use].result_use, ssa->ops[next_use].op1_use, ssa->ops[next_use].op2_use);
+				fprintf(stderr, "next_use var: %d (var=%d)\n", ssa->vars[next_use].var, var);
+				fprintf(stderr, "OP1: %d (var=%d)\n", ssa->vars[ssa->ops[next_use].op1_def].var, var);
+			}
+#endif
+			/* The next use must be an assignment, and there should be no uses after that.
+			 * If there is no next use or the next use is not an assignment, then we cannot safely 
+			 * perform the operation without a copy because the nullified value would be observable indirectly
+			 * through compact(), func_get_args(), ... */
+			if (next_use >= 0
+				&& op_array->opcodes[next_use].opcode == ZEND_ASSIGN
+				&& ssa->ops[next_use].op1_use == v
+				&& ssa->vars[v].var == var
+				&& zend_ssa_next_use(ssa->ops, v, next_use) < 0) {
+				ZEND_ASSERT(op_array->opcodes[use].extended_value == 0);
+				op_array->opcodes[use].extended_value = 1;
+			}
+		}
+	}
+}
+
 void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa, zend_call_info **call_map)
 {
 	if (ctx->debug_level & ZEND_DUMP_BEFORE_DFA_PASS) {
@@ -1124,50 +1173,9 @@ void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx
 #endif
 		}
 
-		// TODO: move me to other function?
-		for (v = 0; v < ssa->vars_count&&op_array->function_name/*TODO*/; v++) {
-			int var = ssa->vars[v].var;
-			if (var >= op_array->last_var) {
-				continue;
-			}
-
-			uint32_t type = ssa->var_info[v].type;
-			if (!(type & (MAY_BE_ANY-(MAY_BE_RC1|MAY_BE_ARRAY|MAY_BE_ARRAY_OF_ANY|MAY_BE_STRING|MAY_BE_NULL)))) {
-				continue;
-			}
-
-#if 0
-			fprintf(stderr, "cv %d: ", v);
-			zend_dump_var(op_array, IS_CV, v);
-			fprintf(stderr, "\n");
-			fprintf(stderr, "type %x\n", type);
-#endif
-
-			int use = ssa->vars[v].use_chain;
-			if (use >= 0
-				&& op_array->opcodes[use].opcode == ZEND_SEND_VAR
-				&& op_array->opcodes[use].op2_type == IS_UNUSED) {
-				int next_use = zend_ssa_next_use(ssa->ops, v, use);
-#if 0
-				if (next_use >= 0 && op_array->opcodes[next_use].opcode == ZEND_ASSIGN) {
-					fprintf(stderr, "v=%d next_use %d (%d, %d, %d, %d)\n", v, next_use, ssa->ops[next_use].result_def, ssa->ops[next_use].result_use, ssa->ops[next_use].op1_use, ssa->ops[next_use].op2_use);
-					fprintf(stderr, "next_use var: %d (var=%d)\n", ssa->vars[next_use].var, var);
-					fprintf(stderr, "OP1: %d (var=%d)\n", ssa->vars[ssa->ops[next_use].op1_def].var, var);
-				}
-#endif
-				/* The next use must be an assignment, and there should be no uses after that.
-				 * If there is no next use or the next use is not an assignment, then we cannot safely 
-				 * perform the operation without a copy because the nullified value would be observable indirectly
-				 * through compact(), func_get_args(), ... */
-				if (next_use >= 0
-					&& op_array->opcodes[next_use].opcode == ZEND_ASSIGN
-					&& ssa->ops[next_use].op1_use == v
-					&& ssa->vars[v].var == var
-					&& zend_ssa_next_use(ssa->ops, v, next_use) < 0) {
-					ZEND_ASSERT(op_array->opcodes[use].extended_value == 0);
-					op_array->opcodes[use].extended_value = 1;
-				}
-			}
+		/* Optimization should not be done on main because of globals */
+		if (op_array->function_name) {
+			zend_dfa_optimize_send_copies(op_array, ssa);
 		}
 
 		for (v = op_array->last_var; v < ssa->vars_count; v++) {