Recommit "[RegAlloc] Make sure live-ranges reflect the state of the IR when

         removing them"

This was temporarily reverted, but now that the fix has been commited (r313197)
it should be put back in place.

https://bugs.llvm.org/show_bug.cgi?id=34502

This reverts commit 9ef93d9dc4c51568e858cf8203cd2c5ce8dca796.

llvm-svn: 313349

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/RegAllocBasic.cpp b/llvm/lib/CodeGen/RegAllocBasic.cpp
index 774306154a8..5ecde0c9d9f 100644
--- a/llvm/lib/CodeGen/RegAllocBasic.cpp
+++ b/llvm/lib/CodeGen/RegAllocBasic.cpp
@@ -143,14 +143,17 @@ INITIALIZE_PASS_END(RABasic, "regallocbasic", "Basic Register Allocator", false,
                     false)
 
 bool RABasic::LRE_CanEraseVirtReg(unsigned VirtReg) {
+  LiveInterval &LI = LIS->getInterval(VirtReg);
   if (VRM->hasPhys(VirtReg)) {
-    LiveInterval &LI = LIS->getInterval(VirtReg);
     Matrix->unassign(LI);
     aboutToRemoveInterval(LI);
     return true;
   }
   // Unassigned virtreg is probably in the priority queue.
   // RegAllocBase will erase it after dequeueing.
+  // Nonetheless, clear the live-range so that the debug
+  // dump will show the right state for that VirtReg.
+  LI.clear();
   return false;
 }