diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/LiveIntervalUnion.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp index 205f28a0d6..51789998c6 100644 --- a/lib/CodeGen/LiveIntervalUnion.cpp +++ b/lib/CodeGen/LiveIntervalUnion.cpp @@ -35,12 +35,20 @@ void LiveIntervalUnion::unify(LiveInterval &VirtReg) { LiveInterval::iterator RegEnd = VirtReg.end(); SegmentIter SegPos = Segments.find(RegPos->start); - for (;;) { + while (SegPos.valid()) { SegPos.insert(RegPos->start, RegPos->end, &VirtReg); if (++RegPos == RegEnd) return; SegPos.advanceTo(RegPos->start); } + + // We have reached the end of Segments, so it is no longer necessary to search + // for the insertion position. + // It is faster to insert the end first. + --RegEnd; + SegPos.insert(RegEnd->start, RegEnd->end, &VirtReg); + for (; RegPos != RegEnd; ++RegPos, ++SegPos) + SegPos.insert(RegPos->start, RegPos->end, &VirtReg); } // Remove a live virtual register's segments from this union. |