From: Richard Biener <rguenther@suse.de>
Date: Fri, 13 Jan 2023 07:37:24 +0000 (+0100)
Subject: tree-optimization/108387 - ICE with VN handling of x << C as x * (1<<C)
X-Git-Tag: basepoints/gcc-14~2071
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=adbee4a197c7b735a3dd58cfac8933f70069f71d;p=thirdparty%2Fgcc.git

tree-optimization/108387 - ICE with VN handling of x << C as x * (1<<C)

The following fixes unexpected simplification of x << C as
x * (1<<C) to a constant.

	PR tree-optimization/108387
	* tree-ssa-sccvn.cc (visit_nary_op): Check for SSA_NAME
	value before inserting expression into the tables.

	* gcc.dg/pr108387.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/pr108387.c b/gcc/testsuite/gcc.dg/pr108387.c
new file mode 100644
index 000000000000..114186b6c5d3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr108387.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-ccp" } */
+
+void bar2 (unsigned char, unsigned char);
+
+void
+foo1 (char c)
+{
+  unsigned char t = c;
+  t *= 2;
+  unsigned char t1 = t << 7;
+  bar2 (t, t1);
+}
diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index a01022b0d121..0dba3f39aa0a 100644
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -5405,7 +5405,8 @@ visit_nary_op (tree lhs, gassign *stmt)
 	      if (result)
 		{
 		  bool changed = set_ssa_val_to (lhs, result);
-		  vn_nary_op_insert_stmt (stmt, result);
+		  if (TREE_CODE (result) == SSA_NAME)
+		    vn_nary_op_insert_stmt (stmt, result);
 		  return changed;
 		}
 	    }