Hi Mikael,
- Array elementals: here it's hard to tell which one is faster; save function
calls to a temporary and use the temporary or do multiple function calls every
time (but without temporary).
I have removed elementals for now. It would probably be best to create
a scalar temporary variable during scalarzation.
- Transpose optimization: here the transpose call is changed into a direct
array access, so your patch will definitely make things worse. Even if
transpose calls are used multiple times as actual argument for example, better
create multiple descriptors than copy the whole lot to a temp. The common
function elimination should be disabled (IMO) in this case.
Removed for transpose.
Please use more descriptive names.
There are 3 cfe* functions and only one has a comment explaining what cfe
means.
Changed.
Is it expected that you allow allocatables with -faggressive-function-
elimination?
No, changed.
+
+ if (!(*e)->value.function.esym->attr.pure
+&& !(*e)->value.function.esym->attr.implicit_pure)
+ return 0;
+ }
+ }
+
+ if ((*e)->value.function.isym)
+ {
+ if ((*e)->value.function.isym->id == GFC_ISYM_CONVERSION)
+ return 0;
+
+ if (! (*e)->value.function.isym->pure
+&& !(*e)->value.function.isym->elemental)
Tobias' comment also applies here, even if there is no intrinsic impure
elemental: the following code in intrinsic.c makes the elemental check
redundant.
next_sym->pure = (cl != CLASS_IMPURE);
next_sym->elemental = (cl == CLASS_ELEMENTAL);
Changed.
+ for (i=expr_count-1; i>=1; i--)
+ {
Tiny optimization here ;-):
/* Don't bother if the expression has been factored already. */
Applied.
if ((*(expr_array[i]))->expr_type == EXPR_VARIABLE)
continue;
+ newvar = NULL;
>> +
> Small comment here, or better, more descriptive name
+static int
+cfe_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
+{
Better comment added.
I have also factored out the code with gfc_dep_compare_expression
into its own function.
Here is the new version of the patch. Regression-tested. OK for trunk?
Thomas
2010-03-20 Thomas Koenig <tkoe...@gcc.gnu.org>
PR fortran/22572
* gfortran.h (gfc_option_t) : Add
flag_aggressive_function_elimination.
(gfc_dep_compare_functions): Add prototype.
* lang.opt: Add faggressive-function-elimination.
* invoke.texi: Document -faggressive-function-elimination.
* frontend_passes (expr_array): New static variable.
(expr_size): Likewise.
(expr_count): Likewise.
(current_code): Likewise.
(current_ns): Likewise.
(gfc_run_passes): Allocate and free space for expressions.
(cfe_register_funcs): New function.
(create_var): New function.
(cfc_expr_0): New function.
(cfe_code): New function.
(optimize_namespace): Invoke gfc_code_walker with cfe_code
and cfe_expr_0.
* dependency.c (gfc_dep_compare_functions): New function.
(gfc_dep_compare_expr): Use it.
* options.c (gfc_init_options): Handle
flag_aggressive_function_elimination.
(gfc_handle_option): Likewise.
2010-03-20 Thomas Koenig <tkoe...@gcc.gnu.org>
PR fortran/22572
* gfortran.dg/function_optimize_1.f90: New test.
* gfortran.dg/function_optimize_2.f90: New test.
