Optimizer: Optimize IS_IDENTICAL with true/false/null to TYPE_CHECK

This optimization is already happening in the compiler for explicit `===`
expressions, but not for `match()`, which also compiles to `IS_IDENTICAL`.

Author: TimWolla

Zend/Optimizer/block_pass.c

@@ -470,7 +470,36 @@ static void zend_optimize_block(zend_basic_block *block, zend_op_array *op_array
 					goto optimize_bool;
 				}
 				break;
+			case ZEND_IS_IDENTICAL:
+				if (opline->op1_type == IS_CONST &&
+					opline->op2_type == IS_CONST) {
+					goto optimize_constant_binary_op;
+				}
 
+				if (opline->op1_type == IS_CONST &&
+					(Z_TYPE(ZEND_OP1_LITERAL(opline)) <= IS_TRUE && Z_TYPE(ZEND_OP1_LITERAL(opline)) >= IS_NULL)) {
+					/* IS_IDENTICAL(TRUE, T)  => TYPE_CHECK(T, TRUE)
+					 * IS_IDENTICAL(FALSE, T) => TYPE_CHECK(T, FALSE)
+					 * IS_IDENTICAL(NULL, T)  => TYPE_CHECK(T, NULL)
+					 */
+					opline->opcode = ZEND_TYPE_CHECK;
+					opline->extended_value = (1 << Z_TYPE(ZEND_OP1_LITERAL(opline)));
+					COPY_NODE(opline->op1, opline->op2);
+					SET_UNUSED(opline->op2);
+					++(*opt_count);
+				} else if (opline->op2_type == IS_CONST &&
+					(Z_TYPE(ZEND_OP2_LITERAL(opline)) <= IS_TRUE && Z_TYPE(ZEND_OP2_LITERAL(opline)) >= IS_NULL)) {
+					/* IS_IDENTICAL(T, TRUE)  => TYPE_CHECK(T, TRUE)
+					 * IS_IDENTICAL(T, FALSE) => TYPE_CHECK(T, FALSE)
+					 * IS_IDENTICAL(T, NULL)  => TYPE_CHECK(T, NULL)
+					 */
+					opline->opcode = ZEND_TYPE_CHECK;
+					opline->extended_value = (1 << Z_TYPE(ZEND_OP2_LITERAL(opline)));
+					SET_UNUSED(opline->op2);
+					++(*opt_count);
+				}
+				break;
+	
 			case ZEND_BOOL:
 			case ZEND_BOOL_NOT:
 			optimize_bool:
@@ -803,7 +832,6 @@ static void zend_optimize_block(zend_basic_block *block, zend_op_array *op_array
 			case ZEND_SR:
 			case ZEND_IS_SMALLER:
 			case ZEND_IS_SMALLER_OR_EQUAL:
-			case ZEND_IS_IDENTICAL:
 			case ZEND_IS_NOT_IDENTICAL:
 			case ZEND_BOOL_XOR:
 			case ZEND_BW_OR:

ext/opcache/tests/match/005.phpt

@@ -0,0 +1,57 @@
+--TEST--
+Match expression true
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.opt_debug_level=0x20000
+zend_test.observer.enabled=0
+--EXTENSIONS--
+opcache
+--FILE--
+<?php
+
+$text = 'Bienvenue chez nous';
+
+$result = match (true) {
+    !!preg_match('/Welcome/', $text), !!preg_match('/Hello/', $text) => 'en',
+    !!preg_match('/Bienvenue/', $text), !!preg_match('/Bonjour/', $text) => 'fr',
+    default => 'other',
+};
+
+var_dump($result);
+
+?>
+--EXPECTF--
+$_main:
+     ; (lines=28, args=0, vars=2, tmps=3)
+     ; (after optimizer)
+     ; %s
+0000 ASSIGN CV0($text) string("Bienvenue chez nous")
+0001 T2 = FRAMELESS_ICALL_2(preg_match) string("/Welcome/") CV0($text)
+0002 T3 = BOOL T2
+0003 T2 = TYPE_CHECK (true) T3
+0004 JMPNZ T2 0018
+0005 T4 = FRAMELESS_ICALL_2(preg_match) string("/Hello/") CV0($text)
+0006 T3 = BOOL T4
+0007 T2 = TYPE_CHECK (true) T3
+0008 JMPNZ T2 0018
+0009 T4 = FRAMELESS_ICALL_2(preg_match) string("/Bienvenue/") CV0($text)
+0010 T3 = BOOL T4
+0011 T2 = TYPE_CHECK (true) T3
+0012 JMPNZ T2 0020
+0013 T4 = FRAMELESS_ICALL_2(preg_match) string("/Bonjour/") CV0($text)
+0014 T3 = BOOL T4
+0015 T2 = TYPE_CHECK (true) T3
+0016 JMPNZ T2 0020
+0017 JMP 0022
+0018 T2 = QM_ASSIGN string("en")
+0019 JMP 0023
+0020 T2 = QM_ASSIGN string("fr")
+0021 JMP 0023
+0022 T2 = QM_ASSIGN string("other")
+0023 ASSIGN CV1($result) T2
+0024 INIT_FCALL 1 %d string("var_dump")
+0025 SEND_VAR CV1($result) 1
+0026 DO_ICALL
+0027 RETURN int(1)
+string(2) "fr"