Add a test case for interval code

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/InductionVars.cpp

@@ -0,0 +1,44 @@
+//===- InductionVars.cpp - Induction Variable Cannonicalization code --------=//
+//
+// This file implements induction variable cannonicalization of loops.
+//
+// Specifically, after this executes, the following is true:
+//   - There is a single induction variable for each loop (that used to contain
+//     at least one induction variable)
+//   - This induction variable starts at 0 and steps by 1 per iteration
+//   - All other preexisting induction variables are adjusted to operate in
+//     terms of this primary induction variable
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/Intervals.h"
+#include "llvm/Opt/AllOpts.h"
+#include "llvm/Assembly/Writer.h"
+
+static void PrintIntervalInfo(cfg::Interval *I) {
+  cerr << "-------------------------------------------------------------\n"
+       << "Interval Contents:\n";
+  
+  // Print out all of the basic blocks in the interval...
+  copy(I->Nodes.begin(), I->Nodes.end(), 
+       ostream_iterator<BasicBlock*>(cerr, "\n"));
+
+  cerr << "Interval Predecessors:\n";
+  copy(I->Predecessors.begin(), I->Predecessors.end(), 
+       ostream_iterator<BasicBlock*>(cerr, "\n"));
+  
+  cerr << "Interval Successors:\n";
+  copy(I->Successors.begin(), I->Successors.end(), 
+       ostream_iterator<BasicBlock*>(cerr, "\n"));
+}
+
+// DoInductionVariableCannonicalize - Simplify induction variables in loops
+//
+bool DoInductionVariableCannonicalize(Method *M) {
+  cfg::IntervalPartition Intervals(M);
+
+  // This currently just prints out information about the interval structure
+  // of the method...
+  for_each(Intervals.begin(), Intervals.end(), PrintIntervalInfo);
+  return false;
+}