/* Code for GIMPLE range related routines.
Copyright (C) 2019-2022 Free Software Foundation, Inc.
Contributed by Andrew MacLeod <amacleod@redhat.com>
and Aldy Hernandez <aldyh@redhat.com>.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "insn-codes.h"
#include "tree.h"
#include "gimple.h"
#include "ssa.h"
#include "gimple-pretty-print.h"
#include "optabs-tree.h"
#include "gimple-fold.h"
#include "wide-int.h"
#include "fold-const.h"
#include "case-cfn-macros.h"
#include "omp-general.h"
#include "cfgloop.h"
#include "tree-ssa-loop.h"
#include "tree-scalar-evolution.h"
#include "langhooks.h"
#include "vr-values.h"
#include "range.h"
#include "value-query.h"
#include "range-op.h"
#include "gimple-range.h"
// Construct a fur_source, and set the m_query field.
fur_source::fur_source (range_query *q)
{
if (q)
m_query = q;
else if (cfun)
m_query = get_range_query (cfun);
else
m_query = get_global_range_query ();
m_gori = NULL;
}
// Invoke range_of_expr on EXPR.
bool
fur_source::get_operand (irange &r, tree expr)
{
return m_query->range_of_expr (r, expr);
}
// Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current
// range_query to get the range on the edge.
bool
fur_source::get_phi_operand (irange &r, tree expr, edge e)
{
return m_query->range_on_edge (r, e, expr);
}
// Default is no relation.
relation_kind
fur_source::query_relation (tree op1 ATTRIBUTE_UNUSED,
tree op2 ATTRIBUTE_UNUSED)
{
return VREL_NONE;
}
// Default registers nothing.
void
fur_source::register_relation (gimple *s ATTRIBUTE_UNUSED,
relation_kind k ATTRIBUTE_UNUSED,
tree op1 ATTRIBUTE_UNUSED,
tree op2 ATTRIBUTE_UNUSED)
{
}
// Default registers nothing.
void
fur_source::register_relation (edge e ATTRIBUTE_UNUSED,
relation_kind k ATTRIBUTE_UNUSED,
tree op1 ATTRIBUTE_UNUSED,
tree op2 ATTRIBUTE_UNUSED)
{
}
// This version of fur_source will pick a range up off an edge.
class fur_edge : public fur_source
{
public:
fur_edge (edge e, range_query *q = NULL);
virtual bool get_operand (irange &r, tree expr) OVERRIDE;
virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
private:
edge m_edge;
};
// Instantiate an edge based fur_source.
inline
fur_edge::fur_edge (edge e, range_query *q) : fur_source (q)
{
m_edge = e;
}
// Get the value of EXPR on edge m_edge.
bool
fur_edge::get_operand (irange &r, tree expr)
{
return m_query->range_on_edge (r, m_edge, expr);
}
// Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current
// range_query to get the range on the edge.
bool
fur_edge::get_phi_operand (irange &r, tree expr, edge e)
{
// Edge to edge recalculations not supoprted yet, until we sort it out.
gcc_checking_assert (e == m_edge);
return m_query->range_on_edge (r, e, expr);
}
// Instantiate a stmt based fur_source.
fur_stmt::fur_stmt (gimple *s, range_query *q) : fur_source (q)
{
m_stmt = s;
}
// Retreive range of EXPR as it occurs as a use on stmt M_STMT.
bool
fur_stmt::get_operand (irange &r, tree expr)
{
return m_query->range_of_expr (r, expr, m_stmt);
}
// Evaluate EXPR for this stmt as a PHI argument on edge E. Use the current
// range_query to get the range on the edge.
bool
fur_stmt::get_phi_operand (irange &r, tree expr, edge e)
{
// Pick up the range of expr from edge E.
fur_edge e_src (e, m_query);
return e_src.get_operand (r, expr);
}
// Return relation based from m_stmt.
relation_kind
fur_stmt::query_relation (tree op1, tree op2)
{
return m_query->query_relation (m_stmt, op1, op2);
}
// Instantiate a stmt based fur_source with a GORI object.
fur_depend::fur_depend (gimple *s, gori_compute *gori, range_query *q)
: fur_stmt (s, q)
{
gcc_checking_assert (gori);
m_gori = gori;
// Set relations if there is an oracle in the range_query.
// This will enable registering of relationships as they are discovered.
m_oracle = q->oracle ();
}
// Register a relation on a stmt if there is an oracle.
void
fur_depend::register_relation (gimple *s, relation_kind k, tree op1, tree op2)
{
if (m_oracle)
m_oracle->register_stmt (s, k, op1, op2);
}
// Register a relation on an edge if there is an oracle.
void
fur_depend::register_relation (edge e, relation_kind k, tree op1, tree op2)
{
if (m_oracle)
m_oracle->register_edge (e, k, op1, op2);
}
// This version of fur_source will pick a range up from a list of ranges
// supplied by the caller.
class fur_list : public fur_source
{
public:
fur_list (irange &r1);
fur_list (irange &r1, irange &r2);
fur_list (unsigned num, irange *list);
virtual bool get_operand (irange &r, tree expr) OVERRIDE;
virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
private:
int_range_max m_local[2];
irange *m_list;
unsigned m_index;
unsigned m_limit;
};
// One range supplied for unary operations.
fur_list::fur_list (irange &r1) : fur_source (NULL)
{
m_list = m_local;
m_index = 0;
m_limit = 1;
m_local[0] = r1;
}
// Two ranges supplied for binary operations.
