From 3294a69abb1749bba8769df867f65cd37a93a30c Mon Sep 17 00:00:00 2001 From: ljedrz Date: Wed, 19 Dec 2018 13:08:17 +0100 Subject: [PATCH] query: faster stack reversal in remove_cycle --- src/librustc/ty/query/job.rs | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/src/librustc/ty/query/job.rs b/src/librustc/ty/query/job.rs index 1439e41bb31f..2e6cd8e0ec3d 100644 --- a/src/librustc/ty/query/job.rs +++ b/src/librustc/ty/query/job.rs @@ -390,11 +390,9 @@ fn remove_cycle<'tcx>( DUMMY_SP, &mut stack, &mut visited) { - // Reverse the stack so earlier entries require later entries - stack.reverse(); - - // The stack is a vector of pairs of spans and queries - let (mut spans, queries): (Vec<_>, Vec<_>) = stack.into_iter().unzip(); + // The stack is a vector of pairs of spans and queries; reverse it so that + // the earlier entries require later entries + let (mut spans, queries): (Vec<_>, Vec<_>) = stack.into_iter().rev().unzip(); // Shift the spans so that queries are matched with the span for their waitee spans.rotate_right(1);