Enables vararg functions that pass all arguments via registers to be optimized into tail-calls when possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131560 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 87 insertions, 2 deletions

diff --git a/test/CodeGen/X86/bool-zext.ll b/test/CodeGen/X86/bool-zext.ll
index d2c30c64f2..e04770e267 100644
--- a/test/CodeGen/X86/bool-zext.ll
+++ b/test/CodeGen/X86/bool-zext.ll
@@ -2,7 +2,7 @@
 
 ; CHECK: @bar1
 ; CHECK: movzbl
-; CHECK: callq
+; CHECK: jmp
 define void @bar1(i1 zeroext %v1) nounwind ssp {
 entry:
   %conv = zext i1 %v1 to i32
@@ -12,7 +12,7 @@ entry:
 
 ; CHECK: @bar2
 ; CHECK-NOT: movzbl
-; CHECK: callq
+; CHECK: jmp
 define void @bar2(i8 zeroext %v1) nounwind ssp {
 entry:
   %conv = zext i8 %v1 to i32
diff --git a/test/CodeGen/X86/vararg_tailcall.ll b/test/CodeGen/X86/vararg_tailcall.ll
new file mode 100644
index 0000000000..1187afcd7a
--- /dev/null
+++ b/test/CodeGen/X86/vararg_tailcall.ll
@@ -0,0 +1,85 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+@.str = private unnamed_addr constant [5 x i8] c"%ld\0A\00"
+@sel = external global i8*
+@sel3 = external global i8*
+@sel4 = external global i8*
+@sel5 = external global i8*
+@sel6 = external global i8*
+@sel7 = external global i8*
+
+; CHECK: @foo
+; CHECK: jmp
+define void @foo(i64 %arg) nounwind optsize ssp noredzone {
+entry:
+  %call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %arg) nounwind optsize noredzone
+  ret void
+}
+
+declare i32 @printf(i8*, ...) optsize noredzone
+
+; CHECK: @bar
+; CHECK: jmp
+define void @bar(i64 %arg) nounwind optsize ssp noredzone {
+entry:
+  tail call void @bar2(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %arg) nounwind optsize noredzone
+  ret void
+}
+
+declare void @bar2(i8*, i64) optsize noredzone
+
+; CHECK: @foo2
+; CHECK: jmp
+define i8* @foo2(i8* %arg) nounwind optsize ssp noredzone {
+entry:
+  %tmp1 = load i8** @sel, align 8, !tbaa !0
+  %call = tail call i8* (i8*, i8*, ...)* @x2(i8* %arg, i8* %tmp1) nounwind optsize noredzone
+  ret i8* %call
+}
+
+declare i8* @x2(i8*, i8*, ...) optsize noredzone
+
+; CHECK: @foo6
+; CHECK: jmp
+define i8* @foo6(i8* %arg1, i8* %arg2) nounwind optsize ssp noredzone {
+entry:
+  %tmp2 = load i8** @sel3, align 8, !tbaa !0
+  %tmp3 = load i8** @sel4, align 8, !tbaa !0
+  %tmp4 = load i8** @sel5, align 8, !tbaa !0
+  %tmp5 = load i8** @sel6, align 8, !tbaa !0
+  %call = tail call i8* (i8*, i8*, i8*, ...)* @x3(i8* %arg1, i8* %arg2, i8* %tmp2, i8* %tmp3, i8* %tmp4, i8* %tmp5) nounwind optsize noredzone
+  ret i8* %call
+}
+
+declare i8* @x3(i8*, i8*, i8*, ...) optsize noredzone
+
+; CHECK: @foo7
+; CHECK: callq
+define i8* @foo7(i8* %arg1, i8* %arg2) nounwind optsize ssp noredzone {
+entry:
+  %tmp2 = load i8** @sel3, align 8, !tbaa !0
+  %tmp3 = load i8** @sel4, align 8, !tbaa !0
+  %tmp4 = load i8** @sel5, align 8, !tbaa !0
+  %tmp5 = load i8** @sel6, align 8, !tbaa !0
+  %tmp6 = load i8** @sel7, align 8, !tbaa !0
+  %call = tail call i8* (i8*, i8*, i8*, i8*, i8*, i8*, i8*, ...)* @x7(i8* %arg1, i8* %arg2, i8* %tmp2, i8* %tmp3, i8* %tmp4, i8* %tmp5, i8* %tmp6) nounwind optsize noredzone
+  ret i8* %call
+}
+
+declare i8* @x7(i8*, i8*, i8*, i8*, i8*, i8*, i8*, ...) optsize noredzone
+
+; CHECK: @foo8
+; CHECK: callq
+define i8* @foo8(i8* %arg1, i8* %arg2) nounwind optsize ssp noredzone {
+entry:
+  %tmp2 = load i8** @sel3, align 8, !tbaa !0
+  %tmp3 = load i8** @sel4, align 8, !tbaa !0
+  %tmp4 = load i8** @sel5, align 8, !tbaa !0
+  %tmp5 = load i8** @sel6, align 8, !tbaa !0
+  %call = tail call i8* (i8*, i8*, i8*, ...)* @x3(i8* %arg1, i8* %arg2, i8* %tmp2, i8* %tmp3, i8* %tmp4, i8* %tmp5, i32 48879, i32 48879) nounwind optsize noredzone
+  ret i8* %call
+}
+
+!0 = metadata !{metadata !"any pointer", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}