diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp index 0db459bb916..8800f22beb5 100644 --- a/lib/CodeGen/LLVMTargetMachine.cpp +++ b/lib/CodeGen/LLVMTargetMachine.cpp @@ -66,6 +66,11 @@ static cl::opt EnableFastISelOption("fast-isel", cl::Hidden, cl::desc("Enable the \"fast\" instruction selector")); +// Enable or disable an experimental optimization to split GEPs +// and run a special GVN pass which does not examine loads, in +// an effort to factor out redundancy implicit in complex GEPs. +static cl::opt EnableSplitGEPGVN("split-gep-gvn", cl::Hidden, + cl::desc("Split GEPs and run no-load GVN")); LLVMTargetMachine::LLVMTargetMachine(const Target &T, const std::string &TargetTriple) @@ -223,6 +228,12 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, CodeGenOpt::Level OptLevel) { // Standard LLVM-Level Passes. + // Optionally, tun split-GEPs and no-load GVN. + if (EnableSplitGEPGVN) { + PM.add(createGEPSplitterPass()); + PM.add(createGVNPass(/*NoPRE=*/false, /*NoLoads=*/true)); + } + // Run loop strength reduction before anything else. if (OptLevel != CodeGenOpt::None && !DisableLSR) { PM.add(createLoopStrengthReducePass(getTargetLowering()));