range-op-float: Further comparison fixes

  On Fri, Mar 31, 2023 at 09:57:54AM +0200, Jakub Jelinek via Gcc-patches wrote:
> and so if maybe_isnan, they always return [0, 1].  Now, thinking about it,
> this is unnecessary pessimization, for the case where the ... block
> returns range_false (type) we actually could do it also if maybe_isnan (op1,
> op2), because if one or both operands are NAN, the comparison will be false,
> and if neither is NAN, the comparison will be also false.  Will fix
> incrementally today.

Here it is.
1) the foperator_{,not_}equal::fold_range cases
   - we have correctly first a case handling known_isnan on either operand,
     return there range_false (type) - EQ, resp. range_true (type) - NE
   - next we handle the singleton cases, maybe_isnan + singleton isn't
     singleton, so these are ok
   - there is a missing case (not handled in this patch) where both operands
     are known to be zeros, but not singleton zeros
   - there is some !maybe_isnan (op1, op2) handling which tries to prove
     when the operands are certainly not equal and results in
     range_false (type) - EQ, resp. range_true (type) - NE
   - otherwise range_true_and_false (type)
   Now, I think (and this patch implements it) that the !maybe_isnan (op1, op2)
   check is unnecessary.  If we prove that when ignoring maybe NANs, the
   ranges don't intersect and so the comparison is always false for EQ or
   always true for NE, if NANs can appear, it doesn't change anything on
   that either, for EQ if NAN appears, the result is false like what we
   proved for the finite ranges, for NE if NAN appears, the result is true
   like what we proved for the finite ranges
2) foperator_{lt,le,gt,ge}::fold_range cases
   - these have correctly known_isnan on either operand first and return
     there range_false (type)
   - then !maybe_isnan (op1, op2) condition guarded checks
   - finally range_true_and_false (type) - so do that for
     maybe_isnan (op1, op2)
   Here in the !maybe_isnan (op1, op2) guarded code we have some condition
   which results in range_true (type), another condition which results in
   range_false (type) and otherwise range_true_and_false (type).
   Now, the condition which results in range_false (type) can be IMHO done
   also for the maybe_isnan (op1, op2) cases, because it is [0, 0]
   if both operands are finite or [0, 0] if either operand is NAN.
3) finally, LTGT_EXPR wasn't handled at all.  LTGT_EXPR is the inverse
   comparision to UNEQ_EXPR, I believe both raise exceptions only if
   either operand is sNaN, UNEQ_EXPR is true if both operands are
   either equal or either of the operands is NAN, while LTGT_EXPR is
   true if the operands compare either smaller or larger and is false if
   either of the operands is NAN.

Ok for trunk if this passes bootstrap/regtest?

2023-03-31  Jakub Jelinek  <jakub@redhat.com>

	* range-op-float.cc (foperator_equal::fold_range): Perform the
	non-singleton handling regardless of maybe_isnan (op1, op2).
	(foperator_not_equal::fold_range): Likewise.
	(foperator_lt::fold_range, foperator_le::fold_range,
	foperator_gt::fold_range, foperator_ge::fold_range): Perform the
	real_* comparison check which results in range_false (type)
	even if maybe_isnan (op1, op2).  Simplify.
	(foperator_ltgt): New class.
	(fop_ltgt): New variable.
	(floating_op_table::floating_op_table): Handle LTGT_EXPR using
	fop_ltgt.



