On Wed, 12 Feb 2014, Andreas Krebbel wrote:
> On 07/02/14 10:33, Richard Biener wrote:
> > + static void
> > + lower_builtin_posix_memalign (gimple_stmt_iterator *gsi)
> > + {
> > + gimple stmt = gsi_stmt (*gsi);
> > + tree pptr = gimple_call_arg (stmt, 0);
> > + tree align = gimple_call_arg (stmt, 1);
> > + tree ptr = create_tmp_reg (ptr_type_node, NULL);
> > + if (TREE_CODE (pptr) == ADDR_EXPR)
> > + {
> > + tree tem = create_tmp_var (ptr_type_node, NULL);
> > + TREE_ADDRESSABLE (tem) = 1;
> > + gimple_call_set_arg (stmt, 0, build_fold_addr_expr (tem));
> > + stmt = gimple_build_assign (ptr, tem);
> > + }
> > + else
> > + stmt = gimple_build_assign (ptr,
> > + fold_build2 (MEM_REF, ptr_type_node, pptr,
> > + build_int_cst (ptr_type_node, 0)));
> > + gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
> > + stmt = gimple_build_call (builtin_decl_implicit
> > (BUILT_IN_ASSUME_ALIGNED),
> > + 2, ptr, align);
> > + gimple_call_set_lhs (stmt, ptr);
> > + gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
> > + stmt = gimple_build_assign (fold_build2 (MEM_REF, ptr_type_node, pptr,
> > + build_int_cst (ptr_type_node, 0)),
> > + ptr);
> > + gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
> > + }
>
> Hi,
>
> creating a new var for the output parameter throws away the value already in
> there. But this value
> must not change when posix_memalign e.g. returns with ENOMEM. It breaks the
> glibc posix_memalign
> testcase on s390 (somewhat reduced here):
Bah. I am testing the following.
Richard.
2014-02-12 Richard Biener <rguent...@suse.de>
PR middle-end/60092
* gimple-low.c (lower_builtin_posix_memalign): Initialize the new
temporary properly.
(lower_stmt): Restrict lowering of posix_memalign to when
-ftree-bit-ccp is enabled.
* gcc.dg/pr60092.c: New testcase.
Index: gcc/gimple-low.c
===================================================================
*** gcc/gimple-low.c (revision 207714)
--- gcc/gimple-low.c (working copy)
*************** lower_stmt (gimple_stmt_iterator *gsi, s
*** 336,342 ****
data->cannot_fallthru = false;
return;
}
! else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN)
{
lower_builtin_posix_memalign (gsi);
return;
--- 336,343 ----
data->cannot_fallthru = false;
return;
}
! else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN
! && flag_tree_bit_ccp)
{
lower_builtin_posix_memalign (gsi);
return;
*************** lower_builtin_setjmp (gimple_stmt_iterat
*** 786,792 ****
tem = __builtin_assume_aligned (tem, align);
*ptr = tem;
or to
! void *tem;
posix_memalign (&tem, align, size);
ttem = tem;
ttem = __builtin_assume_aligned (ttem, align);
--- 787,793 ----
tem = __builtin_assume_aligned (tem, align);
*ptr = tem;
or to
! void *tem = ptr;
posix_memalign (&tem, align, size);
ttem = tem;
ttem = __builtin_assume_aligned (ttem, align);
*************** lower_builtin_posix_memalign (gimple_stm
*** 806,811 ****
--- 807,819 ----
tree tem = create_tmp_var (ptr_type_node, NULL);
TREE_ADDRESSABLE (tem) = 1;
gimple_call_set_arg (stmt, 0, build_fold_addr_expr (tem));
+ /* Initialize tem, ptr has to be unchanged if posix_memalloc fails. */
+ stmt = gimple_build_assign (ptr,
+ fold_build2 (MEM_REF, ptr_type_node, pptr,
+ build_int_cst (ptr_type_node,
0)));
+ gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
+ stmt = gimple_build_assign (tem, ptr);
+ gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
stmt = gimple_build_assign (ptr, tem);
}
else
Index: gcc/testsuite/gcc.dg/torture/pr60092.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr60092.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr60092.c (working copy)
***************
*** 0 ****
--- 1,21 ----
+ /* { dg-do run } */
+ /* { dg-require-weak "" } */
+
+ typedef __SIZE_TYPE__ size_t;
+ extern int posix_memalign(void **memptr, size_t alignment, size_t size)
__attribute__((weak));
+ extern void abort(void);
+ int
+ main (void)
+ {
+ void *p;
+ int ret;
+
+ if (!posix_memalign)
+ return 0;
+
+ p = (void *)&ret;
+ ret = posix_memalign (&p, sizeof (void *), -1);
+ if (p != (void *)&ret)
+ abort ();
+ return 0;
+ }
