[gcc r14-9859] bitint: Don't move debug stmts from before returns_twice calls [PR114628]

[Jakub Jelinek <jakub@gcc.gnu.org>]

https://gcc.gnu.org/g:7dd1f9d2ec422173f490d91b9173d4fa5d32d909

commit r14-9859-g7dd1f9d2ec422173f490d91b9173d4fa5d32d909
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Apr 9 09:28:27 2024 +0200

    bitint: Don't move debug stmts from before returns_twice calls [PR114628]
    
    Debug stmts are allowed by the verifier before the returns_twice calls.
    More importantly, they don't have a lhs, so the current handling of
    arg_stmts statements to force them on the edges ICEs.
    
    The following patch just keeps them where they were before.
    
    2024-04-09  Jakub Jelinek  <jakub@redhat.com>
    
            PR middle-end/114628
            * gimple-lower-bitint.cc (gimple_lower_bitint): Keep debug stmts
            before returns_twice calls as is, don't push them into arg_stmts
            vector/move to edges.
    
            * gcc.dg/bitint-105.c: New test.

Diff:
---
 gcc/gimple-lower-bitint.cc        |  9 +++++++--
 gcc/testsuite/gcc.dg/bitint-105.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 1afd4de445a..4c3b7f7b68e 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -7172,8 +7172,13 @@ gimple_lower_bitint (void)
 	  gimple_stmt_iterator gsi = gsi_after_labels (gimple_bb (stmt));
 	  while (gsi_stmt (gsi) != stmt)
 	    {
-	      arg_stmts.safe_push (gsi_stmt (gsi));
-	      gsi_remove (&gsi, false);
+	      if (is_gimple_debug (gsi_stmt (gsi)))
+		gsi_next (&gsi);
+	      else
+		{
+		  arg_stmts.safe_push (gsi_stmt (gsi));
+		  gsi_remove (&gsi, false);
+		}
 	    }
 	  gimple *g;
 	  basic_block bb = NULL;
diff --git a/gcc/testsuite/gcc.dg/bitint-105.c b/gcc/testsuite/gcc.dg/bitint-105.c
new file mode 100644
index 00000000000..d3215b1d473
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-105.c
@@ -0,0 +1,29 @@
+/* PR middle-end/114628 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2 -g" } */
+
+int foo (int);
+#if __BITINT_MAXWIDTH__ >= 129
+__attribute__((returns_twice)) int bar (_BitInt(129) x);
+
+void
+baz (int x, _BitInt(129) y)
+{
+  void *q[] = { &&l1, &&l2 };
+l2:
+  x = foo (foo (3));
+  bar (y);
+  goto *q[x & 1];
+l1:;
+}
+
+void
+qux (int x, _BitInt(129) y)
+{
+  void *q[] = { &&l1, &&l2 };
+l2:
+  x = foo (foo (3));
+  bar (y);
+l1:;
+}
+#endif