diff --git a/src/interpreter/cast.rs b/src/interpreter/cast.rs
index 70b39fc882e..f14baa2446c 100644
--- a/src/interpreter/cast.rs
+++ b/src/interpreter/cast.rs
@@ -92,21 +92,24 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
     }
 
     fn cast_ptr(&self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<'tcx, PrimVal> {
-        use primval::PrimValKind::*;
         use rustc::ty::TypeVariants::*;
         match ty.sty {
             TyRef(..) | TyRawPtr(_) => Ok(PrimVal::from_ptr(ptr)),
             TyFnPtr(_) => Ok(PrimVal::from_fn_ptr(ptr)),
 
-            TyInt(IntTy::I8)  => Ok(PrimVal::new(ptr.to_int()? as u64, I8)),
-            TyInt(IntTy::I16) => Ok(PrimVal::new(ptr.to_int()? as u64, I16)),
-            TyInt(IntTy::I32) => Ok(PrimVal::new(ptr.to_int()? as u64, I32)),
-            TyInt(IntTy::I64) => Ok(PrimVal::new(ptr.to_int()? as u64, I64)),
-
-            TyUint(UintTy::U8)  => Ok(PrimVal::new(ptr.to_int()? as u64, U8)),
-            TyUint(UintTy::U16) => Ok(PrimVal::new(ptr.to_int()? as u64, U16)),
-            TyUint(UintTy::U32) => Ok(PrimVal::new(ptr.to_int()? as u64, U32)),
-            TyUint(UintTy::U64) => Ok(PrimVal::new(ptr.to_int()? as u64, U64)),
+            TyInt(IntTy::I8) |
+            TyInt(IntTy::I16) |
+            TyInt(IntTy::I32) |
+            TyInt(IntTy::I64) |
+            TyInt(IntTy::Is) |
+            TyUint(UintTy::U8) |
+            TyUint(UintTy::U16) |
+            TyUint(UintTy::U32) |
+            TyUint(UintTy::U64) |
+            TyUint(UintTy::Us) => {
+                let val = PrimVal::from_ptr(ptr);
+                self.transmute_primval(val, ty)
+            }
 
             _ => Err(EvalError::Unimplemented(format!("ptr to {:?} cast", ty))),
         }
diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
index 689ef924536..b15f8b2d2d8 100644
--- a/src/interpreter/mod.rs
+++ b/src/interpreter/mod.rs
@@ -1699,13 +1699,13 @@ pub fn run_mir_passes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     let mut passes = ::rustc::mir::transform::Passes::new();
     passes.push_hook(Box::new(::rustc_mir::transform::dump_mir::DumpMir));
     passes.push_pass(Box::new(::rustc_mir::transform::no_landing_pads::NoLandingPads));
-    passes.push_pass(Box::new(::rustc_mir::transform::simplify_cfg::SimplifyCfg::new("no-landing-pads")));
+    passes.push_pass(Box::new(::rustc_mir::transform::simplify::SimplifyCfg::new("no-landing-pads")));
 
     passes.push_pass(Box::new(::rustc_mir::transform::erase_regions::EraseRegions));
 
     passes.push_pass(Box::new(::rustc_borrowck::ElaborateDrops));
     passes.push_pass(Box::new(::rustc_mir::transform::no_landing_pads::NoLandingPads));
-    passes.push_pass(Box::new(::rustc_mir::transform::simplify_cfg::SimplifyCfg::new("elaborate-drops")));
+    passes.push_pass(Box::new(::rustc_mir::transform::simplify::SimplifyCfg::new("elaborate-drops")));
     passes.push_pass(Box::new(::rustc_mir::transform::dump_mir::Marker("PreMiri")));
 
     passes.run_passes(tcx);