procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

frange: Implement nan_state class [PR109008]

Browse source 
This patch implements a nan_state class, that allows us to query or
pass around the NANness of an frange.  We can store +NAN, -NAN, +-NAN,
or not-a-NAN with it.

I tried to touch as little as possible, leaving other cleanups to the
next release.  For example, we should replace the m_*_nan fields in
frange with nan_state, and provide relevant accessors to nan_state
(isnan, etc).

	PR tree-optimization/109008

gcc/ChangeLog:

	* value-range.cc (frange::set): Add nan_state argument.
	* value-range.h (class nan_state): New.
	(frange::get_nan_state): New.
This commit is contained in:
Aldy Hernandez 2023-03-08 10:58:01 +01:00
parent 5e812e8c1e
commit 81295d445e
2 changed files with 77 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
gcc/value-range.cc
View file

@ -284,7 +284,7 @@ frange::flush_denormals_to_zero ()
void
frange::set (tree type,
const REAL_VALUE_TYPE &min, const REAL_VALUE_TYPE &max,
value_range_kind kind)
const nan_state &nan, value_range_kind kind)
{
switch (kind)
{
@ -316,8 +316,8 @@ frange::set (tree type,
m_max = max;
if (HONOR_NANS (m_type))
{
m_pos_nan = true;
m_neg_nan = true;
m_pos_nan = nan.pos_p ();
m_neg_nan = nan.neg_p ();
}
else
{
@ -367,6 +367,18 @@ frange::set (tree type,
verify_range ();
}
// Setter for an frange defaulting the NAN possibility to +-NAN when
// HONOR_NANS.
void
frange::set (tree type,
const REAL_VALUE_TYPE &min, const REAL_VALUE_TYPE &max,
value_range_kind kind)
{
nan_state nan;
set (type, min, max, nan, kind);
}
void
frange::set (tree min, tree max, value_range_kind kind)
{

62
gcc/value-range.h
View file

@ -268,6 +268,56 @@ public:
virtual void accept (const vrange_visitor &v) const override;
};
// The NAN state as an opaque object. The default constructor is +-NAN.
class nan_state
{
public:
nan_state ();
nan_state (bool pos_nan, bool neg_nan);
bool neg_p () const;
bool pos_p () const;
private:
bool m_pos_nan;
bool m_neg_nan;
};
// Default constructor initializing the object to +-NAN.
inline
nan_state::nan_state ()
{
m_pos_nan = true;
m_neg_nan = true;
}
// Constructor initializing the object to +NAN if POS_NAN is set, -NAN
// if NEG_NAN is set, or +-NAN if both are set. Otherwise POS_NAN and
// NEG_NAN are clear, and the object cannot be a NAN.
inline
nan_state::nan_state (bool pos_nan, bool neg_nan)
{
m_pos_nan = pos_nan;
m_neg_nan = neg_nan;
}
// Return if +NAN is possible.
inline bool
nan_state::pos_p () const
{
return m_pos_nan;
}
// Return if -NAN is possible.
inline bool
nan_state::neg_p () const
{
return m_neg_nan;
}
// A floating point range.
//
// The representation is a type with a couple of endpoints, unioned
@ -295,6 +345,8 @@ public:
virtual void set (tree, tree, value_range_kind = VR_RANGE) override;
void set (tree type, const REAL_VALUE_TYPE &, const REAL_VALUE_TYPE &,
value_range_kind = VR_RANGE);
void set (tree type, const REAL_VALUE_TYPE &, const REAL_VALUE_TYPE &,
const nan_state &, value_range_kind = VR_RANGE);
void set_nan (tree type);
void set_nan (tree type, bool sign);
virtual void set_varying (tree type) override;
@ -315,9 +367,11 @@ public:
bool operator!= (const frange &r) const { return !(*this == r); }
const REAL_VALUE_TYPE &lower_bound () const;
const REAL_VALUE_TYPE &upper_bound () const;
nan_state get_nan_state () const;
void update_nan ();
void update_nan (bool sign);
void update_nan (tree) = delete; // Disallow silent conversion to bool.
void update_nan (const nan_state &);
void clear_nan ();
// fpclassify like API
@ -358,6 +412,14 @@ frange::upper_bound () const
return m_max;
}
// Return the NAN state.
inline nan_state
frange::get_nan_state () const
{
return nan_state (m_pos_nan, m_neg_nan);
}
// is_a<> and as_a<> implementation for vrange.
// Anything we haven't specialized is a hard fail.