Patchwork [Fortran] PR 55806 - Inefficient ANY with array constructors

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Submitter Thomas Koenig
Date Jan. 13, 2013, 10:14 p.m.
Message ID <50F331C8.2000200@netcologne.de>
Download mbox | patch
Permalink /patch/211657/
State New
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Comments

Thomas Koenig - Jan. 13, 2013, 10:14 p.m.
Hi Mikael,

thanks a lot for your comments!

>> +      actual_arglist->expr = gfc_copy_expr (e);
>> +      actual_arglist->next = gfc_get_actual_arglist ();
> Another one is needed.  I get a segmentation fault with SUM.

Fixed by using gfc_build_intrisic_call.  I have also put SUM
into the test case.


>> +  if (dim != NULL)
>> +    {
> Minor, but I think you can assume dim != NULL.  Same for mask.

Fixed.

>> +  /* We changed things from under the expression walker.  Walking the
>> +     old tree would mess up things, so let's not do that.  */
>> +  return 1;
> I think this prevents any further reduction optimization. The following
> variant of your test case doesn't avoid the temporary:

You're right; I also could not come up with a test case where this
didn't work.

I have put this

>      do i=1,3
>         if (any([abs(a(i,1) - b(i,1)) > acc,  &
>              (j==i+1,j=3,8)])) cycle
>         if (any([abs(a(i,2) - b(i,2)) > acc, &
>              abs(a(i,3) - b(i,3)) > acc, lo(i,:)])) cycle
>         c = c + i
>      end do

into the test case.

Updated test case and patch attached.

OK for trunk?

	Thomas

2013-01-13  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/55806
         * frontend-passes.c (optimize_reduction):  New function,
         including prototype.
         (callback_reduction):  Likewise.
         (gfc_run_passes):  Also run optimize_reduction.
         (copy_walk_reduction_arg):  New function.
         (dummy_code_callback):  New function.

2013-01-13  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/55806
         * gfortran.dg/array_constructor_40.f90:  New test.
Mikael Morin - Jan. 14, 2013, 1:29 p.m.
Le 13/01/2013 23:14, Thomas Koenig a écrit :
> Hi Mikael,
>
> thanks a lot for your comments!
>
>>> + actual_arglist->expr = gfc_copy_expr (e); +
>>> actual_arglist->next = gfc_get_actual_arglist ();
>> Another one is needed. I get a segmentation fault with SUM.
>
> Fixed by using gfc_build_intrisic_call.
Nice.


>
> Updated test case and patch attached.
> Index: frontend-passes.c
> ===================================================================
> --- frontend-passes.c	(Revision 195136)
> +++ frontend-passes.c	(Arbeitskopie)
[...]
> +      else if (id == GFC_ISYM_ANY || id == GFC_ISYM_ALL)
> +	fcn = gfc_build_intrinsic_call (current_ns,
> +					fn->value.function.isym->id,
> +					fn->value.function.isym->name,
> +					fn->where, 2, gfc_copy_expr (e),
> +					NULL);
> +      else
> +	gfc_error ("Illegal id in copy_walk_reduction_arg");

This is not very useful for a user.  It should be an internal error (or 
gcc_unreachable would do as well).


> +
> +/* Callback function for optimzation of reductions to scalars.  Transform ANY
> +   ([f1,f2,f3, ...]) to f1 .or. f2 .or. f3 .or. ..., with ANY, SUM and PRODUCT
> +   correspondingly.  Handly only the simple cases without MASK and DIM.  */
> +
> +static int
> +callback_reduction (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED,
> +		    void *data ATTRIBUTE_UNUSED)
> +{
> +  gfc_expr *fn, *arg;
> +  gfc_intrinsic_op op;
> +  gfc_isym_id id;
> +  gfc_actual_arglist *a;
> +  gfc_actual_arglist *dim;
> +  gfc_constructor *c;
> +  gfc_expr *res, *new_expr;
> +  gfc_actual_arglist *mask;
> +
> +  fn = *e;
> +
> +  if (fn->rank != 0 || fn->expr_type != EXPR_FUNCTION
> +      || fn->value.function.isym == NULL)
> +    return 0;
> +
> +  id = fn->value.function.isym->id;
> +
> +  if (id != GFC_ISYM_SUM && id != GFC_ISYM_PRODUCT
> +      && id != GFC_ISYM_ANY && id != GFC_ISYM_ALL)
> +    return 0;
> +
> +  a = fn->value.function.actual;
> +
> +  /* Don't handle MASK or DIM.  */
> +
> +  dim = a->next;
> +
> +  if (dim->expr != NULL)
> +    return 0;
> +
Trailing whitespace.

