Eliminate CHECK_VAR instructions for defined CVs

diff --git a/ext/opcache/Optimizer/dce.c b/ext/opcache/Optimizer/dce.c
index 8370bdc779237c4b5a853a4ee00cd62d9df97cf5..2992bb60b37ec10c6197556c2d8a6d0ddf92d648 100644 (file)
--- a/ext/opcache/Optimizer/dce.c
+++ b/ext/opcache/Optimizer/dce.c
@@ -241,6 +241,8 @@ static inline zend_bool may_have_side_effects(
                                }
                        }
                        return 0;
+               case ZEND_CHECK_VAR:
+                       return (OP1_INFO() & MAY_BE_UNDEF) != 0;
                default:
                        /* For everything we didn't handle, assume a side-effect */
                        return 1;