fix hang by removing cross-BB var reference

Author: XrXr

zjit/src/hir.rs

@@ -6938,32 +6938,32 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                                 let branch_insn_idx = exit_state.insn_idx as u32;
                                 let locals_count = state.locals.len();
                                 let stack_count = state.stack.len();
-                                let (get_field_block, field_block_self, mut get_field_state, _) = new_branch_block(&mut fun, branch_insn_idx, &exit_state, locals_count, stack_count);
+                                let (load_block, load_block_self, mut get_field_state, _) = new_branch_block(&mut fun, branch_insn_idx, &exit_state, locals_count, stack_count);
                                 let expected_shape = fun.push_insn(block, Insn::Const { val: Const::CShape(profiled_type.shape()) });
                                 let test_id = fun.push_insn(block, Insn::IsBitEqual { left: shape, right: expected_shape });
                                 fun.push_insn(block, Insn::IfTrue {
                                     val: test_id,
                                     target: BranchEdge {
-                                        target: get_field_block,
+                                        target: load_block,
                                         args: state.as_args(self_param)
                                     }
                                 });
 
                                 let ivar = if profiled_type.flags().is_embedded() {
                                     // See ROBJECT_FIELDS() from include/ruby/internal/core/robject.h
                                     let offset = ROBJECT_OFFSET_AS_ARY as i32 + (SIZEOF_VALUE * ivar_index.to_usize()) as i32;
-                                    fun.push_insn(get_field_block, Insn::LoadField { recv: self_val, id, offset, return_type: types::BasicObject })
+                                    fun.push_insn(load_block, Insn::LoadField { recv: load_block_self, id, offset, return_type: types::BasicObject })
                                 } else {
-                                    let as_heap = fun.push_insn(get_field_block, Insn::LoadField { recv: self_val, id: ID!(_as_heap), offset: ROBJECT_OFFSET_AS_HEAP_FIELDS as i32, return_type: types::CPtr });
+                                    let as_heap = fun.push_insn(load_block, Insn::LoadField { recv: load_block_self, id: ID!(_as_heap), offset: ROBJECT_OFFSET_AS_HEAP_FIELDS as i32, return_type: types::CPtr });
 
                                     let offset = SIZEOF_VALUE_I32 * ivar_index as i32;
-                                    fun.push_insn(get_field_block, Insn::LoadField { recv: as_heap, id, offset, return_type: types::BasicObject })
+                                    fun.push_insn(load_block, Insn::LoadField { recv: as_heap, id, offset, return_type: types::BasicObject })
                                 };
 
                                 get_field_state.stack_push(ivar);
-                                fun.push_insn(get_field_block, Insn::Jump(BranchEdge {
+                                fun.push_insn(load_block, Insn::Jump(BranchEdge {
                                     target: join_block,
-                                    args: get_field_state.as_args(field_block_self),
+                                    args: get_field_state.as_args(load_block_self),
                                 }));
                             }
 

zjit/src/hir/opt_tests.rs

@@ -3996,7 +3996,38 @@ mod hir_opt_tests {
             b.test
             a.test
         ");
-        assert_snapshot!(hir_string_proc("Tester.instance_method(:test)"), @r"");
+        assert_snapshot!(hir_string_proc("Tester.instance_method(:test)"), @r"
+        fn test@<compiled>:3:
+        bb0():
+          EntryPoint interpreter
+          v1:BasicObject = LoadSelf
+          Jump bb2(v1)
+        bb1(v4:BasicObject):
+          EntryPoint JIT(0)
+          Jump bb2(v4)
+        bb2(v6:BasicObject):
+          PatchPoint SingleRactorMode
+          v11:HeapBasicObject = GuardType v6, HeapBasicObject
+          v12:CShape = LoadField v11, :_shape_id@0x1000
+          v15:CShape[0x1001] = Const CShape(0x1001)
+          v16:CBool = IsBitEqual v12, v15
+          IfTrue v16, bb4(v6)
+          v22:CShape[0x1002] = Const CShape(0x1002)
+          v23:CBool = IsBitEqual v12, v22
+          IfTrue v23, bb5(v6)
+          IncrCounter getivar_fallback_not_monomorphic
+          v27:BasicObject = GetIvar v6, :@foo
+          Jump bb3(v6, v27)
+        bb4(v13:BasicObject):
+          v18:BasicObject = LoadField v13, :@foo@0x1003
+          Jump bb3(v13, v18)
+        bb5(v20:BasicObject):
+          v25:BasicObject = LoadField v20, :@foo@0x1004
+          Jump bb3(v20, v25)
+        bb3(v29:BasicObject, v30:BasicObject):
+          CheckInterrupts
+          Return v30
+        ");
     }
 
     #[test]