fur_list::fur_list (irange &r1, irange &r2) : fur_source (NULL)
{
m_list = m_local;
m_index = 0;
m_limit = 2;
m_local[0] = r1;
m_local[0] = r2;
}
// Arbitrary number of ranges in a vector.
fur_list::fur_list (unsigned num, irange *list) : fur_source (NULL)
{
m_list = list;
m_index = 0;
m_limit = num;
}
// Get the next operand from the vector, ensure types are compatible.
bool
fur_list::get_operand (irange &r, tree expr)
{
if (m_index >= m_limit)
return m_query->range_of_expr (r, expr);
r = m_list[m_index++];
gcc_checking_assert (range_compatible_p (TREE_TYPE (expr), r.type ()));
return true;
}
// This will simply pick the next operand from the vector.
bool
fur_list::get_phi_operand (irange &r, tree expr, edge e ATTRIBUTE_UNUSED)
{
return get_operand (r, expr);
}
// Fold stmt S into range R using R1 as the first operand.
bool
fold_range (irange &r, gimple *s, irange &r1)
{
fold_using_range f;
fur_list src (r1);
return f.fold_stmt (r, s, src);
}
// Fold stmt S into range R using R1 and R2 as the first two operands.
bool
fold_range (irange &r, gimple *s, irange &r1, irange &r2)
{
fold_using_range f;
fur_list src (r1, r2);
return f.fold_stmt (r, s, src);
}
// Fold stmt S into range R using NUM_ELEMENTS from VECTOR as the initial
// operands encountered.
bool
fold_range (irange &r, gimple *s, unsigned num_elements, irange *vector)
{
fold_using_range f;
fur_list src (num_elements, vector);
return f.fold_stmt (r, s, src);
}
// Fold stmt S into range R using range query Q.
bool
fold_range (irange &r, gimple *s, range_query *q)
{
fold_using_range f;
fur_stmt src (s, q);
return f.fold_stmt (r, s, src);
}
// Recalculate stmt S into R using range query Q as if it were on edge ON_EDGE.
bool
fold_range (irange &r, gimple *s, edge on_edge, range_query *q)
{
fold_using_range f;
fur_edge src (on_edge, q);
return f.fold_stmt (r, s, src);
}
// -------------------------------------------------------------------------
// Adjust the range for a pointer difference where the operands came
// from a memchr.
//
// This notices the following sequence:
//
// def = __builtin_memchr (arg, 0, sz)
// n = def - arg
//
// The range for N can be narrowed to [0, PTRDIFF_MAX - 1].
static void
adjust_pointer_diff_expr (irange &res, const gimple *diff_stmt)
{
tree op0 = gimple_assign_rhs1 (diff_stmt);
tree op1 = gimple_assign_rhs2 (diff_stmt);
tree op0_ptype = TREE_TYPE (TREE_TYPE (op0));
tree op1_ptype = TREE_TYPE (TREE_TYPE (op1));
gimple *call;
if (TREE_CODE (op0) == SSA_NAME
&& TREE_CODE (op1) == SSA_NAME
&& (call = SSA_NAME_DEF_STMT (op0))
&& is_gimple_call (call)
&& gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
&& TYPE_MODE (op0_ptype) == TYPE_MODE (char_type_node)
&& TYPE_PRECISION (op0_ptype) == TYPE_PRECISION (char_type_node)
&& TYPE_MODE (op1_ptype) == TYPE_MODE (char_type_node)
&& TYPE_PRECISION (op1_ptype) == TYPE_PRECISION (char_type_node)
&& gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
&& vrp_operand_equal_p (op1, gimple_call_arg (call, 0))
&& integer_zerop (gimple_call_arg (call, 1)))
{
tree max = vrp_val_max (ptrdiff_type_node);
unsigned prec = TYPE_PRECISION (TREE_TYPE (max));
wide_int wmaxm1 = wi::to_wide (max, prec) - 1;
res.intersect (wi::zero (prec), wmaxm1);
}
}
// Adjust the range for an IMAGPART_EXPR.
static void
adjust_imagpart_expr (irange &res, const gimple *stmt)
{
tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
if (TREE_CODE (name) != SSA_NAME || !SSA_NAME_DEF_STMT (name))
return;
gimple *def_stmt = SSA_NAME_DEF_STMT (name);
if (is_gimple_call (def_stmt) && gimple_call_internal_p (def_stmt))
{
switch (gimple_call_internal_fn (def_stmt))
{
case IFN_ADD_OVERFLOW:
case IFN_SUB_OVERFLOW:
case IFN_MUL_OVERFLOW:
case IFN_ATOMIC_COMPARE_EXCHANGE:
{
int_range<2> r;
r.set_varying (boolean_type_node);
tree type = TREE_TYPE (gimple_assign_lhs (stmt));
range_cast (r, type);
res.intersect (r);
}
default:
break;
}
return;
}
if (is_gimple_assign (def_stmt))
{
tree cst = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (cst) == COMPLEX_CST)
{
wide_int imag = wi::to_wide (TREE_IMAGPART (cst));
res.intersect (imag, imag);
}
}
}
// Adjust the range for a REALPART_EXPR.
