From d566faa8fb1f626ef89eb351da3ec9a448c7736c Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 28 Mar 2018 16:16:35 -0700
Subject: [PATCH] Disable preopt at opt_level=fastest.

---
 lib/cretonne/src/context.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/cretonne/src/context.rs b/lib/cretonne/src/context.rs
index fba2cd2cc3..54fce4b84a 100644
--- a/lib/cretonne/src/context.rs
+++ b/lib/cretonne/src/context.rs
@@ -88,7 +88,9 @@ impl Context {
         self.verify_if(isa)?;
 
         self.compute_cfg();
-        self.preopt(isa)?;
+        if isa.flags().opt_level() != OptLevel::Fastest {
+            self.preopt(isa)?;
+        }
         self.legalize(isa)?;
         if isa.flags().opt_level() == OptLevel::Best {
             self.compute_domtree();