Add a quick and dirty "loop aligner pass". x86 uses it to align its loops to 16-byte boundaries.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47703 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 850eb38..ad2775a 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -164,6 +164,13 @@
   return true;  // -print-machineinstr should print after this.
 }
 
+bool X86TargetMachine::addPreEmitPass(FunctionPassManager &PM, bool Fast) {
+  if (Fast) return false;
+
+  PM.add(createLoopAlignerPass());
+  return true;
+}
+
 bool X86TargetMachine::addAssemblyEmitter(FunctionPassManager &PM, bool Fast, 
                                           std::ostream &Out) {
   PM.add(createX86CodePrinterPass(Out, *this));