/* Scalar evolution detector.
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
Contributed by Sebastian Pop <s.pop@laposte.net>
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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/*
Description:
Given a scalar variable to be analyzed, follow the SSA edge to
its definition:
- - When the definition is a MODIFY_EXPR: if the right hand side
+ - When the definition is a GIMPLE_ASSIGN: if the right hand side
(RHS) of the definition cannot be statically analyzed, the answer
of the analyzer is: "don't know".
Otherwise, for all the variables that are not yet analyzed in the
that the scev for "b" is known, it is possible to compute the
scev for "c", that is "c -> {a + 1, +, 1}_1". In order to
determine the number of iterations in the loop_1, we have to
- instantiate_parameters ({a + 1, +, 1}_1), that gives after some
+ instantiate_parameters (loop_1, {a + 1, +, 1}_1), that gives after some
more analysis the scev {4, +, 1}_1, or in other words, this is
the function "f (x) = x + 4", where x is the iteration count of
the loop_1. Now we have to solve the inequality "x + 4 > 10",
| c = x + 4
| }
- Example 2: Illustration of the algorithm on nested loops.
+ Example 2a: Illustration of the algorithm on nested loops.
| loop_1
| a = phi (1, b)
a -> {1, +, 32}_1
c -> {3, +, 32}_1
-
+
+ Example 2b: Multivariate chains of recurrences.
+
+ | loop_1
+ | k = phi (0, k + 1)
+ | loop_2 4 times
+ | j = phi (0, j + 1)
+ | loop_3 4 times
+ | i = phi (0, i + 1)
+ | A[j + k] = ...
+ | endloop
+ | endloop
+ | endloop
+
+ Analyzing the access function of array A with
+ instantiate_parameters (loop_1, "j + k"), we obtain the
+ instantiation and the analysis of the scalar variables "j" and "k"
+ in loop_1. This leads to the scalar evolution {4, +, 1}_1: the end
+ value of loop_2 for "j" is 4, and the evolution of "k" in loop_1 is
+ {0, +, 1}_1. To obtain the evolution function in loop_3 and
+ instantiate the scalar variables up to loop_1, one has to use:
+ instantiate_scev (block_before_loop (loop_1), loop_3, "j + k").
+ The result of this call is {{0, +, 1}_1, +, 1}_2.
+
Example 3: Higher degree polynomials.
| loop_1
c -> {5, +, a}_1
d -> {5 + a, +, a}_1
- instantiate_parameters ({5, +, a}_1) -> {5, +, 2, +, 1}_1
- instantiate_parameters ({5 + a, +, a}_1) -> {7, +, 3, +, 1}_1
+ instantiate_parameters (loop_1, {5, +, a}_1) -> {5, +, 2, +, 1}_1
+ instantiate_parameters (loop_1, {5 + a, +, a}_1) -> {7, +, 3, +, 1}_1
Example 4: Lucas, Fibonacci, or mixers in general.
#include "params.h"
static tree analyze_scalar_evolution_1 (struct loop *, tree, tree);
-static tree resolve_mixers (struct loop *, tree);
-/* The cached information about a ssa name VAR, claiming that inside LOOP,
- the value of VAR can be expressed as CHREC. */
+/* The cached information about an SSA name VAR, claiming that below
+ basic block INSTANTIATED_BELOW, the value of VAR can be expressed
+ as CHREC. */
-struct scev_info_str
-{
+struct GTY(()) scev_info_str {
+ basic_block instantiated_below;
tree var;
tree chrec;
};
happen, then it qualifies it with chrec_known. */
tree chrec_known;
-static bitmap already_instantiated;
-
-static htab_t scalar_evolution_info;
+static GTY ((param_is (struct scev_info_str))) htab_t scalar_evolution_info;
\f
-/* Constructs a new SCEV_INFO_STR structure. */
+/* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW. */
static inline struct scev_info_str *
-new_scev_info_str (tree var)
+new_scev_info_str (basic_block instantiated_below, tree var)
{
struct scev_info_str *res;
- res = XNEW (struct scev_info_str);
+ res = GGC_NEW (struct scev_info_str);
res->var = var;
res->chrec = chrec_not_analyzed_yet;
-
+ res->instantiated_below = instantiated_below;
+
return res;
}
static hashval_t
hash_scev_info (const void *elt)
{
- return SSA_NAME_VERSION (((struct scev_info_str *) elt)->var);
+ return SSA_NAME_VERSION (((const struct scev_info_str *) elt)->var);
}
/* Compares database elements E1 and E2. */
const struct scev_info_str *elt1 = (const struct scev_info_str *) e1;
const struct scev_info_str *elt2 = (const struct scev_info_str *) e2;
- return elt1->var == elt2->var;
+ return (elt1->var == elt2->var
+ && elt1->instantiated_below == elt2->instantiated_below);
}
/* Deletes database element E. */
static void
del_scev_info (void *e)
{
- free (e);
+ ggc_free (e);
}
-/* Get the index corresponding to VAR in the current LOOP. If
- it's the first time we ask for this VAR, then we return
- chrec_not_analyzed_yet for this VAR and return its index. */
+/* Get the scalar evolution of VAR for INSTANTIATED_BELOW basic block.
