On Mon, Dec 05, 2022 at 09:54:09PM +0100, Jakub Jelinek via Gcc-patches wrote:
> On Mon, Dec 05, 2022 at 03:43:16PM -0500, Andrew MacLeod wrote:
> > Id actually prefer to avoid passing the tree code around... we're trying to
> > avoid that sort of thing even though Aldy temporarily introduced them to
> > range-ops. Hes suppose to remove that next stage 1 :-P Ideally anything
> > "special" is locally contained to the specific routine.
>
> Would a bool divide_op2 argument be better (perhaps defaulted to false)?
> Inlining float_binary_op_range_finish by hand doesn't seem to be a good
> idea, if it needs to be changed, it would need to be changed in multiple
> places...
In patch form on top of PR107975 patch.
2022-12-05 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/107972
* range-op-float.cc (frange_drop_infs): New function.
(float_binary_op_range_finish): Add DIV_OP2 argument. If DIV_OP2 is
false and lhs is finite or if DIV_OP2 is true and lhs is non-zero and
not NAN, r must be finite too.
(foperator_div::op2_range): Pass true to DIV_OP2 of
float_binary_op_range_finish.
--- gcc/range-op-float.cc.jj 2022-12-05 11:17:34.900573272 +0100
+++ gcc/range-op-float.cc 2022-12-05 16:13:54.414845672 +0100
@@ -330,6 +330,18 @@ frange_drop_ninf (frange &r, tree type)
r.intersect (tmp);
}
+// Crop R to [MIN, MAX] where MAX is the maximum representable number
+// for TYPE and MIN the minimum representable number for TYPE.
+
+static inline void
+frange_drop_infs (frange &r, tree type)
+{
+ REAL_VALUE_TYPE max = real_max_representable (type);
+ REAL_VALUE_TYPE min = real_min_representable (type);
+ frange tmp (type, min, max);
+ r.intersect (tmp);
+}
+
// If zero is in R, make sure both -0.0 and +0.0 are in the range.
static inline void
@@ -1883,7 +1895,7 @@ foperator_unordered_equal::op1_range (fr
static bool
float_binary_op_range_finish (bool ret, frange &r, tree type,
- const frange &lhs)
+ const frange &lhs, bool div_op2 = false)
{
if (!ret)
return false;
@@ -1904,7 +1916,20 @@ float_binary_op_range_finish (bool ret,
// If lhs isn't NAN, then neither operand could be NAN,
// even if the reverse operation does introduce a maybe_nan.
if (!lhs.maybe_isnan ())
- r.clear_nan ();
+ {
+ r.clear_nan ();
+ if (div_op2
+ ? !(real_compare (LE_EXPR, &lhs.lower_bound (), &dconst0)
+ && real_compare (GE_EXPR, &lhs.upper_bound (), &dconst0))
+ : !(real_isinf (&lhs.lower_bound ())
+ || real_isinf (&lhs.upper_bound ())))
+ // For reverse + or - or * or op1 of /, if result is finite, then
+ // r must be finite too, as X + INF or X - INF or X * INF or
+ // INF / X is always +-INF or NAN. For op2 of /, if result is
+ // non-zero and not NAN, r must be finite, as X / INF is always
+ // 0 or NAN.
+ frange_drop_infs (r, type);
+ }
// If lhs is a maybe or known NAN, the operand could be
// NAN.
else
@@ -2330,7 +2355,7 @@ public:
if (!ret)
return ret;
if (lhs.known_isnan () || op1.known_isnan () || op1.undefined_p ())
- return float_binary_op_range_finish (ret, r, type, lhs);
+ return float_binary_op_range_finish (ret, r, type, lhs, true);
const REAL_VALUE_TYPE &lhs_lb = lhs.lower_bound ();
const REAL_VALUE_TYPE &lhs_ub = lhs.upper_bound ();
const REAL_VALUE_TYPE &op1_lb = op1.lower_bound ();
@@ -2347,7 +2372,7 @@ public:
zero_to_inf_range (lb, ub, signbit_known);
r.set (type, lb, ub);
}
- return float_binary_op_range_finish (ret, r, type, lhs);
+ return float_binary_op_range_finish (ret, r, type, lhs, true);
}
private:
void rv_fold (REAL_VALUE_TYPE &lb, REAL_VALUE_TYPE &ub, bool &maybe_nan,
Jakub
