Use std::vector instead of a hard-coded array. The length of that array could
get *very* large, but we only need it to be the size of thenumber of pregs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108411 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CriticalAntiDepBreaker.cpp b/lib/CodeGen/CriticalAntiDepBreaker.cpp
index e3746a9..9d48665 100644
--- a/lib/CodeGen/CriticalAntiDepBreaker.cpp
+++ b/lib/CodeGen/CriticalAntiDepBreaker.cpp
@@ -34,6 +34,9 @@
   TRI(MF.getTarget().getRegisterInfo()),
   AllocatableSet(TRI->getAllocatableSet(MF))
 {
+  Classes.reserve(TRI->getNumRegs());
+  KillIndices.reserve(TRI->getNumRegs());
+  DefIndices.reserve(TRI->getNumRegs());
 }
 
 CriticalAntiDepBreaker::~CriticalAntiDepBreaker() {
@@ -41,8 +44,7 @@
 
 void CriticalAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
   // Clear out the register class data.
-  std::fill(Classes, array_endof(Classes),
-            static_cast<const TargetRegisterClass *>(0));
+  Classes.clear();
 
   // Initialize the indices to indicate that no registers are live.
   const unsigned BBSize = BB->size();