[PATCH] lower-bitint: Fix up VIEW_CONVERT_EXPR handling in handle_operand_addr [PR113639]

[Jakub Jelinek]

Hi!

Yet another spot where we need to treat VIEW_CONVERT_EXPR differently
from NOP_EXPR/CONVERT_EXPR.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2024-01-31  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/113639
        * gimple-lower-bitint.cc (bitint_large_huge::handle_operand_addr):
        For VIEW_CONVERT_EXPR set rhs1 to its operand.

        * gcc.dg/bitint-79.c: New test.

--- gcc/gimple-lower-bitint.cc.jj       2024-01-27 13:06:49.183671155 +0100
+++ gcc/gimple-lower-bitint.cc  2024-01-30 17:06:56.829144801 +0100
@@ -2159,6 +2159,8 @@ bitint_large_huge::handle_operand_addr (
              gcc_assert (gimple_assign_cast_p (g));
              tree rhs1 = gimple_assign_rhs1 (g);
              bitint_prec_kind kind = bitint_prec_small;
+             if (TREE_CODE (rhs1) == VIEW_CONVERT_EXPR)
+               rhs1 = TREE_OPERAND (rhs1, 0);
              gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)));
              if (TREE_CODE (TREE_TYPE (rhs1)) == BITINT_TYPE)
                kind = bitint_precision_kind (TREE_TYPE (rhs1));
--- gcc/testsuite/gcc.dg/bitint-79.c.jj 2024-01-30 17:18:50.711135054 +0100
+++ gcc/testsuite/gcc.dg/bitint-79.c    2024-01-30 17:18:22.986524397 +0100
@@ -0,0 +1,16 @@
+/* PR tree-optimization/113639 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2 -std=c23" } */
+
+int j, k;
+#if __BITINT_MAXWIDTH__ >= 162
+struct S { _BitInt(162) n; };
+void bar (_BitInt(162) x);
+
+void
+foo (struct S s)
+{
+  bar (s.n * j);
+  (void) (s.n * k);
+}
+#endif

        Jakub