static void
adjust_realpart_expr (irange &res, const gimple *stmt)
{
tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
if (TREE_CODE (name) != SSA_NAME)
return;
gimple *def_stmt = SSA_NAME_DEF_STMT (name);
if (!SSA_NAME_DEF_STMT (name))
return;
if (is_gimple_assign (def_stmt))
{
tree cst = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (cst) == COMPLEX_CST)
{
tree imag = TREE_REALPART (cst);
int_range<2> tmp (imag, imag);
res.intersect (tmp);
}
}
}
// This function looks for situations when walking the use/def chains
// may provide additonal contextual range information not exposed on
// this statement.
static void
gimple_range_adjustment (irange &res, const gimple *stmt)
{
switch (gimple_expr_code (stmt))
{
case POINTER_DIFF_EXPR:
adjust_pointer_diff_expr (res, stmt);
return;
case IMAGPART_EXPR:
adjust_imagpart_expr (res, stmt);
return;
case REALPART_EXPR:
adjust_realpart_expr (res, stmt);
return;
default:
break;
}
}
// Return the base of the RHS of an assignment.
static tree
gimple_range_base_of_assignment (const gimple *stmt)
{
gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
tree op1 = gimple_assign_rhs1 (stmt);
if (gimple_assign_rhs_code (stmt) == ADDR_EXPR)
return get_base_address (TREE_OPERAND (op1, 0));
return op1;
}
// Return the first operand of this statement if it is a valid operand
// supported by ranges, otherwise return NULL_TREE. Special case is
// &(SSA_NAME expr), return the SSA_NAME instead of the ADDR expr.
tree
gimple_range_operand1 (const gimple *stmt)
{
gcc_checking_assert (gimple_range_handler (stmt));
switch (gimple_code (stmt))
{
case GIMPLE_COND:
return gimple_cond_lhs (stmt);
case GIMPLE_ASSIGN:
{
tree base = gimple_range_base_of_assignment (stmt);
if (base && TREE_CODE (base) == MEM_REF)
{
// If the base address is an SSA_NAME, we return it
// here. This allows processing of the range of that
// name, while the rest of the expression is simply
// ignored. The code in range_ops will see the
// ADDR_EXPR and do the right thing.
tree ssa = TREE_OPERAND (base, 0);
if (TREE_CODE (ssa) == SSA_NAME)
return ssa;
}
return base;
}
default:
break;
}
return NULL;
}
// Return the second operand of statement STMT, otherwise return NULL_TREE.
tree
gimple_range_operand2 (const gimple *stmt)
{
gcc_checking_assert (gimple_range_handler (stmt));
switch (gimple_code (stmt))
{
case GIMPLE_COND:
return gimple_cond_rhs (stmt);
case GIMPLE_ASSIGN:
if (gimple_num_ops (stmt) >= 3)
return gimple_assign_rhs2 (stmt);
default:
break;
}
return NULL_TREE;
}
// Calculate a range for statement S and return it in R. If NAME is provided it
// represents the SSA_NAME on the LHS of the statement. It is only required
// if there is more than one lhs/output. If a range cannot
// be calculated, return false.
bool
fold_using_range::fold_stmt (irange &r, gimple *s, fur_source &src, tree name)
{
bool res = false;
// If name and S are specified, make sure it is an LHS of S.
gcc_checking_assert (!name || !gimple_get_lhs (s) ||
name == gimple_get_lhs (s));
if (!name)
name = gimple_get_lhs (s);
// Process addresses.
if (gimple_code (s) == GIMPLE_ASSIGN
&& gimple_assign_rhs_code (s) == ADDR_EXPR)
return range_of_address (r, s, src);
if (gimple_range_handler (s))
res = range_of_range_op (r, s, src);
else if (is_a<gphi *>(s))
res = range_of_phi (r, as_a<gphi *> (s), src);
else if (is_a<gcall *>(s))
res = range_of_call (r, as_a<gcall *> (s), src);
else if (is_a<gassign *> (s) && gimple_assign_rhs_code (s) == COND_EXPR)
res = range_of_cond_expr (r, as_a<gassign *> (s), src);
if (!res)
{
// If no name specified or range is unsupported, bail.
if (!name || !gimple_range_ssa_p (name))
return false;
// We don't understand the stmt, so return the global range.
r = gimple_range_global (name);
return true;
}
if (r.undefined_p ())
return true;
// We sometimes get compatible types copied from operands, make sure
// the correct type is being returned.
if (name && TREE_TYPE (name) != r.type ())
{
gcc_checking_assert (range_compatible_p (r.type (), TREE_TYPE (name)));
range_cast (r, TREE_TYPE (name));
}
return true;
}
// Calculate a range for range_op statement S and return it in R. If any
// If a range cannot be calculated, return false.
bool
fold_using_range::range_of_range_op (irange &r, gimple *s, fur_source &src)
{
int_range_max range1, range2;
tree type = gimple_range_type (s);
if (!type)
return false;
range_operator *handler = gimple_range_handler (s);
gcc_checking_assert (handler);
tree lhs = gimple_get_lhs (s);
tree op1 = gimple_range_operand1 (s);
tree op2 = gimple_range_operand2 (s);
if (src.get_operand (range1, op1))
{
if (!op2)
{
// Fold range, and register any dependency if available.
