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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40022 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 3d8618f6c4cbaaaf2ad4447200276f32086a3a2c..b714bac86a1019ff2b70e03fe564616826dc9124 100644 (file)
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -369,6 +369,9 @@ bool SimpleRegisterCoalescing::JoinCopy(MachineInstr *CopyMI,
   // If the intervals were swapped by Join, swap them back so that the register
   // mapping (in the r2i map) is correct.
   if (Swapped) SrcInt.swap(DstInt);
+
+  // repSrcReg is guarateed to be the register whose live interval that is
+  // being merged.
   li_->removeInterval(repSrcReg);
   r2rMap_[repSrcReg] = repDstReg;