Adding debug output during coalescing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44154 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 9f08b1d..bc9febf 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -233,6 +233,7 @@
 
   // Try to coalesce.
   if (!li_->conflictsWithPhysRegDef(cur, *vrm_, SrcReg)) {
+    DOUT << "Coalescing: " << cur << " -> " << mri_->getName(SrcReg) << '\n';
     vrm_->clearVirt(cur.reg);
     vrm_->assignVirt2Phys(cur.reg, SrcReg);
     ++NumCoalesce;