Re-enable x86 tail call optimization.

llvm-svn: 95295

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -52,7 +52,6 @@ using namespace llvm;
 
 STATISTIC(NumTailCalls, "Number of tail calls");
 
-static cl::opt<unsigned> TailCallLimit("tailcall-limit", cl::init(0));
 static cl::opt<bool>
 DisableMMX("disable-mmx", cl::Hidden, cl::desc("Disable use of MMX"));
 
@@ -2271,8 +2270,6 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
 
   // Look for obvious safe cases to perform tail call optimization that does not
   // requite ABI changes. This is what gcc calls sibcall.
-  if (NumTailCalls >= TailCallLimit)
-    return false;
 
   // Do not tail call optimize vararg calls for now.
   if (isVarArg)

llvm/test/CodeGen/X86/tailcall2.ll

@@ -1,6 +1,5 @@
 ; RUN: llc < %s -march=x86    -asm-verbose=false | FileCheck %s -check-prefix=32
 ; RUN: llc < %s -march=x86-64 -asm-verbose=false | FileCheck %s -check-prefix=64
-; XFAIL: *
 
 define void @t1(i32 %x) nounwind ssp {
 entry:
@@ -107,10 +106,10 @@ declare i32 @bar2(i32, i32, i32)
 define signext i16 @t8() nounwind ssp {
 entry:
 ; 32: t8:
-; 32: jmp {{_?}}bar3
+; 32: call {{_?}}bar3
 
 ; 64: t8:
-; 64: jmp {{_?}}bar3
+; 64: callq {{_?}}bar3
   %0 = tail call signext i16 @bar3() nounwind      ; <i16> [#uses=1]
   ret i16 %0
 }