https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90387
--- Comment #3 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 10 May 2019, JunMa at linux dot alibaba.com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90387 > > JunMa <JunMa at linux dot alibaba.com> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |JunMa at linux dot > alibaba.com > > --- Comment #2 from JunMa <JunMa at linux dot alibaba.com> --- > VRP tries to fold builtin_constant_p when its argument is a function > parameter. > builtin_constant_p should be removed as dead stmt in this case no matter "#if > 1 " or "#if 0", since p_len is function parameter. > > When "#if 1" turns true, vrp pass inserts ASSERT_EXPR to infer value range of > p_len, this changes argument of builtin_constant_p from function parameter to > result of ASSERT_EXPR which breaks the rule. Whether the argument is a function parameter or not is of course somewhat artificial. I have argued the code should be diff --git a/gcc/vr-values.c b/gcc/vr-values.c index 0e10aca92bb..d1d9756c134 100644 --- a/gcc/vr-values.c +++ b/gcc/vr-values.c @@ -1075,15 +1075,8 @@ vr_values::extract_range_basic (value_range *vr, gimple *stmt) switch (cfn) { case CFN_BUILT_IN_CONSTANT_P: - /* If the call is __builtin_constant_p and the argument is a - function parameter resolve it to false. This avoids bogus - array bound warnings. - ??? We could do this as early as inlining is finished. */ - arg = gimple_call_arg (stmt, 0); - if (TREE_CODE (arg) == SSA_NAME - && SSA_NAME_IS_DEFAULT_DEF (arg) - && TREE_CODE (SSA_NAME_VAR (arg)) == PARM_DECL - && cfun->after_inlining) + /* Resolve calls to __builtin_constant_p after inlining. */ + if (cfun->after_inlining) { vr->set_null (type); return;
