* [PATCH] Fix PR79547
@ 2017-02-16 12:47 Richard Biener
2017-02-17 9:45 ` Richard Biener
0 siblings, 1 reply; 5+ messages in thread
From: Richard Biener @ 2017-02-16 12:47 UTC (permalink / raw)
To: gcc-patches
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.
Richard.
2017-02-16 Richard Biener <rguenther@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/tree-ssa-structalias.c
===================================================================
--- gcc/tree-ssa-structalias.c (revision 245501)
+++ gcc/tree-ssa-structalias.c (working copy)
@@ -4474,6 +4474,22 @@ 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. */
+ case BUILT_IN_STRLEN:
+ 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:
+ case BUILT_IN_OBJECT_SIZE:
+ case BUILT_IN_CONSTANT_P:
+ /* We don't need to do anything here. No constraints are necessary
+ for the return value and call handling for pure functions is
+ special-cased in the alias oracle. */
+ return true;
/* Trampolines are special - they set up passing the static
frame. */
case BUILT_IN_INIT_TRAMPOLINE:
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" } } */
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix PR79547
2017-02-16 12:47 [PATCH] Fix PR79547 Richard Biener
@ 2017-02-17 9:45 ` Richard Biener
2017-02-17 10:52 ` Marc Glisse
2017-04-21 13:08 ` Richard Biener
0 siblings, 2 replies; 5+ messages in thread
From: Richard Biener @ 2017-02-17 9:45 UTC (permalink / raw)
To: gcc-patches
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.
Richard.
2017-02-17 Richard Biener <rguenther@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:
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix PR79547
2017-02-17 9:45 ` Richard Biener
@ 2017-02-17 10:52 ` Marc Glisse
2017-02-17 11:32 ` Richard Biener
2017-04-21 13:08 ` Richard Biener
1 sibling, 1 reply; 5+ messages in thread
From: Marc Glisse @ 2017-02-17 10:52 UTC (permalink / raw)
To: Richard Biener; +Cc: gcc-patches
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.
>
> Richard.
>
> 2017-02-17 Richard Biener <rguenther@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.
We have EAF_NOESCAPE that we are using for non-builtins, though it
probably gets little use there. Would it make sense to use it here as
well, or would that be pointless?
--
Marc Glisse
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix PR79547
2017-02-17 10:52 ` Marc Glisse
@ 2017-02-17 11:32 ` Richard Biener
0 siblings, 0 replies; 5+ messages in thread
From: Richard Biener @ 2017-02-17 11:32 UTC (permalink / raw)
To: gcc-patches
On Fri, 17 Feb 2017, Marc Glisse wrote:
> 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.
> >
> > Richard.
> >
> > 2017-02-17 Richard Biener <rguenther@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.
>
> We have EAF_NOESCAPE that we are using for non-builtins, though it probably
> gets little use there. Would it make sense to use it here as well, or would
> that be pointless?
EAF_NOESCAPE doesn't capture what we want here -- for pure and const
functions arguments already don't escape in EAF_NOESCAPEs sense it's
just that EAF_NOESCAPE doesn't cover "escaping" through the return value.
We do not have sth like ERF_RETURNS_NO_ARG.
Generally all explicitely handled builtins do not need any further
fn-spec attributes added in builtins.def.
Richard.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix PR79547
2017-02-17 9:45 ` Richard Biener
2017-02-17 10:52 ` Marc Glisse
@ 2017-04-21 13:08 ` Richard Biener
1 sibling, 0 replies; 5+ messages in thread
From: Richard Biener @ 2017-04-21 13:08 UTC (permalink / raw)
To: gcc-patches
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 <rguenther@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 <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-02-16 12:47 [PATCH] Fix PR79547 Richard Biener
2017-02-17 9:45 ` Richard Biener
2017-02-17 10:52 ` Marc Glisse
2017-02-17 11:32 ` Richard Biener
2017-04-21 13:08 ` Richard Biener
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