re PR middle-end/44071 (ICE with asm goto and __builtin_unreachable())

	PR middle-end/44071
	* cfglayout.c (fixup_reorder_chain): Allow asm goto to have
	no fallthru edge.
	* cfgcleanup.c (try_optimize_cfg): When in cfglayout mode
	optimizing away empty bb with no successors, move over its
	footer chain to fallthru predecessor.
	* cfgrtl.c (patch_jump_insn): Update also REG_LABEL_OPERAND.
	(rtl_split_edge): For asm goto call patch_jump_insn even if
	splitting fallthru edge.

	* c-c++-common/asmgoto-4.c: New test.
	* gcc.target/i386/pr44071.c: New test.

From-SVN: r159288

1 files changed, 44 insertions, 0 deletions

diff --git a/gcc/testsuite/c-c++-common/asmgoto-4.c b/gcc/testsuite/c-c++-common/asmgoto-4.c
new file mode 100644
index 0000000..4532bf1
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asmgoto-4.c
@@ -0,0 +1,44 @@
+/* PR middle-end/44071 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+static inline int
+f1 (void)
+{
+  asm goto ("" : : : : l1, l2);
+  __builtin_unreachable ();
+ l1:
+  return 1;
+ l2:
+  return 0;
+}
+
+int
+b1 (int x)
+{
+  if (f1 () || x == 6)
+    x = 1;
+  else
+    x = 2;
+  return x;
+}
+
+static inline int
+f2 (void)
+{
+  asm goto ("" : : : : l1, l2);
+ l1:
+  return 1;
+ l2:
+  return 0;
+}
+
+int
+b2 (int x)
+{
+  if (f2 () || x == 6)
+    x = 1;
+  else
+    x = 2;
+  return x;
+}