! { dg-do compile }
! { dg-options "-O -fdump-tree-original" }
program main
implicit none
real, dimension(2,2) :: a, b, c, d
integer :: i
real :: x, z
character(60) :: line
real, external :: ext_func
interface
elemental function element(x)
real, intent(in) :: x
real :: elem
end function element
pure function mypure(x)
real, intent(in) :: x
integer :: mypure
end function mypure
elemental impure function elem_impure(x)
real, intent(in) :: x
real :: elem_impure
end function elem_impure
end interface
data a /2., 3., 5., 7./
data b /11., 13., 17., 23./
write (unit=line, fmt='(4F7.2)') matmul(a,b) + matmul(a,b)
z = sin(x) + cos(x) + sin(x) + cos(x)
print *,z
x = ext_func(a) + 23 + ext_func(a)
print *,d,x
z = element(x) + element(x)
print *,z
i = mypure(x) - mypure(x)
print *,i
z = elem_impure(x) - elem_impure(x)
print *,z
end program main
! { dg-final { scan-tree-dump-times "matmul_r4" 1 "original" } }
! { dg-final { scan-tree-dump-times "__builtin_sinf" 1 "original" } }
! { dg-final { scan-tree-dump-times "__builtin_cosf" 1 "original" } }
! { dg-final { scan-tree-dump-times "ext_func" 2 "original" } }
! { dg-final { scan-tree-dump-times "element" 1 "original" } }
! { dg-final { scan-tree-dump-times "mypure" 1 "original" } }
! { dg-final { scan-tree-dump-times "elem_impure" 2 "original" } }
! { dg-final { cleanup-tree-dump "original" } }
! { dg-do compile }
! { dg-options "-O -faggressive-function-elimination -fdump-tree-original" }
program main
implicit none
real, dimension(2,2) :: a, b, c, d
real :: x, z
integer :: i
character(60) :: line
real, external :: ext_func
interface
elemental function element(x)
real, intent(in) :: x
real :: elem
end function element
pure function mypure(x)
real, intent(in) :: x
integer :: mypure
end function mypure
elemental impure function elem_impure(x)
real, intent(in) :: x
real :: elem_impure
end function elem_impure
end interface
data a /2., 3., 5., 7./
data b /11., 13., 17., 23./
write (unit=line, fmt='(4F7.2)') matmul(a,b) + matmul(a,b)
x = 1.2
z = sin(x) + cos(x) + sin(x) + cos(x)
print *,z
x = ext_func(a) + 23 + ext_func(a)
print *,d,x
z = element(x) + element(x)
print *,z
i = mypure(x) - mypure(x)
print *,i
z = elem_impure(x) - elem_impure(x)
print *,z
end program main
! { dg-final { scan-tree-dump-times "matmul_r4" 1 "original" } }
! { dg-final { scan-tree-dump-times "__builtin_sinf" 1 "original" } }
! { dg-final { scan-tree-dump-times "__builtin_cosf" 1 "original" } }
! { dg-final { scan-tree-dump-times "ext_func" 1 "original" } }
! { dg-final { scan-tree-dump-times "element" 1 "original" } }
! { dg-final { scan-tree-dump-times "mypure" 1 "original" } }
! { dg-final { scan-tree-dump-times "elem_impure" 1 "original" } }
! { dg-final { cleanup-tree-dump "original" } }
Index: gfortran.h
===================================================================
--- gfortran.h (Revision 170960)
+++ gfortran.h (Arbeitskopie)
@@ -2232,6 +2232,7 @@ typedef struct
int flag_whole_file;
int flag_protect_parens;
int flag_realloc_lhs;
+ int flag_aggressive_function_elimination;
int fpe;
int rtcheck;
@@ -2865,6 +2866,7 @@ void gfc_global_used (gfc_gsymbol *, locus *);
gfc_namespace* gfc_build_block_ns (gfc_namespace *);
/* dependency.c */
+int gfc_dep_compare_functions (gfc_expr *, gfc_expr *, bool);
int gfc_dep_compare_expr (gfc_expr *, gfc_expr *);
/* check.c */
Index: lang.opt
===================================================================
--- lang.opt (Revision 170960)
+++ lang.opt (Arbeitskopie)
@@ -278,6 +278,10 @@ d
Fortran Joined
; Documented in common.opt
+faggressive-function-elimination
+Fortran
+Eliminate multiple function invokations also for impure functions
+
falign-commons
Fortran
Enable alignment of COMMON blocks
Index: invoke.texi
===================================================================
--- invoke.texi (Revision 170960)
+++ invoke.texi (Arbeitskopie)
@@ -1468,6 +1468,18 @@ need to be in effect.
An allocatable left-hand side of an intrinsic assignment is automatically
(re)allocated if it is either unallocated or has a different shape. The
option is enabled by default except when @option{-std=f95} is given.
+
+@item -faggressive-function-elimination
+@opindex @code{faggressive-function-elimination}
+@cindex Elimination of functions with identical argument lists
+Functions with identical argument lists are eliminated within
+statements, regardless of whether these functions are marked
+@code{PURE} or not. For example, in
+@smallexample
+ a = f(b,c) + f(b,c)
+@end smallexample
+there will only be a single call to @code{f}.
