From: Jiufu Guo Date: Wed, 30 Aug 2023 08:59:16 +0000 (+0800) Subject: Add overflow API for plus minus mult on range X-Git-Tag: basepoints/gcc-15~6557 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=97442a087bed186d96170151c1924344c3370a2b;p=thirdparty%2Fgcc.git Add overflow API for plus minus mult on range In previous reviews, adding overflow APIs to range-op would be useful. Those APIs could help to check if overflow happens when operating between two 'range's, like: plus, minus, and mult. Previous discussions are here: https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624067.html https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624701.html gcc/ChangeLog: * range-op-mixed.h (operator_plus::overflow_free_p): New declare. (operator_minus::overflow_free_p): New declare. (operator_mult::overflow_free_p): New declare. * range-op.cc (range_op_handler::overflow_free_p): New function. (range_operator::overflow_free_p): New default function. (operator_plus::overflow_free_p): New function. (operator_minus::overflow_free_p): New function. (operator_mult::overflow_free_p): New function. * range-op.h (range_op_handler::overflow_free_p): New declare. (range_operator::overflow_free_p): New declare. * value-range.cc (irange::nonnegative_p): New function. (irange::nonpositive_p): New function. * value-range.h (irange::nonnegative_p): New declare. (irange::nonpositive_p): New declare. --- diff --git a/gcc/range-op-mixed.h b/gcc/range-op-mixed.h index 825f934cf603..ef562326c1f7 100644 --- a/gcc/range-op-mixed.h +++ b/gcc/range-op-mixed.h @@ -403,6 +403,10 @@ public: relation_kind rel) const final override; void update_bitmask (irange &r, const irange &lh, const irange &rh) const final override; + + virtual bool overflow_free_p (const irange &lh, const irange &rh, + relation_trio = TRIO_VARYING) const; + private: void wi_fold (irange &r, tree type, const wide_int &lh_lb, const wide_int &lh_ub, const wide_int &rh_lb, @@ -468,6 +472,10 @@ public: relation_kind rel) const final override; void update_bitmask (irange &r, const irange &lh, const irange &rh) const final override; + + virtual bool overflow_free_p (const irange &lh, const irange &rh, + relation_trio = TRIO_VARYING) const; + private: void wi_fold (irange &r, tree type, const wide_int &lh_lb, const wide_int &lh_ub, const wide_int &rh_lb, @@ -547,6 +555,9 @@ public: const REAL_VALUE_TYPE &lh_lb, const REAL_VALUE_TYPE &lh_ub, const REAL_VALUE_TYPE &rh_lb, const REAL_VALUE_TYPE &rh_ub, relation_kind kind) const final override; + virtual bool overflow_free_p (const irange &lh, const irange &rh, + relation_trio = TRIO_VARYING) const; + }; class operator_addr_expr : public range_operator diff --git a/gcc/range-op.cc b/gcc/range-op.cc index 268f6b6f0250..619979f2f61d 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -377,6 +377,22 @@ range_op_handler::op1_op2_relation (const vrange &lhs, } } +bool +range_op_handler::overflow_free_p (const vrange &lh, + const vrange &rh, + relation_trio rel) const +{ + gcc_checking_assert (m_operator); + switch (dispatch_kind (lh, lh, rh)) + { + case RO_III: + return m_operator->overflow_free_p(as_a (lh), + as_a (rh), + rel); + default: + return false; + } +} // Update the known bitmasks in R when applying the operation CODE to // LH and RH. @@ -706,6 +722,13 @@ range_operator::op1_op2_relation_effect (irange &lhs_range ATTRIBUTE_UNUSED, return false; } +bool +range_operator::overflow_free_p (const irange &, const irange &, + relation_trio) const +{ + return false; +} + // Apply any known bitmask updates based on this operator. void @@ -4364,6 +4387,107 @@ range_op_table::initialize_integral_ops () } +bool +operator_plus::overflow_free_p (const irange &lh, const irange &rh, + relation_trio) const +{ + if (lh.undefined_p () || rh.undefined_p ()) + return