lower-bitint: Handle uninitialized large/huge SSA_NAMEs as inline asm inputs [PR113699]

Similar problem to calls with uninitialized large/huge _BitInt SSA_NAME
arguments, var_to_partition will not work for those, but unlike calls
where we just create a new uninitialized SSA_NAME here we need to change
the inline asm input to be an uninitialized VAR_DECL.

2024-02-02  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/113699
	* gimple-lower-bitint.cc (bitint_large_huge::lower_asm): Handle
	uninitialized large/huge _BitInt SSA_NAME inputs.

	* gcc.dg/bitint-81.c: New test.

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index a3802c61816a561be5a165efafc75d8d1dcf2fe8..758815039219f96f57df05a24fe76704c69cb66b 100644 (file)
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -5200,9 +5200,18 @@ bitint_large_huge::lower_asm (gimple *stmt)
          && TREE_CODE (TREE_TYPE (s)) == BITINT_TYPE
          && bitint_precision_kind (TREE_TYPE (s)) >= bitint_prec_large)
        {
-         int part = var_to_partition (m_map, s);
-         gcc_assert (m_vars[part] != NULL_TREE);
-         TREE_VALUE (t) = m_vars[part];
+         if (SSA_NAME_IS_DEFAULT_DEF (s)
+             && (!SSA_NAME_VAR (s) || VAR_P (SSA_NAME_VAR (s))))
+           {
+             TREE_VALUE (t) = create_tmp_var (TREE_TYPE (s), "bitint");
+             mark_addressable (TREE_VALUE (t));
+           }
+         else
+           {
+             int part = var_to_partition (m_map, s);
+             gcc_assert (m_vars[part] != NULL_TREE);
+             TREE_VALUE (t) = m_vars[part];
+           }
        }
     }
   update_stmt (stmt);

diff --git a/gcc/testsuite/gcc.dg/bitint-81.c b/gcc/testsuite/gcc.dg/bitint-81.c
new file mode 100644 (file)
index 0000000..33162fd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-81.c
@@ -0,0 +1,12 @@
+/* PR middle-end/113699 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2 -std=c23" } */
+
+void
+foo (void)
+{
+#if __BITINT_MAXWIDTH__ >= 129
+  _BitInt(129) i;
+  __asm__ ("" : : "rm" (i));
+#endif
+}