Implement ADJCALLSTACKUP and ADJCALLSTACKDOWN



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/Mips16FrameLowering.cpp b/lib/Target/Mips/Mips16FrameLowering.cpp
index 74cffd2..4e6b21f 100644
--- a/lib/Target/Mips/Mips16FrameLowering.cpp
+++ b/lib/Target/Mips/Mips16FrameLowering.cpp
@@ -115,8 +115,10 @@
 
 bool
 Mips16FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
-  // FIXME: implement.
-  return true;
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  // Reserve call frame if the size of the maximum call frame fits into 15-bit
+  // immediate field and there are no variable sized objects on the stack.
+  return isInt<15>(MFI->getMaxCallFrameSize()) && !MFI->hasVarSizedObjects();
 }
 
 void Mips16FrameLowering::