c: Fix up __builtin_assoc_barrier handling in the C FE [PR104427]
Commit Message
Hi!
The following testcase ICEs, because when creating PAREN_EXPR for
__builtin_assoc_barrier the FE doesn't do the usual tweaks for
EXCESS_PRECISION_EXPR or C_MAYBE_CONST_EXPR. I believe that the
declared effect of the builtin is just association barrier, so
e.g. excess precision should be still handled like if it wasn't
there.
The following patch uses build_unary_op to handle those.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-02-08 Jakub Jelinek <jakub@redhat.com>
PR c/104427
* c-parser.cc (c_parser_postfix_expression)
<case RID_BUILTIN_ASSOC_BARRIER>: Use parser_build_unary_op
instead of build1_loc to build PAREN_EXPR.
* c-typeck.cc (build_unary_op): Handle PAREN_EXPR.
* c-fold.cc (c_fully_fold_internal): Likewise.
* gcc.dg/pr104427.c: New test.
Jakub
Comments
On Wed, 9 Feb 2022, Jakub Jelinek via Gcc-patches wrote:
> Hi!
>
> The following testcase ICEs, because when creating PAREN_EXPR for
> __builtin_assoc_barrier the FE doesn't do the usual tweaks for
> EXCESS_PRECISION_EXPR or C_MAYBE_CONST_EXPR. I believe that the
> declared effect of the builtin is just association barrier, so
> e.g. excess precision should be still handled like if it wasn't
> there.
>
> The following patch uses build_unary_op to handle those.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
@@ -10128,8 +10128,7 @@ c_parser_postfix_expression (c_parser *p
mark_exp_read (e1.value);
location_t end_loc = c_parser_peek_token (parser)->get_finish ();
parens.skip_until_found_close (parser);
- expr.value = build1_loc (loc, PAREN_EXPR, TREE_TYPE (e1.value),
- e1.value);
+ expr = parser_build_unary_op (loc, PAREN_EXPR, e1);
set_c_expr_source_range (&expr, start_loc, end_loc);
}
break;
@@ -4921,6 +4921,10 @@ build_unary_op (location_t location, enu
ret = val;
goto return_build_unary_op;
+ case PAREN_EXPR:
+ ret = build1 (code, TREE_TYPE (arg), arg);
+ goto return_build_unary_op;
+
default:
gcc_unreachable ();
}
@@ -465,6 +465,7 @@ c_fully_fold_internal (tree expr, bool i
case BIT_NOT_EXPR:
case TRUTH_NOT_EXPR:
case CONJ_EXPR:
+ case PAREN_EXPR:
unary:
/* Unary operations. */
orig_op0 = op0 = TREE_OPERAND (expr, 0);
@@ -0,0 +1,13 @@
+/* PR c/104427 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+/* { dg-add-options float16 } */
+/* { dg-require-effective-target float16 } */
+
+_Float16 x, y;
+
+int
+foo ()
+{
+ return __builtin_assoc_barrier (x + y) - y;
+}