+ A first query on VAR returns chrec_not_analyzed_yet. */
static tree *
-find_var_scev_info (tree var)
+find_var_scev_info (basic_block instantiated_below, tree var)
{
struct scev_info_str *res;
struct scev_info_str tmp;
PTR *slot;
tmp.var = var;
+ tmp.instantiated_below = instantiated_below;
slot = htab_find_slot (scalar_evolution_info, &tmp, INSERT);
if (!*slot)
- *slot = new_scev_info_str (var);
+ *slot = new_scev_info_str (instantiated_below, var);
res = (struct scev_info_str *) *slot;
return &res->chrec;
LOOP_NB. */
bool
-chrec_contains_symbols_defined_in_loop (tree chrec, unsigned loop_nb)
+chrec_contains_symbols_defined_in_loop (const_tree chrec, unsigned loop_nb)
{
+ int i, n;
+
if (chrec == NULL_TREE)
return false;
- if (TREE_INVARIANT (chrec))
+ if (is_gimple_min_invariant (chrec))
return false;
if (TREE_CODE (chrec) == VAR_DECL
if (TREE_CODE (chrec) == SSA_NAME)
{
- tree def = SSA_NAME_DEF_STMT (chrec);
+ gimple def = SSA_NAME_DEF_STMT (chrec);
struct loop *def_loop = loop_containing_stmt (def);
- struct loop *loop = current_loops->parray[loop_nb];
+ struct loop *loop = get_loop (loop_nb);
if (def_loop == NULL)
return false;
return false;
}
- switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
- {
- case 3:
- if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, 2),
- loop_nb))
- return true;
-
- case 2:
- if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, 1),
- loop_nb))
- return true;
-
- case 1:
- if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, 0),
- loop_nb))
- return true;
-
- default:
- return false;
- }
+ n = TREE_OPERAND_LENGTH (chrec);
+ for (i = 0; i < n; i++)
+ if (chrec_contains_symbols_defined_in_loop (TREE_OPERAND (chrec, i),
+ loop_nb))
+ return true;
+ return false;
}
/* Return true when PHI is a loop-phi-node. */
static bool
-loop_phi_node_p (tree phi)
+loop_phi_node_p (gimple phi)
{
/* The implementation of this function is based on the following
property: "all the loop-phi-nodes of a loop are contained in the
loop's header basic block". */
- return loop_containing_stmt (phi)->header == bb_for_stmt (phi);
+ return loop_containing_stmt (phi)->header == gimple_bb (phi);
}
/* Compute the scalar evolution for EVOLUTION_FN after crossing LOOP.
EVOLUTION_FN = {i_0, +, 2}_1.
*/
-static tree
+tree
compute_overall_effect_of_inner_loop (struct loop *loop, tree evolution_fn)
{
bool val = false;
else if (TREE_CODE (evolution_fn) == POLYNOMIAL_CHREC)
{
- if (CHREC_VARIABLE (evolution_fn) >= (unsigned) loop->num)
+ struct loop *inner_loop = get_chrec_loop (evolution_fn);
+
+ if (inner_loop == loop
+ || flow_loop_nested_p (loop, inner_loop))
{
- struct loop *inner_loop =
- current_loops->parray[CHREC_VARIABLE (evolution_fn)];
- tree nb_iter = number_of_iterations_in_loop (inner_loop);
+ tree nb_iter = number_of_latch_executions (inner_loop);
if (nb_iter == chrec_dont_know)
return chrec_dont_know;
{
tree res;
- /* Number of iterations is off by one (the ssa name we
- analyze must be defined before the exit). */
- nb_iter = chrec_fold_minus (chrec_type (nb_iter),
- nb_iter,
- build_int_cst_type (chrec_type (nb_iter), 1));
-
/* evolution_fn is the evolution function in LOOP. Get
its value in the nb_iter-th iteration. */
res = chrec_apply (inner_loop->num, evolution_fn, nb_iter);
-
+
+ if (chrec_contains_symbols_defined_in_loop (res, loop->num))
+ res = instantiate_parameters (loop, res);
+
/* Continue the computation until ending on a parent of LOOP. */
return compute_overall_effect_of_inner_loop (loop, res);
}
bool
chrec_is_positive (tree chrec, bool *value)
{
- bool value0, value1;
- bool value2;
- tree end_value;
- tree nb_iter;
+ bool value0, value1, value2;
+ tree end_value, nb_iter;
switch (TREE_CODE (chrec))
{
if (!evolution_function_is_affine_p (chrec))
return false;
- nb_iter = number_of_iterations_in_loop
