fix: 负零字面量折叠保符号不丢负号

Cargo.lock

@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1228,7 +1228,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1237,7 +1237,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1257,7 +1257,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1271,7 +1271,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1287,7 +1287,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1299,7 +1299,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1308,7 +1308,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1322,7 +1322,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1334,7 +1334,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1343,11 +1343,11 @@ dependencies = [
 
 [[package]]
 name = "oxide_net"
-version = "0.16.18"
+version = "0.16.19"
 
 [[package]]
 name = "oxide_parser"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1362,7 +1362,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1378,7 +1378,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1391,7 +1391,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1411,7 +1411,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1424,7 +1424,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.16.18"
+version = "0.16.19"
 dependencies = [
  "bumpalo",
  "chrono",

Cargo.toml

@@ -24,7 +24,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.16.18"
+version = "0.16.19"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"

crates/oxide_emit/src/expr/operator/fold.rs

@@ -34,10 +34,17 @@ use crate::shared::string_pool::{pool_key_marker, pool_key_plain};
 ///
 /// 一元负号只沿 `UnaryNegation` 链剥（含嵌套负号与括号），其余一元运算符
 /// （`!`/`typeof`/`void`/`~`/`+`/`delete`）终止剥壳不折。
+///
+/// 负零字面量（`-0`/`-0.0`）定值 `Number(-0.0)` 保符号：`is_int_literal(-0.0)`
+/// 为真，走 i32 臂会在 `as i32` 处丢符号。
 pub(crate) fn literal_constant(expr: &Expression) -> Option<Constant> {
     let (inner, negated) = peel_negation(expr);
     match inner {
         Expression::NumericLiteral(n) => {
+            // 负零直接定值 `Number(-0.0)`，镜像运行时 `NEG` 对零的产物。
+            if negated && n.value == 0.0 {
+                return Some(Constant::Number(-0.0));
+            }
             let value = if negated { -n.value } else { n.value };
             if is_int_literal(value) {
                 Some(Constant::Int(value as i32))

crates/oxide_emit/tests/fold_tests.rs

@@ -243,3 +243,35 @@ fn fold_deterministic() {
         }
     }
 }
+
+/// 负零字面量符号保真：折叠后常量池须含 `Number(-0.0)`（符号位置位），
+/// 不得走 i32 臂（`-0.0 as i32` 丢符号成 `Int(0)`）。符号位经 `to_bits`
+/// 比对——`Number(-0.0)` 与 `Number(0.0)` 的 `PartialEq` 相等，不能用
+/// `pool_contains` 判别。
+#[test]
+fn fold_negative_zero_sign() {
+    let cases: &[(&str, OpCode)] = &[
+        ("-0 - 0", OpCode::SUB),
+        ("-0 * 1", OpCode::MUL),
+        ("-0 / 1", OpCode::DIV),
+        ("-0 % 1", OpCode::MOD),
+        ("(-0) ** 3", OpCode::EXP),
+    ];
+    let neg_zero_bits = (-0.0f64).to_bits();
+    for (src, op) in cases {
+        let ir = emit_ir(src);
+        assert_eq!(
+            count_op(&ir.insts, *op),
+            0,
+            "{src:?} 应折叠，目标操作码 {op:?} 计数应为 0"
+        );
+        let has_neg_zero = ir
+            .constants
+            .iter()
+            .any(|c| matches!(c, Constant::Number(d) if d.to_bits() == neg_zero_bits));
+        assert!(
+            has_neg_zero,
+            "{src:?} 常量池应含折值 Number(-0.0)（符号位置位）"
+        );
+    }
+}