1 files changed, 104 insertions, 0 deletions
diff --git a/llvm/test/Transforms/CallSiteSplitting/musttail.ll b/llvm/test/Transforms/CallSiteSplitting/musttail.ll
new file mode 100644
index 00000000000..d8f76aed3dc
--- /dev/null
+++ b/llvm/test/Transforms/CallSiteSplitting/musttail.ll
@@ -0,0 +1,104 @@
+; RUN: opt < %s -callsite-splitting -verify-dom-info -S | FileCheck %s
+
+;CHECK-LABEL: @caller
+;CHECK-LABEL: Top.split:
+;CHECK: %ca1 = musttail call i8* @callee(i8* null, i8* %b)
+;CHECK: %cb2 = bitcast i8* %ca1 to i8*
+;CHECK: ret i8* %cb2
+;CHECK-LABEL: TBB.split
+;CHECK: %ca3 = musttail call i8* @callee(i8* nonnull %a, i8* null)
+;CHECK: %cb4 = bitcast i8* %ca3 to i8*
+;CHECK: ret i8* %cb4
+define i8* @caller(i8* %a, i8* %b) {
+Top:
+  %c = icmp eq i8* %a, null
+  br i1 %c, label %Tail, label %TBB
+TBB:
+  %c2 = icmp eq i8* %b, null
+  br i1 %c2, label %Tail, label %End
+Tail:
+  %ca = musttail call i8* @callee(i8* %a, i8* %b)
+  %cb = bitcast i8* %ca to i8*
+  ret i8* %cb
+End:
+  ret i8* null
+}
+
+define i8* @callee(i8* %a, i8* %b) noinline {
+  ret i8* %a
+}
+
+;CHECK-LABEL: @no_cast_caller
+;CHECK-LABEL: Top.split:
+;CHECK: %ca1 = musttail call i8* @callee(i8* null, i8* %b)
+;CHECK: ret i8* %ca1
+;CHECK-LABEL: TBB.split
+;CHECK: %ca2 = musttail call i8* @callee(i8* nonnull %a, i8* null)
+;CHECK: ret i8* %ca2
+define i8* @no_cast_caller(i8* %a, i8* %b) {
+Top:
+  %c = icmp eq i8* %a, null
+  br i1 %c, label %Tail, label %TBB
+TBB:
+  %c2 = icmp eq i8* %b, null
+  br i1 %c2, label %Tail, label %End
+Tail:
+  %ca = musttail call i8* @callee(i8* %a, i8* %b)
+  ret i8* %ca
+End:
+  ret i8* null
+}
+
+;CHECK-LABEL: @void_caller
+;CHECK-LABEL: Top.split:
+;CHECK: musttail call void @void_callee(i8* null, i8* %b)
+;CHECK: ret void
+;CHECK-LABEL: TBB.split
+;CHECK: musttail call void @void_callee(i8* nonnull %a, i8* null)
+;CHECK: ret void
+define void @void_caller(i8* %a, i8* %b) {
+Top:
+  %c = icmp eq i8* %a, null
+  br i1 %c, label %Tail, label %TBB
+TBB:
+  %c2 = icmp eq i8* %b, null
+  br i1 %c2, label %Tail, label %End
+Tail:
+  musttail call void @void_callee(i8* %a, i8* %b)
+  ret void
+End:
+  ret void
+}
+
+define void @void_callee(i8* %a, i8* %b) noinline {
+  ret void
+}
+
+;   Include a test with a larger CFG that exercises the DomTreeUpdater
+;   machinery a bit more.
+;CHECK-LABEL: @larger_cfg_caller
+;CHECK-LABEL: Top.split:
+;CHECK: %r1 = musttail call i8* @callee(i8* null, i8* %b)
+;CHECK: ret i8* %r1
+;CHECK-LABEL: TBB.split
+;CHECK: %r2 = musttail call i8* @callee(i8* nonnull %a, i8* null)
+;CHECK: ret i8* %r2
+define i8* @larger_cfg_caller(i8* %a, i8* %b) {
+Top:
+  %cond1 = icmp eq i8* %a, null
+  br i1 %cond1, label %Tail, label %ExtraTest
+ExtraTest:
+  %a0 = load i8, i8* %a
+  %cond2 = icmp eq i8 %a0, 0
+  br i1 %cond2, label %TBB_pred, label %End
+TBB_pred:
+  br label %TBB
+TBB:
+  %cond3 = icmp eq i8* %b, null
+  br i1 %cond3, label %Tail, label %End
+Tail:
+  %r = musttail call i8* @callee(i8* %a, i8* %b)
+  ret i8* %r
+End:
+  ret i8* null
+}