Print the LSBs of a SlotIndex symbolically using letters referring to the
[L]oad, [u]se, [d]ef, or [S]tore slots.

This makes it easier to see if two indices refer to the same instruction,
avoiding mental mod 4 calculations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106766 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SlotIndexes.cpp b/lib/CodeGen/SlotIndexes.cpp
index 6110ef5..7a227cf 100644
--- a/lib/CodeGen/SlotIndexes.cpp
+++ b/lib/CodeGen/SlotIndexes.cpp
@@ -213,9 +213,11 @@
 
 // Print a SlotIndex to a raw_ostream.
 void SlotIndex::print(raw_ostream &os) const {
-  os << getIndex();
+  os << entry().getIndex();
   if (isPHI())
     os << "*";
+  else
+    os << "LudS"[getSlot()];
 }
 
 // Dump a SlotIndex to stderr.