diff --git a/examples/example.rs b/examples/example.rs
index ecc5db5c0db1..05b370f91e08 100644
--- a/examples/example.rs
+++ b/examples/example.rs
@@ -150,3 +150,7 @@ fn use_array(arr: [u8; 3]) -> u8 {
 fn repeat_array() -> [u8; 3] {
     [0; 3]
 }
+
+unsafe fn use_ctlz_nonzero(a: u16) -> u16 {
+    intrinsics::ctlz_nonzero(a)
+}
diff --git a/examples/mini_core.rs b/examples/mini_core.rs
index dc19d66b2144..17d321db345d 100644
--- a/examples/mini_core.rs
+++ b/examples/mini_core.rs
@@ -139,6 +139,7 @@ pub mod intrinsics {
         pub fn copy<T>(src: *const T, dst: *mut T, count: usize);
         pub fn transmute<T, U>(e: T) -> U;
         pub fn uninit<T>() -> T;
+        pub fn ctlz_nonzero<T>(x: T) -> T;
     }
 }
 
diff --git a/src/abi.rs b/src/abi.rs
index 929002f0e803..0d44952dc0d5 100644
--- a/src/abi.rs
+++ b/src/abi.rs
@@ -500,6 +500,24 @@ pub fn codegen_call<'a, 'tcx: 'a>(
                     let uninit_val = uninit_place.to_cvalue(fx);
                     ret.write_cvalue(fx, uninit_val);
                 }
+                "ctlz" | "ctlz_nonzero" => {
+                    assert_eq!(args.len(), 1);
+                    let arg = args[0].load_value(fx);
+                    let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
+                    ret.write_cvalue(fx, res);
+                }
+                "cttz" | "cttz_nonzero" => {
+                    assert_eq!(args.len(), 1);
+                    let arg = args[0].load_value(fx);
+                    let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
+                    ret.write_cvalue(fx, res);
+                }
+                "ctpop" => {
+                    assert_eq!(args.len(), 1);
+                    let arg = args[0].load_value(fx);
+                    let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), args[0].layout());
+                    ret.write_cvalue(fx, res);
+                }
                 _ => fx
                     .tcx
                     .sess
diff --git a/src/base.rs b/src/base.rs
index d479e9350686..31be6e58f420 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -359,7 +359,8 @@ fn trans_stmt<'a, 'tcx: 'a>(
                         UnOp::Not => fx.bcx.ins().bnot(val),
                         UnOp::Neg => match ty.sty {
                             TypeVariants::TyInt(_) => {
-                                let zero = fx.bcx.ins().iconst(types::I64, 0);
+                                let clif_ty = fx.cton_type(ty).unwrap();
+                                let zero = fx.bcx.ins().iconst(clif_ty, 0);
                                 fx.bcx.ins().isub(zero, val)
                             }
                             TypeVariants::TyFloat(_) => fx.bcx.ins().fneg(val),