optimize strstr, PR5783

[oota-llvm.git] / lib / CodeGen / LLVMTargetMachine.cpp

diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 740c95084281266b11e92096be11fb8601543ad7..297dd31676236ebc1ed8b2349071cd71c3c534a2 100644 (file)
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -35,6 +35,8 @@ static cl::opt<bool> DisablePostRA("disable-post-ra", cl::Hidden,
     cl::desc("Disable Post Regalloc"));
 static cl::opt<bool> DisableBranchFold("disable-branch-fold", cl::Hidden,
     cl::desc("Disable branch folding"));
+static cl::opt<bool> DisableTailDuplicate("disable-tail-duplicate", cl::Hidden,
+    cl::desc("Disable tail duplication"));
 static cl::opt<bool> DisableCodePlace("disable-code-place", cl::Hidden,
     cl::desc("Disable code placement"));
 static cl::opt<bool> DisableSSC("disable-ssc", cl::Hidden,
@@ -72,6 +74,9 @@ EnableFastISelOption("fast-isel", cl::Hidden,
 static cl::opt<bool> EnableSplitGEPGVN("split-gep-gvn", cl::Hidden,
     cl::desc("Split GEPs and run no-load GVN"));
 
+static cl::opt<bool> PreAllocTailDup("pre-regalloc-taildup", cl::Hidden,
+    cl::desc("Pre-register allocation tail duplication"));
+
 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
                                      const std::string &TargetTriple)
   : TargetMachine(T) {
@@ -300,6 +305,13 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
                    /* allowDoubleDefs= */ true);
   }
 
+  // Pre-ra tail duplication.
+  if (OptLevel != CodeGenOpt::None &&
+      !DisableTailDuplicate && PreAllocTailDup) {
+    PM.add(createTailDuplicatePass(true));
+    printAndVerify(PM, "After Pre-RegAlloc TailDuplicate");
+  }
+
   // Run pre-ra passes.
   if (addPreRegAlloc(PM, OptLevel))
     printAndVerify(PM, "After PreRegAlloc passes",
@@ -344,6 +356,12 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
     printAndVerify(PM, "After BranchFolding");
   }
 
+  // Tail duplication.
+  if (OptLevel != CodeGenOpt::None && !DisableTailDuplicate) {
+    PM.add(createTailDuplicatePass(false));
+    printAndVerify(PM, "After TailDuplicate");
+  }
+
   PM.add(createGCMachineCodeAnalysisPass());
 
   if (PrintGCInfo)