From 20f152296ac397f900fc033587a231a3a3d2e4df Mon Sep 17 00:00:00 2001
From: Scott Olson <scott@solson.me>
Date: Sat, 19 Mar 2016 11:01:33 -0600
Subject: [PATCH] Implement min_align_of and a hacky mul_with_overflow.

---
 src/interpreter.rs | 23 +++++++++++++++++++++++
 src/lib.rs         |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/interpreter.rs b/src/interpreter.rs
index 73011886cdb..3f710ba2e2b 100644
--- a/src/interpreter.rs
+++ b/src/interpreter.rs
@@ -339,6 +339,29 @@ impl<'a, 'tcx: 'a, 'arena> Interpreter<'a, 'tcx, 'arena> {
             // TODO(tsion): Mark as dropped?
             "forget" => {}
 
+            "min_align_of" => {
+                try!(self.memory.write_int(dest, 1, dest_size));
+            }
+
+            // FIXME(tsion): Handle different integer types correctly.
+            "mul_with_overflow" => {
+                let ty = *substs.types.get(subst::FnSpace, 0);
+                let size = self.ty_size(ty);
+
+                let left_arg  = try!(self.eval_operand(&args[0]));
+                let right_arg = try!(self.eval_operand(&args[1]));
+
+                let left = try!(self.memory.read_int(left_arg, size));
+                let right = try!(self.memory.read_int(right_arg, size));
+
+                let (n, overflowed) = unsafe {
+                    ::std::intrinsics::mul_with_overflow::<i64>(left, right)
+                };
+
+                try!(self.memory.write_int(dest, n, size));
+                try!(self.memory.write_bool(dest.offset(size as isize), overflowed));
+            }
+
             "offset" => {
                 let pointee_ty = *substs.types.get(subst::FnSpace, 0);
                 let pointee_size = self.ty_size(pointee_ty) as isize;
diff --git a/src/lib.rs b/src/lib.rs
index 8646db3c222..d231e6f1a6b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-#![feature(btree_range, collections_bound, rustc_private)]
+#![feature(btree_range, collections_bound, core_intrinsics, rustc_private)]
 
 // From rustc.
 extern crate arena;