int_range<2> r2 (type);
handler->fold_range (r, type, range1, r2);
if (lhs && gimple_range_ssa_p (op1))
{
if (src.gori ())
src.gori ()->register_dependency (lhs, op1);
relation_kind rel;
rel = handler->lhs_op1_relation (r, range1, range1);
if (rel != VREL_NONE)
src.register_relation (s, rel, lhs, op1);
}
}
else if (src.get_operand (range2, op2))
{
relation_kind rel = src.query_relation (op1, op2);
if (dump_file && (dump_flags & TDF_DETAILS) && rel != VREL_NONE)
{
fprintf (dump_file, " folding with relation ");
print_generic_expr (dump_file, op1, TDF_SLIM);
print_relation (dump_file, rel);
print_generic_expr (dump_file, op2, TDF_SLIM);
fputc ('\n', dump_file);
}
// Fold range, and register any dependency if available.
handler->fold_range (r, type, range1, range2, rel);
relation_fold_and_or (r, s, src);
if (lhs)
{
if (src.gori ())
{
src.gori ()->register_dependency (lhs, op1);
src.gori ()->register_dependency (lhs, op2);
}
if (gimple_range_ssa_p (op1))
{
rel = handler->lhs_op1_relation (r, range1, range2);
if (rel != VREL_NONE)
src.register_relation (s, rel, lhs, op1);
}
if (gimple_range_ssa_p (op2))
{
rel= handler->lhs_op2_relation (r, range1, range2);
if (rel != VREL_NONE)
src.register_relation (s, rel, lhs, op2);
}
}
// Check for an existing BB, as we maybe asked to fold an
// artificial statement not in the CFG.
else if (is_a<gcond *> (s) && gimple_bb (s))
{
basic_block bb = gimple_bb (s);
edge e0 = EDGE_SUCC (bb, 0);
edge e1 = EDGE_SUCC (bb, 1);
if (!single_pred_p (e0->dest))
e0 = NULL;
if (!single_pred_p (e1->dest))
e1 = NULL;
src.register_outgoing_edges (as_a<gcond *> (s), r, e0, e1);
}
}
else
r.set_varying (type);
}
else
r.set_varying (type);
// Make certain range-op adjustments that aren't handled any other way.
gimple_range_adjustment (r, s);
return true;
}
// Calculate the range of an assignment containing an ADDR_EXPR.
// Return the range in R.
// If a range cannot be calculated, set it to VARYING and return true.
bool
fold_using_range::range_of_address (irange &r, gimple *stmt, fur_source &src)
{
gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
gcc_checking_assert (gimple_assign_rhs_code (stmt) == ADDR_EXPR);
bool strict_overflow_p;
tree expr = gimple_assign_rhs1 (stmt);
poly_int64 bitsize, bitpos;
tree offset;
machine_mode mode;
int unsignedp, reversep, volatilep;
tree base = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize,
&bitpos, &offset, &mode, &unsignedp,
&reversep, &volatilep);
if (base != NULL_TREE
&& TREE_CODE (base) == MEM_REF
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
{
tree ssa = TREE_OPERAND (base, 0);
tree lhs = gimple_get_lhs (stmt);
if (lhs && gimple_range_ssa_p (ssa) && src.gori ())
src.gori ()->register_dependency (lhs, ssa);
gcc_checking_assert (irange::supports_type_p (TREE_TYPE (ssa)));
src.get_operand (r, ssa);
range_cast (r, TREE_TYPE (gimple_assign_rhs1 (stmt)));
poly_offset_int off = 0;
bool off_cst = false;
if (offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
{
off = mem_ref_offset (base);
if (offset)
off += poly_offset_int::from (wi::to_poly_wide (offset),
SIGNED);
off <<= LOG2_BITS_PER_UNIT;
off += bitpos;
off_cst = true;
}
/* If &X->a is equal to X, the range of X is the result. */
if (off_cst && known_eq (off, 0))
return true;
else if (flag_delete_null_pointer_checks
&& !TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr)))
{
/* For -fdelete-null-pointer-checks -fno-wrapv-pointer we don't
allow going from non-NULL pointer to NULL. */
if (!range_includes_zero_p (&r))
{
/* We could here instead adjust r by off >> LOG2_BITS_PER_UNIT
using POINTER_PLUS_EXPR if off_cst and just fall back to
this. */
r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
return true;
}
}
/* If MEM_REF has a "positive" offset, consider it non-NULL
always, for -fdelete-null-pointer-checks also "negative"
ones. Punt for unknown offsets (e.g. variable ones). */
if (!TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr))
&& off_cst
&& known_ne (off, 0)
&& (flag_delete_null_pointer_checks || known_gt (off, 0)))
{
r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
return true;
}
r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
return true;
}
// Handle "= &a".
if (tree_single_nonzero_warnv_p (expr, &strict_overflow_p))
{
r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
return true;
}
// Otherwise return varying.
r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
return true;
}
// Calculate a range for phi statement S and return it in R.
// If a range cannot be calculated, return false.
bool
fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
{
tree phi_def = gimple_phi_result (phi);
tree type = gimple_range_type (phi);
int_range_max arg_range;
int_range_max equiv_range;
unsigned x;
if (!type)
return false;
// Track if all executable arguments are the same.
tree single_arg = NULL_TREE;
bool seen_arg = false;
// Start with an empty range, unioning in each argument's range.
r.set_undefined ();
for (x = 0; x < gimple_phi_num_args (phi); x++)
{
tree arg = gimple_phi_arg_def (phi, x);
// An argument that is the same as the def provides no new range.
if (arg == phi_def)
continue;
edge e = gimple_phi_arg_edge (phi, x);
// Get the range of the argument on its edge.
src.get_phi_operand (arg_range, arg, e);
if (!arg_range.undefined_p ())
{
// Register potential dependencies for stale value tracking.
