re PR fortran/40472 (Simplification of spread intrinsic takes a long time)

2009-06-22  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/40472
	* simplify.c (gfc_simplify_spread): Restrict the result size to
	the limit for an array constructor.

2009-06-22  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/40472
	* gfortran.dg/spread_size_limit.f90: New test.

From-SVN: r148775

gcc/fortran/ChangeLog

+2009-06-22  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/40472
+	* simplify.c (gfc_simplify_spread): Restrict the result size to
+	the limit for an array constructor.
+
 2009-06-21  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/39850

gcc/fortran/simplify.c

@@ -5099,6 +5099,7 @@ gfc_simplify_spread (gfc_expr *source, gfc_expr *dim_expr, gfc_expr *ncopies_exp
 {
   gfc_expr *result = 0L;
   int i, j, dim, ncopies;
+  mpz_t size;
 
   if ((!gfc_is_constant_expr (source)
        && !is_constant_array_expr (source))
@@ -5114,6 +5115,12 @@ gfc_simplify_spread (gfc_expr *source, gfc_expr *dim_expr, gfc_expr *ncopies_exp
   gfc_extract_int (ncopies_expr, &ncopies);
   ncopies = MAX (ncopies, 0);
 
+  /* Do not allow the array size to exceed the limit for an array
+     constructor.  */
+  gfc_array_size (source, &size);
+  if (mpz_get_si (size)*ncopies > gfc_option.flag_max_array_constructor)
+    return NULL;
+
   if (source->expr_type == EXPR_CONSTANT)
     {
       gcc_assert (dim == 0);

gcc/testsuite/ChangeLog

+2009-06-22  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/40472
+	* gfortran.dg/spread_size_limit.f90: New test.
+
 2009-06-21  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.c-torture/unsorted/dump-noaddr.x (dump_compare): Use --dumpbase

gcc/testsuite/gfortran.dg/spread_size_limit.f90

+! { dg-do compile }
+! { dg-options "-fdump-tree-original" }
+!
+! Test the fix for PR40472 in which simplify_spread had mo limit on the
+! siz that it would try to expand to.
+!
+! Contributed by Philippe Marguinaud <philippe.marguinaud@meteo.fr>
+!
+REAL, DIMENSION(720,360)          :: ZLON_MASK
+ZLON_MASK(:,:)= SPREAD( (/ (JLON , JLON=1,720) /) , DIM=2, NCOPIES=360 )
+print *, zlon_mask(100,100)
+END
+! { dg-final { scan-tree-dump-times "_gfortran_spread" 1 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
+