false; + + tree type = lh.type (); + if (TYPE_OVERFLOW_UNDEFINED (type)) + return true; + + wi::overflow_type ovf; + signop sgn = TYPE_SIGN (type); + wide_int wmax0 = lh.upper_bound (); + wide_int wmax1 = rh.upper_bound (); + wi::add (wmax0, wmax1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + if (TYPE_UNSIGNED (type)) + return true; + + wide_int wmin0 = lh.lower_bound (); + wide_int wmin1 = rh.lower_bound (); + wi::add (wmin0, wmin1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + return true; +} + +bool +operator_minus::overflow_free_p (const irange &lh, const irange &rh, + relation_trio) const +{ + if (lh.undefined_p () || rh.undefined_p ()) + return false; + + tree type = lh.type (); + if (TYPE_OVERFLOW_UNDEFINED (type)) + return true; + + wi::overflow_type ovf; + signop sgn = TYPE_SIGN (type); + wide_int wmin0 = lh.lower_bound (); + wide_int wmax1 = rh.upper_bound (); + wi::sub (wmin0, wmax1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + if (TYPE_UNSIGNED (type)) + return true; + + wide_int wmax0 = lh.upper_bound (); + wide_int wmin1 = rh.lower_bound (); + wi::sub (wmax0, wmin1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + return true; +} + +bool +operator_mult::overflow_free_p (const irange &lh, const irange &rh, + relation_trio) const +{ + if (lh.undefined_p () || rh.undefined_p ()) + return false; + + tree type = lh.type (); + if (TYPE_OVERFLOW_UNDEFINED (type)) + return true; + + wi::overflow_type ovf; + signop sgn = TYPE_SIGN (type); + wide_int wmax0 = lh.upper_bound (); + wide_int wmax1 = rh.upper_bound (); + wi::mul (wmax0, wmax1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + if (TYPE_UNSIGNED (type)) + return true; + + wide_int wmin0 = lh.lower_bound (); + wide_int wmin1 = rh.lower_bound (); + wi::mul (wmin0, wmin1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + wi::mul (wmin0, wmax1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + wi::mul (wmax0, wmin1, sgn, &ovf); + if (ovf != wi::OVF_NONE) + return false; + + return true; +} + #if CHECKING_P #include "selftest.h" diff --git a/gcc/range-op.h b/gcc/range-op.h index 51121410233f..21d401cc83d9 100644 --- a/gcc/range-op.h +++ b/gcc/range-op.h @@ -154,6 +154,9 @@ public: virtual relation_kind op1_op2_relation (const frange &lhs, const frange &op1, const frange &op2) const; + + virtual bool overflow_free_p (const irange &lh, const irange &rh, + relation_trio = TRIO_VARYING) const; protected: // Perform an integral operation between 2 sub-ranges and return it. virtual void wi_fold (irange &r, tree type, @@ -223,6 +226,8 @@ public: relation_kind op1_op2_relation (const vrange &lhs, const vrange &op1, const vrange &op2) const; + bool overflow_free_p (const vrange &lh, const vrange &rh, + relation_trio = TRIO_VARYING) const; protected: unsigned dispatch_kind (const vrange &lhs, const vrange &op1, const vrange& op2) const; diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 60180c80e55b..391cef64cd13 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -313,6 +313,18 @@ add_vrange (const vrange &v, inchash::hash &hstate, } //namespace inchash +bool +irange::nonnegative_p () const +{ + return wi::ge_p (lower_bound (), 0, TYPE_SIGN (type ())); +} + +bool +irange::nonpositive_p () const +{ + return wi::le_p (upper_bound (), 0, TYPE_SIGN (type ())); +} + bool irange::supports_type_p (const_tree type) const { diff --git a/gcc/value-range.h b/gcc/value-range.h index 622b68863d26..6c5be36d74d2 100644 --- a/gcc/value-range.h +++ b/gcc/value-range.h @@ -288,6 +288,8 @@ public: virtual bool singleton_p (tree *result = NULL) const override; bool singleton_p (wide_int &) const; bool contains_p (const wide_int &) const; + bool nonnegative_p () const; + bool nonpositive_p () const; // In-place operators. virtual bool union_ (const vrange &) override;