stage1 重制类型转换系统 修复问题 提供更多表达式

stage1/spl_intrin.c

@@ -12,6 +12,26 @@ static const spl_intrin_info_t g_intrin_table[] = {
                                SPL_INTRIN_RESULT_UNIT},
     [SPL_INTRIN_LEN] = {"len", SPL_INTRIN_LEN, SPL_INTRIN_FORM_FIELD, 0, 0,
                         SPL_INTRIN_RESULT_USIZE},
+    [SPL_INTRIN_INT_CAST] = {"@int_cast", SPL_INTRIN_INT_CAST, SPL_INTRIN_FORM_CALL, 2, 2,
+                             SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_TRUNCATE] = {"@truncate", SPL_INTRIN_TRUNCATE, SPL_INTRIN_FORM_CALL, 2, 2,
+                             SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_BIT_CAST] = {"@bit_cast", SPL_INTRIN_BIT_CAST, SPL_INTRIN_FORM_CALL, 2, 2,
+                             SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_FLOAT_CAST] = {"@float_cast", SPL_INTRIN_FLOAT_CAST, SPL_INTRIN_FORM_CALL, 2, 2,
+                               SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_INT_FROM_FLOAT] = {"@int_from_float", SPL_INTRIN_INT_FROM_FLOAT,
+                                   SPL_INTRIN_FORM_CALL, 2, 2, SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_FLOAT_FROM_INT] = {"@float_from_int", SPL_INTRIN_FLOAT_FROM_INT,
+                                   SPL_INTRIN_FORM_CALL, 2, 2, SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_INT_FROM_BOOL] = {"@int_from_bool", SPL_INTRIN_INT_FROM_BOOL, SPL_INTRIN_FORM_CALL,
+                                  1, 2, SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_INT_FROM_PTR] = {"@int_from_ptr", SPL_INTRIN_INT_FROM_PTR, SPL_INTRIN_FORM_CALL, 1,
+                                 2, SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_PTR_FROM_INT] = {"@ptr_from_int", SPL_INTRIN_PTR_FROM_INT, SPL_INTRIN_FORM_CALL, 2,
+                                 2, SPL_INTRIN_RESULT_UNIT},
+    [SPL_INTRIN_PTR_CAST] = {"@ptr_cast", SPL_INTRIN_PTR_CAST, SPL_INTRIN_FORM_CALL, 2, 2,
+                             SPL_INTRIN_RESULT_UNIT},
 };
 
 static const usize g_intrin_count = sizeof(g_intrin_table) / sizeof(g_intrin_table[0]);
@@ -46,3 +66,34 @@ spl_intrin_t spl_intrin_lookup_field(spl_lang_type_kind_t recv_kind, const char
     }
     return SPL_INTRIN_NONE;
 }
+
+spl_intrin_t spl_intrin_lookup_cast(spl_type_t *type, spl_type_id_t ft, spl_type_id_t tt) {
+    /* 这是 `as` 的展开规则表。要调整 as 的语义，改这里。 */
+    spl_type_node_t *f = spl_type_node(type, ft);
+    spl_type_node_t *t = spl_type_node(type, tt);
+    if (!f || !t)
+        return SPL_INTRIN_NONE;
+
+    if (f->kind == SPL_TYPE_INT && t->kind == SPL_TYPE_INT) {
+        usize fb = f->int_type.bits;
+        usize tb = t->int_type.bits;
+        if (fb == tb)
+            return SPL_INTRIN_BIT_CAST;
+        if (fb > tb)
+            return SPL_INTRIN_TRUNCATE;
+        return SPL_INTRIN_INT_CAST;
+    }
+    if (f->kind == SPL_TYPE_FLOAT && t->kind == SPL_TYPE_FLOAT)
+        return SPL_INTRIN_FLOAT_CAST;
+    if (f->kind == SPL_TYPE_BOOL && t->kind == SPL_TYPE_INT)
+        return SPL_INTRIN_INT_FROM_BOOL;
+    if (f->kind == SPL_TYPE_PTR && t->kind == SPL_TYPE_INT)
+        return SPL_INTRIN_INT_FROM_PTR;
+    if (f->kind == SPL_TYPE_INT && t->kind == SPL_TYPE_PTR)
+        return SPL_INTRIN_PTR_FROM_INT;
+    if (f->kind == SPL_TYPE_PTR && t->kind == SPL_TYPE_PTR)
+        return SPL_INTRIN_PTR_CAST;
+
+    /* int float 刻意不在这里：只能通过显式 builtin 调用。 */
+    return SPL_INTRIN_NONE;
+}