Allow an experimental VM with tail call dispatch technique (disabled by default).

This VM may work only if all tail calls are optimized, otherwaise it will crach because of stack overflow.
Unfortunately, we can't guarantee tail call optimization in C.

diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index 253a2d7a13ea6854dd1a4b769108c9ee8281d6d3..035f4ab7af0d5784d855c524d1042bb4a6951145 100644 (file)
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -337,8 +337,12 @@ register const zend_op* volatile opline __asm__(ZEND_VM_IP_GLOBAL_REG);
 #if defined(ZEND_VM_FP_GLOBAL_REG) && defined(ZEND_VM_IP_GLOBAL_REG)
 # define ZEND_OPCODE_HANDLER_RET void
 # define ZEND_VM_TAIL_CALL(call) call; return
-# define ZEND_VM_CONTINUE()      return
-# define ZEND_VM_RETURN()        opline = NULL; ZEND_VM_CONTINUE()
+# ifdef ZEND_VM_TAIL_CALL_DISPATCH
+#  define ZEND_VM_CONTINUE()     ((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU); return
+# else
+#  define ZEND_VM_CONTINUE()     return
+# endif
+# define ZEND_VM_RETURN()        opline = NULL; return
 #else
 # define ZEND_OPCODE_HANDLER_RET int
 # define ZEND_VM_TAIL_CALL(call) return call

diff --git a/Zend/zend_vm_gen.php b/Zend/zend_vm_gen.php
index 8f06bb48945881028149ef3500425af92ee004f4..613b4c9338dc27a11bf8588b5acb32d41c4984d2 100644 (file)
--- a/Zend/zend_vm_gen.php
+++ b/Zend/zend_vm_gen.php
@@ -1058,8 +1058,12 @@ function gen_executor($f, $skl, $spec, $kind, $executor_name, $initializer_name)
                                                        out($f,"#if defined(ZEND_VM_FP_GLOBAL_REG) && defined(ZEND_VM_IP_GLOBAL_REG)\n");
                                                        out($f,"# define ZEND_OPCODE_HANDLER_RET void\n");
                                                        out($f,"# define ZEND_VM_TAIL_CALL(call) call; return\n");
-                                                       out($f,"# define ZEND_VM_CONTINUE()      return\n");
-                                                       out($f,"# define ZEND_VM_RETURN()        opline = NULL; ZEND_VM_CONTINUE()\n");
+                                                       out($f,"# ifdef ZEND_VM_TAIL_CALL_DISPATCH\n");
+                                                       out($f,"#  define ZEND_VM_CONTINUE()     ((opcode_handler_t)OPLINE->handler)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU); return\n");
+                                                       out($f,"# else\n");
+                                                       out($f,"#  define ZEND_VM_CONTINUE()     return\n");
+                                                       out($f,"# endif\n");
+                                                       out($f,"# define ZEND_VM_RETURN()        opline = NULL; return\n");
                                                        out($f,"#else\n");
                                                        out($f,"# define ZEND_OPCODE_HANDLER_RET int\n");
                                                        out($f,"# define ZEND_VM_TAIL_CALL(call) return call\n");