On Fri, 17 Feb 2017, Richard Biener wrote:
> On Thu, 16 Feb 2017, Richard Biener wrote:
>
> >
> > I am testing the following patch for PR79547. Those builtins do not
> > return anything that can be used to re-construct the pointer(s) passed
> > to them.
> >
> > Queued for GCC 8.
>
> Actually we need calluse constraints. Thus adjusted as follows.
Re-bootstrapped & tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
> Richard.
>
> 2017-02-17 Richard Biener <rguent...@suse.de>
>
> PR tree-optimization/79547
> * tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
> Handle strlen, strcmp, strncmp, strcasecmp, strncasecmp, memcmp,
> bcmp, strspn, strcspn, __builtin_object_size and __builtin_constant_p
> without any constraints.
>
> * gcc.dg/tree-ssa/strlen-2.c: New testcase.
>
> Index: gcc/testsuite/gcc.dg/tree-ssa/strlen-2.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/tree-ssa/strlen-2.c (nonexistent)
> +++ gcc/testsuite/gcc.dg/tree-ssa/strlen-2.c (working copy)
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-strlen" } */
> +
> +void f (unsigned);
> +
> +void f3 (void)
> +{
> + char s[] = "1234";
> +
> + f (__builtin_strlen (s));
> + f (__builtin_strlen (s));
> + f (__builtin_strlen (s));
> +}
> +
> +/* { dg-final { scan-tree-dump-times "strlen" 1 "strlen" } } */
> Index: gcc/tree-ssa-structalias.c
> ===================================================================
> --- gcc/tree-ssa-structalias.c (revision 245501)
> +++ gcc/tree-ssa-structalias.c (working copy)
> @@ -4474,6 +4474,40 @@ find_func_aliases_for_builtin_call (stru
> process_all_all_constraints (lhsc, rhsc);
> }
> return true;
> + /* Pure functions that return something not based on any object and
> + that use the memory pointed to by their arguments (but not
> + transitively). */
> + case BUILT_IN_STRCMP:
> + case BUILT_IN_STRNCMP:
> + case BUILT_IN_STRCASECMP:
> + case BUILT_IN_STRNCASECMP:
> + case BUILT_IN_MEMCMP:
> + case BUILT_IN_BCMP:
> + case BUILT_IN_STRSPN:
> + case BUILT_IN_STRCSPN:
> + {
> + varinfo_t uses = get_call_use_vi (t);
> + make_any_offset_constraints (uses);
> + make_constraint_to (uses->id, gimple_call_arg (t, 0));
> + make_constraint_to (uses->id, gimple_call_arg (t, 1));
> + /* No constraints are necessary for the return value. */
> + return true;
> + }
> + case BUILT_IN_STRLEN:
> + {
> + varinfo_t uses = get_call_use_vi (t);
> + make_any_offset_constraints (uses);
> + make_constraint_to (uses->id, gimple_call_arg (t, 0));
> + /* No constraints are necessary for the return value. */
> + return true;
> + }
> + case BUILT_IN_OBJECT_SIZE:
> + case BUILT_IN_CONSTANT_P:
> + {
> + /* No constraints are necessary for the return value or the
> + arguments. */
> + return true;
> + }
> /* Trampolines are special - they set up passing the static
> frame. */
> case BUILT_IN_INIT_TRAMPOLINE:
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
