From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 12 Jan 2024 10:20:40 +0000 (+0100)
Subject: lower-bitint: Fix a typo in a condition [PR113323]
X-Git-Tag: basepoints/gcc-15~2959
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a2d66158541c0923620b044098bf66a73b51c463;p=thirdparty%2Fgcc.git

lower-bitint: Fix a typo in a condition [PR113323]

The following testcase revealed a typo in condition, as the comment
says the intent is
       /*  If lhs of stmt is large/huge _BitInt SSA_NAME not in m_names
           it means it will be handled in a loop or straight line code
           at the location of its (ultimate) immediate use, so for
           vop checking purposes check these only at the ultimate
           immediate use.  */
but the condition was using != BITINT_TYPE rather than == BITINT_TYPE,
so e.g. it used bitint_precision_kind on non-BITINT_TYPEs (e.g. on vector
types it will crash because TYPE_PRECISION means something different there,
or on say INTEGER_TYPEs the precision will never be large enough to be >=
bitint_prec_large).

The following patch fixes that.

2024-01-12  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113323
	* gimple-lower-bitint.cc (bitint_dom_walker::before_dom_children): Fix
	check for lhs being large/huge _BitInt not in m_names.

	* gcc.dg/bitint-68.c: New test.
---

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index ea616ea41534..f1e4cd01cb06 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -5513,7 +5513,7 @@ bitint_dom_walker::before_dom_children (basic_block bb)
       tree lhs = gimple_get_lhs (stmt);
       if (lhs
 	  && TREE_CODE (lhs) == SSA_NAME
-	  && TREE_CODE (TREE_TYPE (lhs)) != BITINT_TYPE
+	  && TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE
 	  && bitint_precision_kind (TREE_TYPE (lhs)) >= bitint_prec_large
 	  && !bitmap_bit_p (m_names, SSA_NAME_VERSION (lhs)))
 	/* If lhs of stmt is large/huge _BitInt SSA_NAME not in m_names,
diff --git a/gcc/testsuite/gcc.dg/bitint-68.c b/gcc/testsuite/gcc.dg/bitint-68.c
new file mode 100644
index 000000000000..092f31adde45
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-68.c
@@ -0,0 +1,14 @@
+/* PR tree-optimization/113323 */
+/* { dg-do compile { target bitint575 } } */
+/* { dg-options "-std=c23 -O2" } */
+
+typedef long __attribute__((__vector_size__ (16))) V;
+V u, v;
+_BitInt(535) i;
+
+void
+foo (void)
+{
+  while (i)
+    u = v;
+}