From 814d1728aafea39c6f6a1ca76eee88c73fae1800 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Thu, 3 Nov 2016 17:55:41 -0700
Subject: [PATCH] Add a Value::unwrap_direct() method.

When it is known that a value is the first result of an instruction, it
is safe to unwrap the instruction reference.
---
 lib/cretonne/src/ir/entities.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/cretonne/src/ir/entities.rs b/lib/cretonne/src/ir/entities.rs
index 384e4d3ae9..df7d81988f 100644
--- a/lib/cretonne/src/ir/entities.rs
+++ b/lib/cretonne/src/ir/entities.rs
@@ -164,6 +164,19 @@ impl Value {
             Table(index)
         }
     }
+
+    /// Assuming that this is a direct value, get the referenced instruction.
+    ///
+    /// # Panics
+    ///
+    /// If this is not a value created with `new_direct()`.
+    pub fn unwrap_direct(&self) -> Inst {
+        if let ExpandedValue::Direct(inst) = self.expand() {
+            inst
+        } else {
+            panic!("{} is not a direct value", self)
+        }
+    }
 }
 
 /// Display a `Value` reference as "v7" or "v2x".