Allow more kinds of invariant addresses in GIMPLE FE

Message ID 62358537-7r12-74ps-1335-1s446q69npo@fhfr.qr
State Committed
Commit d4f6dbe18374385b8199ca3d6121e37a1189b589
Headers
Series Allow more kinds of invariant addresses in GIMPLE FE |

Commit Message

Richard Biener Oct. 5, 2021, 12:54 p.m. UTC
  The gimple FE is too restrictive in what it accepts as
literals, the following makes it also accept &a[10] for example.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

Richard.

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.
---
 gcc/c/gimple-parser.c              | 14 +++++++++-----
 gcc/testsuite/gcc.dg/gimplefe-46.c | 23 +++++++++++++++++++++++
 2 files changed, 32 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/gimplefe-46.c
  

Patch

diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
index c8d9db61f0a..c43ee38a2cf 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 00000000000..fb91f7d2a90
--- /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;
+}