Add CodeGen support for indirect goto.

 - Follows emission scheme used by llvm-gcc, i.e. invent an id for
   each label whose address is taken and replace each indirect goto by
   a switch to each possible target.
 - Currently we emit a switch for each indirect goto instead of
   merging them as llvm-gcc does.

llvm-svn: 54318

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/CodeGen/indirect-goto.c b/clang/test/CodeGen/indirect-goto.c
new file mode 100644
index 00000000000..c0dc8a8298d
--- /dev/null
+++ b/clang/test/CodeGen/indirect-goto.c
@@ -0,0 +1,20 @@
+// RUN: clang -emit-llvm-bc -o - %s | opt -std-compile-opts | llvm-dis > %t &&
+// RUN: grep "ret i32" %t | count 1 &&
+// RUN: grep "ret i32 210" %t | count 1
+
+static int foo(unsigned i) {
+  const void *addrs[] = { &&L1, &&L2, &&L3, &&L4, &&L5 };
+  int res = 1;
+
+  goto *addrs[i];
+ L5: res *= 11;
+ L4: res *= 7;
+ L3: res *= 5;
+ L2: res *= 3;
+ L1: res *= 2; 
+  return res;
+}
+
+int bar() {
+  return foo(3);
+}