Added TLI hook for isFPExtFree. Some of the FMA combine heuristics are now guarded with that hook.

llvm-svn: 225795
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 30f08d0..2157003 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -9817,6 +9817,11 @@
   return TargetLowering::isZExtFree(Val, VT2);
 }
 
+bool PPCTargetLowering::isFPExtFree(EVT VT) const {
+  assert(VT.isFloatingPoint());
+  return true;
+}
+
 bool PPCTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
   return isInt<16>(Imm) || isUInt<16>(Imm);
 }