From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 17 Jan 2024 12:55:50 +0000 (+0100)
Subject: lower-bitint: Fix up VIEW_CONVERT_EXPR handling [PR113408]
X-Git-Tag: basepoints/gcc-15~1955
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2fb78d431ff3c05997ef31837d6eb319d84a4239;p=thirdparty%2Fgcc.git

lower-bitint: Fix up VIEW_CONVERT_EXPR handling [PR113408]

Unlike NOP_EXPR/CONVERT_EXPR which are GIMPLE_UNARY_RHS, VIEW_CONVERT_EXPR
is GIMPLE_SINGLE_RHS and so gimple_assign_rhs1 contains the operand wrapped
in VIEW_CONVERT_EXPR tree.

So, to handle it like other casts we need to look through it.

2024-01-17  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113408
	* gimple-lower-bitint.cc (bitint_large_huge::handle_stmt): For
	VIEW_CONVERT_EXPR, pass TREE_OPERAND (rhs1, 0) rather than rhs1
	to handle_cast.

	* gcc.dg/bitint-71.c: New test.
---

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 672a9a33751a..d3d113578d91 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -1975,9 +1975,12 @@ bitint_large_huge::handle_stmt (gimple *stmt, tree idx)
 	case INTEGER_CST:
 	  return handle_operand (gimple_assign_rhs1 (stmt), idx);
 	CASE_CONVERT:
-	case VIEW_CONVERT_EXPR:
 	  return handle_cast (TREE_TYPE (gimple_assign_lhs (stmt)),
 			      gimple_assign_rhs1 (stmt), idx);
+	case VIEW_CONVERT_EXPR:
+	  return handle_cast (TREE_TYPE (gimple_assign_lhs (stmt)),
+			      TREE_OPERAND (gimple_assign_rhs1 (stmt), 0),
+			      idx);
 	default:
 	  break;
 	}
diff --git a/gcc/testsuite/gcc.dg/bitint-71.c b/gcc/testsuite/gcc.dg/bitint-71.c
new file mode 100644
index 000000000000..f7ff8716f36a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-71.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/113408 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c23 -O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 713
+struct A { _BitInt(713) b; } g;
+#else
+struct A { _BitInt(49) b; } g;
+#endif
+int f;
+
+void
+foo (void)
+{
+  struct A j = g;
+  if (j.b)
+    f = 0;
+}