fix(gen): CDefine 常量（含 mod.N 属性形态）拓宽方向单独判定——负值 sext、非负 zext，修 zlib 窗口尺寸被 sext 成负数与 Z_DEFAULT_COMPRESSION->255

App/lib/core/Gen/Expr/ExprGenOps.vp

@@ -135,6 +135,15 @@ novirtual class ExprGenOps(ExprGenBase.ExprGenBase):
         if narrow_val is None or narrow_val.Ty is None: return 0
         narrow_bits: int = self.get_llvm_type_bits(narrow_val.Ty)
         if narrow_bits == 1: return 1
+        # 编译期 CDefine 常量（裸名 `N` 或模块属性 `mod.N`）单独判定，必须**早于**下方「i8 默认 zext」：
+        #   · 负值 → sext（有符号语义，如 `define Z_DEFAULT_COMPRESSION = (-1)` 必须变 i32 -1，而非 255）；
+        #   · 非负 → zext（无符号位模式，如 `define WINDOW_SIZE = (1 << 15)` 必须变 32768，而非 -32768）。
+        # 否则这两类常量拓宽时必有一类被弄错（i8 位型走「默认 zext」；i16 位型若判不出无符号则走 sext）。
+        if narrow_node is not None:
+            cd_v_zw: int64 = self._cdefine_int_of(narrow_node)
+            if self.Gen.TypeGenCDef.is_cdefine_found() != 0:
+                if cd_v_zw < 0: return 0
+                return 1
         if narrow_bits == 8:
             # i8 defaults to unsigned-byte handling (systems convention), but an explicitly signed source annotation
             # must sext to preserve sign: `int32(v)` with v: int8 = -50 must stay -50, not become 206.
@@ -154,16 +163,28 @@ novirtual class ExprGenOps(ExprGenBase.ExprGenBase):
         # 50000 in 16 bits) is materialized as an unsigned bit pattern -> zext. Covered by
         # _node_type_unsigned below (which delegates to _cdefine_unsigned_bitpattern); keep return 0.
         return 0
+    # _cdefine_int_of - 取节点引用的 CDefine 常量值。支持两种引用形态：
+    #   · 裸名       `N`
+    #   · 模块属性   `mod.N`（跨模块经 .vpi 注册；常量名就是 at.attr）
+    # 未命中时 `Gen.TypeGenCDef.is_cdefine_found()` 为 0 —— 本函数每次都刷新该标志（空名也走一次 lookup）。
+    def _cdefine_int_of(self, node: ast.AST*) -> int64:
+        """CDefine integer value referenced by node (bare name or `mod.N`); check is_cdefine_found()."""
+        nm_cd: str = ""
+        if node is not None:
+            if node.kind() == ast.ASTKind.Name:
+                n_cd: ast.Name* = ast.Name*(node)
+                if n_cd.id is not None: nm_cd = n_cd.id
+            elif node.kind() == ast.ASTKind.Attribute:
+                a_cd: ast.Attribute* = ast.Attribute*(node)
+                if a_cd.attr is not None: nm_cd = a_cd.attr
+        return self.Gen.TypeGenCDef.lookup_cdefine_constant(nm_cd)
     # _cdefine_unsigned_bitpattern - 1 if node 是**非负 CDefine 常量**，且按它的最小可容纳位宽 W_min
     # 取无符号位模式时 high bit 已置位（如 50000 → W_min=16 → 0xC350）。规范：非负数按无符号位模式
     # 物化、负值按有符号解释（Debugger/define-constants.md §7.2）。这类常量在**宽化**与**比较**
     # （for-range 边界）时必须按无符号处理，否则 32768..65535 的常量会被读成负数（range 变 0 次）。
     def _cdefine_unsigned_bitpattern(self, node: ast.AST*) -> int:
         """1 = node is a non-negative CDefine whose minimal width's high bit is set; else 0."""
-        if node is None or node.kind() != ast.ASTKind.Name: return 0
-        nm_cd: ast.Name* = ast.Name*(node)
-        if nm_cd.id is None: return 0
-        v_cd: int64 = self.Gen.TypeGenCDef.lookup_cdefine_constant(nm_cd.id)
+        v_cd: int64 = self._cdefine_int_of(node)
         if self.Gen.TypeGenCDef.is_cdefine_found() == 0: return 0
         if v_cd < 0: return 0
         w_cd: int = self.Gen.AssignGen.define_min_width(v_cd)