[FastISel][ARM] Use MOVT/MOVW if the subtarget requests it.

This change is also in preparation for a future change to make sure that
the constant materialization uses MOVT/MOVW when available and not a load
from the constant pool.

llvm-svn: 215584

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp
index 5d33303ffa1..5cb6d9a0a77 100644
--- a/llvm/lib/Target/ARM/ARMFastISel.cpp
+++ b/llvm/lib/Target/ARM/ARMFastISel.cpp
@@ -546,6 +546,9 @@ unsigned ARMFastISel::ARMMaterializeInt(const Constant *C, MVT VT) {
     }
   }
 
+  if (Subtarget->useMovt(*FuncInfo.MF))
+    return FastEmit_i(VT, VT, ISD::Constant, CI->getZExtValue());
+
   // Load from constant pool.  For now 32-bit only.
   if (VT != MVT::i32)
     return false;