- (current_loops->parray[CHREC_VARIABLE (chrec)]);
-
+ nb_iter = number_of_latch_executions (get_chrec_loop (chrec));
if (chrec_contains_undetermined (nb_iter))
return false;
- nb_iter = chrec_fold_minus
- (chrec_type (nb_iter), nb_iter,
- build_int_cst (chrec_type (nb_iter), 1));
-
#if 0
/* TODO -- If the test is after the exit, we may decrease the number of
iterations by one. */
if (after_exit)
- nb_iter = chrec_fold_minus
- (chrec_type (nb_iter), nb_iter,
- build_int_cst (chrec_type (nb_iter), 1));
+ nb_iter = chrec_fold_minus (type, nb_iter, build_int_cst (type, 1));
#endif
end_value = chrec_apply (CHREC_VARIABLE (chrec), chrec, nb_iter);
/* Associate CHREC to SCALAR. */
static void
-set_scalar_evolution (tree scalar, tree chrec)
+set_scalar_evolution (basic_block instantiated_below, tree scalar, tree chrec)
{
tree *scalar_info;
if (TREE_CODE (scalar) != SSA_NAME)
return;
- scalar_info = find_var_scev_info (scalar);
+ scalar_info = find_var_scev_info (instantiated_below, scalar);
if (dump_file)
{
if (dump_flags & TDF_DETAILS)
{
fprintf (dump_file, "(set_scalar_evolution \n");
+ fprintf (dump_file, " instantiated_below = %d \n",
+ instantiated_below->index);
fprintf (dump_file, " (scalar = ");
print_generic_expr (dump_file, scalar, 0);
fprintf (dump_file, ")\n (scalar_evolution = ");
*scalar_info = chrec;
}
-/* Retrieve the chrec associated to SCALAR in the LOOP. */
+/* Retrieve the chrec associated to SCALAR instantiated below
+ INSTANTIATED_BELOW block. */
static tree
-get_scalar_evolution (tree scalar)
+get_scalar_evolution (basic_block instantiated_below, tree scalar)
{
tree res;
switch (TREE_CODE (scalar))
{
case SSA_NAME:
- res = *find_var_scev_info (scalar);
+ res = *find_var_scev_info (instantiated_below, scalar);
break;
case REAL_CST:
+ case FIXED_CST:
case INTEGER_CST:
res = scalar;
break;
part for this loop. */
static tree
-add_to_evolution_1 (unsigned loop_nb,
- tree chrec_before,
- tree to_add)
+add_to_evolution_1 (unsigned loop_nb, tree chrec_before, tree to_add,
+ gimple at_stmt)
{
+ tree type, left, right;
+ struct loop *loop = get_loop (loop_nb), *chloop;
+
switch (TREE_CODE (chrec_before))
{
case POLYNOMIAL_CHREC:
- if (CHREC_VARIABLE (chrec_before) <= loop_nb)
+ chloop = get_chrec_loop (chrec_before);
+ if (chloop == loop
+ || flow_loop_nested_p (chloop, loop))
{
unsigned var;
- tree left, right;
- tree type = chrec_type (chrec_before);
+
+ type = chrec_type (chrec_before);
/* When there is no evolution part in this loop, build it. */
- if (CHREC_VARIABLE (chrec_before) < loop_nb)
+ if (chloop != loop)
{
var = loop_nb;
left = chrec_before;
right = CHREC_RIGHT (chrec_before);
}
- return build_polynomial_chrec
- (var, left, chrec_fold_plus (type, right, to_add));
+ to_add = chrec_convert (type, to_add, at_stmt);
+ right = chrec_convert_rhs (type, right, at_stmt);
+ right = chrec_fold_plus (chrec_type (right), right, to_add);
+ return build_polynomial_chrec (var, left, right);
}
else
- /* Search the evolution in LOOP_NB. */
- return build_polynomial_chrec
- (CHREC_VARIABLE (chrec_before),
- add_to_evolution_1 (loop_nb, CHREC_LEFT (chrec_before), to_add),
- CHREC_RIGHT (chrec_before));
+ {
+ gcc_assert (flow_loop_nested_p (loop, chloop));
+
+ /* Search the evolution in LOOP_NB. */
+ left = add_to_evolution_1 (loop_nb, CHREC_LEFT (chrec_before),
+ to_add, at_stmt);
+ right = CHREC_RIGHT (chrec_before);
+ right = chrec_convert_rhs (chrec_type (left), right, at_stmt);
+ return build_polynomial_chrec (CHREC_VARIABLE (chrec_before),
+ left, right);
+ }
default:
/* These nodes do not depend on a loop. */
if (chrec_before == chrec_dont_know)
return chrec_dont_know;
- return build_polynomial_chrec (loop_nb, chrec_before, to_add);
+
+ left = chrec_before;
+ right = chrec_convert_rhs (chrec_type (left), to_add, at_stmt);
+ return build_polynomial_chrec (loop_nb, left, right);
}
}
*/
