1 files changed, 71 insertions, 4 deletions
diff --git a/test/CodeGen/X86/musttail.ll b/test/CodeGen/X86/musttail.ll
index 75b217f994..ca5d3119cf 100644
--- a/test/CodeGen/X86/musttail.ll
+++ b/test/CodeGen/X86/musttail.ll
@@ -1,8 +1,6 @@
 ; RUN: llc -march=x86 < %s | FileCheck %s
-
-; FIXME: Eliminate this tail call at -O0, since musttail is a correctness
-; requirement.
-; RUN: not llc -march=x86 -O0 < %s
+; RUN: llc -march=x86 -O0 < %s | FileCheck %s
+; RUN: llc -march=x86 -disable-tail-calls < %s | FileCheck %s
 
 declare void @t1_callee(i8*)
 define void @t1(i32* %a) {
@@ -21,3 +19,72 @@ define i32* @t2() {
   %w = bitcast i8* %v to i32*
   ret i32* %w
 }
+
+; Complex frame layout: stack realignment with dynamic alloca.
+define void @t3(i32 %n) alignstack(32) nounwind {
+entry:
+; CHECK: t3:
+; CHECK: pushl %ebp
+; CHECK: pushl %esi
+; CHECK: andl $-32, %esp
+; CHECK: movl %esp, %esi
+; CHECK: popl %esi
+; CHECK: popl %ebp
+; CHECK-NEXT: jmp {{_?}}t3_callee
+  %a = alloca i8, i32 %n
+  call void @capture(i8* %a)
+  musttail call void @t3_callee(i32 %n) nounwind
+  ret void
+}
+
+declare void @capture(i8*)
+declare void @t3_callee(i32)
+
+; Test that we actually copy in and out stack arguments that aren't forwarded
+; without modification.
+define i32 @t4({}* %fn, i32 %n, i32 %r) {
+; CHECK-LABEL: t4:
+; CHECK: incl %[[r:.*]]
+; CHECK: decl %[[n:.*]]
+; CHECK: movl %[[r]], {{[0-9]+}}(%esp)
+; CHECK: movl %[[n]], {{[0-9]+}}(%esp)
+; CHECK: jmpl *%{{.*}}
+
+entry:
+  %r1 = add i32 %r, 1
+  %n1 = sub i32 %n, 1
+  %fn_cast = bitcast {}* %fn to i32 ({}*, i32, i32)*
+  %r2 = musttail call i32 %fn_cast({}* %fn, i32 %n1, i32 %r1)
+  ret i32 %r2
+}
+
+; Combine the complex stack frame with the parameter modification.
+define i32 @t5({}* %fn, i32 %n, i32 %r) alignstack(32) {
+; CHECK-LABEL: t5:
+; CHECK: pushl %ebp
+; CHECK: movl %esp, %ebp
+; CHECK: pushl %esi
+; 	Align the stack.
+; CHECK: andl $-32, %esp
+; CHECK: movl %esp, %esi
+; 	Modify the args.
+; CHECK: incl %[[r:.*]]
+; CHECK: decl %[[n:.*]]
+; 	Store them through ebp, since that's the only stable arg pointer.
+; CHECK: movl %[[r]], {{[0-9]+}}(%ebp)
+; CHECK: movl %[[n]], {{[0-9]+}}(%ebp)
+; 	Epilogue.
+; CHECK: leal {{[-0-9]+}}(%ebp), %esp
+; CHECK: popl %esi
+; CHECK: popl %ebp
+; CHECK: jmpl *%{{.*}}
+
+entry:
+  %a = alloca i8, i32 %n
+  call void @capture(i8* %a)
+  %r1 = add i32 %r, 1
+  %n1 = sub i32 %n, 1
+  %fn_cast = bitcast {}* %fn to i32 ({}*, i32, i32)*
+  %r2 = musttail call i32 %fn_cast({}* %fn, i32 %n1, i32 %r1)
+  ret i32 %r2
+}