Optimize $x === null into is_null($x)

Author: dstogov

Zend/zend_compile.c

@@ -7385,8 +7385,28 @@ void zend_compile_binary_op(znode *result, zend_ast *ast) /* {{{ */
 					break;
 				}
 			}
-		}
-		if (opcode == ZEND_CONCAT) {
+		} else if (opcode == ZEND_IS_IDENTICAL || opcode == ZEND_IS_NOT_IDENTICAL) {
+			/* convert $x === null to is_null($x) (i.e. ZEND_TYPE_CHECK opcode). Do the same thing for false/true. (covers IS_NULL, IS_FALSE, and IS_TRUE) */
+			if (left_node.op_type == IS_CONST) {
+				if (Z_TYPE(left_node.u.constant) <= IS_TRUE && Z_TYPE(left_node.u.constant) >= IS_NULL) {
+					zend_op *opline = zend_emit_op_tmp(result, ZEND_TYPE_CHECK, &right_node, NULL);
+					opline->extended_value =
+						(opcode == ZEND_IS_IDENTICAL) ?
+							(1 << Z_TYPE(left_node.u.constant)) :
+							(MAY_BE_ANY - (1 << Z_TYPE(left_node.u.constant)));
+					return;
+				}
+			} else if (right_node.op_type == IS_CONST) {
+				if (Z_TYPE(right_node.u.constant) <= IS_TRUE && Z_TYPE(right_node.u.constant) >= IS_NULL) {
+					zend_op *opline = zend_emit_op_tmp(result, ZEND_TYPE_CHECK, &left_node, NULL);
+					opline->extended_value =
+						(opcode == ZEND_IS_IDENTICAL) ?
+							(1 << Z_TYPE(right_node.u.constant)) :
+							(MAY_BE_ANY - (1 << Z_TYPE(right_node.u.constant)));
+					return;
+				}
+			}
+		} else if (opcode == ZEND_CONCAT) {
 			/* convert constant operands to strings at compile-time */
 			if (left_node.op_type == IS_CONST) {
 				if (Z_TYPE(left_node.u.constant) == IS_ARRAY) {

Zend/zend_vm_def.h

@@ -7848,7 +7848,7 @@ ZEND_VM_HOT_NOCONST_HANDLER(123, ZEND_TYPE_CHECK, CONST|TMPVAR|CV, ANY, TYPE_MAS
 	value = GET_OP1_ZVAL_PTR_UNDEF(BP_VAR_R);
 	if ((opline->extended_value >> (uint32_t)Z_TYPE_P(value)) & 1) {
 ZEND_VM_C_LABEL(type_check_resource):
-		if (EXPECTED(Z_TYPE_P(value) != IS_RESOURCE)
+		if (opline->extended_value != MAY_BE_RESOURCE
 		 || EXPECTED(NULL != zend_rsrc_list_get_rsrc_type(Z_RES_P(value)))) {
 			result = 1;
 		}

Zend/zend_vm_execute.h

@@ -4436,7 +4436,7 @@ static ZEND_VM_COLD ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_TYPE_CHECK_SPEC_C
 	value = RT_CONSTANT(opline, opline->op1);
 	if ((opline->extended_value >> (uint32_t)Z_TYPE_P(value)) & 1) {
 type_check_resource:
-		if (EXPECTED(Z_TYPE_P(value) != IS_RESOURCE)
+		if (opline->extended_value != MAY_BE_RESOURCE
 		 || EXPECTED(NULL != zend_rsrc_list_get_rsrc_type(Z_RES_P(value)))) {
 			result = 1;
 		}
@@ -13254,7 +13254,7 @@ static ZEND_VM_HOT ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_TYPE_CHECK_SPEC_TM
 	value = _get_zval_ptr_var(opline->op1.var EXECUTE_DATA_CC);
 	if ((opline->extended_value >> (uint32_t)Z_TYPE_P(value)) & 1) {
 type_check_resource:
-		if (EXPECTED(Z_TYPE_P(value) != IS_RESOURCE)
+		if (opline->extended_value != MAY_BE_RESOURCE
 		 || EXPECTED(NULL != zend_rsrc_list_get_rsrc_type(Z_RES_P(value)))) {
 			result = 1;
 		}
@@ -36407,7 +36407,7 @@ static ZEND_VM_HOT ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_TYPE_CHECK_SPEC_CV
 	value = EX_VAR(opline->op1.var);
 	if ((opline->extended_value >> (uint32_t)Z_TYPE_P(value)) & 1) {
 type_check_resource:
-		if (EXPECTED(Z_TYPE_P(value) != IS_RESOURCE)
+		if (opline->extended_value != MAY_BE_RESOURCE
 		 || EXPECTED(NULL != zend_rsrc_list_get_rsrc_type(Z_RES_P(value)))) {
 			result = 1;
 		}

ext/opcache/Optimizer/zend_dump.c

@@ -516,7 +516,8 @@ static void zend_dump_op(const zend_op_array *op_array, const zend_basic_block *
 				fprintf(stderr, " (bool)");
 				break;
 			default:
-				fprintf(stderr, " (\?\?\?)");
+				fprintf(stderr, " TYPE");
+				zend_dump_type_info(opline->extended_value, NULL, 0, dump_flags);
 				break;
 		}
 	} else if (ZEND_VM_EXT_EVAL == (flags & ZEND_VM_EXT_MASK)) {

ext/opcache/Optimizer/zend_ssa.c

@@ -161,7 +161,7 @@ static inline void pi_not_type_mask(zend_ssa_phi *phi, uint32_t type_mask) {
 }
 static inline uint32_t mask_for_type_check(uint32_t type) {
 	if (type & MAY_BE_ARRAY) {
-		return MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_ANY|MAY_BE_ARRAY_OF_ANY|MAY_BE_ARRAY_OF_REF;
+		return type | (MAY_BE_ARRAY_KEY_ANY|MAY_BE_ARRAY_OF_ANY|MAY_BE_ARRAY_OF_REF);
 	} else {
 		return type;
 	}

ext/opcache/jit/zend_jit_x86.dasc

@@ -8003,7 +8003,7 @@ static int zend_jit_type_check(dasm_State **Dst, const zend_op *opline, int b, i
 	zend_bool smart_branch = 0;
 	zend_jit_addr op1_addr = zend_jit_decode_op(op_array, opline->op1_type, opline->op1, opline, NULL, -1);
 
-	if (opline->extended_value & MAY_BE_RESOURCE) {
+	if (opline->extended_value == MAY_BE_RESOURCE) {
 		// TODO: support for is_resource() ???
 		goto fallback;
 	}