Don't accidentally leave small gaps in the live ranges when leaving the active

interval after an instruction. The leaveIntvAfter() method only adds liveness
from the instruction's boundary index to the inserted copy.

Ideally, SplitKit should be smarter about this, perhaps by combining useIntv()
and leaveIntvAfter() into one method that guarantees continuity.

llvm-svn: 123858

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/RegAllocGreedy.cpp b/llvm/lib/CodeGen/RegAllocGreedy.cpp
index fa3b5871fce..2083c4bdc41 100644
--- a/llvm/lib/CodeGen/RegAllocGreedy.cpp
+++ b/llvm/lib/CodeGen/RegAllocGreedy.cpp
@@ -757,7 +757,7 @@ void RAGreedy::splitAroundRegion(LiveInterval &VirtReg, unsigned PhysReg,
       }
       if (!BI.LiveThrough) {
         DEBUG(dbgs() << ", killed in block.\n");
-        SE.useIntv(Start, BI.Kill);
+        SE.useIntv(Start, BI.Kill.getBoundaryIndex());
         SE.leaveIntvAfter(BI.Kill);
         continue;
       }
@@ -765,7 +765,7 @@ void RAGreedy::splitAroundRegion(LiveInterval &VirtReg, unsigned PhysReg,
         // Block is live-through, but exit bundle is on the stack.
         // Spill immediately after the last use.
         DEBUG(dbgs() << ", uses, stack-out.\n");
-        SE.useIntv(Start, BI.LastUse);
+        SE.useIntv(Start, BI.LastUse.getBoundaryIndex());
         SE.leaveIntvAfter(BI.LastUse);
         continue;
       }
@@ -789,6 +789,7 @@ void RAGreedy::splitAroundRegion(LiveInterval &VirtReg, unsigned PhysReg,
       SlotIndex Use = std::lower_bound(SA->UseSlots.begin(), SA->UseSlots.end(),
                                        IP.second)[-1];
       DEBUG(dbgs() << ", free use at " << Use << ".\n");
+      Use = Use.getBoundaryIndex();
       assert(Use >= BI.FirstUse && Use < IP.first);
       SE.useIntv(Start, Use);
       SE.leaveIntvAfter(Use);