Re: [PATCH] range-op: Handle op?.undefined_p () in op[12]_range of comparisons [PR108647]

[Aldy Hernandez <aldyh@redhat.com>]

LGTM

On 2/3/23 19:59, Jakub Jelinek wrote:
> Hi!
> 
> As mentioned in the PR, we ICE because lhs is singleton [0, 0]
> or [1, 1] but op2 (or in other cases op1) is undefined and op?.*_bound ()
> ICEs on those because there are no pairs for UNDEFINED.
> 
> The following patch makes us set r to varying or return false in those
> cases.
> 
> Included is a version of the patch I've bootstrapped/regtested successfully
> on x86_64-linux and i686-linux, attached is a slight modification more
> consistent with the range-op-float.cc patch.
> 
> Ok for trunk (and which one)?
> 
> 2023-02-03  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/108647
> 	* range-op.cc (operator_equal::op1_range,
> 	operator_not_equal::op1_range): Don't test op2 bound
> 	equality if op2.undefined_p (), instead set_varying.
> 	(operator_lt::op1_range, operator_le::op1_range,
> 	operator_gt::op1_range, operator_ge::op1_range): Return false if
> 	op2.undefined_p ().
> 	(operator_lt::op2_range, operator_le::op2_range,
> 	operator_gt::op2_range, operator_ge::op2_range): Return false if
> 	op1.undefined_p ().
> 
> 	* g++.dg/torture/pr108647.C: New test.
> 
> --- gcc/range-op.cc.jj	2023-02-03 10:51:40.699003658 +0100
> +++ gcc/range-op.cc	2023-02-03 17:26:02.204429931 +0100
> @@ -642,7 +642,8 @@ operator_equal::op1_range (irange &r, tr
>       case BRS_FALSE:
>         // If the result is false, the only time we know anything is
>         // if OP2 is a constant.
> -      if (wi::eq_p (op2.lower_bound(), op2.upper_bound()))
> +      if (!op2.undefined_p ()
> +	  && wi::eq_p (op2.lower_bound(), op2.upper_bound()))
>   	{
>   	  r = op2;
>   	  r.invert ();
> @@ -755,7 +756,8 @@ operator_not_equal::op1_range (irange &r
>       case BRS_TRUE:
>         // If the result is true, the only time we know anything is if
>         // OP2 is a constant.
> -      if (wi::eq_p (op2.lower_bound(), op2.upper_bound()))
> +      if (!op2.undefined_p ()
> +	  && wi::eq_p (op2.lower_bound(), op2.upper_bound()))
>   	{
>   	  r = op2;
>   	  r.invert ();
> @@ -920,6 +922,9 @@ operator_lt::op1_range (irange &r, tree
>   			const irange &op2,
>   			relation_trio) const
>   {
> +  if (op2.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -942,6 +947,9 @@ operator_lt::op2_range (irange &r, tree
>   			const irange &op1,
>   			relation_trio) const
>   {
> +  if (op1.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1031,6 +1039,9 @@ operator_le::op1_range (irange &r, tree
>   			const irange &op2,
>   			relation_trio) const
>   {
> +  if (op2.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1053,6 +1064,9 @@ operator_le::op2_range (irange &r, tree
>   			const irange &op1,
>   			relation_trio) const
>   {
> +  if (op1.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1141,6 +1155,9 @@ operator_gt::op1_range (irange &r, tree
>   			const irange &lhs, const irange &op2,
>   			relation_trio) const
>   {
> +  if (op2.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1163,6 +1180,9 @@ operator_gt::op2_range (irange &r, tree
>   			const irange &op1,
>   			relation_trio) const
>   {
> +  if (op1.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1252,6 +1272,9 @@ operator_ge::op1_range (irange &r, tree
>   			const irange &op2,
>   			relation_trio) const
>   {
> +  if (op2.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> @@ -1274,6 +1297,9 @@ operator_ge::op2_range (irange &r, tree
>   			const irange &op1,
>   			relation_trio) const
>   {
> +  if (op1.undefined_p ())
> +    return false;
> +
>     switch (get_bool_state (r, lhs, type))
>       {
>       case BRS_TRUE:
> --- gcc/testsuite/g++.dg/torture/pr108647.C.jj	2023-02-03 16:36:18.347255058 +0100
> +++ gcc/testsuite/g++.dg/torture/pr108647.C	2023-02-03 16:32:16.338811259 +0100
> @@ -0,0 +1,25 @@
> +// PR tree-optimization/108647
> +// { dg-do compile }
> +
> +bool a;
> +int b, c;
> +
> +inline const bool &
> +foo (bool &e, const bool &f)
> +{
> +  return f < e ? f : e;
> +}
> +
> +void
> +bar (signed char e, bool *f, bool *h, bool *g)
> +{
> +  for (;;)
> +    if (g)
> +      for (signed char j = 0; j < 6;
> +	   j += ((f[0] & c ? g[0] : int(0 >= e))
> +		 ? 0 : foo (g[0], g[0] > h[0]) + 1))
> +	{
> +	  a = 0;
> +	  b = 0;
> +	}
> +}
> 
> 	Jakub