// Likewise, if the incoming PHI argument is equivalent to this
// PHI definition, it provides no new info. Accumulate these ranges
// in case all arguments are equivalences.
if (src.query ()->query_relation (e, arg, phi_def, false) == EQ_EXPR)
equiv_range.union_(arg_range);
else
r.union_ (arg_range);
if (gimple_range_ssa_p (arg) && src.gori ())
src.gori ()->register_dependency (phi_def, arg);
// Track if all arguments are the same.
if (!seen_arg)
{
seen_arg = true;
single_arg = arg;
}
else if (single_arg != arg)
single_arg = NULL_TREE;
}
// Once the value reaches varying, stop looking.
if (r.varying_p () && single_arg == NULL_TREE)
break;
}
// If all arguments were equivalences, use the equivalence ranges as no
// arguments were processed.
if (r.undefined_p () && !equiv_range.undefined_p ())
r = equiv_range;
// If the PHI boils down to a single effective argument, look at it.
if (single_arg)
{
// Symbolic arguments are equivalences.
if (gimple_range_ssa_p (single_arg))
src.register_relation (phi, EQ_EXPR, phi_def, single_arg);
else if (src.get_operand (arg_range, single_arg)
&& arg_range.singleton_p ())
{
// Numerical arguments that are a constant can be returned as
// the constant. This can help fold later cases where even this
// constant might have been UNDEFINED via an unreachable edge.
r = arg_range;
return true;
}
}
// If SCEV is available, query if this PHI has any knonwn values.
if (scev_initialized_p () && !POINTER_TYPE_P (TREE_TYPE (phi_def)))
{
value_range loop_range;
class loop *l = loop_containing_stmt (phi);
if (l && loop_outer (l))
{
range_of_ssa_name_with_loop_info (loop_range, phi_def, l, phi, src);
if (!loop_range.varying_p ())
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Loops range found for ");
print_generic_expr (dump_file, phi_def, TDF_SLIM);
fprintf (dump_file, ": ");
loop_range.dump (dump_file);
fprintf (dump_file, " and calculated range :");
r.dump (dump_file);
fprintf (dump_file, "\n");
}
r.intersect (loop_range);
}
}
}
return true;
}
// Calculate a range for call statement S and return it in R.
// If a range cannot be calculated, return false.
bool
fold_using_range::range_of_call (irange &r, gcall *call, fur_source &src)
{
tree type = gimple_range_type (call);
if (!type)
return false;
tree lhs = gimple_call_lhs (call);
bool strict_overflow_p;
if (range_of_builtin_call (r, call, src))
;
else if (gimple_stmt_nonnegative_warnv_p (call, &strict_overflow_p))
r.set (build_int_cst (type, 0), TYPE_MAX_VALUE (type));
else if (gimple_call_nonnull_result_p (call)
|| gimple_call_nonnull_arg (call))
r = range_nonzero (type);
else
r.set_varying (type);
// If there is an LHS, intersect that with what is known.
if (lhs)
{
value_range def;
def = gimple_range_global (lhs);
r.intersect (def);
}
return true;
}
// Return the range of a __builtin_ubsan* in CALL and set it in R.
// CODE is the type of ubsan call (PLUS_EXPR, MINUS_EXPR or
// MULT_EXPR).
void
fold_using_range::range_of_builtin_ubsan_call (irange &r, gcall *call,
tree_code code, fur_source &src)
{
gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR
|| code == MULT_EXPR);
tree type = gimple_range_type (call);
range_operator *op = range_op_handler (code, type);
gcc_checking_assert (op);
int_range_max ir0, ir1;
tree arg0 = gimple_call_arg (call, 0);
tree arg1 = gimple_call_arg (call, 1);
src.get_operand (ir0, arg0);
src.get_operand (ir1, arg1);
// Check for any relation between arg0 and arg1.
relation_kind relation = src.query_relation (arg0, arg1);
bool saved_flag_wrapv = flag_wrapv;
// Pretend the arithmetic is wrapping. If there is any overflow,
// we'll complain, but will actually do wrapping operation.
flag_wrapv = 1;
op->fold_range (r, type, ir0, ir1, relation);
flag_wrapv = saved_flag_wrapv;
// If for both arguments vrp_valueize returned non-NULL, this should
// have been already folded and if not, it wasn't folded because of
// overflow. Avoid removing the UBSAN_CHECK_* calls in that case.
if (r.singleton_p ())
r.set_varying (type);
}
// Return TRUE if we recognize the target character set and return the
// range for lower case and upper case letters.
static bool
get_letter_range (tree type, irange &lowers, irange &uppers)
{
// ASCII
int a = lang_hooks.to_target_charset ('a');
int z = lang_hooks.to_target_charset ('z');
int A = lang_hooks.to_target_charset ('A');
int Z = lang_hooks.to_target_charset ('Z');
if ((z - a == 25) && (Z - A == 25))
{
lowers = int_range<2> (build_int_cst (type, a), build_int_cst (type, z));
uppers = int_range<2> (build_int_cst (type, A), build_int_cst (type, Z));
return true;
}
// Unknown character set.
return false;
}
// For a builtin in CALL, return a range in R if known and return
// TRUE. Otherwise return FALSE.
