------- Comment #3 from fxcoudert at gcc dot gnu dot org 2007-03-14 12:31
-------
Here's a patch that should make the code in gfc_conv_cst_int_power() work in
all cases:
Index: trans-expr.c
===================================================================
--- trans-expr.c (revision 122912)
+++ trans-expr.c (working copy)
@@ -634,7 +634,7 @@
/* Recursive function to expand the power operator. The temporary
values are put in tmpvar. The function returns tmpvar[1] ** n. */
static tree
-gfc_conv_powi (gfc_se * se, int n, tree * tmpvar)
+gfc_conv_powi (gfc_se * se, unsigned HOST_WIDE_INT n, tree * tmpvar)
{
tree op0;
tree op1;
@@ -681,15 +681,25 @@
tree tmp;
tree type;
tree vartmp[POWI_TABLE_SIZE];
- int n;
+ HOST_WIDE_INT m;
+ unsigned HOST_WIDE_INT n;
int sgn;
+ /* If exponent is too large, we won't expand it anyway, so don't bother
+ with large integer values. */
+ if (!double_int_fits_in_shwi_p (TREE_INT_CST (rhs)))
+ return 0;
+
+ m = double_int_to_shwi (TREE_INT_CST (rhs));
+ /* There's no ABS for HOST_WIDE_INT, so here we go. It also takes care
+ of the asymmetric range of the integer type. */
+ n = (unsigned HOST_WIDE_INT) (m < 0 ? -m : m);
+
type = TREE_TYPE (lhs);
- n = abs (TREE_INT_CST_LOW (rhs));
sgn = tree_int_cst_sgn (rhs);
- if (((FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations) ||
optimize_siz
e)
- && (n > 2 || n < -1))
+ if (((FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
+ || optimize_size) && (m > 2 || m < -1))
return 0;
/* rhs == 0 */
@@ -698,6 +708,7 @@
se->expr = gfc_build_const (type, integer_one_node);
return 1;
}
+
/* If rhs < 0 and lhs is an integer, the result is -1, 0 or 1. */
if ((sgn == -1) && (TREE_CODE (type) == INTEGER_TYPE))
{
It's regtesting right now. The following should now be done:
* write a testcase, using both kind=4 and 8 integers as exponents, and
testing difficult cases (huge(),-huge(),-huge()-1, etc.); the testcase should
also check constant vs. non-constant results, to make sure the testcase run
isn't rendered useless by constant folding
* the code generated should be manually checked in the above-mentionned
difficult cases (huge(), -huge(), ...)
If nobody does it before the week-end, I'll do it then (but won't have time
before that). And Dominique, I would appreciate if you could test the patch on
ppc-darwin7.
--
fxcoudert at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |fxcoudert at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
Keywords| |patch
Last reconfirmed|2007-03-10 12:15:25 |2007-03-14 12:31:35
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31120
