Re: [PATCH][PR67666] Handle single restrict pointer in struct in create_variable_info_for_1

[Tom de Vries]

On 22/09/15 09:49, Richard Biener wrote:
On Tue, 22 Sep 2015, Tom de Vries wrote:
Hi,

Consider this test-case:

struct ps
{
   int *__restrict__ p;
};

void
f (struct ps &__restrict__ ps1)
{
   *(ps1.p) = 1;
}


Atm, the restrict on p has no effect. Now, say we add a field to the struct:

struct ps
{
   int *__restrict__ p;
   int a;
};


Then the restrict on p does have the desired effect.


This patch fixes the handling of structs with a single field in alias
analysis.

Bootstrapped and reg-tested on x86_64.

OK for trunk?

Ok.


Hi,

I wonder if this follow-up patch is necessary.

Now that we handle structs with one field in the final loop of 
create_variable_info_for_1, should we set the is_full_var field as well? 
It used to be set for such structs before I committed the "Handle single 
restrict pointer in struct in create_variable_info_for_1" patch.

Thanks,
- Tom

diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 8d86dcb..26d97a3 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -5720,6 +5720,8 @@ create_variable_info_for_1 (tree decl, const char 
*name)
       newvi->offset = fo->offset;
       newvi->size = fo->size;
       newvi->fullsize = vi->fullsize;
+      if (fieldstack.length () == 1)
+       newvi->is_full_var = true;
       newvi->may_have_pointers = fo->may_have_pointers;
       newvi->only_restrict_pointers = fo->only_restrict_pointers;
       if (i + 1 < fieldstack.length ())