OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Prevent exponential range calculations.

Browse Source 
Produce a summary result for any operation involving too many subranges.

	PR tree-optimization/103821
	* range-op.cc (range_operator::fold_range): Only do precise ranges
	when there are not too many subranges.
This commit is contained in:
Andrew MacLeod 2022-01-10 13:33:44 -05:00
parent 4f34f8cc1d
commit 71b7213201
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/range-op.cc
View File

@ -209,10 +209,12 @@ range_operator::fold_range (irange &r, tree type,
unsigned num_rh = rh.num_pairs ();
// If both ranges are single pairs, fold directly into the result range.
if (num_lh == 1 && num_rh == 1)
// If the number of subranges grows too high, produce a summary result as the
// loop becomes exponential with little benefit. See PR 103821.
if ((num_lh == 1 && num_rh == 1) || num_lh * num_rh > 12)
{
wi_fold_in_parts (r, type, lh.lower_bound (0), lh.upper_bound (0),
rh.lower_bound (0), rh.upper_bound (0));
wi_fold_in_parts (r, type, lh.lower_bound (), lh.upper_bound (),
rh.lower_bound (), rh.upper_bound ());
op1_op2_relation_effect (r, type, lh, rh, rel);
return true;
}