static tree
-add_to_evolution (unsigned loop_nb,
- tree chrec_before,
- enum tree_code code,
- tree to_add)
+add_to_evolution (unsigned loop_nb, tree chrec_before, enum tree_code code,
+ tree to_add, gimple at_stmt)
{
tree type = chrec_type (to_add);
tree res = NULL_TREE;
? build_real (type, dconstm1)
: build_int_cst_type (type, -1));
- res = add_to_evolution_1 (loop_nb, chrec_before, to_add);
+ res = add_to_evolution_1 (loop_nb, chrec_before, to_add, at_stmt);
if (dump_file && (dump_flags & TDF_DETAILS))
{
set_nb_iterations_in_loop (struct loop *loop,
tree res)
{
- res = chrec_fold_plus (chrec_type (res), res,
- build_int_cst_type (chrec_type (res), 1));
-
- /* FIXME HWI: However we want to store one iteration less than the
- count of the loop in order to be compatible with the other
- nb_iter computations in loop-iv. This also allows the
- representation of nb_iters that are equal to MAX_INT. */
- if (TREE_CODE (res) == INTEGER_CST
- && (TREE_INT_CST_LOW (res) == 0
- || TREE_OVERFLOW (res)))
- res = chrec_dont_know;
-
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (set_nb_iterations_in_loop = ");
scalar evolution analysis. For the moment, greedily select all the
loop nests we could analyze. */
-/* Return true when it is possible to analyze the condition expression
- EXPR. */
-
-static bool
-analyzable_condition (tree expr)
-{
- tree condition;
-
- if (TREE_CODE (expr) != COND_EXPR)
- return false;
-
- condition = TREE_OPERAND (expr, 0);
-
- switch (TREE_CODE (condition))
- {
- case SSA_NAME:
- return true;
-
- case LT_EXPR:
- case LE_EXPR:
- case GT_EXPR:
- case GE_EXPR:
- case EQ_EXPR:
- case NE_EXPR:
- return true;
-
- default:
- return false;
- }
-
- return false;
-}
-
/* For a loop with a single exit edge, return the COND_EXPR that
guards the exit edge. If the expression is too difficult to
analyze, then give up. */
-tree
-get_loop_exit_condition (struct loop *loop)
+gimple
+get_loop_exit_condition (const struct loop *loop)
{
- tree res = NULL_TREE;
- edge exit_edge = loop->single_exit;
-
+ gimple res = NULL;
+ edge exit_edge = single_exit (loop);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(get_loop_exit_condition \n ");
if (exit_edge)
{
- tree expr;
+ gimple stmt;
- expr = last_stmt (exit_edge->src);
- if (analyzable_condition (expr))
- res = expr;
+ stmt = last_stmt (exit_edge->src);
+ if (gimple_code (stmt) == GIMPLE_COND)
+ res = stmt;
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
- print_generic_expr (dump_file, res, 0);
+ print_gimple_stmt (dump_file, res, 0, 0);
fprintf (dump_file, ")\n");
}
static void
get_exit_conditions_rec (struct loop *loop,
- VEC(tree,heap) **exit_conditions)
+ VEC(gimple,heap) **exit_conditions)
{
if (!loop)
return;
get_exit_conditions_rec (loop->inner, exit_conditions);
get_exit_conditions_rec (loop->next, exit_conditions);
- if (loop->single_exit)
+ if (single_exit (loop))
{
- tree loop_condition = get_loop_exit_condition (loop);
+ gimple loop_condition = get_loop_exit_condition (loop);
if (loop_condition)
- VEC_safe_push (tree, heap, *exit_conditions, loop_condition);
+ VEC_safe_push (gimple, heap, *exit_conditions, loop_condition);
}
}
initializes the EXIT_CONDITIONS array. */
static void
-select_loops_exit_conditions (struct loops *loops,
- VEC(tree,heap) **exit_conditions)
+select_loops_exit_conditions (VEC(gimple,heap) **exit_conditions)
{
- struct loop *function_body = loops->parray[0];
+ struct loop *function_body = current_loops->tree_root;
get_exit_conditions_rec (function_body->inner, exit_conditions);
}
} t_bool;
-static t_bool follow_ssa_edge (struct loop *loop, tree, tree, tree *, int);
+static t_bool follow_ssa_edge (struct loop *loop, gimple, gimple, tree *, int);
-/* Follow the ssa edge into the right hand side RHS of an assignment.
+/* Follow the ssa edge into the binary expression RHS0 CODE RHS1.
