From: Richard Biener <rguenther@suse.de>
Date: Tue, 5 Mar 2024 09:55:56 +0000 (+0100)
Subject: tree-optimization/114231 - use patterns for BB SLP discovery root stmts
X-Git-Tag: basepoints/gcc-15~823
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7890836de20912bd92afaf5abbeaf9d8c5b86542;p=thirdparty%2Fgcc.git

tree-optimization/114231 - use patterns for BB SLP discovery root stmts

The following makes sure to use recognized patterns when vectorizing
roots during BB SLP discovery.  We need to apply those late since
during root discovery we've not yet done pattern recognition.
All parts of the vectorizer assume patterns get used, for the testcase
we mix this up when doing live lane computation.

	PR tree-optimization/114231
	* tree-vect-slp.cc (vect_analyze_slp): Lookup patterns when
	processing a BB SLP root.

	* gcc.dg/vect/pr114231.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/vect/pr114231.c b/gcc/testsuite/gcc.dg/vect/pr114231.c
new file mode 100644
index 000000000000..5e3a81039188
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr114231.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+void f(long*);
+int ff[2];
+void f2(long, long, unsigned long);
+void k(unsigned long x, unsigned long y)
+{
+  long t = x >> ff[0];
+  long t1 = ff[1];
+  unsigned long t2 = y >> ff[0];
+  f2(t1, t+t2, t2);
+}
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 895f4f7fb6be..324400db19ec 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -3649,6 +3649,10 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size)
       for (unsigned i = 0; i < bb_vinfo->roots.length (); ++i)
 	{
 	  vect_location = bb_vinfo->roots[i].roots[0]->stmt;
+	  /* Apply patterns.  */
+	  for (unsigned j = 0; j < bb_vinfo->roots[i].stmts.length (); ++j)
+	    bb_vinfo->roots[i].stmts[j]
+	      = vect_stmt_to_vectorize (bb_vinfo->roots[i].stmts[j]);
 	  if (vect_build_slp_instance (bb_vinfo, bb_vinfo->roots[i].kind,
 				       bb_vinfo->roots[i].stmts,
 				       bb_vinfo->roots[i].roots,