diff options
| -rw-r--r-- | src/librustc_mir/borrow_check/nll/type_check/mod.rs | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs index 060313399cb..697287d80c3 100644 --- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs +++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs @@ -759,6 +759,11 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> { sup: Ty<'tcx>, locations: Locations, ) -> UnitResult<'tcx> { + // Micro-optimization. + if sub == sup { + return Ok(()); + } + self.fully_perform_op( locations, || format!("sub_types({:?} <: {:?})", sub, sup), @@ -772,6 +777,11 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> { #[inline(never)] fn eq_types(&mut self, a: Ty<'tcx>, b: Ty<'tcx>, locations: Locations) -> UnitResult<'tcx> { + // Micro-optimization. + if a == b { + return Ok(()); + } + self.fully_perform_op( locations, || format!("eq_types({:?} = {:?})", a, b), |