From 129fd4b06e4e5d39ab24b08395efa85e856d611e Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Thu, 10 Nov 2016 10:40:53 -0800
Subject: [PATCH] Add TypeVar.strip_sameas().

Strips out any type variable copies from an expression.
---
 lib/cretonne/meta/cdsl/typevar.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/cretonne/meta/cdsl/typevar.py b/lib/cretonne/meta/cdsl/typevar.py
index 66786f53cf..c2aeb5de97 100644
--- a/lib/cretonne/meta/cdsl/typevar.py
+++ b/lib/cretonne/meta/cdsl/typevar.py
@@ -313,6 +313,19 @@ class TypeVar(object):
         self.base = base
         self.derived_func = derived_func
 
+    def strip_sameas(self):
+        # type: () -> TypeVar
+        """
+        Strip any `SAMEAS` functions from this typevar.
+
+        Also rewrite any `SAMEAS` functions nested under this typevar.
+        """
+        if self.is_derived:
+            self.base = self.base.strip_sameas()
+            if self.derived_func == self.SAMEAS:
+                return self.base
+        return self
+
     def lane_of(self):
         # type: () -> TypeVar
         """