Re: [PATCH] Make IPA-CP work on aggregates

[Martin Jambor]

Hi,

On Wed, Nov 07, 2012 at 03:55:16PM +0100, Jan Hubicka wrote:
> > On Wed, Nov 07, 2012 at 03:39:15PM +0100, Martin Jambor wrote:
> > > another bootstrap finishes.  I'm not sure if it would be OK to commit
> > > it now, given it is stage3, though.  OTOH, I think it would be worth
> > > it.
> > 
> > I'm ok with getting that in now from RM POV, but not familiar with the
> > code enough to review it.  So, if somebody acks it (Honza?), it can be
> > added.
> > 
> > > 2012-11-07  Martin Jambor  <mjam...@suse.cz>
> > > 
> > >   * ipa-prop.c (determine_known_aggregate_parts): Skip writes to
> > >   different declarations when tracking writes to a declaration.
> > > 
> > > Index: src/gcc/ipa-prop.c
> > > ===================================================================
> > > --- src.orig/gcc/ipa-prop.c
> > > +++ src/gcc/ipa-prop.c
> > > @@ -1318,7 +1318,12 @@ determine_known_aggregate_parts (gimple
> > >       break;
> > >   }
> > >        else if (lhs_base != arg_base)
> > > - break;
> > > + {
> > > +   if (DECL_P (lhs_base))
> > > +     continue;
> > > +   else
> > > +     break;
> > > + }
> 
> OK, so the point of patch is to not stop on writes to decls while looking
> for value the field is initialized to?
> 
> It looks OK.

Yes, when we are looking for writes to a decl and come accross a write
to another decl, we just skip it instead of bailing out completely.
The reason my original implementation missed it is that I relied on
stmt_may_clobber_ref_p_1 to determine it could not clobber the decl
but apprently it does not... perhaps that is a bug?

Anyway, I added a testcase to the above and this is what I am about to
commit.

Thanks a lot,

Martin


2012-11-07  Martin Jambor  <mjam...@suse.cz>

        * ipa-prop.c (determine_known_aggregate_parts): Skip writes to
        different declarations when tracking writes to a declaration.

        * gfortran.dg/ipcp-array-1.f90: New test.

Index: src/gcc/ipa-prop.c
===================================================================
--- src.orig/gcc/ipa-prop.c
+++ src/gcc/ipa-prop.c
@@ -1318,7 +1318,12 @@ determine_known_aggregate_parts (gimple
            break;
        }
       else if (lhs_base != arg_base)
-       break;
+       {
+         if (DECL_P (lhs_base))
+           continue;
+         else
+           break;
+       }
 
       if (lhs_offset + lhs_size < arg_offset
          || lhs_offset >= (arg_offset + arg_size))
Index: src/gcc/testsuite/gfortran.dg/ipcp-array-1.f90
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gfortran.dg/ipcp-array-1.f90
@@ -0,0 +1,19 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-ipa-cp-details -fno-inline -fdump-tree-optimized" }
+
+subroutine bar (a, b, n)
+  integer :: a(n), b(n)
+  call foo (a, b)
+contains
+subroutine foo (a, b)
+  integer :: a(:), b(:)
+  a = b
+end subroutine
+end
+
+! { dg-final { scan-ipa-dump "Creating a specialized node of foo" "cp" } }
+! { dg-final { scan-ipa-dump-times "Aggregate 
replacements\[^=\]*=\[^=\]*=\[^=\]*=\[^=\]*=\[^=\]*=\[^=\]*=\[^=\]*=\[^=\]*=" 2 
"cp" } }
+! { dg-final { cleanup-ipa-dump "cp" } }
+! { dg-final { scan-tree-dump-not "stride;" "optimized" } }
+! { dg-final { scan-tree-dump-not "lbound;" "optimized" } }
+! { dg-final { cleanup-tree-dump "optimized" } }