diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc index ef51b7538e3..283eb134c78 100644 --- a/gcc/range-op-float.cc +++ b/gcc/range-op-float.cc @@ -1132,6 +1132,95 @@ foperator_ordered::op1_range (frange &r, tree type, return true; } +class foperator_abs : public range_operator_float +{ + using range_operator_float::fold_range; + using range_operator_float::op1_range; +public: + bool fold_range (frange &r, tree type, + const frange &op1, const frange &, + relation_kind) const final override; + bool op1_range (frange &r, tree type, + const frange &lhs, const frange &op2, + relation_kind rel) const final override; +} fop_abs; + +bool +foperator_abs::fold_range (frange &r, tree type, + const frange &op1, const frange &op2, + relation_kind) const +{ + if (empty_range_varying (r, type, op1, op2)) + return true; + if (op1.known_isnan ()) + { + r.set_nan (type, /*sign=*/false); + return true; + } + + const REAL_VALUE_TYPE lh_lb = op1.lower_bound (); + const REAL_VALUE_TYPE lh_ub = op1.upper_bound (); + // Handle the easy case where everything is positive. + if (real_compare (GE_EXPR, &lh_lb, &dconst0) + && !real_iszero (&lh_lb, /*sign=*/true) + && !op1.maybe_isnan (/*sign=*/true)) + { + r = op1; + return true; + } + + REAL_VALUE_TYPE min = real_value_abs (&lh_lb); + REAL_VALUE_TYPE max = real_value_abs (&lh_ub); + // If the range contains zero then we know that the minimum value in the + // range will be zero. + if (real_compare (LE_EXPR, &lh_lb, &dconst0) + && real_compare (GE_EXPR, &lh_ub, &dconst0)) + { + if (real_compare (GT_EXPR, &min, &max)) + max = min; + min = dconst0; + } + else + { + // If the range was reversed, swap MIN and MAX. + if (real_compare (GT_EXPR, &min, &max)) + std::swap (min, max); + } + + r.set (type, min, max); + if (op1.maybe_isnan ()) + r.update_nan (/*sign=*/false); + else + r.clear_nan (); + return true; +} + +bool +foperator_abs::op1_range (frange &r, tree type, + const frange &lhs, const frange &op2, + relation_kind) const +{ + if (empty_range_varying (r, type, lhs, op2)) + return true; + if (lhs.known_isnan ()) + { + r.set_nan (type); + return true; + } + + // Start with the positives because negatives are an impossible result. + frange positives (type, dconst0, frange_val_max (type)); + positives.update_nan (/*sign=*/false); + positives.intersect (lhs); + r = positives; + // Then add the negative of each pair: + // ABS(op1) = [5,20] would yield op1 => [-20,-5][5,20]. + r.union_ (frange (type, + real_value_negate (&positives.upper_bound ()), + real_value_negate (&positives.lower_bound ()))); + return true; +} + class foperator_unordered_lt : public range_operator_float { using range_operator_float::fold_range; @@ -1502,6 +1591,8 @@ floating_op_table::floating_op_table () set (UNEQ_EXPR, fop_unordered_equal); set (ORDERED_EXPR, fop_ordered); set (UNORDERED_EXPR, fop_unordered); + + set (ABS_EXPR, fop_abs); } // Return a pointer to the range_operator_float instance, if there is diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-abs-1.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-abs-1.c new file mode 100644 index 00000000000..4b7b75833e0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-abs-1.c @@ -0,0 +1,17 @@ +// { dg-do compile } +// { dg-options "-O2 -fno-thread-jumps -fdump-tree-evrp" } + +void link_error (); + +void +foo (double x, double y) +{ + if (x > y && __builtin_signbit (y) == 0) + { + // y == +INF is impossible. + if (__builtin_isinf (y)) + link_error (); + } +} + +// { dg-final { scan-tree-dump-not "link_error" "evrp" } }