Add an option to disable 32 -> 16-bit Thumb2 size reduction pass for experimentation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110579 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index 9d7bf75cf1..2c8460b877 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -16,11 +16,17 @@
 #include "ARM.h"
 #include "llvm/PassManager.h"
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Target/TargetRegistry.h"
 using namespace llvm;
 
+static cl::opt<bool>
+Prefer32BitThumbInstrs("prefer-32bit-thumb",
+                       cl::desc("Prefer 32-bit Thumb instructions"),
+                       cl::init(false));
+
 static MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
   Triple TheTriple(TT);
   switch (TheTriple.getOS()) {
@@ -31,7 +37,6 @@ static MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
   }
 }
 
-
 extern "C" void LLVMInitializeARMTarget() {
   // Register the target.
   RegisterTargetMachine<ARMTargetMachine> X(TheARMTarget);
@@ -138,7 +143,7 @@ bool ARMBaseTargetMachine::addPreSched2(PassManagerBase &PM,
 
 bool ARMBaseTargetMachine::addPreEmitPass(PassManagerBase &PM,
                                           CodeGenOpt::Level OptLevel) {
-  if (Subtarget.isThumb2())
+  if (!Prefer32BitThumbInstrs && Subtarget.isThumb2())
     PM.add(createThumb2SizeReductionPass());
 
   PM.add(createARMConstantIslandPass());