Hello world,
the attached patch does the following:
- It removes the restriction on functions returning allocatables
for elimination (unnecessary since the introduction of allocatable
temporary variables)
- It allows character function elimination if the character length is
a constant known at compile time
- It removes introducing temporary variables for the TRANSFER function;
this is better be handled by the middle-end.
Regression-tested.
OK for trunk?
Thomas
2011-05-18 Thomas Koenig <tkoe...@gcc.gnu.org>
* frontend-passes.c (cfe_register_funcs): Also register
character functions if their charlens are known and constant.
Also register allocatable functions.
2011-05-18 Thomas Koenig <tkoe...@gcc.gnu.org>
* gfortran.dg/function_optimize_8.f90: New test case.
Index: frontend-passes.c
===================================================================
--- frontend-passes.c (Revision 173754)
+++ frontend-passes.c (Arbeitskopie)
@@ -137,8 +137,7 @@ optimize_expr (gfc_expr **e, int *walk_subtrees AT
/* 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. */
+ Put all eligible function expressions into expr_array. */
static int
cfe_register_funcs (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED,
@@ -148,8 +147,10 @@ cfe_register_funcs (gfc_expr **e, int *walk_subtre
if ((*e)->expr_type != EXPR_FUNCTION)
return 0;
- /* We don't do character functions (yet). */
- if ((*e)->ts.type == BT_CHARACTER)
+ /* We don't do character functions with unknown charlens. */
+ if ((*e)->ts.type == BT_CHARACTER
+ && ((*e)->ts.u.cl == NULL || (*e)->ts.u.cl->length == NULL
+ || (*e)->ts.u.cl->length->expr_type != EXPR_CONSTANT))
return 0;
/* If we don't know the shape at compile time, we create an allocatable
@@ -163,9 +164,6 @@ cfe_register_funcs (gfc_expr **e, int *walk_subtre
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;
@@ -181,9 +179,10 @@ cfe_register_funcs (gfc_expr **e, int *walk_subtre
if ((*e)->value.function.isym)
{
/* Conversions are handled on the fly by the middle end,
- transpose during trans-* stages. */
+ transpose during trans-* stages and TRANSFER by the middle end. */
if ((*e)->value.function.isym->id == GFC_ISYM_CONVERSION
- || (*e)->value.function.isym->id == GFC_ISYM_TRANSPOSE)
+ || (*e)->value.function.isym->id == GFC_ISYM_TRANSPOSE
+ || (*e)->value.function.isym->id == GFC_ISYM_TRANSFER)
return 0;
/* Don't create an array temporary for elemental functions,
! { dg-do compile }
! { dg-options "-O -fdump-tree-original" }
! Check that duplicate function calls are removed for
! - Functions returning allocatables
! - Character functions with known length
module x
implicit none
contains
pure function myfunc(x) result(y)
integer, intent(in) :: x
integer, dimension(:), allocatable :: y
allocate (y(3))
y(1) = x
y(2) = 2*x
y(3) = 3*x
end function myfunc
pure function mychar(x) result(r)
integer, intent(in) :: x
character(len=2) :: r
r = achar(x + iachar('0')) // achar(x + iachar('1'))
end function mychar
end module x
program main
use x
implicit none
integer :: n
character(len=20) :: line
n = 3
write (unit=line,fmt='(3I2)') myfunc(n) + myfunc(n)
if (line /= ' 61218') call abort
write (unit=line,fmt='(A)') mychar(2) // mychar(2)
if (line /= '2323') call abort
end program main
! { dg-final { scan-tree-dump-times "myfunc" 2 "original" } }
! { dg-final { scan-tree-dump-times "mychar" 2 "original" } }
! { dg-final { cleanup-tree-dump "original" } }
! { dg-final { cleanup-modules "x" } }
