From 6710216e96a78bd06b049cbcd0a64d5a110af726 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 20 Sep 2017 12:38:13 -0700
Subject: [PATCH] Add next_inst and prev_inst helper functions to Layout.

---
 lib/cretonne/src/ir/layout.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/cretonne/src/ir/layout.rs b/lib/cretonne/src/ir/layout.rs
index c2c8f5ea7a..2139848382 100644
--- a/lib/cretonne/src/ir/layout.rs
+++ b/lib/cretonne/src/ir/layout.rs
@@ -482,6 +482,16 @@ impl Layout {
         self.ebbs[ebb].last_inst.into()
     }
 
+    /// Fetch the instruction following `inst`.
+    pub fn next_inst(&self, inst: Inst) -> Option<Inst> {
+        self.insts[inst].next.expand()
+    }
+
+    /// Fetch the instruction preceding `inst`.
+    pub fn prev_inst(&self, inst: Inst) -> Option<Inst> {
+        self.insts[inst].prev.expand()
+    }
+
     /// Insert `inst` before the instruction `before` in the same EBB.
     pub fn insert_inst(&mut self, inst: Inst, before: Inst) {
         assert_eq!(self.inst_ebb(inst), None);