	Jakub
  

On 3/31/23 12:45, Jakub Jelinek wrote:
> On Fri, Mar 31, 2023 at 09:57:54AM +0200, Jakub Jelinek via Gcc-patches wrote:
>> and so if maybe_isnan, they always return [0, 1].  Now, thinking about it,
>> this is unnecessary pessimization, for the case where the ... block
>> returns range_false (type) we actually could do it also if maybe_isnan (op1,
>> op2), because if one or both operands are NAN, the comparison will be false,
>> and if neither is NAN, the comparison will be also false.  Will fix
>> incrementally today.
> 
> Here it is.
> 1) the foperator_{,not_}equal::fold_range cases
>     - we have correctly first a case handling known_isnan on either operand,
>       return there range_false (type) - EQ, resp. range_true (type) - NE
>     - next we handle the singleton cases, maybe_isnan + singleton isn't
>       singleton, so these are ok
>     - there is a missing case (not handled in this patch) where both operands
>       are known to be zeros, but not singleton zeros
>     - there is some !maybe_isnan (op1, op2) handling which tries to prove
>       when the operands are certainly not equal and results in
>       range_false (type) - EQ, resp. range_true (type) - NE
>     - otherwise range_true_and_false (type)
>     Now, I think (and this patch implements it) that the !maybe_isnan (op1, op2)
>     check is unnecessary.  If we prove that when ignoring maybe NANs, the
>     ranges don't intersect and so the comparison is always false for EQ or
>     always true for NE, if NANs can appear, it doesn't change anything on
>     that either, for EQ if NAN appears, the result is false like what we
>     proved for the finite ranges, for NE if NAN appears, the result is true
>     like what we proved for the finite ranges
> 2) foperator_{lt,le,gt,ge}::fold_range cases
>     - these have correctly known_isnan on either operand first and return
>       there range_false (type)
>     - then !maybe_isnan (op1, op2) condition guarded checks
>     - finally range_true_and_false (type) - so do that for
>       maybe_isnan (op1, op2)
>     Here in the !maybe_isnan (op1, op2) guarded code we have some condition
>     which results in range_true (type), another condition which results in
>     range_false (type) and otherwise range_true_and_false (type).
>     Now, the condition which results in range_false (type) can be IMHO done
>     also for the maybe_isnan (op1, op2) cases, because it is [0, 0]
>     if both operands are finite or [0, 0] if either operand is NAN.
> 3) finally, LTGT_EXPR wasn't handled at all.  LTGT_EXPR is the inverse
>     comparision to UNEQ_EXPR, I believe both raise exceptions only if
>     either operand is sNaN, UNEQ_EXPR is true if both operands are
>     either equal or either of the operands is NAN, while LTGT_EXPR is
>     true if the operands compare either smaller or larger and is false if
>     either of the operands is NAN.
> 
> Ok for trunk if this passes bootstrap/regtest?

