On Tue, 5 Feb 2013, Jakub Jelinek wrote:
> Hi!
>
> The following testcase is miscompiled on ppc64, because the stdarg pass
> didn't figure out that va_list was escaping.
> The problem was that we've processed the
> # z.2_31 = PHI <z.2_27(11), z.2_24(12)>
> stmt was processed before processing z.2_27 and z.2_24 assignments,
> so neither of them was in va_list_escape_vars at that point and so
> z.2_31 wasn't added. As we don't iterate in the first pass, we need
> to just give up if we see this during check_all_va_list_escapes.
> I don't think it happens often enough to warrant the need to iterate
> instead.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2013-02-05 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/56205
> * tree-stdarg.c (check_all_va_list_escapes): Return true if
> there are any PHI nodes that set non-va_list_escape_vars SSA_NAME
> and some va_list_escape_vars SSA_NAME appears in some PHI argument.
>
> * gcc.dg/tree-ssa/stdarg-6.c: New test.
> * gcc.c-torture/execute/pr56205.c: New test.
>
> --- gcc/tree-stdarg.c.jj 2013-01-11 09:02:48.000000000 +0100
> +++ gcc/tree-stdarg.c 2013-02-05 10:47:13.292700397 +0100
> @@ -526,6 +526,37 @@ check_all_va_list_escapes (struct stdarg
> {
> gimple_stmt_iterator i;
>
> + for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i))
> + {
> + tree lhs;
> + use_operand_p uop;
> + ssa_op_iter soi;
> + gimple phi = gsi_stmt (i);
> +
> + lhs = PHI_RESULT (phi);
> + if (virtual_operand_p (lhs)
> + || bitmap_bit_p (si->va_list_escape_vars,
> + SSA_NAME_VERSION (lhs)))
> + continue;
> +
> + FOR_EACH_PHI_ARG (uop, phi, soi, SSA_OP_USE)
> + {
> + tree rhs = USE_FROM_PTR (uop);
> + if (TREE_CODE (rhs) == SSA_NAME
> + && bitmap_bit_p (si->va_list_escape_vars,
> + SSA_NAME_VERSION (rhs)))
> + {
> + 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);
> + }
> + return true;
> + }
> + }
> + }
> +
> for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
> {
> gimple stmt = gsi_stmt (i);
> --- gcc/testsuite/gcc.dg/tree-ssa/stdarg-6.c.jj 2013-02-05
> 11:01:37.518935765 +0100
> +++ gcc/testsuite/gcc.dg/tree-ssa/stdarg-6.c 2013-02-05 11:15:01.511610919
> +0100
> @@ -0,0 +1,35 @@
> +/* PR tree-optimization/56205 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -fdump-tree-stdarg" } */
> +
> +#include <stdarg.h>
> +
> +int a, b;
> +char c[128];
> +
> +static inline void
> +foo (int x, char const *y, va_list z)
> +{
> + __builtin_printf ("%s %d %s", x ? "" : "foo", ++a, (y && *y) ? "bar" : "");
> + if (y && *y)
> + __builtin_vprintf (y, z);
> +}
> +
> +void
> +bar (int x, char const *y, ...)
> +{
> + va_list z;
> + va_start (z, y);
> + if (!x && *c == '\0')
> + ++b;
> + foo (x, y, z);
> + va_end (z);
> +}
> +
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units and all FPR units" "stdarg" { target { { i?86-*-* x86_64-*-* } && {
> ! { ia32 } } } } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units and all FPR units" "stdarg" { target { powerpc*-*-linux* && ilp32 }
> } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units and all FPR units" "stdarg" { target alpha*-*-linux* } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units and all FPR units" "stdarg" { target s390*-*-linux* } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units" "stdarg" { target { { i?86-*-* x86_64-*-* } && ia32 } } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units" "stdarg" { target ia64-*-* } } } */
> +/* { dg-final { scan-tree-dump "bar: va_list escapes 1, needs to save all
> GPR units" "stdarg" { target { powerpc*-*-* && lp64 } } } } */
> --- gcc/testsuite/gcc.c-torture/execute/pr56205.c.jj 2013-02-05
> 11:36:30.693183702 +0100
> +++ gcc/testsuite/gcc.c-torture/execute/pr56205.c 2013-02-05
> 11:34:34.000000000 +0100
> @@ -0,0 +1,61 @@
> +/* PR tree-optimization/56205 */
> +
> +#include <stdarg.h>
> +
> +int a, b;
> +char c[128];
> +
> +__attribute__((noinline, noclone)) static void
> +f1 (const char *fmt, ...)
> +{
> + va_list ap;
> + asm volatile ("" : : : "memory");
> + if (__builtin_strcmp (fmt, "%s %d %s") != 0)
> + __builtin_abort ();
> + va_start (ap, fmt);
> + if (__builtin_strcmp (va_arg (ap, const char *), "foo") != 0
> + || va_arg (ap, int) != 1
> + || __builtin_strcmp (va_arg (ap, const char *), "bar") != 0)
> + __builtin_abort ();
> + va_end (ap);
> +}
> +
> +__attribute__((noinline, noclone)) static void
> +f2 (const char *fmt, va_list ap)
> +{
> + asm volatile ("" : : : "memory");
> + if (__builtin_strcmp (fmt, "baz") != 0
> + || __builtin_strcmp (va_arg (ap, const char *), "foo") != 0
> + || va_arg (ap, double) != 12.0
> + || va_arg (ap, int) != 26)
> + __builtin_abort ();
> +}
> +
> +static void
> +f3 (int x, char const *y, va_list z)
> +{
> + f1 ("%s %d %s", x ? "" : "foo", ++a, (y && *y) ? "bar" : "");
> + if (y && *y)
> + f2 (y, z);
> +}
> +
> +__attribute__((noinline, noclone)) void
> +f4 (int x, char const *y, ...)
> +{
> + va_list z;
> + va_start (z, y);
> + if (!x && *c == '\0')
> + ++b;
> + f3 (x, y, z);
> + va_end (z);
> +}
> +
> +int
> +main ()
> +{
> + asm volatile ("" : : : "memory");
> + f4 (0, "baz", "foo", 12.0, 26);
> + if (a != 1 || b != 1)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imend
