From 06407dd337a501931076c3fa68d6503bd72532c6 Mon Sep 17 00:00:00 2001
From: Trevor Elliott <telliott@fastly.com>
Date: Wed, 20 Jul 2022 17:01:33 -0700
Subject: [PATCH] Add a test to prevent x64 Inst size slipping further (#4489)

* Add a test to prevent x64 Inst size slipping further

* Enable the test for 64-bit pointers only
---
 cranelift/codegen/src/isa/x64/inst/mod.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/cranelift/codegen/src/isa/x64/inst/mod.rs b/cranelift/codegen/src/isa/x64/inst/mod.rs
index a9d0a79146..f888bb9af3 100644
--- a/cranelift/codegen/src/isa/x64/inst/mod.rs
+++ b/cranelift/codegen/src/isa/x64/inst/mod.rs
@@ -43,6 +43,14 @@ pub struct CallInfo {
     pub opcode: Opcode,
 }
 
+#[test]
+#[cfg(target_pointer_width = "64")]
+fn inst_size_test() {
+    // This test will help with unintentionally growing the size
+    // of the Inst enum.
+    assert_eq!(72, std::mem::size_of::<Inst>());
+}
+
 pub(crate) fn low32_will_sign_extend_to_64(x: u64) -> bool {
     let xs = x as i64;
     xs == ((xs << 32) >> 32)