Return true if the strongly connected component has been found. */
static t_bool
-follow_ssa_edge_in_rhs (struct loop *loop, tree at_stmt, tree rhs,
- tree halting_phi, tree *evolution_of_loop, int limit)
+follow_ssa_edge_binary (struct loop *loop, gimple at_stmt,
+ tree type, tree rhs0, enum tree_code code, tree rhs1,
+ gimple halting_phi, tree *evolution_of_loop, int limit)
{
t_bool res = t_false;
- tree rhs0, rhs1;
- tree type_rhs = TREE_TYPE (rhs);
tree evol;
-
- /* The RHS is one of the following cases:
- - an SSA_NAME,
- - an INTEGER_CST,
- - a PLUS_EXPR,
- - a MINUS_EXPR,
- - an ASSERT_EXPR,
- - other cases are not yet handled. */
- switch (TREE_CODE (rhs))
- {
- case NOP_EXPR:
- /* This assignment is under the form "a_1 = (cast) rhs. */
- res = follow_ssa_edge_in_rhs (loop, at_stmt, TREE_OPERAND (rhs, 0),
- halting_phi, evolution_of_loop, limit);
- *evolution_of_loop = chrec_convert (TREE_TYPE (rhs),
- *evolution_of_loop, at_stmt);
- break;
- case INTEGER_CST:
- /* This assignment is under the form "a_1 = 7". */
- res = t_false;
- break;
-
- case SSA_NAME:
- /* This assignment is under the form: "a_1 = b_2". */
- res = follow_ssa_edge
- (loop, SSA_NAME_DEF_STMT (rhs), halting_phi, evolution_of_loop, limit);
- break;
-
+ switch (code)
+ {
+ case POINTER_PLUS_EXPR:
case PLUS_EXPR:
- /* This case is under the form "rhs0 + rhs1". */
- rhs0 = TREE_OPERAND (rhs, 0);
- rhs1 = TREE_OPERAND (rhs, 1);
- STRIP_TYPE_NOPS (rhs0);
- STRIP_TYPE_NOPS (rhs1);
-
if (TREE_CODE (rhs0) == SSA_NAME)
{
if (TREE_CODE (rhs1) == SSA_NAME)
{
/* Match an assignment under the form:
"a = b + c". */
+
+ /* We want only assignments of form "name + name" contribute to
+ LIMIT, as the other cases do not necessarily contribute to
+ the complexity of the expression. */
+ limit++;
+
evol = *evolution_of_loop;
res = follow_ssa_edge
- (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi,
- &evol, limit);
+ (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi, &evol, limit);
if (res == t_true)
*evolution_of_loop = add_to_evolution
(loop->num,
- chrec_convert (type_rhs, evol, at_stmt),
- PLUS_EXPR, rhs1);
+ chrec_convert (type, evol, at_stmt),
+ code, rhs1, at_stmt);
else if (res == t_false)
{
if (res == t_true)
*evolution_of_loop = add_to_evolution
(loop->num,
- chrec_convert (type_rhs, *evolution_of_loop, at_stmt),
- PLUS_EXPR, rhs0);
+ chrec_convert (type, *evolution_of_loop, at_stmt),
+ code, rhs0, at_stmt);
else if (res == t_dont_know)
*evolution_of_loop = chrec_dont_know;
evolution_of_loop, limit);
if (res == t_true)
*evolution_of_loop = add_to_evolution
- (loop->num, chrec_convert (type_rhs, *evolution_of_loop,
+ (loop->num, chrec_convert (type, *evolution_of_loop,
at_stmt),
- PLUS_EXPR, rhs1);
+ code, rhs1, at_stmt);
else if (res == t_dont_know)
*evolution_of_loop = chrec_dont_know;
evolution_of_loop, limit);
if (res == t_true)
*evolution_of_loop = add_to_evolution
- (loop->num, chrec_convert (type_rhs, *evolution_of_loop,
+ (loop->num, chrec_convert (type, *evolution_of_loop,
at_stmt),
- PLUS_EXPR, rhs0);
+ code, rhs0, at_stmt);
else if (res == t_dont_know)
*evolution_of_loop = chrec_dont_know;
"a = ... + ...". */
/* And there is nothing to do. */
res = t_false;
-
break;
case MINUS_EXPR:
/* This case is under the form "opnd0 = rhs0 - rhs1". */
- rhs0 = TREE_OPERAND (rhs, 0);
- rhs1 = TREE_OPERAND (rhs, 1);
- STRIP_TYPE_NOPS (rhs0);
- STRIP_TYPE_NOPS (rhs1);
-
if (TREE_CODE (rhs0) == SSA_NAME)
{
/* Match an assignment under the form:
"a = b - ...". */
+
+ /* We want only assignments of form "name - name" contribute to
+ LIMIT, as the other cases do not necessarily contribute to
+ the complexity of the expression. */
+ if (TREE_CODE (rhs1) == SSA_NAME)
+ limit++;
+
res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0), halting_phi,
evolution_of_loop, limit);
if (res == t_true)
*evolution_of_loop = add_to_evolution
- (loop->num, chrec_convert (type_rhs, *evolution_of_loop, at_stmt),
- MINUS_EXPR, rhs1);
+ (loop->num, chrec_convert (type, *evolution_of_loop, at_stmt),
+ MINUS_EXPR, rhs1, at_stmt);
else if (res == t_dont_know)
*evolution_of_loop = chrec_dont_know;
"a = ... - ...". */
/* And there is nothing to do. */
res = t_false;
-
break;
+
+ default:
+ res = t_false;
+ }
+
+ return res;
+}
- case ASSERT_EXPR:
- {
- /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
- It must be handled as a copy assignment of the form a_1 = a_2. */
- tree op0 = ASSERT_EXPR_VAR (rhs);
- if (TREE_CODE (op0) == SSA_NAME)
- res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (op0),
- halting_phi, evolution_of_loop, limit);
- else
- res = t_false;
- break;
- }
+/* Follow the ssa edge into the expression EXPR.