+
@end table
@xref{Code Gen Options,,Options for Code Generation Conventions,
@@ -1475,7 +1487,6 @@ gcc,Using the GNU Compiler Collection (GCC)}, for
offered by the GBE
shared by @command{gfortran}, @command{gcc}, and other GNU compilers.
-
@c man end
@node Environment Variables
Index: frontend-passes.c
===================================================================
--- frontend-passes.c (Revision 170960)
+++ frontend-passes.c (Arbeitskopie)
@@ -40,6 +40,21 @@ static bool optimize_trim (gfc_expr *);
static int count_arglist;
+/* Pointer to an array of gfc_expr ** we operate on, plus its size
+ and counter. */
+
+static gfc_expr ***expr_array;
+static int expr_size, expr_count;
+
+/* Pointer to the gfc_code we currently work on - to be able to insert
+ a statement before. */
+
+static gfc_code **current_code;
+
+/* The namespace we are currently dealing with. */
+
+gfc_namespace *current_ns;
+
/* Entry point - run all passes for a namespace. So far, only an
optimization pass is run. */
@@ -48,9 +63,16 @@ gfc_run_passes (gfc_namespace *ns)
{
if (optimize)
{
+ expr_size = 20;
+ expr_array = XNEWVEC(gfc_expr **, expr_size);
+
optimize_namespace (ns);
if (gfc_option.dump_fortran_optimized)
gfc_dump_parse_tree (ns, stdout);
+
+ /* FIXME: The following should be XDELETEVEC(expr_array);
+ but we cannot do that because it depends on free. */
+ gfc_free (expr_array);
}
}
@@ -106,11 +128,214 @@ optimize_expr (gfc_expr **e, int *walk_subtrees AT
return 0;
}
+
+/* Callback function for common function elimination, called from cfe_expr_0.
+ Put all eligible function expressions into expr_array. We can't do
+ allocatable functions. */
+
+static int
+cfe_register_funcs (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
+{
+ if ((*e)->expr_type != EXPR_FUNCTION)
+ return 0;
+
+ /* We don't do character functions (yet). */
+ if ((*e)->ts.type == BT_CHARACTER)
+ return 0;
+
+ /* If we don't know the shape at compile time, we do not create a temporary
+ variable to hold the intermediate result. FIXME: Change this later when
+ allocation on assignment works for intrinsics. */
+
+ if ((*e)->rank > 0 && (*e)->shape == NULL)
+ return 0;
+
+ /* Skip the test for pure functions if -faggressive-function-elimination
+ is specified. */
+ if ((*e)->value.function.esym)
+ {
+ if ((*e)->value.function.esym->attr.allocatable)
+ return 0;
+
+ /* Don't create an array temporary for elemental functions. */
+ if ((*e)->value.function.esym->attr.elemental && (*e)->rank > 0)
+ return 0;
+
+ /* Only eliminate potentially impure functions if the
+ user specifically requested it. */
+ if (!gfc_option.flag_aggressive_function_elimination
+ && !(*e)->value.function.esym->attr.pure
+ && !(*e)->value.function.esym->attr.implicit_pure)
+ return 0;
+ }
+
+ if ((*e)->value.function.isym)
+ {
+ /* Conversions are handled on the fly by the middle end,
+ transpose during trans-* stages. */
+ if ((*e)->value.function.isym->id == GFC_ISYM_CONVERSION
+ || (*e)->value.function.isym->id == GFC_ISYM_TRANSPOSE)
+ return 0;
+
+ /* Don't create an array temporary for elemental functions,
+ as this would be wasteful of memory.
