From ed143e0c8e08b9192439ff4b7892a91ffa9bfd12 Mon Sep 17 00:00:00 2001 From: Aldy Hernandez Date: Thu, 22 Sep 2022 18:20:39 +0200 Subject: [PATCH] frange: drop endpoints to min/max representable numbers for -ffinite-math-only. Similarly to how we drop NANs to UNDEFINED when -ffinite-math-only, I think we can drop the numbers outside of the min/max representable numbers to the representable number. This means the endpoings to VR_VARYING for -ffinite-math-only can now be the min/max representable, instead of -INF and +INF. Saturating in the setter means that the upcoming implementation for binary operators no longer have to worry about doing the right thing for -ffinite-math-only. If the range goes outside the limits, it'll get chopped down. Tested on x86-64 Linux. gcc/ChangeLog: * range-op-float.cc (build_le): Use vrp_val_*. (build_lt): Same. (build_ge): Same. (build_gt): Same. * value-range.cc (frange::set): Chop ranges outside of the representable numbers for -ffinite-math-only. (frange::normalize_kind): Use vrp_val*. (frange::verify_range): Same. (frange::set_nonnegative): Same. (range_tests_floats): Remove tests that depend on -INF and +INF. * value-range.h (real_max_representable): Add prototype. (real_min_representable): Same. (vrp_val_max): Set max representable number for -ffinite-math-only. (vrp_val_min): Same but for min. (frange::set_varying): Use vrp_val*. --- gcc/range-op-float.cc | 18 ++++++----- gcc/value-range.cc | 46 ++++++++++++-------------- gcc/value-range.h | 75 ++++++++++++++++++++++++++++++++++++------- 3 files changed, 94 insertions(+), 45 deletions(-) diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc index 2bd3dc9253f..84f1ebe5a61 100644 --- a/gcc/range-op-float.cc +++ b/gcc/range-op-float.cc @@ -190,8 +190,7 @@ frelop_early_resolve (irange &r, tree type, static inline void frange_drop_inf (frange &r, tree type) { - REAL_VALUE_TYPE max; - real_max_representable (&max, type); + REAL_VALUE_TYPE max = real_max_representable (type); frange tmp (type, r.lower_bound (), max); r.intersect (tmp); } @@ -202,8 +201,7 @@ frange_drop_inf (frange &r, tree type) static inline void frange_drop_ninf (frange &r, tree type) { - REAL_VALUE_TYPE min; - real_min_representable (&min, type); + REAL_VALUE_TYPE min = real_min_representable (type); frange tmp (type, min, r.upper_bound ()); r.intersect (tmp); } @@ -232,7 +230,8 @@ build_le (frange &r, tree type, const frange &val) { gcc_checking_assert (!val.known_isnan ()); - r.set (type, dconstninf, val.upper_bound ()); + REAL_VALUE_TYPE ninf = frange_val_min (type); + r.set (type, ninf, val.upper_bound ()); // Add both zeros if there's the possibility of zero equality. frange_add_zeros (r, type); @@ -257,7 +256,8 @@ build_lt (frange &r, tree type, const frange &val) return false; } // We only support closed intervals. - r.set (type, dconstninf, val.upper_bound ()); + REAL_VALUE_TYPE ninf = frange_val_min (type); + r.set (type, ninf, val.upper_bound ()); return true; } @@ -268,7 +268,8 @@ build_ge (frange &r, tree type, const frange &val) { gcc_checking_assert (!val.known_isnan ()); - r.set (type, val.lower_bound (), dconstinf); + REAL_VALUE_TYPE inf = frange_val_max (type); + r.set (type, val.lower_bound (), inf); // Add both zeros if there's the possibility of zero equality. frange_add_zeros (r, type); @@ -294,7 +295,8 @@ build_gt (frange &r, tree type, const frange &val) } // We only support closed intervals. - r.set (type, val.lower_bound (), dconstinf); + REAL_VALUE_TYPE inf = frange_val_max (type); + r.set (type, val.lower_bound (), inf); return true; } diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 7e8028eced2..43905ba4901 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -338,6 +338,18 @@ frange::set (tree min, tree max, value_range_kind kind) m_neg_nan = false; } + // For -ffinite-math-only we can drop ranges outside the + // representable numbers to min/max for the type. + if (flag_finite_math_only) + { + REAL_VALUE_TYPE min_repr = frange_val_min (m_type); + REAL_VALUE_TYPE max_repr = frange_val_max (m_type); + if (real_less (&m_min, &min_repr)) + m_min = min_repr; + if (real_less (&max_repr, &m_max)) + m_max = max_repr; + } + // Check for swapped ranges. gcc_checking_assert (tree_compare (LE_EXPR, min, max)); @@ -371,8 +383,8 @@ bool frange::normalize_kind () { if (m_kind == VR_RANGE - && real_isinf (&m_min, 1) - && real_isinf (&m_max, 0)) + && frange_val_is_min (m_min, m_type) + && frange_val_is_max (m_max, m_type)) { if (m_pos_nan && m_neg_nan) { @@ -385,8 +397,8 @@ frange::normalize_kind () if (!m_pos_nan || !m_neg_nan) { m_kind = VR_RANGE; - m_min = dconstninf; - m_max = dconstinf; + m_min = frange_val_min (m_type); + m_max = frange_val_max (m_type); return true; } } @@ -706,8 +718,8 @@ frange::verify_range () case VR_VARYING: gcc_checking_assert (m_type); gcc_checking_assert (m_pos_nan && m_neg_nan); - gcc_checking_assert (real_isinf (&m_min, 1)); - gcc_checking_assert (real_isinf (&m_max, 