Add an option to disable spill fusing in the X86 backend

llvm-svn: 11531

llvm/lib/Target/X86/X86RegisterInfo.cpp

@@ -31,6 +31,9 @@ namespace {
   cl::opt<bool>
   NoFPElim("disable-fp-elim",
 	   cl::desc("Disable frame pointer elimination optimization"));
+  cl::opt<bool>
+  NoFusing("disable-spill-fusing",
+           cl::desc("Disable fusing of spill code into instructions"));
 }
 
 X86RegisterInfo::X86RegisterInfo()
@@ -106,6 +109,8 @@ static MachineInstr *MakeRMIInst(unsigned Opcode, unsigned FrameIndex,
 
 bool X86RegisterInfo::foldMemoryOperand(MachineBasicBlock::iterator &MI,
                                         unsigned i, int FrameIndex) const {
+  if (NoFusing) return false;
+
   /// FIXME: This should obviously be autogenerated by tablegen when patterns
   /// are available!
   MachineBasicBlock& MBB = *MI->getParent();