> +  mask = dim->next;
> +  if (mask != NULL)
> +    if ( mask->expr != NULL)
> +      return 0;
This is a bit confusing as mask is the first argument in the ANY/ALL 
case.  You can use something like this instead:
if (id == GFC_ISYM_SUM || id == GFC_ISYM_PRODUCT)
   {
     mask = dim->next;
     if (mask->expr != NULL)
       return 0;
   }



>
> OK for trunk?
>
OK with the changes suggested above. Thanks.

Mikael
Thomas Koenig - Jan. 14, 2013, 9:51 p.m.
Am 14.01.2013 14:29, schrieb Mikael Morin:
> Le 13/01/2013 23:14, Thomas Koenig a écrit :

>> OK for trunk?
>>
> OK with the changes suggested above. Thanks.

Committed as rev. 195179 with your changes.

Thanks a lot for the thorough review!

	Thomas

Patch

Index: frontend-passes.c
===================================================================
--- frontend-passes.c	(Revision 195136)
+++ frontend-passes.c	(Arbeitskopie)
@@ -40,6 +40,8 @@  static bool optimize_lexical_comparison (gfc_expr
 static void optimize_minmaxloc (gfc_expr **);
 static bool is_empty_string (gfc_expr *e);
 static void doloop_warn (gfc_namespace *);
+static void optimize_reduction (gfc_namespace *);
+static int callback_reduction (gfc_expr **, int *, void *);
 
 /* How deep we are inside an argument list.  */
 
@@ -107,6 +109,7 @@  gfc_run_passes (gfc_namespace *ns)
       expr_array = XNEWVEC(gfc_expr **, expr_size);
 
       optimize_namespace (ns);
+      optimize_reduction (ns);
       if (gfc_option.dump_fortran_optimized)
 	gfc_dump_parse_tree (ns, stdout);
 
@@ -180,7 +183,144 @@  optimize_expr (gfc_expr **e, int *walk_subtrees AT
   return 0;
 }
 
+/* Auxiliary function to handle the arguments to reduction intrnisics.  If the
+   function is a scalar, just copy it; otherwise returns the new element, the
+   old one can be freed.  */
 