+ FIXME: Create a scalar temporary during scalarization. */
+ if ((*e)->value.function.isym->elemental && (*e)->rank > 0)
+ return 0;
+
+ if (!(*e)->value.function.isym->pure)
+ return 0;
+ }
+
+ if (expr_count >= expr_size)
+ {
+ expr_size += expr_size;
+ expr_array = XRESIZEVEC(gfc_expr **, expr_array, expr_size);
+ }
+ expr_array[expr_count] = e;
+ expr_count ++;
+ return 0;
+}
+
+/* Returns a new expression (a variable) to be used in place of the old one,
+ with an an assignment statement before the current statement to set
+ the value of the variable. */
+
+static gfc_expr*
+create_var (gfc_expr * e)
+{
+ char name[GFC_MAX_SYMBOL_LEN +1];
+ static int num = 1;
+ gfc_symtree *symtree;
+ gfc_symbol *symbol;
+ gfc_expr *result;
+ gfc_code *n;
+ int i;
+
+ sprintf(name, "__var_%d",num++);
+ if (gfc_get_sym_tree (name, current_ns, &symtree, false) != 0)
+ gcc_unreachable ();
+
+ symbol = symtree->n.sym;
+ symbol->ts = e->ts;
+ symbol->as = gfc_get_array_spec ();
+ symbol->as->rank = e->rank;
+ symbol->as->type = AS_EXPLICIT;
+ for (i=0; i<e->rank; i++)
+ {
+ gfc_expr *p, *q;
+
+ p = gfc_get_constant_expr (BT_INTEGER, gfc_default_integer_kind,
+ &(e->where));
+ mpz_set_si (p->value.integer, 1);
+ symbol->as->lower[i] = p;
+
+ q = gfc_get_constant_expr (BT_INTEGER, gfc_index_integer_kind,
+ &(e->where));
+ mpz_set (q->value.integer, e->shape[i]);
+ symbol->as->upper[i] = q;
+ }
+
+ symbol->attr.flavor = FL_VARIABLE;
+ symbol->attr.referenced = 1;
+ symbol->attr.dimension = e->rank > 0;
+ gfc_commit_symbol (symbol);
+
+ result = gfc_get_expr ();
+ result->expr_type = EXPR_VARIABLE;
+ result->ts = e->ts;
+ result->rank = e->rank;
+ result->shape = gfc_copy_shape (e->shape, e->rank);
+ result->symtree = symtree;
+ result->where = e->where;
+ if (e->rank > 0)
+ {
+ result->ref = gfc_get_ref ();
+ result->ref->type = REF_ARRAY;
+ result->ref->u.ar.type = AR_FULL;
+ result->ref->u.ar.where = e->where;
+ result->ref->u.ar.as = symbol->as;
+ }
+
+ /* Generate the new assignment. */
+ n = XCNEW (gfc_code);
+ n->op = EXEC_ASSIGN;
+ n->loc = (*current_code)->loc;
+ n->next = *current_code;
+ n->expr1 = gfc_copy_expr (result);
+ n->expr2 = e;
+ *current_code = n;
+
+ return result;
+}
+
+/* Callback function for the code walker for doing common function
+ elimination. This builds up the list of functions in the expression
+ and goes through them to detect duplicates, which it then replaces
+ by variables. */
+
+static int
+cfe_expr_0 (gfc_expr **e, int *walk_subtrees,
+ void *data ATTRIBUTE_UNUSED)
+{
+ int i,j;
+ gfc_expr *newvar;
+
+ expr_count = 0;
+
+ gfc_expr_walker (e, cfe_register_funcs, NULL);
+
+ /* Walk backwards through all the functions to make sure we
+ catch the leaf functions first. */
+ for (i=expr_count-1; i>=1; i--)
+ {
+ /* Skip if the function has been replaced by a variable already. */
+ if ((*(expr_array[i]))->expr_type == EXPR_VARIABLE)
+ continue;
+
+ newvar = NULL;
+ for (j=i-1; j>=0; j--)
+ {
+ if (gfc_dep_compare_functions(*(expr_array[i]),
+ *(expr_array[j]), true) == 0)
+ {
+ if (newvar == NULL)
+ newvar = create_var (*(expr_array[i]));
+ gfc_free (*(expr_array[j]));
+ *(expr_array[j]) = gfc_copy_expr (newvar);
+ }
+ }
+ if (newvar)
+ *(expr_array[i]) = newvar;
+ }
+
+ /* We did all the necessary walking in this function. */
+ *walk_subtrees = 0;
+ return 0;
+}
+
+/* Callback function for common function elimination, called from
+ gfc_code_walker. This keeps track of the current code, in order
+ to insert statements as needed. */
+
+static int
+cfe_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
+{
+ current_code = c;
+ return 0;
+}
+
/* Optimize a namespace, including all contained namespaces. */
static void
optimize_namespace (gfc_namespace *ns)
{
+
+ current_ns = ns;
+
