Reenable tail duplication of bb with just an unconditional jump, but

don't remove blocks that have their address taken.

llvm-svn: 133659

1 files changed, 28 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/tail-dup-addr.ll b/llvm/test/CodeGen/X86/tail-dup-addr.ll
new file mode 100644
index 00000000000..c5a105cb587
--- /dev/null
+++ b/llvm/test/CodeGen/X86/tail-dup-addr.ll
@@ -0,0 +1,28 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s
+
+; Test that we don't drop a block that has its address taken.
+
+; CHECK: Ltmp1:                                  ## Block address taken
+; CHECK: Ltmp2:                                  ## Block address taken
+
+@a = common global i32 0, align 4
+@p = common global i8* null, align 8
+
+define void @foo() noreturn nounwind uwtable ssp {
+entry:
+  %tmp = load i32* @a, align 4
+  %foo = icmp eq i32 0, %tmp
+  br i1 %foo, label %sw.bb, label %sw.default
+
+sw.bb:                                            ; preds = %entry
+  store i8* blockaddress(@foo, %sw.bb1), i8** @p, align 8
+  br label %sw.bb1
+
+sw.bb1:                                           ; preds = %sw.default, %sw.bb, %entry
+  store i8* blockaddress(@foo, %sw.default), i8** @p, align 8
+  br label %sw.default
+
+sw.default:                                       ; preds = %sw.bb1, %entry
+  store i8* blockaddress(@foo, %sw.bb1), i8** @p, align 8
+  br label %sw.bb1
+}