Hi,
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79908 shows a case where
pass_stdarg ICEs attempting to gimplify a COMPLEX_EXPR with side
effects as an lvalue. This occurs when the LHS of a VA_ARG has been
cast away. This patch, credit to Richard Biener, uses
force_gimple_operand to instantiate the necessary side effects rather
than gimplify_expr using is_gimple_lvalue. The test case is taken
wholesale from the bug report.
Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no
regressions. Is this ok for trunk?
Thanks,
Bill
[gcc]
2017-03-20 Bill Schmidt <wschm...@linux.vnet.ibm.com>
Richard Biener <rgue...@suse.com>
PR tree-optimization/79908
* tree-stdarg.c (expand_ifn_va_arg_1): For a VA_ARG whose LHS has
been cast away, use force_gimple_operand to construct the side
effects.
[gcc/testsuite]
2017-03-20 Bill Schmidt <wschm...@linux.vnet.ibm.com>
Richard Biener <rguent...@suse.de>
PR tree-optimization/79908
* gcc.dg/torture/pr79908.c: New file.
Index: gcc/testsuite/gcc.dg/torture/pr79908.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr79908.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr79908.c (working copy)
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+/* Used to fail in the stdarg pass before fix for PR79908. */
+
+typedef __builtin_va_list __gnuc_va_list;
+typedef __gnuc_va_list va_list;
+
+void testva (int n, ...)
+{
+ va_list ap;
+ _Complex int i = __builtin_va_arg (ap, _Complex int);
+}
Index: gcc/tree-stdarg.c
===================================================================
--- gcc/tree-stdarg.c (revision 246286)
+++ gcc/tree-stdarg.c (working copy)
@@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-iterator.h"
#include "gimple-walk.h"
#include "gimplify.h"
+#include "gimplify-me.h"
#include "tree-into-ssa.h"
#include "tree-cfg.h"
#include "tree-stdarg.h"
@@ -1058,12 +1059,16 @@ expand_ifn_va_arg_1 (function *fun)
gimplify_assign (lhs, expr, &pre);
}
else
- gimplify_expr (&expr, &pre, &post, is_gimple_lvalue, fb_lvalue);
+ {
+ gimple_seq tmp_seq;
+ force_gimple_operand (expr, &tmp_seq, false, NULL_TREE);
+ gimple_seq_add_seq_without_update (&pre, tmp_seq);
+ }
input_location = saved_location;
pop_gimplify_context (NULL);
- gimple_seq_add_seq (&pre, post);
+ gimple_seq_add_seq_without_update (&pre, post);
update_modified_stmts (pre);
/* Add the sequence after IFN_VA_ARG. This splits the bb right
@@ -1072,11 +1077,10 @@ expand_ifn_va_arg_1 (function *fun)
gimple_find_sub_bbs (pre, &i);
/* Remove the IFN_VA_ARG gimple_call. It's the last stmt in the
- bb. */
+ bb if we added any stmts. */
unlink_stmt_vdef (stmt);
release_ssa_name_fn (fun, gimple_vdef (stmt));
gsi_remove (&i, true);
- gcc_assert (gsi_end_p (i));
/* We're walking here into the bbs which contain the expansion of
IFN_VA_ARG, and will not contain another IFN_VA_ARG that needs