+ Return true if the strongly connected component has been found. */
+
+static t_bool
+follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr,
+ gimple halting_phi, tree *evolution_of_loop, int limit)
+{
+ enum tree_code code = TREE_CODE (expr);
+ tree type = TREE_TYPE (expr), rhs0, rhs1;
+ t_bool res;
+
+ /* The EXPR is one of the following cases:
+ - an SSA_NAME,
+ - an INTEGER_CST,
+ - a PLUS_EXPR,
+ - a POINTER_PLUS_EXPR,
+ - a MINUS_EXPR,
+ - an ASSERT_EXPR,
+ - other cases are not yet handled. */
+
+ switch (code)
+ {
+ CASE_CONVERT:
+ /* This assignment is under the form "a_1 = (cast) rhs. */
+ res = follow_ssa_edge_expr (loop, at_stmt, TREE_OPERAND (expr, 0),
+ halting_phi, evolution_of_loop, limit);
+ *evolution_of_loop = chrec_convert (type, *evolution_of_loop, at_stmt);
+ break;
+
+ case INTEGER_CST:
+ /* This assignment is under the form "a_1 = 7". */
+ res = t_false;
+ break;
+
+ case SSA_NAME:
+ /* This assignment is under the form: "a_1 = b_2". */
+ res = follow_ssa_edge
+ (loop, SSA_NAME_DEF_STMT (expr), halting_phi, evolution_of_loop, limit);
+ break;
+
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ /* This case is under the form "rhs0 +- rhs1". */
+ rhs0 = TREE_OPERAND (expr, 0);
+ rhs1 = TREE_OPERAND (expr, 1);
+ type = TREE_TYPE (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs1);
+ res = follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1,
+ halting_phi, evolution_of_loop, limit);
+ break;
+ case ASSERT_EXPR:
+ /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
+ It must be handled as a copy assignment of the form a_1 = a_2. */
+ rhs0 = ASSERT_EXPR_VAR (expr);
+ if (TREE_CODE (rhs0) == SSA_NAME)
+ res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
default:
res = t_false;
break;
}
-
+
+ return res;
+}
+
+/* Follow the ssa edge into the right hand side of an assignment STMT.
+ Return true if the strongly connected component has been found. */
+
+static t_bool
+follow_ssa_edge_in_rhs (struct loop *loop, gimple stmt,
+ gimple halting_phi, tree *evolution_of_loop, int limit)
+{
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ tree type = gimple_expr_type (stmt), rhs1, rhs2;
+ t_bool res;
+
+ switch (code)
+ {
+ CASE_CONVERT:
+ /* This assignment is under the form "a_1 = (cast) rhs. */
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt);
+ break;
+
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ rhs1 = gimple_assign_rhs1 (stmt);
+ rhs2 = gimple_assign_rhs2 (stmt);
+ type = TREE_TYPE (rhs1);
+ res = follow_ssa_edge_binary (loop, stmt, type, rhs1, code, rhs2,
+ halting_phi, evolution_of_loop, limit);
+ break;
+
+ default:
+ if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
+ }
+
return res;
}
/* Checks whether the I-th argument of a PHI comes from a backedge. */
static bool
-backedge_phi_arg_p (tree phi, int i)
+backedge_phi_arg_p (gimple phi, int i)
{
- edge e = PHI_ARG_EDGE (phi, i);
+ const_edge e = gimple_phi_arg_edge (phi, i);
/* We would in fact like to test EDGE_DFS_BACK here, but we do not care
about updating it anywhere, and this should work as well most of the
static inline t_bool
follow_ssa_edge_in_condition_phi_branch (int i,
struct loop *loop,
- tree condition_phi,
- tree halting_phi,
+ gimple condition_phi,
+ gimple halting_phi,
tree *evolution_of_branch,
tree init_cond, int limit)
{
static t_bool
follow_ssa_edge_in_condition_phi (struct loop *loop,
- tree condition_phi,
- tree halting_phi,
+ gimple condition_phi,
+ gimple halting_phi,
tree *evolution_of_loop, int limit)
{
- int i;
+ int i, n;
tree init = *evolution_of_loop;
tree evolution_of_branch;
t_bool res = follow_ssa_edge_in_condition_phi_branch (0, loop, condition_phi,
*evolution_of_loop = evolution_of_branch;
- for (i = 1; i < PHI_NUM_ARGS (condition_phi); i++)
+ n = gimple_phi_num_args (condition_phi);
+ for (i = 1; i < n; i++)
{
/* Quickly give up when the evolution of one of the branches is
not known. */
if (*evolution_of_loop == chrec_dont_know)
return t_true;
+ /* Increase the limit by the PHI argument number to avoid exponential
+ time and memory complexity. */
res = follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi,
halting_phi,
&evolution_of_branch,
- init, limit);
+ init, limit + i);
if (res == t_false || res == t_dont_know)
return res;
static t_bool
follow_ssa_edge_inner_loop_phi (struct loop *outer_loop,
- tree loop_phi_node,
- tree halting_phi,
+ gimple loop_phi_node,
+ gimple halting_phi,
tree *evolution_of_loop, int limit)
{
struct loop *loop = loop_containing_stmt (loop_phi_node);
if (ev == PHI_RESULT (loop_phi_node))
{
t_bool res = t_false;
- int i;
+ int i, n = gimple_phi_num_args (loop_phi_node);
