Add optimize-for-size knob.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48793 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index 554a32b..72bb272 100644
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -78,6 +78,10 @@
   /// on the commandline. When the flag is on, the target will perform tail call
   /// optimization (pop the caller's stack) providing it supports it.
   extern bool PerformTailCallOpt;
+
+  /// OptimizeForSize - When this flags is set, code generator avoids optimization
+  /// that increases size.
+  extern bool OptimizeForSize;
 } // End llvm namespace
 
 #endif
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index 15164ca2..b9a6878 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -34,6 +34,7 @@
   Reloc::Model RelocationModel;
   CodeModel::Model CMModel;
   bool PerformTailCallOpt;
+  bool OptimizeForSize;
 }
 namespace {
   cl::opt<bool, true> PrintCode("print-machineinstrs",
@@ -123,6 +124,11 @@
                            cl::desc("Turn on tail call optimization."),
                            cl::location(PerformTailCallOpt),
                            cl::init(false));
+  cl::opt<bool, true>
+  EnableOptimizeForSize("optimizeforsize",
+                        cl::desc("Optimize for size."),
+                           cl::location(OptimizeForSize),
+                           cl::init(false));
 }
 
 //---------------------------------------------------------------------------