diff options
Diffstat (limited to 'gcc/value-query.cc')
| -rw-r--r-- | gcc/value-query.cc | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/gcc/value-query.cc b/gcc/value-query.cc index 509d2d3..f8b457d 100644 --- a/gcc/value-query.cc +++ b/gcc/value-query.cc @@ -31,6 +31,7 @@ along with GCC; see the file COPYING3. If not see #include "value-range-equiv.h" #include "value-query.h" #include "alloc-pool.h" +#include "gimple-range.h" // value_query default methods. @@ -180,3 +181,149 @@ range_query::~range_query () equiv_alloc->release (); delete equiv_alloc; } + +// Return the range for NAME from SSA_NAME_RANGE_INFO. + +static inline void +get_ssa_name_range_info (irange &r, const_tree name) +{ + tree type = TREE_TYPE (name); + gcc_checking_assert (!POINTER_TYPE_P (type)); + gcc_checking_assert (TREE_CODE (name) == SSA_NAME); + + range_info_def *ri = SSA_NAME_RANGE_INFO (name); + + // Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs + // with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. + if (!ri || (GET_MODE_PRECISION (SCALAR_INT_TYPE_MODE (TREE_TYPE (name))) + > 2 * HOST_BITS_PER_WIDE_INT)) + r.set_varying (type); + else + r.set (wide_int_to_tree (type, ri->get_min ()), + wide_int_to_tree (type, ri->get_max ()), + SSA_NAME_RANGE_TYPE (name)); +} + +// Return nonnull attribute of pointer NAME from SSA_NAME_PTR_INFO. + +static inline bool +get_ssa_name_ptr_info_nonnull (const_tree name) +{ + gcc_assert (POINTER_TYPE_P (TREE_TYPE (name))); + struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name); + if (pi == NULL) + return false; + /* TODO Now pt->null is conservatively set to true in PTA + analysis. vrp is the only pass (including ipa-vrp) + that clears pt.null via set_ptr_nonull when it knows + for sure. PTA will preserves the pt.null value set by VRP. + + When PTA analysis is improved, pt.anything, pt.nonlocal + and pt.escaped may also has to be considered before + deciding that pointer cannot point to NULL. */ + return !pi->pt.null; +} + +// Return the legacy global range for NAME if it has one, otherwise +// return VARYING. + +static void +get_range_global (irange &r, tree name) +{ + tree type = TREE_TYPE (name); + + if (SSA_NAME_IS_DEFAULT_DEF (name)) + { + tree sym = SSA_NAME_VAR (name); + // Adapted from vr_values::get_lattice_entry(). + // Use a range from an SSA_NAME's available range. + if (TREE_CODE (sym) == PARM_DECL) + { + // Try to use the "nonnull" attribute to create ~[0, 0] + // anti-ranges for pointers. Note that this is only valid with + // default definitions of PARM_DECLs. + if (POINTER_TYPE_P (type) + && ((cfun && nonnull_arg_p (sym)) + || get_ssa_name_ptr_info_nonnull (name))) + r.set_nonzero (type); + else if (INTEGRAL_TYPE_P (type)) + { + get_ssa_name_range_info (r, name); + if (r.undefined_p ()) + r.set_varying (type); + } + else + r.set_varying (type); + } + // If this is a local automatic with no definition, use undefined. + else if (TREE_CODE (sym) != RESULT_DECL) + r.set_undefined (); + else + r.set_varying (type); + } + else if (!POINTER_TYPE_P (type) && SSA_NAME_RANGE_INFO (name)) + { + get_ssa_name_range_info (r, name); + if (r.undefined_p ()) + r.set_varying (type); + } + else if (POINTER_TYPE_P (type) && SSA_NAME_PTR_INFO (name)) + { + if (get_ssa_name_ptr_info_nonnull (name)) + r.set_nonzero (type); + else + r.set_varying (type); + } + else + r.set_varying (type); +} + +// ?? Like above, but only for default definitions of NAME. This is +// so VRP passes using ranger do not start with known ranges, +// otherwise we'd eliminate builtin_unreachables too early because of +// inlining. +// +// Without this restriction, the test in g++.dg/tree-ssa/pr61034.C has +// all of its unreachable calls removed too early. We should +// investigate whether we should just adjust the test above. + +value_range +gimple_range_global (tree name) +{ + gcc_checking_assert (gimple_range_ssa_p (name)); + tree type = TREE_TYPE (name); + + if (SSA_NAME_IS_DEFAULT_DEF (name)) + { + value_range vr; + get_range_global (vr, name); + return vr; + } + return value_range (type); +} + +// ---------------------------------------------- +// global_range_query implementation. + +global_range_query global_ranges; + +// Like get_range_query, but for accessing global ranges. + +range_query * +get_global_range_query () +{ + return &global_ranges; +} + +bool +global_range_query::range_of_expr (irange &r, tree expr, gimple *) +{ + tree type = TREE_TYPE (expr); + + if (!irange::supports_type_p (type) || !gimple_range_ssa_p (expr)) + return get_tree_range (r, expr); + + get_range_global (r, expr); + + return true; +} |