- for (i = 0; i < PHI_NUM_ARGS (loop_phi_node); i++)
+ for (i = 0; i < n; i++)
{
tree arg = PHI_ARG_DEF (loop_phi_node, i);
basic_block bb;
/* Follow the edges that exit the inner loop. */
- bb = PHI_ARG_EDGE (loop_phi_node, i)->src;
+ bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
if (!flow_bb_inside_loop_p (loop, bb))
- res = follow_ssa_edge_in_rhs (outer_loop, loop_phi_node,
- arg, halting_phi,
- evolution_of_loop, limit);
+ res = follow_ssa_edge_expr (outer_loop, loop_phi_node,
+ arg, halting_phi,
+ evolution_of_loop, limit);
if (res == t_true)
break;
}
/* Otherwise, compute the overall effect of the inner loop. */
ev = compute_overall_effect_of_inner_loop (loop, ev);
- return follow_ssa_edge_in_rhs (outer_loop, loop_phi_node, ev, halting_phi,
- evolution_of_loop, limit);
+ return follow_ssa_edge_expr (outer_loop, loop_phi_node, ev, halting_phi,
+ evolution_of_loop, limit);
}
/* Follow an SSA edge from a loop-phi-node to itself, constructing a
path that is analyzed on the return walk. */
static t_bool
-follow_ssa_edge (struct loop *loop, tree def, tree halting_phi,
+follow_ssa_edge (struct loop *loop, gimple def, gimple halting_phi,
tree *evolution_of_loop, int limit)
{
struct loop *def_loop;
- if (TREE_CODE (def) == NOP_EXPR)
+ if (gimple_nop_p (def))
return t_false;
/* Give up if the path is longer than the MAX that we allow. */
- if (limit++ > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
+ if (limit > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
return t_dont_know;
def_loop = loop_containing_stmt (def);
- switch (TREE_CODE (def))
+ switch (gimple_code (def))
{
- case PHI_NODE:
+ case GIMPLE_PHI:
if (!loop_phi_node_p (def))
/* DEF is a condition-phi-node. Follow the branches, and
record their evolutions. Finally, merge the collected
/* Inner loop. */
if (flow_loop_nested_p (loop, def_loop))
return follow_ssa_edge_inner_loop_phi
- (loop, def, halting_phi, evolution_of_loop, limit);
+ (loop, def, halting_phi, evolution_of_loop, limit + 1);
/* Outer loop. */
return t_false;
- case MODIFY_EXPR:
- return follow_ssa_edge_in_rhs (loop, def,
- TREE_OPERAND (def, 1),
- halting_phi,
+ case GIMPLE_ASSIGN:
+ return follow_ssa_edge_in_rhs (loop, def, halting_phi,
evolution_of_loop, limit);
default:
/* At this level of abstraction, the program is just a set
- of MODIFY_EXPRs and PHI_NODEs. In principle there is no
+ of GIMPLE_ASSIGNs and PHI_NODEs. In principle there is no
other node to be handled. */
return t_false;
}
function from LOOP_PHI_NODE to LOOP_PHI_NODE in the loop. */
static tree
-analyze_evolution_in_loop (tree loop_phi_node,
+analyze_evolution_in_loop (gimple loop_phi_node,
tree init_cond)
{
- int i;
+ int i, n = gimple_phi_num_args (loop_phi_node);
tree evolution_function = chrec_not_analyzed_yet;
struct loop *loop = loop_containing_stmt (loop_phi_node);
basic_block bb;
{
fprintf (dump_file, "(analyze_evolution_in_loop \n");
fprintf (dump_file, " (loop_phi_node = ");
- print_generic_expr (dump_file, loop_phi_node, 0);
+ print_gimple_stmt (dump_file, loop_phi_node, 0, 0);
fprintf (dump_file, ")\n");
}
- for (i = 0; i < PHI_NUM_ARGS (loop_phi_node); i++)
+ for (i = 0; i < n; i++)
{
tree arg = PHI_ARG_DEF (loop_phi_node, i);
- tree ssa_chain, ev_fn;
+ gimple ssa_chain;
+ tree ev_fn;
t_bool res;
/* Select the edges that enter the loop body. */
- bb = PHI_ARG_EDGE (loop_phi_node, i)->src;
+ bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
if (!flow_bb_inside_loop_p (loop, bb))
continue;
loop, and leaves this task to the on-demand tree reconstructor. */
static tree
-analyze_initial_condition (tree loop_phi_node)
+analyze_initial_condition (gimple loop_phi_node)
{
- int i;
+ int i, n;
tree init_cond = chrec_not_analyzed_yet;
- struct loop *loop = bb_for_stmt (loop_phi_node)->loop_father;
+ struct loop *loop = loop_containing_stmt (loop_phi_node);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "(analyze_initial_condition \n");
fprintf (dump_file, " (loop_phi_node = \n");
- print_generic_expr (dump_file, loop_phi_node, 0);
+ print_gimple_stmt (dump_file, loop_phi_node, 0, 0);
fprintf (dump_file, ")\n");
}
- for (i = 0; i < PHI_NUM_ARGS (loop_phi_node); i++)
+ n = gimple_phi_num_args (loop_phi_node);
+ for (i = 0; i < n; i++)
{
tree branch = PHI_ARG_DEF (loop_phi_node, i);
- basic_block bb = PHI_ARG_EDGE (loop_phi_node, i)->src;
+ basic_block bb = gimple_phi_arg_edge (loop_phi_node, i)->src;
/* When the branch is oriented to the loop's body, it does
not contribute to the initial condition. */
if (init_cond == chrec_not_analyzed_yet)
init_cond = chrec_dont_know;
+ /* During early loop unrolling we do not have fully constant propagated IL.
