Rollup merge of #53551 - nnethercote:access_place_error_reported, r=varkor

kennytm · kennytm · commit e3887e6c8afb · 2018-08-21T22:09:35.000+08:00
Avoid some Place clones.

This is a 0.5% speedup on ripgrep.
diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs
@@ -1080,7 +1080,10 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             }
         }
 
-        if self
+        // Check is_empty() first because it's the common case, and doing that
+        // way we avoid the clone() call.
+        if !self.access_place_error_reported.is_empty() &&
+           self
             .access_place_error_reported
             .contains(&(place_span.0.clone(), place_span.1))
         {

Original file line number	Diff line number	Diff line change
`@@ -1080,7 +1080,10 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {`
`1080`	`1080`	`}`
`1081`	`1081`	`}`
`1082`	`1082`
`1083`		`- if self`
	`1083`	`+ // Check is_empty() first because it's the common case, and doing that`
	`1084`	`+ // way we avoid the clone() call.`
	`1085`	`+ if !self.access_place_error_reported.is_empty() &&`
	`1086`	`+ self`
`1084`	`1087`	`.access_place_error_reported`
`1085`	`1088`	`.contains(&(place_span.0.clone(), place_span.1))`
`1086`	`1089`	`{`