From: Richard Biener <rguenther@suse.de>
Date: Tue, 5 Oct 2021 12:18:09 +0000 (+0200)
Subject: Allow more kinds of invariant addresses in GIMPLE FE
X-Git-Tag: basepoints/gcc-13~4126
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d4f6dbe18374385b8199ca3d6121e37a1189b589;p=thirdparty%2Fgcc.git

Allow more kinds of invariant addresses in GIMPLE FE

The gimple FE is too restrictive in what it accepts as
literals, the following makes it also accept &a[10] for example.

2021-10-05  Richard Biener  <rguenther@suse.de>

	PR c/102605
gcc/c/
	* gimple-parser.c (c_parser_gimple_postfix_expression):
	Accept more address _Literals.

gcc/testsuite/
	* gcc.dg/gimplefe-46.c: New testcase.
---

diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
index c8d9db61f0aa..c43ee38a2cfd 100644
--- a/gcc/c/gimple-parser.c
+++ b/gcc/c/gimple-parser.c
@@ -1622,16 +1622,20 @@ c_parser_gimple_postfix_expression (gimple_parser &parser)
 		  tree val = c_parser_gimple_postfix_expression (parser).value;
 		  if (! val
 		      || val == error_mark_node
-		      || (!CONSTANT_CLASS_P (val)
-			  && !(addr_p
-			       && (TREE_CODE (val) == STRING_CST
-				   || DECL_P (val)))))
+		      || (!CONSTANT_CLASS_P (val) && !addr_p))
 		    {
 		      c_parser_error (parser, "invalid _Literal");
 		      return expr;
 		    }
 		  if (addr_p)
-		    val = build1 (ADDR_EXPR, type, val);
+		    {
+		      val = build1 (ADDR_EXPR, type, val);
+		      if (!is_gimple_invariant_address (val))
+			{
+			  c_parser_error (parser, "invalid _Literal");
+			  return expr;
+			}
+		    }
 		  if (neg_p)
 		    {
 		      val = const_unop (NEGATE_EXPR, TREE_TYPE (val), val);
diff --git a/gcc/testsuite/gcc.dg/gimplefe-46.c b/gcc/testsuite/gcc.dg/gimplefe-46.c
new file mode 100644
index 000000000000..fb91f7d2a902
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gimplefe-46.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-fgimple" } */
+
+char global[10];
+
+void bar (void);
+
+void __GIMPLE (ssa)
+foo (char * p)
+{
+  __BB(2):
+  if (p_2(D) == _Literal (char *)&global[2])
+    goto __BB3;
+  else
+    goto __BB4;
+
+  __BB(3):
+  bar ();
+  goto __BB4;
+
+  __BB(4):
+  return;
+}