bool
fold_using_range::range_of_builtin_call (irange &r, gcall *call,
fur_source &src)
{
combined_fn func = gimple_call_combined_fn (call);
if (func == CFN_LAST)
return false;
tree type = gimple_range_type (call);
tree arg;
int mini, maxi, zerov = 0, prec;
scalar_int_mode mode;
switch (func)
{
case CFN_BUILT_IN_CONSTANT_P:
arg = gimple_call_arg (call, 0);
if (src.get_operand (r, arg) && r.singleton_p ())
{
r.set (build_one_cst (type), build_one_cst (type));
return true;
}
if (cfun->after_inlining)
{
r.set_zero (type);
// r.equiv_clear ();
return true;
}
break;
case CFN_BUILT_IN_TOUPPER:
{
arg = gimple_call_arg (call, 0);
// If the argument isn't compatible with the LHS, do nothing.
if (!range_compatible_p (type, TREE_TYPE (arg)))
return false;
if (!src.get_operand (r, arg))
return false;
int_range<3> lowers;
int_range<3> uppers;
if (!get_letter_range (type, lowers, uppers))
return false;
// Return the range passed in without any lower case characters,
// but including all the upper case ones.
lowers.invert ();
r.intersect (lowers);
r.union_ (uppers);
return true;
}
case CFN_BUILT_IN_TOLOWER:
{
arg = gimple_call_arg (call, 0);
// If the argument isn't compatible with the LHS, do nothing.
if (!range_compatible_p (type, TREE_TYPE (arg)))
return false;
if (!src.get_operand (r, arg))
return false;
int_range<3> lowers;
int_range<3> uppers;
if (!get_letter_range (type, lowers, uppers))
return false;
// Return the range passed in without any upper case characters,
// but including all the lower case ones.
uppers.invert ();
r.intersect (uppers);
r.union_ (lowers);
return true;
}
CASE_CFN_FFS:
CASE_CFN_POPCOUNT:
// __builtin_ffs* and __builtin_popcount* return [0, prec].
arg = gimple_call_arg (call, 0);
prec = TYPE_PRECISION (TREE_TYPE (arg));
mini = 0;
maxi = prec;
src.get_operand (r, arg);
// If arg is non-zero, then ffs or popcount are non-zero.
if (!range_includes_zero_p (&r))
mini = 1;
// If some high bits are known to be zero, decrease the maximum.
if (!r.undefined_p ())
{
if (TYPE_SIGN (r.type ()) == SIGNED)
range_cast (r, unsigned_type_for (r.type ()));
wide_int max = r.upper_bound ();
maxi = wi::floor_log2 (max) + 1;
}
r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
return true;
CASE_CFN_PARITY:
r.set (build_zero_cst (type), build_one_cst (type));
return true;
CASE_CFN_CLZ:
// __builtin_c[lt]z* return [0, prec-1], except when the
// argument is 0, but that is undefined behavior.
//
// For __builtin_c[lt]z* consider argument of 0 always undefined
// behavior, for internal fns depending on C?Z_DEFINED_VALUE_AT_ZERO.
arg = gimple_call_arg (call, 0);
prec = TYPE_PRECISION (TREE_TYPE (arg));
mini = 0;
maxi = prec - 1;
mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
if (gimple_call_internal_p (call))
{
if (optab_handler (clz_optab, mode) != CODE_FOR_nothing
&& CLZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2)
{
// Only handle the single common value.
if (zerov == prec)
maxi = prec;
else
// Magic value to give up, unless we can prove arg is non-zero.
mini = -2;
}
}
src.get_operand (r, arg);
// From clz of minimum we can compute result maximum.
if (!r.undefined_p ())
{
// From clz of minimum we can compute result maximum.
if (wi::gt_p (r.lower_bound (), 0, TYPE_SIGN (r.type ())))
{
maxi = prec - 1 - wi::floor_log2 (r.lower_bound ());
if (mini == -2)
mini = 0;
}
else if (!range_includes_zero_p (&r))
{
mini = 0;
maxi = prec - 1;
}
if (mini == -2)
break;
// From clz of maximum we can compute result minimum.
wide_int max = r.upper_bound ();
int newmini = prec - 1 - wi::floor_log2 (max);
if (max == 0)
{
// If CLZ_DEFINED_VALUE_AT_ZERO is 2 with VALUE of prec,
// return [prec, prec], otherwise ignore the range.
if (maxi == prec)
mini = prec;
}
else
mini = newmini;
}
if (mini == -2)
break;
r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
return true;
CASE_CFN_CTZ:
// __builtin_ctz* return [0, prec-1], except for when the
// argument is 0, but that is undefined behavior.
//
// For __builtin_ctz* consider argument of 0 always undefined
// behavior, for internal fns depending on CTZ_DEFINED_VALUE_AT_ZERO.
arg = gimple_call_arg (call, 0);
prec = TYPE_PRECISION (TREE_TYPE (arg));
mini = 0;
maxi = prec - 1;
mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
if (gimple_call_internal_p (call))
{
if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing
&& CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2)
{
// Handle only the two common values.
if (zerov == -1)
mini = -1;
else if (zerov == prec)
maxi = prec;
else
// Magic value to give up, unless we can prove arg is non-zero.
mini = -2;
}
}
src.get_operand (r, arg);
if (!r.undefined_p ())
{
// If arg is non-zero, then use [0, prec - 1].
if (!range_includes_zero_p (&r))
{
mini = 0;
maxi = prec - 1;
}
// If some high bits are known to be zero, we can decrease
// the maximum.
wide_int max = r.upper_bound ();
if (max == 0)
{
// Argument is [0, 0]. If CTZ_DEFINED_VALUE_AT_ZERO
// is 2 with value -1 or prec, return [-1, -1] or [prec, prec].