LGTM
Aldy

> 
> 2023-03-31  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* range-op-float.cc (foperator_equal::fold_range): Perform the
> 	non-singleton handling regardless of maybe_isnan (op1, op2).
> 	(foperator_not_equal::fold_range): Likewise.
> 	(foperator_lt::fold_range, foperator_le::fold_range,
> 	foperator_gt::fold_range, foperator_ge::fold_range): Perform the
> 	real_* comparison check which results in range_false (type)
> 	even if maybe_isnan (op1, op2).  Simplify.
> 	(foperator_ltgt): New class.
> 	(fop_ltgt): New variable.
> 	(floating_op_table::floating_op_table): Handle LTGT_EXPR using
> 	fop_ltgt.
> 
> --- gcc/range-op-float.cc.jj	2023-03-31 09:30:11.245296618 +0200
> +++ gcc/range-op-float.cc	2023-03-31 11:23:04.817876083 +0200
> @@ -616,7 +616,7 @@ foperator_equal::fold_range (irange &r,
>         else
>   	r = range_false (type);
>       }
> -  else if (!maybe_isnan (op1, op2))
> +  else
>       {
>         // If ranges do not intersect, we know the range is not equal,
>         // otherwise we don't know anything for sure.
> @@ -638,8 +638,6 @@ foperator_equal::fold_range (irange &r,
>         else
>   	r = range_true_and_false (type);
>       }
> -  else
> -    r = range_true_and_false (type);
>     return true;
>   }
>   
> @@ -734,7 +732,7 @@ foperator_not_equal::fold_range (irange
>         else
>   	r = range_true (type);
>       }
> -  else if (!maybe_isnan (op1, op2))
> +  else
>       {
>         // If ranges do not intersect, we know the range is not equal,
>         // otherwise we don't know anything for sure.
> @@ -756,8 +754,6 @@ foperator_not_equal::fold_range (irange
>         else
>   	r = range_true_and_false (type);
>       }
> -  else
> -    r = range_true_and_false (type);
>     return true;
>   }
>   
> @@ -839,17 +835,13 @@ foperator_lt::fold_range (irange &r, tre
>     if (frelop_early_resolve (r, type, op1, op2, rel, VREL_LT))
>       return true;
>   
> -  if (op1.known_isnan () || op2.known_isnan ())
> +  if (op1.known_isnan ()
> +      || op2.known_isnan ()
> +      || !real_less (&op1.lower_bound (), &op2.upper_bound ()))
>       r = range_false (type);
> -  else if (!maybe_isnan (op1, op2))
> -    {
> -      if (real_less (&op1.upper_bound (), &op2.lower_bound ()))
> -	r = range_true (type);
> -      else if (!real_less (&op1.lower_bound (), &op2.upper_bound ()))
> -	r = range_false (type);
> -      else
> -	r = range_true_and_false (type);
> -    }
> +  else if (!maybe_isnan (op1, op2)
> +	   && real_less (&op1.upper_bound (), &op2.lower_bound ()))
> +    r = range_true (type);
>     else
>       r = range_true_and_false (type);
>     return true;
> @@ -959,17 +951,13 @@ foperator_le::fold_range (irange &r, tre
>     if (frelop_early_resolve (r, type, op1, op2, rel, VREL_LE))
>       return true;
>   
> -  if (op1.known_isnan () || op2.known_isnan ())
> +  if (op1.known_isnan ()
> +      || op2.known_isnan ()
> +      || !real_compare (LE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
>       r = range_false (type);
> -  else if (!maybe_isnan (op1, op2))
> -    {
> -      if (real_compare (LE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
> -	r = range_true (type);
> -      else if (!real_compare (LE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
> -	r = range_false (type);
> -      else
> -	r = range_true_and_false (type);
> -    }
> +  else if (!maybe_isnan (op1, op2)
> +	   && real_compare (LE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
> +    r = range_true (type);
>     else
>       r = range_true_and_false (type);
>     return true;
> @@ -1073,17 +1061,13 @@ foperator_gt::fold_range (irange &r, tre
>     if (frelop_early_resolve (r, type, op1, op2, rel, VREL_GT))
>       return true;
>   
> -  if (op1.known_isnan () || op2.known_isnan ())
> +  if (op1.known_isnan ()
> +      || op2.known_isnan ()
> +      || !real_compare (GT_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
>       r = range_false (type);
> -  else if (!maybe_isnan (op1, op2))
> -    {
> -      if (real_compare (GT_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
> -	r = range_true (type);
> -      else if (!real_compare (GT_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
