Fix Bug 4278: X86-64 with -tailcallopt calling convention
out of sync with regular cc.

The only difference between the tail call cc and the normal
cc was that one parameter register - R9 - was reserved for
calling functions through a function pointer. After time the
tail call cc has gotten out of sync with the regular cc. 

We can use R11 which is also caller saved but not used as
parameter register for potential function pointers and
remove the special tail call cc on x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73233 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/tailcallstack64.ll b/test/CodeGen/X86/tailcallstack64.ll
index d734065..c81327e 100644
--- a/test/CodeGen/X86/tailcallstack64.ll
+++ b/test/CodeGen/X86/tailcallstack64.ll
@@ -3,19 +3,19 @@
 ; Move param %in1 to temp register (%eax).
 ; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	40(%rsp), %eax}
 ; Add %in1 %p1 to another temporary register (%r9d).
-; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	%edi, %r9d}
-; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {addl	32(%rsp), %r9d}
+; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	%edi, %r10d}
+; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {addl	32(%rsp), %r10d}
 ; Move result of addition to stack.
-; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	%r9d, 40(%rsp)}
+; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	%r10d, 40(%rsp)}
 ; Move param %in2 to stack.
 ; RUN: llvm-as < %s | llc -tailcallopt -march=x86-64 -x86-asm-syntax=att | grep {movl	%eax, 32(%rsp)}
 
-declare fastcc i32 @tailcallee(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %a, i32 %b)
+declare fastcc i32 @tailcallee(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %p6, i32 %a, i32 %b)
 
-define fastcc i32 @tailcaller(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %in1, i32 %in2) {
+define fastcc i32 @tailcaller(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %p6, i32 %in1, i32 %in2) {
 entry:
         %tmp = add i32 %in1, %p1
-        %retval = tail call fastcc i32 @tailcallee(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %in2,i32 %tmp)
+        %retval = tail call fastcc i32 @tailcallee(i32 %p1, i32 %p2, i32 %p3, i32 %p4, i32 %p5, i32 %p6, i32 %in2,i32 %tmp)
         ret i32 %retval
 }