The following fixes unexpected simplification of x << C as
x * (1<<C) to a constant.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
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.
---
gcc/testsuite/gcc.dg/pr108387.c | 13 +++++++++++++
gcc/tree-ssa-sccvn.cc | 3 ++-
2 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr108387.c
diff --git a/gcc/testsuite/gcc.dg/pr108387.c b/gcc/testsuite/gcc.dg/pr108387.c
new file mode 100644
index 00000000000..114186b6c5d
--- /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 a01022b0d12..0dba3f39aa0 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;
}
}
--
2.35.3
