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| author | Jakub Jelinek <jakub@redhat.com> | 2023-03-28 11:00:32 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2023-03-28 11:00:32 +0200 |
| commit | ce3974e5962b0e1f72a1f71ebda39d53a77b7cc9 (patch) | |
| tree | 5cdedd975249b8b02713510b7b83a40b07e8bdee | |
| parent | 39a43dc336561e0eba0de477b16c7355f19d84ee (diff) | |
| download | gcc-ce3974e5962b0e1f72a1f71ebda39d53a77b7cc9.zip gcc-ce3974e5962b0e1f72a1f71ebda39d53a77b7cc9.tar.gz gcc-ce3974e5962b0e1f72a1f71ebda39d53a77b7cc9.tar.bz2 | |
range-op-float: Only flush_denormals_to_zero for +-*/ [PR109154]
As discussed in the PR, flushing denormals to zero on every frange::set
might be harmful for e.g. x < 0.0 comparisons, because we then on both
sides use ranges that include zero [-Inf, -0.0] on the true side, and
[-0.0, +Inf] NAN on the false side, rather than [-Inf, nextafter (-0.0, -Inf)]
on the true side.
The following patch does it only in range_operator_float::fold_range
which is right now used for +-*/ (both normal and reverse ops of those).
Though, I don't see any difference on the testcase in the PR, but not sure
what I should be looking at and the reduced testcase there has undefined
behavior.
2023-03-28 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/109154
* value-range.h (frange::flush_denormals_to_zero): Make it public
rather than private.
* value-range.cc (frange::set): Don't call flush_denormals_to_zero
here.
* range-op-float.cc (range_operator_float::fold_range): Call
flush_denormals_to_zero.
| -rw-r--r-- | gcc/range-op-float.cc | 2 | ||||
| -rw-r--r-- | gcc/value-range.cc | 2 | ||||
| -rw-r--r-- | gcc/value-range.h | 2 |
3 files changed, 3 insertions, 3 deletions
diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc index dc9789b..d212e64 100644 --- a/gcc/range-op-float.cc +++ b/gcc/range-op-float.cc @@ -112,6 +112,8 @@ range_operator_float::fold_range (frange &r, tree type, } } + r.flush_denormals_to_zero (); + return true; } diff --git a/gcc/value-range.cc b/gcc/value-range.cc index ec97e76..ec826c2 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -361,8 +361,6 @@ frange::set (tree type, normalize_kind (); - flush_denormals_to_zero (); - if (flag_checking) verify_range (); } diff --git a/gcc/value-range.h b/gcc/value-range.h index 2b4f6e9..969b2b6 100644 --- a/gcc/value-range.h +++ b/gcc/value-range.h @@ -373,6 +373,7 @@ public: void update_nan (tree) = delete; // Disallow silent conversion to bool. void update_nan (const nan_state &); void clear_nan (); + void flush_denormals_to_zero (); // fpclassify like API bool known_isfinite () const; @@ -389,7 +390,6 @@ private: bool union_nans (const frange &); bool intersect_nans (const frange &); bool combine_zeros (const frange &, bool union_p); - void flush_denormals_to_zero (); tree m_type; REAL_VALUE_TYPE m_min; |