From: Tamar Christina <tamar.christina@arm.com>
Date: Fri, 8 Jul 2022 07:30:22 +0000 (+0100)
Subject: middle-end: don't lower past veclower [PR106063]
X-Git-Tag: basepoints/gcc-14~5634
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7854e2faf7640230062dec3596e71773ca500ed;p=thirdparty%2Fgcc.git

middle-end: don't lower past veclower [PR106063]

Hi All,

My previous patch can cause a problem if the pattern matches after veclower
as it may replace the construct with a vector sequence which the target may not
directly support.

As such don't perform the rewriting if after veclower unless the target supports
the operation.  If before veclower do the rewriting as well if the target didn't
support the original operation either.

gcc/ChangeLog:

	PR tree-optimization/106063
	* match.pd: Do not apply pattern after veclower is not supported.

gcc/testsuite/ChangeLog:

	PR tree-optimization/106063
	* gcc.dg/pr106063.c: New test.
---

diff --git a/gcc/match.pd b/gcc/match.pd
index c43c528424e..6603f29f58a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -6008,10 +6008,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (cmp (bit_and:c@2 @0 cst@1) integer_zerop)
     (with { tree csts = bitmask_inv_cst_vector_p (@1); }
      (if (csts && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2)))
-      (if (TYPE_UNSIGNED (TREE_TYPE (@1)))
-       (icmp @0 { csts; })
-       (with { tree utype = unsigned_type_for (TREE_TYPE (@1)); }
-	 (icmp (view_convert:utype @0) { csts; }))))))))
+      (with { auto optab = VECTOR_TYPE_P (TREE_TYPE (@1))
+			 ? optab_vector : optab_default;
+	      tree utype = unsigned_type_for (TREE_TYPE (@1)); }
+       (if (target_supports_op_p (utype, icmp, optab)
+	    || (optimize_vectors_before_lowering_p ()
+		&& (!target_supports_op_p (type, cmp, optab)
+		    || !target_supports_op_p (type, BIT_AND_EXPR, optab))))
+	(if (TYPE_UNSIGNED (TREE_TYPE (@1)))
+	 (icmp @0 { csts; })
+	 (icmp (view_convert:utype @0) { csts; })))))))))
 
 /* When one argument is a constant, overflow detection can be simplified.
    Currently restricted to single use so as not to interfere too much with
diff --git a/gcc/testsuite/gcc.dg/pr106063.c b/gcc/testsuite/gcc.dg/pr106063.c
new file mode 100644
index 00000000000..b23596724f6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr106063.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-forwprop --disable-tree-evrp" } */
+typedef __int128 __attribute__((__vector_size__ (16))) V;
+
+V
+foo (V v)
+{
+  return (v & (V){15}) == v;
+}