On Fri, Dec 22, 2017 at 04:18:05PM +0100, Martin Liška wrote: > In order to fix the PR, I save temporary expression to a SSA_NAME that > is then used in the gcall.
You need to do that only if (!is_gimple_val (arg1_len)). Can you please emit the additional stmt only if that isn't true? > --- a/gcc/tree-ssa-strlen.c > +++ b/gcc/tree-ssa-strlen.c > @@ -3005,12 +3005,17 @@ fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple > *stmt) > { > gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); > tree strncmp_decl = builtin_decl_explicit (BUILT_IN_STRNCMP); > + > + tree arg1_len_tmp = make_ssa_name (TREE_TYPE (arg1_len)); > + gassign *arg1_stmt = gimple_build_assign (arg1_len_tmp, arg1_len); > gcall *strncmp_call = gimple_build_call (strncmp_decl, 3, > - arg0, arg1, arg1_len); > + arg0, arg1, > + arg1_len_tmp); > tree strncmp_lhs = make_ssa_name (integer_type_node); > gimple_set_vuse (strncmp_call, gimple_vuse (call_stmt)); > gimple_call_set_lhs (strncmp_call, strncmp_lhs); > gsi_remove (&gsi, true); > + gsi_insert_before (&gsi, arg1_stmt, GSI_SAME_STMT); > gsi_insert_before (&gsi, strncmp_call, GSI_SAME_STMT); > tree zero = build_zero_cst (TREE_TYPE (strncmp_lhs)); > > Jakub