+static gfc_expr *
+copy_walk_reduction_arg (gfc_expr *e, gfc_expr *fn)
+{
+  gfc_expr *fcn;
+  gfc_isym_id id;
+
+  if (e->rank == 0 || e->expr_type == EXPR_FUNCTION)
+    fcn = gfc_copy_expr (e);
+  else
+    {
+      id = fn->value.function.isym->id;
+
+      if (id == GFC_ISYM_SUM || id == GFC_ISYM_PRODUCT)
+	fcn = gfc_build_intrinsic_call (current_ns,
+					fn->value.function.isym->id,
+					fn->value.function.isym->name,
+					fn->where, 3, gfc_copy_expr (e),
+					NULL, NULL);
+      else if (id == GFC_ISYM_ANY || id == GFC_ISYM_ALL)
+	fcn = gfc_build_intrinsic_call (current_ns,
+					fn->value.function.isym->id,
+					fn->value.function.isym->name,
+					fn->where, 2, gfc_copy_expr (e),
+					NULL);
+      else
+	gfc_error ("Illegal id in copy_walk_reduction_arg");
+
+      fcn->symtree->n.sym->attr.access = ACCESS_PRIVATE;
+    }
+
+  (void) gfc_expr_walker (&fcn, callback_reduction, NULL);
+
+  return fcn;
+}
+
+/* Callback function for optimzation of reductions to scalars.  Transform ANY
+   ([f1,f2,f3, ...]) to f1 .or. f2 .or. f3 .or. ..., with ANY, SUM and PRODUCT
+   correspondingly.  Handly only the simple cases without MASK and DIM.  */
+
+static int
+callback_reduction (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED,
+		    void *data ATTRIBUTE_UNUSED)
+{
+  gfc_expr *fn, *arg;
+  gfc_intrinsic_op op;
+  gfc_isym_id id;
+  gfc_actual_arglist *a;
+  gfc_actual_arglist *dim;
+  gfc_constructor *c;
+  gfc_expr *res, *new_expr;
+  gfc_actual_arglist *mask;
+
+  fn = *e;
+
+  if (fn->rank != 0 || fn->expr_type != EXPR_FUNCTION
+      || fn->value.function.isym == NULL)
+    return 0;
+
+  id = fn->value.function.isym->id;
+
+  if (id != GFC_ISYM_SUM && id != GFC_ISYM_PRODUCT
+      && id != GFC_ISYM_ANY && id != GFC_ISYM_ALL)
+    return 0;
+
+  a = fn->value.function.actual;
+
+  /* Don't handle MASK or DIM.  */
+
+  dim = a->next;
+
+  if (dim->expr != NULL)
+    return 0;
+      
+  mask = dim->next;
+  if (mask != NULL)
+    if ( mask->expr != NULL)
+      return 0;
+
+  arg = a->expr;
+
+  if (arg->expr_type != EXPR_ARRAY)
+    return 0;
+
+  switch (id)
+    {
+    case GFC_ISYM_SUM:
+      op = INTRINSIC_PLUS;
+      break;
+
+    case GFC_ISYM_PRODUCT:
+      op = INTRINSIC_TIMES;
+      break;
+
+    case GFC_ISYM_ANY:
+      op = INTRINSIC_OR;
+      break;
+
+    case GFC_ISYM_ALL:
+      op = INTRINSIC_AND;
+      break;
+
+    default:
+      return 0;
+    }
+
+  c = gfc_constructor_first (arg->value.constructor);
+
+  if (c == NULL)
+    return 0;
+
+  res = copy_walk_reduction_arg (c->expr, fn);
+
+  c = gfc_constructor_next (c);
+  while (c)
+    {
+      new_expr = gfc_get_expr ();
+      new_expr->ts = fn->ts;
+      new_expr->expr_type = EXPR_OP;
+      new_expr->rank = fn->rank;
+      new_expr->where = fn->where;
+      new_expr->value.op.op = op;
+      new_expr->value.op.op1 = res;
+      new_expr->value.op.op2 = copy_walk_reduction_arg (c->expr, fn);
+      res = new_expr;
+      c = gfc_constructor_next (c);
+    }
+
+  gfc_simplify_expr (res, 0);
+  *e = res;
+  gfc_free_expr (fn);
+
+  return 0;
+}
+
 /* Callback function for common function elimination, called from cfe_expr_0.
    Put all eligible function expressions into expr_array.  */
 
@@ -484,6 +624,16 @@  dummy_expr_callback (gfc_expr **e ATTRIBUTE_UNUSED
   return 0;
 }
 
+/* Dummy function for code callback, for use when we really
+   don't want to do anything.  */
+static int
+dummy_code_callback (gfc_code **e ATTRIBUTE_UNUSED,
+		     int *walk_subtrees ATTRIBUTE_UNUSED,
+		     void *data ATTRIBUTE_UNUSED)
+{
+  return 0;
+}
+
 /* Code callback function for converting
    do while(a)
    end do
@@ -639,6 +789,20 @@  optimize_namespace (gfc_namespace *ns)
     }
 }
 
+static void
+optimize_reduction (gfc_namespace *ns)
+{
+  current_ns = ns;
+  gfc_code_walker (&ns->code, dummy_code_callback, callback_reduction, NULL);
+
+/* BLOCKs are handled in the expression walker below.  */
+  for (ns = ns->contained; ns; ns = ns->sibling)
+    {
+      if (ns->code == NULL || ns->code->op != EXEC_BLOCK)
+	optimize_reduction (ns);
+    }
+}
+
 /* Replace code like
    a = matmul(b,c) + d
    with