> -	r = range_false (type);
> -      else
> -	r = range_true_and_false (type);
> -    }
> +  else if (!maybe_isnan (op1, op2)
> +	   && real_compare (GT_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
> +    r = range_true (type);
>     else
>       r = range_true_and_false (type);
>     return true;
> @@ -1197,17 +1181,13 @@ foperator_ge::fold_range (irange &r, tre
>     if (frelop_early_resolve (r, type, op1, op2, rel, VREL_GE))
>       return true;
>   
> -  if (op1.known_isnan () || op2.known_isnan ())
> +  if (op1.known_isnan ()
> +      || op2.known_isnan ()
> +      || !real_compare (GE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
>       r = range_false (type);
> -  else if (!maybe_isnan (op1, op2))
> -    {
> -      if (real_compare (GE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
> -	r = range_true (type);
> -      else if (!real_compare (GE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
> -	r = range_false (type);
> -      else
> -	r = range_true_and_false (type);
> -    }
> +  else if (!maybe_isnan (op1, op2)
> +	   && real_compare (GE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
> +    r = range_true (type);
>     else
>       r = range_true_and_false (type);
>     return true;
> @@ -2092,6 +2072,87 @@ foperator_unordered_equal::op1_range (fr
>     return true;
>   }
>   
> +class foperator_ltgt : public range_operator_float
> +{
> +  using range_operator_float::fold_range;
> +  using range_operator_float::op1_range;
> +  using range_operator_float::op2_range;
> +public:
> +  bool fold_range (irange &r, tree type,
> +		   const frange &op1, const frange &op2,
> +		   relation_trio rel = TRIO_VARYING) const final override
> +  {
> +    if (op1.known_isnan () || op2.known_isnan ())
> +      {
> +	r = range_false (type);
> +	return true;
> +      }
> +    frange op1_no_nan = op1;
> +    frange op2_no_nan = op2;
> +    if (op1.maybe_isnan ())
> +      op1_no_nan.clear_nan ();
> +    if (op2.maybe_isnan ())
> +      op2_no_nan.clear_nan ();
> +    if (!fop_not_equal.fold_range (r, type, op1_no_nan, op2_no_nan, rel))
> +      return false;
> +    // The result is the same as the ordered version when the
> +    // comparison is true or when the operands cannot be NANs.
> +    if (!maybe_isnan (op1, op2) || r == range_false (type))
> +      return true;
> +    else
> +      {
> +	r = range_true_and_false (type);
> +	return true;
> +      }
> +  }
> +  bool op1_range (frange &r, tree type,
> +		  const irange &lhs, const frange &op2,
> +		  relation_trio = TRIO_VARYING) const final override;
> +  bool op2_range (frange &r, tree type,
> +		  const irange &lhs, const frange &op1,
> +		  relation_trio rel = TRIO_VARYING) const final override
> +  {
> +    return op1_range (r, type, lhs, op1, rel.swap_op1_op2 ());
> +  }
> +} fop_ltgt;
> +
> +bool
> +foperator_ltgt::op1_range (frange &r, tree type,
> +			   const irange &lhs,
> +			   const frange &op2,
> +			   relation_trio) const
> +{
> +  switch (get_bool_state (r, lhs, type))
> +    {
> +    case BRS_TRUE:
> +      // A true LTGT means both operands are !NAN, so it's
> +      // impossible for op2 to be a NAN.
> +      if (op2.known_isnan ())
> +	r.set_undefined ();
> +      else
> +	{
> +	  // The true side indicates !NAN and not equal.  We can at least
> +	  // represent !NAN.
> +	  r.set_varying (type);
> +	  r.clear_nan ();
> +	}
> +      break;
> +
> +    case BRS_FALSE:
> +      // If it's false, the result is the same as OP2 plus a NAN.
> +      r = op2;
> +      // Add both zeros if there's the possibility of zero equality.
> +      frange_add_zeros (r, type);
> +      // Add the possibility of a NAN.
> +      r.update_nan ();
> +      break;
> +
> +    default:
> +      break;
> +    }
> +  return true;
> +}
> +
>   // Final tweaks for float binary op op1_range/op2_range.
>   // Return TRUE if the operation is performed and a valid range is available.
>   
> @@ -2767,6 +2828,7 @@ floating_op_table::floating_op_table ()
>     set (UNEQ_EXPR, fop_unordered_equal);
>     set (ORDERED_EXPR, fop_ordered);
>     set (UNORDERED_EXPR, fop_unordered);
> +  set (LTGT_EXPR, fop_ltgt);
>   
>     set (ABS_EXPR, fop_abs);
>     set (NEGATE_EXPR, fop_negate);
> 
> 
> 	Jakub
>
  