// Otherwise ignore the range.
if (mini == -1)
maxi = -1;
else if (maxi == prec)
mini = prec;
}
// If value at zero is prec and 0 is in the range, we can't lower
// the upper bound. We could create two separate ranges though,
// [0,floor_log2(max)][prec,prec] though.
else if (maxi != prec)
maxi = wi::floor_log2 (max);
}
if (mini == -2)
break;
r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
return true;
CASE_CFN_CLRSB:
arg = gimple_call_arg (call, 0);
prec = TYPE_PRECISION (TREE_TYPE (arg));
r.set (build_int_cst (type, 0), build_int_cst (type, prec - 1));
return true;
case CFN_UBSAN_CHECK_ADD:
range_of_builtin_ubsan_call (r, call, PLUS_EXPR, src);
return true;
case CFN_UBSAN_CHECK_SUB:
range_of_builtin_ubsan_call (r, call, MINUS_EXPR, src);
return true;
case CFN_UBSAN_CHECK_MUL:
range_of_builtin_ubsan_call (r, call, MULT_EXPR, src);
return true;
case CFN_GOACC_DIM_SIZE:
case CFN_GOACC_DIM_POS:
// Optimizing these two internal functions helps the loop
// optimizer eliminate outer comparisons. Size is [1,N]
// and pos is [0,N-1].
{
bool is_pos = func == CFN_GOACC_DIM_POS;
int axis = oacc_get_ifn_dim_arg (call);
int size = oacc_get_fn_dim_size (current_function_decl, axis);
if (!size)
// If it's dynamic, the backend might know a hardware limitation.
size = targetm.goacc.dim_limit (axis);
r.set (build_int_cst (type, is_pos ? 0 : 1),
size
? build_int_cst (type, size - is_pos) : vrp_val_max (type));
return true;
}
case CFN_BUILT_IN_STRLEN:
if (tree lhs = gimple_call_lhs (call))
if (ptrdiff_type_node
&& (TYPE_PRECISION (ptrdiff_type_node)
== TYPE_PRECISION (TREE_TYPE (lhs))))
{
tree type = TREE_TYPE (lhs);
tree max = vrp_val_max (ptrdiff_type_node);
wide_int wmax
= wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
tree range_min = build_zero_cst (type);
// To account for the terminating NULL, the maximum length
// is one less than the maximum array size, which in turn
// is one less than PTRDIFF_MAX (or SIZE_MAX where it's
// smaller than the former type).
// FIXME: Use max_object_size() - 1 here.
tree range_max = wide_int_to_tree (type, wmax - 2);
r.set (range_min, range_max);
return true;
}
break;
default:
break;
}
return false;
}
// Calculate a range for COND_EXPR statement S and return it in R.
// If a range cannot be calculated, return false.
bool
fold_using_range::range_of_cond_expr (irange &r, gassign *s, fur_source &src)
{
int_range_max cond_range, range1, range2;
tree cond = gimple_assign_rhs1 (s);
tree op1 = gimple_assign_rhs2 (s);
tree op2 = gimple_assign_rhs3 (s);
tree type = gimple_range_type (s);
if (!type)
return false;
gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR);
gcc_checking_assert (range_compatible_p (TREE_TYPE (op1), TREE_TYPE (op2)));
src.get_operand (cond_range, cond);
src.get_operand (range1, op1);
src.get_operand (range2, op2);
// If the condition is known, choose the appropriate expression.
if (cond_range.singleton_p ())
{
// False, pick second operand.
if (cond_range.zero_p ())
r = range2;
else
r = range1;
}
else
{
r = range1;
r.union_ (range2);
}
gcc_checking_assert (r.undefined_p ()
|| range_compatible_p (r.type (), type));
return true;
}
// If SCEV has any information about phi node NAME, return it as a range in R.
void
fold_using_range::range_of_ssa_name_with_loop_info (irange &r, tree name,
class loop *l, gphi *phi,
fur_source &src)
{
gcc_checking_assert (TREE_CODE (name) == SSA_NAME);
tree min, max, type = TREE_TYPE (name);
if (bounds_of_var_in_loop (&min, &max, src.query (), l, phi, name))
{
if (TREE_CODE (min) != INTEGER_CST)
{
if (src.query ()->range_of_expr (r, min, phi) && !r.undefined_p ())
min = wide_int_to_tree (type, r.lower_bound ());
else
min = vrp_val_min (type);
}
if (TREE_CODE (max) != INTEGER_CST)
{
if (src.query ()->range_of_expr (r, max, phi) && !r.undefined_p ())
max = wide_int_to_tree (type, r.upper_bound ());
else
max = vrp_val_max (type);
}
r.set (min, max);
}
else
r.set_varying (type);
}
// -----------------------------------------------------------------------
// Check if an && or || expression can be folded based on relations. ie
// c_2 = a_6 > b_7
// c_3 = a_6 < b_7
// c_4 = c_2 && c_3
// c_2 and c_3 can never be true at the same time,
// Therefore c_4 can always resolve to false based purely on the relations.
void
fold_using_range::relation_fold_and_or (irange& lhs_range, gimple *s,
fur_source &src)
{
// No queries or already folded.
if (!src.gori () || !src.query ()->oracle () || lhs_range.singleton_p ())
return;
// Only care about AND and OR expressions.
enum tree_code code = gimple_expr_code (s);
bool is_and = false;
if (code == BIT_AND_EXPR || code == TRUTH_AND_EXPR)
is_and = true;
else if (code != BIT_IOR_EXPR && code != TRUTH_OR_EXPR)
return;
tree lhs = gimple_get_lhs (s);
tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s));
tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s));
// Deal with || and && only when there is a full set of symbolics.
if (!lhs || !ssa1 || !ssa2
|| (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE)
|| (TREE_CODE (TREE_TYPE (ssa1)) != BOOLEAN_TYPE)
|| (TREE_CODE (TREE_TYPE (ssa2)) != BOOLEAN_TYPE))
return;
// Now we know its a boolean AND or OR expression with boolean operands.
