From 79d3780fbda475a50d6e0ca53d51c9e7c7690ab1 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Wed, 16 Mar 2022 21:22:02 -0700
Subject: [PATCH] stage2: bit_not on u0 is always 0

---
 src/value.zig          | 5 +++++
 test/behavior/math.zig | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/src/value.zig b/src/value.zig
index d63452ee56..005f1f1ffd 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -2977,6 +2977,11 @@ pub const Value = extern union {
 
         const info = ty.intInfo(target);
 
+        if (info.bits == 0) {
+            assert(val.isZero()); // Sema should guarantee
+            return val;
+        }
+
         // TODO is this a performance issue? maybe we should try the operation without
         // resorting to BigInt first.
         var val_space: Value.BigIntSpace = undefined;
diff --git a/test/behavior/math.zig b/test/behavior/math.zig
index 05decb348e..5b91ceed47 100644
--- a/test/behavior/math.zig
+++ b/test/behavior/math.zig
@@ -375,6 +375,9 @@ test "binary not" {
     try expect(comptime x: {
         break :x ~@as(u64, 2147483647) == 18446744071562067968;
     });
+    try expect(comptime x: {
+        break :x ~@as(u0, 0) == 0;
+    });
     try testBinaryNot(0b1010101010101010);
 }