Turn the EdgeBundles class into a stand-alone machine CFG analysis pass.

The analysis will be needed by both the greedy register allocator and the
X86FloatingPoint pass. It only needs to be computed once when the CFG doesn't
change.

This pass is very fast, usually showing up as 0.0% wall time.

llvm-svn: 122832

llvm/lib/Target/X86/X86FloatingPoint.cpp

@@ -32,6 +32,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/CodeGen/EdgeBundles.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -51,6 +52,7 @@ namespace {
   struct FPS : public MachineFunctionPass {
     static char ID;
     FPS() : MachineFunctionPass(ID) {
+      initializeEdgeBundlesPass(*PassRegistry::getPassRegistry());
       // This is really only to keep valgrind quiet.
       // The logic in isLive() is too much for it.
       memset(Stack, 0, sizeof(Stack));
@@ -59,6 +61,7 @@ namespace {
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.setPreservesCFG();
+      AU.addRequired<EdgeBundles>();
       AU.addPreservedID(MachineLoopInfoID);
       AU.addPreservedID(MachineDominatorsID);
       MachineFunctionPass::getAnalysisUsage(AU);