On Fri, Mar 31, 2023 at 01:28:35PM +0200, Aldy Hernandez wrote:
> > Ok for trunk if this passes bootstrap/regtest?
> 
> LGTM

Unfortunately I ran into 4 tests where we run into the known bug
where if ranger finds out a range of some floating point operation
it folds it and throws away the trapping side-effects with it.
In particular, e.g. VARYING > __builtin_inf () is now folded to false
because no finite or infinite value is larger than +inf, and if
NAN is compared against it, the result is false as well.

Given that it is a known problem we need to find some solution for
in GCC 14, I've just changed those testcases to disable dom and vrp
passes which were optimizing it.  Another workaround would be
to hide the infinity from the optimizers, but given that the test was
added exactly to verify match.pd doesn't optimize this for -ftrapping-math,
I think disabling dom/vrp is better.

So, here is what I've committed (the other patch committed unchanged):

2023-04-01  Jakub Jelinek  <jakub@redhat.com>

	* range-op-float.cc (foperator_equal::fold_range): Perform the
	non-singleton handling regardless of maybe_isnan (op1, op2).
	(foperator_not_equal::fold_range): Likewise.
	(foperator_lt::fold_range, foperator_le::fold_range,
	foperator_gt::fold_range, foperator_ge::fold_range): Perform the
	real_* comparison check which results in range_false (type)
	even if maybe_isnan (op1, op2).  Simplify.
	(foperator_ltgt): New class.
	(fop_ltgt): New variable.
	(floating_op_table::floating_op_table): Handle LTGT_EXPR using
	fop_ltgt.

	* gcc.dg/torture/inf-compare-1.c: Add dg-additional-options
	-fno-tree-dominator-opts -fno-tree-vrp.
	* gcc.dg/torture/inf-compare-1-float.c: Likewise.
	* gcc.dg/torture/inf-compare-2.c: Likewise.
	* gcc.dg/torture/inf-compare-2-float.c: Likewise.

--- gcc/range-op-float.cc.jj	2023-03-31 09:30:11.245296618 +0200
+++ gcc/range-op-float.cc	2023-03-31 11:23:04.817876083 +0200
@@ -616,7 +616,7 @@ foperator_equal::fold_range (irange &r,
       else
 	r = range_false (type);
     }
-  else if (!maybe_isnan (op1, op2))
+  else
     {
       // If ranges do not intersect, we know the range is not equal,
       // otherwise we don't know anything for sure.
@@ -638,8 +638,6 @@ foperator_equal::fold_range (irange &r,
       else
 	r = range_true_and_false (type);
     }
-  else
-    r = range_true_and_false (type);
   return true;
 }
 
@@ -734,7 +732,7 @@ foperator_not_equal::fold_range (irange
       else
 	r = range_true (type);
     }
-  else if (!maybe_isnan (op1, op2))
+  else
     {
       // If ranges do not intersect, we know the range is not equal,
       // otherwise we don't know anything for sure.
@@ -756,8 +754,6 @@ foperator_not_equal::fold_range (irange
       else
 	r = range_true_and_false (type);
     }
-  else
-    r = range_true_and_false (type);
   return true;
 }
 
@@ -839,17 +835,13 @@ foperator_lt::fold_range (irange &r, tre
   if (frelop_early_resolve (r, type, op1, op2, rel, VREL_LT))
     return true;
 
-  if (op1.known_isnan () || op2.known_isnan ())
+  if (op1.known_isnan ()
+      || op2.known_isnan ()
+      || !real_less (&op1.lower_bound (), &op2.upper_bound ()))
     r = range_false (type);
-  else if (!maybe_isnan (op1, op2))
-    {
-      if (real_less (&op1.upper_bound (), &op2.lower_bound ()))
-	r = range_true (type);
-      else if (!real_less (&op1.lower_bound (), &op2.upper_bound ()))
-	r = range_false (type);
-      else
-	r = range_true_and_false (type);
-    }
+  else if (!maybe_isnan (op1, op2)
+	   && real_less (&op1.upper_bound (), &op2.lower_bound ()))
+    r = range_true (type);
   else
     r = range_true_and_false (type);
   return true;
@@ -959,17 +951,13 @@ foperator_le::fold_range (irange &r, tre
   if (frelop_early_resolve (r, type, op1, op2, rel, VREL_LE))
     return true;
 
-  if (op1.known_isnan () || op2.known_isnan ())
+  if (op1.known_isnan ()
+      || op2.known_isnan ()
+      || !real_compare (LE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
     r = range_false (type);
-  else if (!maybe_isnan (op1, op2))
-    {
-      if (real_compare (LE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
-	r = range_true (type);
-      else if (!real_compare (LE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
-	r = range_false (type);
-      else
-	r = range_true_and_false (type);
-    }
+  else if (!maybe_isnan (op1, op2)
+	   && real_compare (LE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
+    r = range_true (type);
   else
     r = range_true_and_false (type);
   return true;
@@ -1073,17 +1061,13 @@ foperator_gt::fold_range (irange &r, tre
   if (frelop_early_resolve (r, type, op1, op2, rel, VREL_GT))
     return true;
 
