On Mon, Feb 09, 2015 at 01:05:23PM +0100, Jakub Jelinek wrote:
> As you can see, the updated testcase fails even on x86_64-linux.
Here is an updated patch that succeeds even on i686-linux.
2015-02-09 Jakub Jelinek <ja...@redhat.com>
PR target/64979
* tree-stdarg.c (pass_stdarg::execute): Scan phi node args for
va_list escapes.
* gcc.dg/tree-ssa/stdarg-7.c: New test.
* gcc.c-torture/execute/pr64979.c: New test.
--- gcc/tree-stdarg.c.jj 2015-01-09 21:59:44.000000000 +0100
+++ gcc/tree-stdarg.c 2015-02-09 13:14:43.880406573 +0100
@@ -856,22 +856,23 @@ pass_stdarg::execute (function *fun)
/* For va_list_simple_ptr, we have to check PHI nodes too. We treat
them as assignments for the purpose of escape analysis. This is
not needed for non-simple va_list because virtual phis don't perform
- any real data movement. */
- if (va_list_simple_ptr)
+ any real data movement. Also, check PHI nodes for taking address of
+ the va_list vars. */
+ tree lhs, rhs;
+ use_operand_p uop;
+ ssa_op_iter soi;
+
+ for (gphi_iterator i = gsi_start_phis (bb); !gsi_end_p (i);
+ gsi_next (&i))
{
- tree lhs, rhs;
- use_operand_p uop;
- ssa_op_iter soi;
+ gphi *phi = i.phi ();
+ lhs = PHI_RESULT (phi);
- for (gphi_iterator i = gsi_start_phis (bb); !gsi_end_p (i);
- gsi_next (&i))
- {
- gphi *phi = i.phi ();
- lhs = PHI_RESULT (phi);
-
- if (virtual_operand_p (lhs))
- continue;
+ if (virtual_operand_p (lhs))
+ continue;
+ if (va_list_simple_ptr)
+ {
FOR_EACH_PHI_ARG (uop, phi, soi, SSA_OP_USE)
{
rhs = USE_FROM_PTR (uop);
@@ -894,6 +895,22 @@ pass_stdarg::execute (function *fun)
}
}
}
+
+ for (unsigned j = 0; !va_list_escapes
+ && j < gimple_phi_num_args (phi); ++j)
+ if ((!va_list_simple_ptr
+ || TREE_CODE (gimple_phi_arg_def (phi, j)) != SSA_NAME)
+ && walk_tree (gimple_phi_arg_def_ptr (phi, j),
+ find_va_list_reference, &wi, NULL))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fputs ("va_list escapes in ", dump_file);
+ print_gimple_stmt (dump_file, phi, 0, dump_flags);
+ fputc ('\n', dump_file);
+ }
+ va_list_escapes = true;
+ }
}
for (gimple_stmt_iterator i = gsi_start_bb (bb);
@@ -916,8 +933,8 @@ pass_stdarg::execute (function *fun)
if (is_gimple_assign (stmt))
{
- tree lhs = gimple_assign_lhs (stmt);
- tree rhs = gimple_assign_rhs1 (stmt);
+ lhs = gimple_assign_lhs (stmt);
+ rhs = gimple_assign_rhs1 (stmt);
if (va_list_simple_ptr)
{
--- gcc/testsuite/gcc.dg/tree-ssa/stdarg-7.c.jj 2015-02-09 12:54:44.222284401
+0100
+++ gcc/testsuite/gcc.dg/tree-ssa/stdarg-7.c 2015-02-09 12:58:10.406875647
+0100
@@ -0,0 +1,22 @@
+/* PR target/64979 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-stdarg" } */
+
+#include <stdarg.h>
+
+void bar (int x, va_list *ap);
+
+void
+foo (int x, ...)
+{
+ va_list ap;
+ int n;
+
+ va_start (ap, x);
+ n = va_arg (ap, int);
+ bar (x, (va_list *) ((n == 0) ? ((void *) 0) : &ap));
+ va_end (ap);
+}
+
+/* { dg-final { scan-tree-dump "foo: va_list escapes 1, needs to save all GPR
units and all FPR units" "stdarg" } } */
+/* { dg-final { cleanup-tree-dump "stdarg" } } */
--- gcc/testsuite/gcc.c-torture/execute/pr64979.c.jj 2015-02-09
12:54:01.867984625 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr64979.c 2015-02-09
13:08:17.458818847 +0100
@@ -0,0 +1,36 @@
+/* PR target/64979 */
+
+#include <stdarg.h>
+
+void __attribute__((noinline, noclone))
+bar (int x, va_list *ap)
+{
+ if (ap)
+ {
+ int i;
+ for (i = 0; i < 10; i++)
+ if (i != va_arg (*ap, int))
+ __builtin_abort ();
+ if (va_arg (*ap, double) != 0.5)
+ __builtin_abort ();
+ }
+}
+
+void __attribute__((noinline, noclone))
+foo (int x, ...)
+{
+ va_list ap;
+ int n;
+
+ va_start (ap, x);
+ n = va_arg (ap, int);
+ bar (x, (va_list *) ((n == 0) ? ((void *) 0) : &ap));
+ va_end (ap);
+}
+
+int
+main ()
+{
+ foo (100, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.5);
+ return 0;
+}
Jakub
