--- a/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp	Tue Jan 26 22:56:36 2016 +0900
+++ b/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp	Fri Nov 25 19:14:25 2016 +0900
@@ -14,6 +14,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "HexagonTargetTransformInfo.h"
+#include "llvm/IR/Instructions.h"
 #include "llvm/Support/Debug.h"
 
 using namespace llvm;
@@ -36,3 +37,35 @@
 unsigned HexagonTTIImpl::getNumberOfRegisters(bool vector) const {
   return vector ? 0 : 32;
 }
+
+unsigned HexagonTTIImpl::getPrefetchDistance() const {
+  return getST()->getL1PrefetchDistance();
+}
+
+unsigned HexagonTTIImpl::getCacheLineSize() const {
+  return getST()->getL1CacheLineSize();
+}
+
+int HexagonTTIImpl::getUserCost(const User *U) {
+  auto isCastFoldedIntoLoad = [] (const CastInst *CI) -> bool {
+    if (!CI->isIntegerCast())
+      return false;
+    const LoadInst *LI = dyn_cast<const LoadInst>(CI->getOperand(0));
+    // Technically, this code could allow multiple uses of the load, and
+    // check if all the uses are the same extension operation, but this
+    // should be sufficient for most cases.
+    if (!LI || !LI->hasOneUse())
+      return false;
+
+    // Only extensions from an integer type shorter than 32-bit to i32
+    // can be folded into the load.
+    unsigned SBW = CI->getSrcTy()->getIntegerBitWidth();
+    unsigned DBW = CI->getDestTy()->getIntegerBitWidth();
+    return DBW == 32 && (SBW < DBW);
+  };
+
+  if (const CastInst *CI = dyn_cast<const CastInst>(U))
+    if (isCastFoldedIntoLoad(CI))
+      return TargetTransformInfo::TCC_Free;
+  return BaseT::getUserCost(U);
+}