Function reuse_results

cranelift/codegen/src/ir/builder.rs:339–359

()

    #[test]
    fn reuse_results() {
        let mut func = Function::new();
        let block0 = func.dfg.make_block();
        let arg0 = func.dfg.append_block_param(block0, I32);
        let mut pos = FuncCursor::new(&mut func);
        pos.insert_block(block0);

        let v0 = pos.ins().iadd_imm(arg0, 17);
        assert_eq!(pos.func.dfg.value_type(v0), I32);
        let iadd = pos.prev_inst().unwrap();
        assert_eq!(pos.func.dfg.value_def(v0), ValueDef::Result(iadd, 0));

        // Detach v0 and reuse it for a different instruction.
        pos.func.dfg.clear_results(iadd);
        let v0b = pos.ins().with_result(v0).iconst(I32, 3);
        assert_eq!(v0, v0b);
        assert_eq!(pos.current_inst(), Some(iadd));
        let iconst = pos.prev_inst().unwrap();
        assert!(iadd != iconst);
        assert_eq!(pos.func.dfg.value_def(v0), ValueDef::Result(iconst, 0));
    }

    #[test]
    fn replace_with_imm_method() {