// Ideally we search dependencies for common names, and see what pops out.
// until then, simply try to resolve direct dependencies.
// Both names will need to have 2 direct dependencies.
tree ssa1_dep2 = src.gori ()->depend2 (ssa1);
tree ssa2_dep2 = src.gori ()->depend2 (ssa2);
if (!ssa1_dep2 || !ssa2_dep2)
return;
tree ssa1_dep1 = src.gori ()->depend1 (ssa1);
tree ssa2_dep1 = src.gori ()->depend1 (ssa2);
// Make sure they are the same dependencies, and detect the order of the
// relationship.
bool reverse_op2 = true;
if (ssa1_dep1 == ssa2_dep1 && ssa1_dep2 == ssa2_dep2)
reverse_op2 = false;
else if (ssa1_dep1 != ssa2_dep2 || ssa1_dep2 != ssa2_dep1)
return;
range_operator *handler1 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa1));
range_operator *handler2 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa2));
// If either handler is not present, no relation is found.
if (!handler1 || !handler2)
return;
int_range<2> bool_one (boolean_true_node, boolean_true_node);
relation_kind relation1 = handler1->op1_op2_relation (bool_one);
relation_kind relation2 = handler2->op1_op2_relation (bool_one);
if (relation1 == VREL_NONE || relation2 == VREL_NONE)
return;
if (reverse_op2)
relation2 = relation_negate (relation2);
// x && y is false if the relation intersection of the true cases is NULL.
if (is_and && relation_intersect (relation1, relation2) == VREL_EMPTY)
lhs_range = int_range<2> (boolean_false_node, boolean_false_node);
// x || y is true if the union of the true cases is NO-RELATION..
// ie, one or the other being true covers the full range of possibilties.
else if (!is_and && relation_union (relation1, relation2) == VREL_NONE)
lhs_range = bool_one;
else
return;
range_cast (lhs_range, TREE_TYPE (lhs));
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Relation adjustment: ");
print_generic_expr (dump_file, ssa1, TDF_SLIM);
fprintf (dump_file, " and ");
print_generic_expr (dump_file, ssa2, TDF_SLIM);
fprintf (dump_file, " combine to produce ");
lhs_range.dump (dump_file);
fputc ('\n', dump_file);
}
return;
}
// Register any outgoing edge relations from a conditional branch.
void
fur_source::register_outgoing_edges (gcond *s, irange &lhs_range, edge e0, edge e1)
{
int_range_max r;
int_range<2> e0_range, e1_range;
tree name;
range_operator *handler;
basic_block bb = gimple_bb (s);
if (e0)
{
// If this edge is never taken, ignore it.
gcond_edge_range (e0_range, e0);
e0_range.intersect (lhs_range);
if (e0_range.undefined_p ())
e0 = NULL;
}
if (e1)
{
// If this edge is never taken, ignore it.
gcond_edge_range (e1_range, e1);
e1_range.intersect (lhs_range);
if (e1_range.undefined_p ())
e1 = NULL;
}
if (!e0 && !e1)
return;
// First, register the gcond itself. This will catch statements like
// if (a_2 < b_5)
tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s));
tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s));
if (ssa1 && ssa2)
{
handler = gimple_range_handler (s);
gcc_checking_assert (handler);
if (e0)
{
relation_kind relation = handler->op1_op2_relation (e0_range);
if (relation != VREL_NONE)
register_relation (e0, relation, ssa1, ssa2);
}
if (e1)
{
relation_kind relation = handler->op1_op2_relation (e1_range);
if (relation != VREL_NONE)
register_relation (e1, relation, ssa1, ssa2);
}
}
// Outgoing relations of GORI exports require a gori engine.
if (!gori ())
return;
// Now look for other relations in the exports. This will find stmts
// leading to the condition such as:
// c_2 = a_4 < b_7
// if (c_2)
FOR_EACH_GORI_EXPORT_NAME (*(gori ()), bb, name)
{
if (TREE_CODE (TREE_TYPE (name)) != BOOLEAN_TYPE)
continue;
gimple *stmt = SSA_NAME_DEF_STMT (name);
handler = gimple_range_handler (stmt);
if (!handler)
continue;
tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (stmt));
tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (stmt));
if (ssa1 && ssa2)
{
if (e0 && gori ()->outgoing_edge_range_p (r, e0, name, *m_query)
&& r.singleton_p ())
{
relation_kind relation = handler->op1_op2_relation (r);
if (relation != VREL_NONE)
register_relation (e0, relation, ssa1, ssa2);
}
if (e1 && gori ()->outgoing_edge_range_p (r, e1, name, *m_query)
&& r.singleton_p ())
{
relation_kind relation = handler->op1_op2_relation (r);
if (relation != VREL_NONE)
register_relation (e1, relation, ssa1, ssa2);
}
}
}
}