-  if (op1.known_isnan () || op2.known_isnan ())
+  if (op1.known_isnan ()
+      || op2.known_isnan ()
+      || !real_compare (GT_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
     r = range_false (type);
-  else if (!maybe_isnan (op1, op2))
-    {
-      if (real_compare (GT_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
-	r = range_true (type);
-      else if (!real_compare (GT_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
-	r = range_false (type);
-      else
-	r = range_true_and_false (type);
-    }
+  else if (!maybe_isnan (op1, op2)
+	   && real_compare (GT_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
+    r = range_true (type);
   else
     r = range_true_and_false (type);
   return true;
@@ -1197,17 +1181,13 @@ foperator_ge::fold_range (irange &r, tre
   if (frelop_early_resolve (r, type, op1, op2, rel, VREL_GE))
     return true;
 
-  if (op1.known_isnan () || op2.known_isnan ())
+  if (op1.known_isnan ()
+      || op2.known_isnan ()
+      || !real_compare (GE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
     r = range_false (type);
-  else if (!maybe_isnan (op1, op2))
-    {
-      if (real_compare (GE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
-	r = range_true (type);
-      else if (!real_compare (GE_EXPR, &op1.upper_bound (), &op2.lower_bound ()))
-	r = range_false (type);
-      else
-	r = range_true_and_false (type);
-    }
+  else if (!maybe_isnan (op1, op2)
+	   && real_compare (GE_EXPR, &op1.lower_bound (), &op2.upper_bound ()))
+    r = range_true (type);
   else
     r = range_true_and_false (type);
   return true;
@@ -2092,6 +2072,87 @@ foperator_unordered_equal::op1_range (fr
   return true;
 }
 
+class foperator_ltgt : public range_operator_float
+{
+  using range_operator_float::fold_range;
+  using range_operator_float::op1_range;
+  using range_operator_float::op2_range;
+public:
+  bool fold_range (irange &r, tree type,
+		   const frange &op1, const frange &op2,
+		   relation_trio rel = TRIO_VARYING) const final override
+  {
+    if (op1.known_isnan () || op2.known_isnan ())
+      {
+	r = range_false (type);
+	return true;
+      }
+    frange op1_no_nan = op1;
+    frange op2_no_nan = op2;
+    if (op1.maybe_isnan ())
+      op1_no_nan.clear_nan ();
+    if (op2.maybe_isnan ())
+      op2_no_nan.clear_nan ();
+    if (!fop_not_equal.fold_range (r, type, op1_no_nan, op2_no_nan, rel))
+      return false;
+    // The result is the same as the ordered version when the
+    // comparison is true or when the operands cannot be NANs.
+    if (!maybe_isnan (op1, op2) || r == range_false (type))
+      return true;
+    else
+      {
+	r = range_true_and_false (type);
+	return true;
+      }
+  }
+  bool op1_range (frange &r, tree type,
+		  const irange &lhs, const frange &op2,
+		  relation_trio = TRIO_VARYING) const final override;
+  bool op2_range (frange &r, tree type,
+		  const irange &lhs, const frange &op1,
+		  relation_trio rel = TRIO_VARYING) const final override
+  {
+    return op1_range (r, type, lhs, op1, rel.swap_op1_op2 ());
+  }
+} fop_ltgt;
+
+bool
+foperator_ltgt::op1_range (frange &r, tree type,
+			   const irange &lhs,
+			   const frange &op2,
+			   relation_trio) const
+{
+  switch (get_bool_state (r, lhs, type))
+    {
+    case BRS_TRUE:
+      // A true LTGT means both operands are !NAN, so it's
+      // impossible for op2 to be a NAN.
+      if (op2.known_isnan ())
+	r.set_undefined ();
+      else
+	{
+	  // The true side indicates !NAN and not equal.  We can at least
+	  // represent !NAN.
+	  r.set_varying (type);
+	  r.clear_nan ();
+	}
+      break;
+
+    case BRS_FALSE:
+      // If it's false, the result is the same as OP2 plus a NAN.
+      r = op2;
+      // Add both zeros if there's the possibility of zero equality.
+      frange_add_zeros (r, type);
+      // Add the possibility of a NAN.
+      r.update_nan ();
+      break;
+
+    default:
+      break;
+    }
+  return true;
+}
+
 // Final tweaks for float binary op op1_range/op2_range.
 // Return TRUE if the operation is performed and a valid range is available.
 
