From 7da9ecf9677b751d81515f95168ae3cb2df54160 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Wed, 13 Jan 2010 00:30:23 +0000 Subject: Add a quick pass to optimize sign / zero extension instructions. For targets where the pre-extension values are available in the subreg of the result of the extension, replace the uses of the pre-extension value with the result + extract_subreg. For now, this pass is fairly conservative. It only perform the replacement when both the pre- and post- extension values are used in the block. It will miss cases where the post-extension values are live, but not used. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93278 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LLVMTargetMachine.cpp | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'lib/CodeGen/LLVMTargetMachine.cpp') diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp index 8757c9f..84eb71c 100644 --- a/lib/CodeGen/LLVMTargetMachine.cpp +++ b/lib/CodeGen/LLVMTargetMachine.cpp @@ -62,6 +62,10 @@ static cl::opt VerifyMachineCode("verify-machineinstrs", cl::Hidden, cl::desc("Verify generated machine code"), cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL)); +#if 1 +static cl::opt XX("xx", cl::Hidden); +#endif + // Enable or disable FastISel. Both options are needed, because // FastISel is enabled by default with -fast, and we wish to be // able to enable or disable fast-isel independently from -O0. @@ -324,6 +328,7 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, /* allowDoubleDefs= */ true); if (OptLevel != CodeGenOpt::None) { + PM.add(createOptimizeExtsPass()); if (!DisableMachineLICM) PM.add(createMachineLICMPass()); if (!DisableMachineSink) -- cgit v1.1