Don't insert nearly as many redundant phi nodes.

[oota-llvm.git] / lib / Transforms / Scalar / GCSE.cpp

diff --git a/lib/Transforms/Scalar/GCSE.cpp b/lib/Transforms/Scalar/GCSE.cpp
index 7dbdf0ab96a6016e0d5f26670f1617d93bd2589e..93ed8c4fa9c663443407eb93222dfb91619e7143 100644 (file)
--- a/lib/Transforms/Scalar/GCSE.cpp
+++ b/lib/Transforms/Scalar/GCSE.cpp
@@ -14,29 +14,32 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "gcse"
 #include "llvm/Transforms/Scalar.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Constant.h"
 #include "llvm/Instructions.h"
+#include "llvm/Function.h"
 #include "llvm/Type.h"
+#include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/ValueNumbering.h"
-#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Compiler.h"
 #include <algorithm>
 using namespace llvm;
 
+STATISTIC(NumInstRemoved, "Number of instructions removed");
+STATISTIC(NumLoadRemoved, "Number of loads removed");
+STATISTIC(NumCallRemoved, "Number of calls removed");
+STATISTIC(NumNonInsts   , "Number of instructions removed due "
+                          "to non-instruction values");
+STATISTIC(NumArgsRepl   , "Number of function arguments replaced "
+                          "with constant values");
 namespace {
-  Statistic<> NumInstRemoved("gcse", "Number of instructions removed");
-  Statistic<> NumLoadRemoved("gcse", "Number of loads removed");
-  Statistic<> NumCallRemoved("gcse", "Number of calls removed");
-  Statistic<> NumNonInsts   ("gcse", "Number of instructions removed due "
-                             "to non-instruction values");
-  Statistic<> NumArgsRepl   ("gcse", "Number of function arguments replaced "
-                             "with constant values");
-
-  struct GCSE : public FunctionPass {
+  struct VISIBILITY_HIDDEN GCSE : public FunctionPass {
+    static char ID; // Pass identification, replacement for typeid
+    GCSE() : FunctionPass((intptr_t)&ID) {}
+
     virtual bool runOnFunction(Function &F);
 
   private:
@@ -45,12 +48,12 @@ namespace {
     // This transformation requires dominator and immediate dominator info
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.setPreservesCFG();
-      AU.addRequired<ETForest>();
       AU.addRequired<DominatorTree>();
       AU.addRequired<ValueNumbering>();
     }
   };
 
+  char GCSE::ID = 0;
   RegisterPass<GCSE> X("gcse", "Global Common Subexpression Elimination");
 }
 
@@ -64,16 +67,15 @@ bool GCSE::runOnFunction(Function &F) {
   bool Changed = false;
 
   // Get pointers to the analysis results that we will be using...
-  ETForest &EF = getAnalysis<ETForest>();
-  ValueNumbering &VN = getAnalysis<ValueNumbering>();
   DominatorTree &DT = getAnalysis<DominatorTree>();
+  ValueNumbering &VN = getAnalysis<ValueNumbering>();
 
   std::vector<Value*> EqualValues;
 
   // Check for value numbers of arguments.  If the value numbering
   // implementation can prove that an incoming argument is a constant or global
   // value address, substitute it, making the argument dead.
-  for (Function::arg_iterator AI = F.arg_begin(), E = F.arg_end(); AI != E; ++AI)
+  for (Function::arg_iterator AI = F.arg_begin(), E = F.arg_end(); AI != E;++AI)
     if (!AI->use_empty()) {
       VN.getEqualNumberNodes(AI, EqualValues);
       if (!EqualValues.empty()) {
@@ -90,7 +92,7 @@ bool GCSE::runOnFunction(Function &F) {
 
   // Traverse the CFG of the function in dominator order, so that we see each
   // instruction after we see its operands.
-  for (df_iterator<DominatorTree::Node*> DI = df_begin(DT.getRootNode()),
+  for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
          E = df_end(DT.getRootNode()); DI != E; ++DI) {
     BasicBlock *BB = DI->getBlock();
 
@@ -141,7 +143,7 @@ bool GCSE::runOnFunction(Function &F) {
             if (OtherI->getParent() == BB)
               Dominates = BlockInsts.count(OtherI);
             else
-              Dominates = EF.dominates(OtherI->getParent(), BB);
+              Dominates = DT.dominates(OtherI->getParent(), BB);
 
             if (Dominates) {
               // Okay, we found an instruction with the same value as this one