diff options
| -rw-r--r-- | src/librustc_passes/liveness.rs | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/librustc_passes/liveness.rs b/src/librustc_passes/liveness.rs index 606947bfbdd..b355a47c394 100644 --- a/src/librustc_passes/liveness.rs +++ b/src/librustc_passes/liveness.rs @@ -824,6 +824,12 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> { let mut any_changed = false; self.indices2(ln, succ_ln, |this, idx, succ_idx| { + // This is a special case, pulled out from the code below, where we + // don't have to do anything. It occurs about 60-70% of the time. + if this.rwu_table.packed_rwus[succ_idx] == INV_INV_FALSE { + return; + } + let mut changed = false; let mut rwu = this.rwu_table.get(idx); let succ_rwu = this.rwu_table.get(succ_idx); |