From: Richard Biener <rguenther@suse.de>
Date: Mon, 17 Jul 2023 07:20:33 +0000 (+0200)
Subject: tree-optimization/110669 - bogus matching of loop bitop
X-Git-Tag: basepoints/gcc-15~7580
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3228e5c078ed2b505e4ad238b09c1817b38f9cfb;p=thirdparty%2Fgcc.git

tree-optimization/110669 - bogus matching of loop bitop

The matching code lacked a check that we end up with a PHI node
in the loop header.  This caused us to match a random PHI argument
now catched by the extra PHI_ARG_DEF_FROM_EDGE checking.

	PR tree-optimization/110669
	* tree-scalar-evolution.cc (analyze_and_compute_bitop_with_inv_effect):
	Check we matched a header PHI.

	* gcc.dg/torture/pr110669.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr110669.c b/gcc/testsuite/gcc.dg/torture/pr110669.c
new file mode 100644
index 000000000000..b0a9ea448f43
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr110669.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+int g_29, func_47_p_48, func_47_p_51_l_129;
+void func_47_p_51()
+{
+  for (;;)
+    {
+      func_47_p_51_l_129 = 0;
+      for (; func_47_p_51_l_129 <= 1; func_47_p_51_l_129 += 1)
+	{
+	  short *l_160 = (short *)(__UINTPTR_TYPE__)(func_47_p_48 || *l_160);
+	  *l_160 &= g_29;
+	}
+    }
+}
diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index ba47a684f4b3..2abe8fa0b90d 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3674,6 +3674,7 @@ analyze_and_compute_bitop_with_inv_effect (class loop* loop, tree phidef,
   if (TREE_CODE (match_op[1]) != SSA_NAME
       || !expr_invariant_in_loop_p (loop, match_op[0])
       || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[1])))
+      || gimple_bb (header_phi) != loop->header
       || gimple_phi_num_args (header_phi) != 2)
     return NULL_TREE;