From: Richard Biener <rguenther@suse.de>
Date: Tue, 14 Nov 2023 11:53:18 +0000 (+0100)
Subject: Loop distribution fix for SCC detection
X-Git-Tag: basepoints/gcc-15~4694
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bc390ae72ff974d6985639b5b392f6e9192c2ee7;p=thirdparty%2Fgcc.git

Loop distribution fix for SCC detection

The following adjusts data_dep_in_cycle_p to properly consider the
whole loop nest when looking for data dep cycles and exempting
zero-distance DDRs instead of just the outermost loop.

	* tree-loop-distribution.cc (loop_distribution::data_dep_in_cycle_p):
	Consider all loops in the nest when looking for
	lambda_vector_zerop.
---

diff --git a/gcc/tree-loop-distribution.cc b/gcc/tree-loop-distribution.cc
index 8e92af61c57f..5ededd97c3d6 100644
--- a/gcc/tree-loop-distribution.cc
+++ b/gcc/tree-loop-distribution.cc
@@ -1440,7 +1440,7 @@ loop_distribution::data_dep_in_cycle_p (struct graph *rdg,
   else if (DDR_NUM_DIST_VECTS (ddr) > 1)
     return true;
   else if (DDR_REVERSED_P (ddr)
-	   || lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), 1))
+	   || lambda_vector_zerop (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr)))
     return false;
 
   return true;