Make the use of the vmla and vmls VFP instructions controllable via cmd line.
Preliminary testing shows significant performance wins by not using these
instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99436 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp
index 2dad7f1..6b4438d 100644
--- a/lib/Target/ARM/ARMSubtarget.cpp
+++ b/lib/Target/ARM/ARMSubtarget.cpp
@@ -26,6 +26,10 @@
 UseNEONFP("arm-use-neon-fp",
           cl::desc("Use NEON for single-precision FP"),
           cl::init(false), cl::Hidden);
+static cl::opt<bool>
+UseVMLxInstructions("arm-use-vmlx",
+                    cl::desc("Use VFP vmla and vmls instructions"),
+                    cl::init(true), cl::Hidden);
 
 static cl::opt<bool>
 UseMOVT("arm-use-movt",
@@ -36,6 +40,7 @@
   : ARMArchVersion(V4)
   , ARMFPUType(None)
   , UseNEONForSinglePrecisionFP(UseNEONFP)
+  , UseVMLx(UseVMLxInstructions)
   , IsThumb(isT)
   , ThumbMode(Thumb1)
   , PostRAScheduler(false)