Merge branch 'PHP-8.4'

* PHP-8.4:
  Improve JIT TRACE coverage (#16171)

Author: dstogov

ext/opcache/jit/zend_jit_internal.h

@@ -647,7 +647,12 @@ ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_jit_ret_trace_helper(ZEND_OPCODE_HAND
 ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_jit_loop_trace_helper(ZEND_OPCODE_HANDLER_ARGS);
 
 int ZEND_FASTCALL zend_jit_trace_hot_root(zend_execute_data *execute_data, const zend_op *opline);
-zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data *execute_data, const zend_op *opline, zend_jit_trace_rec *trace_buffer, uint8_t start, uint32_t is_megamorphc);
+zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data  *execute_data,
+                                                         const zend_op      *opline,
+                                                         zend_jit_trace_rec *trace_buffer,
+                                                         uint8_t             start,
+                                                         uint32_t            is_megamorphc,
+                                                         int                 ret_depth);
 
 static zend_always_inline const zend_op* zend_jit_trace_get_exit_opline(zend_jit_trace_rec *trace, const zend_op *opline, bool *exit_if_true)
 {

ext/opcache/jit/zend_jit_trace.c

@@ -8066,7 +8066,7 @@ int ZEND_FASTCALL zend_jit_trace_hot_root(zend_execute_data *execute_data, const
 
 	JIT_G(tracing) = 1;
 	stop = zend_jit_trace_execute(execute_data, opline, trace_buffer,
-		ZEND_OP_TRACE_INFO(opline, offset)->trace_flags & ZEND_JIT_TRACE_START_MASK, 0);
+		ZEND_OP_TRACE_INFO(opline, offset)->trace_flags & ZEND_JIT_TRACE_START_MASK, 0, 0);
 	JIT_G(tracing) = 0;
 
 	if (stop & ZEND_JIT_TRACE_HALT) {
@@ -8390,6 +8390,8 @@ int ZEND_FASTCALL zend_jit_trace_hot_side(zend_execute_data *execute_data, uint3
 	zend_jit_trace_rec trace_buffer[ZEND_JIT_TRACE_MAX_LENGTH];
 	uint32_t is_megamorphic = 0;
 	uint32_t polymorphism = 0;
+	uint32_t root;
+	int ret_depth = 0;
 
 	trace_num = ZEND_JIT_TRACE_NUM;
 
@@ -8414,7 +8416,8 @@ int ZEND_FASTCALL zend_jit_trace_hot_side(zend_execute_data *execute_data, uint3
 		goto abort;
 	}
 
-	if (zend_jit_traces[zend_jit_traces[parent_num].root].child_count >= JIT_G(max_side_traces)) {
+	root = zend_jit_traces[parent_num].root;
+	if (zend_jit_traces[root].child_count >= JIT_G(max_side_traces)) {
 		stop = ZEND_JIT_TRACE_STOP_TOO_MANY_CHILDREN;
 		goto abort;
 	}
@@ -8434,8 +8437,29 @@ int ZEND_FASTCALL zend_jit_trace_hot_side(zend_execute_data *execute_data, uint3
 		}
 	}
 
+	/* Check if this is a side trace of a root LOOP trace */
+	if ((zend_jit_traces[root].flags & ZEND_JIT_TRACE_LOOP)
+	 && zend_jit_traces[root].op_array != &EX(func)->op_array) {
+		const zend_op_array *op_array = zend_jit_traces[root].op_array;
+		const zend_op *opline = zend_jit_traces[root].opline;
+		zend_jit_op_array_trace_extension *jit_extension =
+				(zend_jit_op_array_trace_extension*)ZEND_FUNC_INFO(op_array);
+
+		if (jit_extension->trace_info[opline - op_array->opcodes].trace_flags & ZEND_JIT_TRACE_START_LOOP) {
+			zend_execute_data *ex = execute_data;
+			int n = 0;
+			do {
+				ex = ex->prev_execute_data;
+				n++;
+			} while (ex && zend_jit_traces[root].op_array != &ex->func->op_array);
+			if (ex && n <= ZEND_JIT_TRACE_MAX_RET_DEPTH) {
+				ret_depth = n;
+			}
+		}
+	}
+
 	JIT_G(tracing) = 1;
-	stop = zend_jit_trace_execute(execute_data, EX(opline), trace_buffer, ZEND_JIT_TRACE_START_SIDE, is_megamorphic);
+	stop = zend_jit_trace_execute(execute_data, EX(opline), trace_buffer, ZEND_JIT_TRACE_START_SIDE, is_megamorphic, ret_depth);
 	JIT_G(tracing) = 0;
 
 	if (stop & ZEND_JIT_TRACE_HALT) {

ext/opcache/jit/zend_jit_vm_helpers.c

@@ -575,7 +575,7 @@ static int zend_jit_trace_subtrace(zend_jit_trace_rec *trace_buffer, int start,
  * +--------+----------+----------+----------++----------+----------+----------+
  * | RETURN |INNER_LOOP|          |  rec-ret ||   LINK   |          |   LINK   |
  * +--------+----------+----------+----------++----------+----------+----------+
- * | SIDE   |  unroll  |          |  return  ||   LINK   |   LINK   |   LINK   |
+ * | SIDE   |  unroll  |          | side-ret ||   LINK   |   LINK   |   LINK   |
  * +--------+----------+----------+----------++----------+----------+----------+
  *
  * loop:       LOOP if "cycle" and level == 0, otherwise INNER_LOOP
@@ -586,10 +586,16 @@ static int zend_jit_trace_subtrace(zend_jit_trace_rec *trace_buffer, int start,
  * loop-ret:   LOOP_EXIT if level == 0, otherwise continue (wait for loop)
  * return:     RETURN if level == 0
  * rec_ret:    RECURSIVE_RET if "cycle" and ret_level > N, otherwise continue
+ * side_ret:   RETURN if level == 0 && ret_level == ret_depth, otherwise continue
  *
  */
 
-zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data *ex, const zend_op *op, zend_jit_trace_rec *trace_buffer, uint8_t start, uint32_t is_megamorphic)
+zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data  *ex,
+                                                         const zend_op      *op,
+                                                         zend_jit_trace_rec *trace_buffer,
+                                                         uint8_t             start,
+                                                         uint32_t            is_megamorphic,
+                                                         int                 ret_depth)
 
 {
 #ifdef HAVE_GCC_GLOBAL_REGS
@@ -1060,6 +1066,20 @@ zend_jit_trace_stop ZEND_FASTCALL zend_jit_trace_execute(zend_execute_data *ex,
 							ZEND_JIT_TRACE_STOP_RECURSION_EXIT) {
 						stop = ZEND_JIT_TRACE_STOP_RECURSION_EXIT;
 						break;
+					} else if ((start & ZEND_JIT_TRACE_START_SIDE)
+					 && ret_level < ret_depth) {
+						TRACE_RECORD(ZEND_JIT_TRACE_BACK, 0, op_array);
+						ret_level++;
+						last_loop_opline = NULL;
+
+						if (prev_call) {
+							int ret = zend_jit_trace_record_fake_init_call(prev_call, trace_buffer, idx, 0);
+							if (ret < 0) {
+								stop = ZEND_JIT_TRACE_STOP_BAD_FUNC;
+								break;
+							}
+							idx = ret;
+						}
 					} else {
 						stop = ZEND_JIT_TRACE_STOP_RETURN;
 						break;