@@ -2767,6 +2828,7 @@ floating_op_table::floating_op_table ()
   set (UNEQ_EXPR, fop_unordered_equal);
   set (ORDERED_EXPR, fop_ordered);
   set (UNORDERED_EXPR, fop_unordered);
+  set (LTGT_EXPR, fop_ltgt);
 
   set (ABS_EXPR, fop_abs);
   set (NEGATE_EXPR, fop_negate);
--- gcc/testsuite/gcc.dg/torture/inf-compare-1.c.jj	2022-10-21 08:56:19.330180242 +0200
+++ gcc/testsuite/gcc.dg/torture/inf-compare-1.c	2023-04-01 09:26:24.385274181 +0200
@@ -3,6 +3,7 @@
 /* { dg-add-options ieee } */
 /* { dg-require-effective-target fenv_exceptions_double } */
 /* { dg-skip-if "fenv" { powerpc-ibm-aix* } } */
+/* { dg-additional-options "-fno-tree-dominator-opts -fno-tree-vrp" } */
 
 #include <fenv.h>
 
--- gcc/testsuite/gcc.dg/torture/inf-compare-1-float.c.jj	2022-10-21 08:56:19.330180242 +0200
+++ gcc/testsuite/gcc.dg/torture/inf-compare-1-float.c	2023-04-01 09:26:15.380403321 +0200
@@ -3,6 +3,7 @@
 /* { dg-add-options ieee } */
 /* { dg-require-effective-target fenv_exceptions } */
 /* { dg-skip-if "fenv" { powerpc-ibm-aix* } } */
+/* { dg-additional-options "-fno-tree-dominator-opts -fno-tree-vrp" } */
 
 #include <fenv.h>
 
--- gcc/testsuite/gcc.dg/torture/inf-compare-2.c.jj	2022-10-21 08:56:19.330180242 +0200
+++ gcc/testsuite/gcc.dg/torture/inf-compare-2.c	2023-04-01 09:26:43.555999258 +0200
@@ -3,6 +3,7 @@
 /* { dg-add-options ieee } */
 /* { dg-require-effective-target fenv_exceptions_double } */
 /* { dg-skip-if "fenv" { powerpc-ibm-aix* } } */
+/* { dg-additional-options "-fno-tree-dominator-opts -fno-tree-vrp" } */
 
 #include <fenv.h>
 
--- gcc/testsuite/gcc.dg/torture/inf-compare-2-float.c.jj	2022-10-21 08:56:19.330180242 +0200
+++ gcc/testsuite/gcc.dg/torture/inf-compare-2-float.c	2023-04-01 09:26:32.682155200 +0200
@@ -3,6 +3,7 @@
 /* { dg-add-options ieee } */
 /* { dg-require-effective-target fenv_exceptions } */
 /* { dg-skip-if "fenv" { powerpc-ibm-aix* } } */
+/* { dg-additional-options "-fno-tree-dominator-opts -fno-tree-vrp" } */
 
 #include <fenv.h>
 


	Jakub
  

On 4/1/23 09:39, Jakub Jelinek wrote:
> On Fri, Mar 31, 2023 at 01:28:35PM +0200, Aldy Hernandez wrote:
>>> Ok for trunk if this passes bootstrap/regtest?
>>
>> LGTM
> 
> Unfortunately I ran into 4 tests where we run into the known bug
> where if ranger finds out a range of some floating point operation
> it folds it and throws away the trapping side-effects with it.

Is VRP folding it, or is some other pass using ranger making a decision 
based on INF > INF being false?  Cause we'd ultimately like to keep 
ranger honest...that is returning FALSE for the above, so the onus is on 
the ranger callers on making correct decisions.

IMO.
Aldy