Revert r127953, "SimplifyCFG has stopped duplicating returns into predecessors

to canonicalize IR", it broke a lot of things.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127954 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 0 insertions, 15 deletions

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 58acf4f..576c879 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -45,7 +45,6 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/VectorExtras.h"
-#include "llvm/Support/CallSite.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -1596,18 +1595,6 @@ static bool IsTailCallConvention(CallingConv::ID CC) {
   return (CC == CallingConv::Fast || CC == CallingConv::GHC);
 }
 
-bool X86TargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
-  if (!CI->isTailCall())
-    return false;
-
-  CallSite CS(CI);
-  CallingConv::ID CalleeCC = CS.getCallingConv();
-  if (!IsTailCallConvention(CalleeCC) && CalleeCC != CallingConv::C)
-    return false;
-
-  return true;
-}
-
 /// FuncIsMadeTailCallSafe - Return true if the function is being made into
 /// a tailcall target by changing its ABI.
 static bool FuncIsMadeTailCallSafe(CallingConv::ID CC) {
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 6301057..7c1b13a 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -843,8 +843,6 @@ namespace llvm {
 
     virtual bool isUsedByReturnOnly(SDNode *N) const;
 
-    virtual bool mayBeEmittedAsTailCall(CallInst *CI) const;
-
     virtual EVT
     getTypeForExtArgOrReturn(LLVMContext &Context, EVT VT,
                              ISD::NodeType ExtendKind) const;