Added tail call optimization to the x86 back end. It can be
enabled by passing -tailcallopt to llc.  The optimization is
performed if the following conditions are satisfied:
* caller/callee are fastcc
* elf/pic is disabled OR
  elf/pic enabled + callee is in module + callee has
  visibility protected or hidden


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42870 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 986aa0b..9d5e637 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -706,6 +706,8 @@
   if (MBB.empty()) return false;
   
   switch (MBB.back().getOpcode()) {
+  case X86::TCRETURNri:
+  case X86::TCRETURNdi:
   case X86::RET:     // Return.
   case X86::RETI:
   case X86::TAILJMPd: