From: Richard Biener <rguenther@suse.de>
Date: Thu, 25 Aug 2022 14:27:12 +0000 (+0200)
Subject: Improve uninit_analysis::collect_phi_def_edges
X-Git-Tag: basepoints/gcc-14~4997
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b4d528d8c57ad7a2d5e39427bf4af7b8c1668c3;p=thirdparty%2Fgcc.git

Improve uninit_analysis::collect_phi_def_edges

This avoids expanding an edge to those of a PHI def if it is not
may-undefined, reducing the number of compute_control_dep_chain calls.

	* gimple-predicate-analysis.cc
	(uninit_analysis::collect_phi_def_edges): Only expand a
	PHI def edge when it is possibly undefined.
---

diff --git a/gcc/gimple-predicate-analysis.cc b/gcc/gimple-predicate-analysis.cc
index 079e06009fde..0d973a9e25a0 100644
--- a/gcc/gimple-predicate-analysis.cc
+++ b/gcc/gimple-predicate-analysis.cc
@@ -605,11 +605,7 @@ uninit_analysis::collect_phi_def_edges (gphi *phi, basic_block cd_root,
 	{
 	  gimple *def = SSA_NAME_DEF_STMT (opnd);
 
-	  if (gimple_code (def) == GIMPLE_PHI
-	      && dominated_by_p (CDI_DOMINATORS, gimple_bb (def), cd_root))
-	    collect_phi_def_edges (as_a<gphi *> (def), cd_root, edges,
-				   visited);
-	  else if (!m_eval (opnd))
+	  if (!m_eval (opnd))
 	    {
 	      if (dump_file && (dump_flags & TDF_DETAILS))
 		{
@@ -622,6 +618,10 @@ uninit_analysis::collect_phi_def_edges (gphi *phi, basic_block cd_root,
 		}
 	      edges->safe_push (opnd_edge);
 	    }
+	  else if (gimple_code (def) == GIMPLE_PHI
+		   && dominated_by_p (CDI_DOMINATORS, gimple_bb (def), cd_root))
+	    collect_phi_def_edges (as_a<gphi *> (def), cd_root, edges,
+				   visited);
 	}
       else
 	{