Replce ZEND_FETCH_* instructions with IS_CV if possible

ext/opcache/Optimizer/pass1_5.c

@@ -388,6 +388,58 @@ if (ZEND_OPTIMIZER_PASS_1 & OPTIMIZATION_LEVEL) {
 				}
 			}
 			break;
+
+#if ZEND_EXTENSION_API_NO >= PHP_5_5_X_API_NO
+		case ZEND_FETCH_R:
+		case ZEND_FETCH_W:
+		case ZEND_FETCH_RW:
+		case ZEND_FETCH_FUNC_ARG:
+		case ZEND_FETCH_IS:
+		case ZEND_FETCH_UNSET:
+			if (opline != op_array->opcodes &&
+			    (opline-1)->opcode == ZEND_BEGIN_SILENCE &&
+			    (opline->extended_value & ZEND_FETCH_TYPE_MASK) == ZEND_FETCH_LOCAL &&
+				opline->op1_type == IS_CONST &&
+			    opline->op2_type == IS_UNUSED &&
+			    Z_TYPE(ZEND_OP1_LITERAL(opline)) == IS_STRING &&
+			    (Z_STRLEN(ZEND_OP1_LITERAL(opline)) != sizeof("this")-1 ||
+			     memcmp(Z_STRVAL(ZEND_OP1_LITERAL(opline)), "this", sizeof("this")) != 0)) {
+
+			    int var = opline->result.var;
+			    int level = 0;
+				zend_op *op = opline + 1;
+
+				while (op < end) {
+					if (op->opcode == ZEND_BEGIN_SILENCE) {
+						level++;
+					} else if (op->opcode == ZEND_END_SILENCE) {
+						if (level == 0) {
+							break;
+						} else {
+							level--;
+						}
+					}
+					if (op->op1_type == IS_VAR && op->op1.var == var) {
+						op->op1_type = IS_CV;
+						op->op1.var = zend_optimizer_lookup_cv(op_array,
+							Z_STRVAL(ZEND_OP1_LITERAL(opline)),
+							Z_STRLEN(ZEND_OP1_LITERAL(opline)));
+						MAKE_NOP(opline);
+						break;
+					} else if (op->op2_type == IS_VAR && op->op2.var == var) {
+						op->op2_type = IS_CV;
+						op->op2.var = zend_optimizer_lookup_cv(op_array,
+							Z_STRVAL(ZEND_OP1_LITERAL(opline)),
+							Z_STRLEN(ZEND_OP1_LITERAL(opline)));
+						MAKE_NOP(opline);
+						break;
+					}
+					op++;
+				}
+			}
+			break;
+#endif
+		
 		}
 		opline++;
 		i++;

ext/opcache/Optimizer/zend_optimizer.c

@@ -28,6 +28,35 @@
 #define OPTIMIZATION_LEVEL \
 	ZCG(accel_directives).optimization_level
 
+#if ZEND_EXTENSION_API_NO >= PHP_5_5_X_API_NO
+static int zend_optimizer_lookup_cv(zend_op_array *op_array, char* name, int name_len)
+{
+	int i = 0;
+	ulong hash_value = zend_inline_hash_func(name, name_len+1);
+
+	while (i < op_array->last_var) {
+		if (op_array->vars[i].name == name ||
+		    (op_array->vars[i].hash_value == hash_value &&
+		     op_array->vars[i].name_len == name_len &&
+		     memcmp(op_array->vars[i].name, name, name_len) == 0)) {
+			return i;
+		}
+		i++;
+	}
+	i = op_array->last_var;
+	op_array->last_var++;
+	op_array->vars = erealloc(op_array->vars, op_array->last_var * sizeof(zend_compiled_variable));
+	if (IS_INTERNED(name)) {
+		op_array->vars[i].name = name;
+	} else {
+		op_array->vars[i].name = estrndup(name, name_len);
+	}
+	op_array->vars[i].name_len = name_len;
+	op_array->vars[i].hash_value = hash_value;
+	return i;
+}
+#endif
+
 #if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
 int zend_optimizer_add_literal(zend_op_array *op_array, const zval *zv TSRMLS_DC)
 {