From: Aldy Hernandez <aldyh@redhat.com>
Date: Thu, 21 Oct 2021 11:18:49 +0000 (+0200)
Subject: Revert the avoid threading circular paths commit.
X-Git-Tag: basepoints/gcc-13~3707
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d6a3c0cfb852dbeee4255e3588e9a1f52e376042;p=thirdparty%2Fgcc.git

Revert the avoid threading circular paths commit.

I've tested this patch on the wrong tree, and picked up the test changes
in a pending patch, without which this patch is no longer obvious.
Plus, it causes a regression in an invalid test I've recommended we remove.

I'm reverting this patch until the dependencies are reviewed.

Sorry for the noise.

gcc/ChangeLog:

	* tree-ssa-threadbackward.c
	(back_threader::maybe_register_path): Remove circular paths check.
---

diff --git a/gcc/tree-ssa-threadbackward.c b/gcc/tree-ssa-threadbackward.c
index 38913b06717c..d94e3b962db4 100644
--- a/gcc/tree-ssa-threadbackward.c
+++ b/gcc/tree-ssa-threadbackward.c
@@ -140,10 +140,6 @@ back_threader::maybe_register_path ()
 
   if (taken_edge && taken_edge != UNREACHABLE_EDGE)
     {
-      // Avoid circular paths.
-      if (m_visited_bbs.contains (taken_edge->dest))
-	return UNREACHABLE_EDGE;
-
       bool irreducible = false;
       bool profitable
 	= m_profit.profitable_path_p (m_path, m_name, taken_edge, &irreducible);