0)); + gcc_checking_assert (frange_val_is_min (m_min, m_type)); + gcc_checking_assert (frange_val_is_max (m_max, m_type)); return; case VR_RANGE: gcc_checking_assert (m_type); @@ -732,7 +744,8 @@ frange::verify_range () // If all the properties are clear, we better not span the entire // domain, because that would make us varying. if (m_pos_nan && m_neg_nan) - gcc_checking_assert (!real_isinf (&m_min, 1) || !real_isinf (&m_max, 0)); + gcc_checking_assert (!frange_val_is_min (m_min, m_type) + || !frange_val_is_max (m_max, m_type)); } // We can't do much with nonzeros yet. @@ -779,7 +792,7 @@ frange::zero_p () const void frange::set_nonnegative (tree type) { - set (type, dconst0, dconstinf); + set (type, dconst0, frange_val_max (type)); // Set +NAN as the only possibility. if (HONOR_NANS (type)) @@ -3886,23 +3899,6 @@ range_tests_floats () r0.clear_nan (); ASSERT_FALSE (r0.varying_p ()); - // The endpoints of a VARYING are +-INF. - r0.set_varying (float_type_node); - ASSERT_TRUE (real_identical (&r0.lower_bound (), &dconstninf)); - ASSERT_TRUE (real_identical (&r0.upper_bound (), &dconstinf)); - - // The maximum representable range for a type is still a subset of VARYING. - REAL_VALUE_TYPE q, r; - real_min_representable (&q, float_type_node); - real_max_representable (&r, float_type_node); - r0 = frange (float_type_node, q, r); - // r0 is not a varying, because it does not include -INF/+INF. - ASSERT_FALSE (r0.varying_p ()); - // The upper bound of r0 must be less than +INF. - ASSERT_TRUE (real_less (&r0.upper_bound (), &dconstinf)); - // The lower bound of r0 must be greater than -INF. - ASSERT_TRUE (real_less (&dconstninf, &r0.lower_bound ())); - // For most architectures, where float and double are different // sizes, having the same endpoints does not necessarily mean the // ranges are equal. diff --git a/gcc/value-range.h b/gcc/value-range.h index 3668b331187..413e54bda6f 100644 --- a/gcc/value-range.h +++ b/gcc/value-range.h @@ -593,6 +593,8 @@ extern void dump_value_range (FILE *, const vrange *); extern bool vrp_val_is_min (const_tree); extern bool vrp_val_is_max (const_tree); extern bool vrp_operand_equal_p (const_tree, const_tree); +inline REAL_VALUE_TYPE frange_val_min (const_tree type); +inline REAL_VALUE_TYPE frange_val_max (const_tree type); inline value_range_kind vrange::kind () const @@ -1009,7 +1011,10 @@ vrp_val_max (const_tree type) return wide_int_to_tree (const_cast (type), max); } if (frange::supports_p (type)) - return build_real (const_cast (type), dconstinf); + { + REAL_VALUE_TYPE r = frange_val_max (type); + return build_real (const_cast (type), r); + } return NULL_TREE; } @@ -1023,7 +1028,10 @@ vrp_val_min (const_tree type) if (POINTER_TYPE_P (type)) return build_zero_cst (const_cast (type)); if (frange::supports_p (type)) - return build_real (const_cast (type), dconstninf); + { + REAL_VALUE_TYPE r = frange_val_min (type); + return build_real (const_cast (type), r); + } return NULL_TREE; } @@ -1073,8 +1081,8 @@ frange::set_varying (tree type) { m_kind = VR_VARYING; m_type = type; - m_min = dconstninf; - m_max = dconstinf; + m_min = frange_val_min (type); + m_max = frange_val_max (type); m_pos_nan = true; m_neg_nan = true; } @@ -1132,23 +1140,66 @@ frange::clear_nan () // Set R to maximum representable value for TYPE. -inline void -real_max_representable (REAL_VALUE_TYPE *r, tree type) +inline REAL_VALUE_TYPE +real_max_representable (const_tree type) { + REAL_VALUE_TYPE r; char buf[128]; get_max_float (REAL_MODE_FORMAT (TYPE_MODE (type)), buf, sizeof (buf), false); - int res = real_from_string (r, buf); + int res = real_from_string (&r, buf); gcc_checking_assert (!res); + return r; } -// Set R to minimum representable value for TYPE. +// Return the minimum representable value for TYPE. -inline void -real_min_representable (REAL_VALUE_TYPE *r, tree type) +inline REAL_VALUE_TYPE +real_min_representable (const_tree type) +{ + REAL_VALUE_TYPE r = real_max_representable (type); + r = real_value_negate (&r); + return r; +} + +// Return the minimum value for TYPE. + +inline REAL_VALUE_TYPE +frange_val_min (const_tree type) +{ + if (flag_finite_math_only) + return real_min_representable (type); + else + return dconstninf; +} + +// Return the maximum value for TYPE. + +inline REAL_VALUE_TYPE +frange_val_max (const_tree type) +{ + if (flag_finite_math_only) + return real_max_representable (type); + else + return dconstinf; +} + +// Return TRUE if R is the minimum value for TYPE. + +inline bool +frange_val_is_min (const REAL_VALUE_TYPE &r, const_tree type) +{ + REAL_VALUE_TYPE min = frange_val_min (type); + return real_identical (&min, &r); +} + +// Return TRUE if R is the max value for TYPE. + +inline bool +frange_val_is_max (const REAL_VALUE_TYPE &r, const_tree type) { - real_max_representable (r, type); - *r = real_value_negate (r); + REAL_VALUE_TYPE max = frange_val_max (type); + return real_identical (&max, &r); } // Build a signless NAN of type TYPE. -- 2.37.1