4 files changed, 18 insertions, 16 deletions
diff --git a/src/librustc_codegen_llvm/common.rs b/src/librustc_codegen_llvm/common.rs
index d1a7b4dd6bf..cc2f1b6776e 100644
--- a/src/librustc_codegen_llvm/common.rs
+++ b/src/librustc_codegen_llvm/common.rs
@@ -245,21 +245,19 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         struct_in_context(self.llcx, elts, packed)
     }
 
-    fn const_to_uint(&self, v: &'ll Value) -> u64 {
-        unsafe {
-            llvm::LLVMConstIntGetZExtValue(v)
-        }
-    }
-
-    fn is_const_integral(&self, v: &'ll Value) -> bool {
-        unsafe {
-            llvm::LLVMIsAConstantInt(v).is_some()
+    fn const_to_opt_uint(&self, v: &'ll Value) -> Option<u64> {
+        if is_const_integral(v) {
+            unsafe {
+                Some(llvm::LLVMConstIntGetZExtValue(v))
+            }
+        } else {
+            None
         }
     }
 
     fn const_to_opt_u128(&self, v: &'ll Value, sign_ext: bool) -> Option<u128> {
         unsafe {
-            if self.is_const_integral(v) {
+            if is_const_integral(v) {
                 let (mut lo, mut hi) = (0u64, 0u64);
                 let success = llvm::LLVMRustConstInt128Get(v, sign_ext,
                                                            &mut hi, &mut lo);
@@ -388,3 +386,9 @@ pub fn struct_in_context(
 fn hi_lo_to_u128(lo: u64, hi: u64) -> u128 {
     ((hi as u128) << 64) | (lo as u128)
 }
+
+fn is_const_integral(v: &'ll Value) -> bool {
+    unsafe {
+        llvm::LLVMIsAConstantInt(v).is_some()
+    }
+}
diff --git a/src/librustc_codegen_ssa/mir/place.rs b/src/librustc_codegen_ssa/mir/place.rs
index 2d97f828f07..1d1bc2a81a2 100644
--- a/src/librustc_codegen_ssa/mir/place.rs
+++ b/src/librustc_codegen_ssa/mir/place.rs
@@ -394,8 +394,8 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         // Statically compute the offset if we can, otherwise just use the element size,
         // as this will yield the lowest alignment.
         let layout = self.layout.field(bx, 0);
-        let offset = if bx.is_const_integral(llindex) {
-            layout.size.checked_mul(bx.const_to_uint(llindex), bx).unwrap_or(layout.size)
+        let offset = if let Some(llindex) = bx.const_to_opt_uint(llindex) {
+            layout.size.checked_mul(llindex, bx).unwrap_or(layout.size)
         } else {
             layout.size
         };
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 978e7218aa7..3e88c7379da 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -95,7 +95,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     let size = bx.const_usize(dest.layout.size.bytes());
 
                     // Use llvm.memset.p0i8.* to initialize all zero arrays
-                    if bx.cx().is_const_integral(v) && bx.cx().const_to_uint(v) == 0 {
+                    if bx.cx().const_to_opt_uint(v) == Some(0) {
                         let fill = bx.cx().const_u8(0);
                         bx.memset(start, fill, size, dest.align, MemFlags::empty());
                         return bx;
diff --git a/src/librustc_codegen_ssa/traits/consts.rs b/src/librustc_codegen_ssa/traits/consts.rs
index e7ce03f1836..95ada60fae0 100644
--- a/src/librustc_codegen_ssa/traits/consts.rs
+++ b/src/librustc_codegen_ssa/traits/consts.rs
@@ -21,11 +21,9 @@ pub trait ConstMethods<'tcx>: BackendTypes {
 
     fn const_struct(&self, elts: &[Self::Value], packed: bool) -> Self::Value;
 
-    fn const_to_uint(&self, v: Self::Value) -> u64;
+    fn const_to_opt_uint(&self, v: Self::Value) -> Option<u64>;
     fn const_to_opt_u128(&self, v: Self::Value, sign_ext: bool) -> Option<u128>;
 
-    fn is_const_integral(&self, v: Self::Value) -> bool;
-
     fn scalar_to_backend(
         &self,
         cv: Scalar,