+ gfc_code_walker (&ns->code, cfe_code, cfe_expr_0, NULL);
gfc_code_walker (&ns->code, optimize_code, optimize_expr, NULL);
for (ns = ns->contained; ns; ns = ns->sibling)
Index: dependency.c
===================================================================
--- dependency.c (Revision 170960)
+++ dependency.c (Arbeitskopie)
@@ -177,16 +177,60 @@ gfc_are_identical_variables (gfc_expr *e1, gfc_exp
return true;
}
+/* Compare two functions for equality. Only the first expression is known
+ to be a function. Returns 0 if e1==e2, -2 otherwise. If impure_ok is
+ false, only return 0 for pure functions. */
+
+int
+gfc_dep_compare_functions (gfc_expr *e1, gfc_expr *e2, bool impure_ok)
+{
+
+ gfc_actual_arglist *args1;
+ gfc_actual_arglist *args2;
+
+ if (e2->expr_type != EXPR_FUNCTION)
+ return -2;
+
+ if ((e1->value.function.esym && e2->value.function.esym
+ && e1->value.function.esym == e2->value.function.esym
+ && (e1->value.function.esym->result->attr.pure || impure_ok))
+ || (e1->value.function.isym && e2->value.function.isym
+ && e1->value.function.isym == e2->value.function.isym
+ && (e1->value.function.isym->pure || impure_ok)))
+ {
+ args1 = e1->value.function.actual;
+ args2 = e2->value.function.actual;
+
+ /* Compare the argument lists for equality. */
+ while (args1 && args2)
+ {
+ /* Bitwise xor, since C has no non-bitwise xor operator. */
+ if ((args1->expr == NULL) ^ (args2->expr == NULL))
+ return -2;
+
+ if (args1->expr != NULL && args2->expr != NULL
+ && gfc_dep_compare_expr (args1->expr, args2->expr) != 0)
+ return -2;
+
+ args1 = args1->next;
+ args2 = args2->next;
+ }
+ return (args1 || args2) ? -2 : 0;
+ }
+ else
+ return -2;
+}
+
/* Compare two values. Returns 0 if e1 == e2, -1 if e1 < e2, +1 if e1 > e2,
and -2 if the relationship could not be determined. */
int
gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2)
{
+ int i;
+ gfc_expr *n1, *n2;
gfc_actual_arglist *args1;
gfc_actual_arglist *args2;
- int i;
- gfc_expr *n1, *n2;
n1 = NULL;
n2 = NULL;
@@ -399,36 +443,7 @@ gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2)
return -2;
case EXPR_FUNCTION:
-
- /* PURE functions can be compared for argument equality. */
- if ((e1->value.function.esym && e2->value.function.esym
- && e1->value.function.esym == e2->value.function.esym
- && e1->value.function.esym->result->attr.pure)
- || (e1->value.function.isym && e2->value.function.isym
- && e1->value.function.isym == e2->value.function.isym
- && e1->value.function.isym->pure))
- {
- args1 = e1->value.function.actual;
- args2 = e2->value.function.actual;
-
- /* Compare the argument lists for equality. */
- while (args1 && args2)
- {
- /* Bitwise xor, since C has no non-bitwise xor operator. */
- if ((args1->expr == NULL) ^ (args2->expr == NULL))
- return -2;
-
- if (args1->expr != NULL && args2->expr != NULL
- && gfc_dep_compare_expr (args1->expr, args2->expr) != 0)
- return -2;
-
- args1 = args1->next;
- args2 = args2->next;
- }
- return (args1 || args2) ? -2 : 0;
- }
- else
- return -2;
+ return gfc_dep_compare_functions (e1, e2, false);
break;
default:
Index: options.c
===================================================================
--- options.c (Revision 170960)
+++ options.c (Arbeitskopie)
@@ -150,6 +150,7 @@ gfc_init_options (unsigned int decoded_options_cou
gfc_option.flag_align_commons = 1;
gfc_option.flag_protect_parens = 1;
gfc_option.flag_realloc_lhs = -1;
+ gfc_option.flag_aggressive_function_elimination = 0;
gfc_option.fpe = 0;
gfc_option.rtcheck = 0;
@@ -972,6 +973,10 @@ gfc_handle_option (size_t scode, const char *arg,
gfc_option.flag_align_commons = value;
break;
+ case OPT_faggressive_function_elimination:
+ gfc_option.flag_aggressive_function_elimination = value;
+ break;
+
case OPT_fprotect_parens:
gfc_option.flag_protect_parens = value;
break;