+ Handle degenerate PHIs here to not miss important unrollings. */
+ if (TREE_CODE (init_cond) == SSA_NAME)
+ {
+ gimple def = SSA_NAME_DEF_STMT (init_cond);
+ tree res;
+ if (gimple_code (def) == GIMPLE_PHI
+ && (res = degenerate_phi_result (def)) != NULL_TREE
+ /* Only allow invariants here, otherwise we may break
+ loop-closed SSA form. */
+ && is_gimple_min_invariant (res))
+ init_cond = res;
+ }
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (init_cond = ");
/* Analyze the scalar evolution for LOOP_PHI_NODE. */
static tree
-interpret_loop_phi (struct loop *loop, tree loop_phi_node)
+interpret_loop_phi (struct loop *loop, gimple loop_phi_node)
{
tree res;
struct loop *phi_loop = loop_containing_stmt (loop_phi_node);
(phi_loop, PHI_RESULT (loop_phi_node));
/* Dive one level deeper. */
- subloop = superloop_at_depth (phi_loop, loop->depth + 1);
+ subloop = superloop_at_depth (phi_loop, loop_depth (loop) + 1);
/* Interpret the subloop. */
res = compute_overall_effect_of_inner_loop (subloop, evolution_fn);
analyzed. */
static tree
-interpret_condition_phi (struct loop *loop, tree condition_phi)
+interpret_condition_phi (struct loop *loop, gimple condition_phi)
{
- int i;
+ int i, n = gimple_phi_num_args (condition_phi);
tree res = chrec_not_analyzed_yet;
- for (i = 0; i < PHI_NUM_ARGS (condition_phi); i++)
+ for (i = 0; i < n; i++)
{
tree branch_chrec;
return res;
}
-/* Interpret the right hand side of a modify_expr OPND1. If we didn't
+/* Interpret the operation RHS1 OP RHS2. If we didn't
analyze this node before, follow the definitions until ending
- either on an analyzed modify_expr, or on a loop-phi-node. On the
+ either on an analyzed GIMPLE_ASSIGN, or on a loop-phi-node. On the
return path, this function propagates evolutions (ala constant copy
propagation). OPND1 is not a GIMPLE expression because we could
analyze the effect of an inner loop: see interpret_loop_phi. */
static tree
-interpret_rhs_modify_expr (struct loop *loop, tree at_stmt,
- tree opnd1, tree type)
+interpret_rhs_expr (struct loop *loop, gimple at_stmt,
+ tree type, tree rhs1, enum tree_code code, tree rhs2)
{
- tree res, opnd10, opnd11, chrec10, chrec11;
+ tree res, chrec1, chrec2;
+
+ if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ {
+ if (is_gimple_min_invariant (rhs1))
+ return chrec_convert (type, rhs1, at_stmt);
- if (is_gimple_min_invariant (opnd1))
- return chrec_convert (type, opnd1, at_stmt);
+ if (code == SSA_NAME)
+ return chrec_convert (type, analyze_scalar_evolution (loop, rhs1),
+ at_stmt);
- switch (TREE_CODE (opnd1))
+ if (code == ASSERT_EXPR)
+ {
+ rhs1 = ASSERT_EXPR_VAR (rhs1);
+ return chrec_convert (type, analyze_scalar_evolution (loop, rhs1),
+ at_stmt);
+ }
+
+ return chrec_dont_know;
+ }
+
+ switch (code)
{
+ case POINTER_PLUS_EXPR:
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec2 = analyze_scalar_evolution (loop, rhs2);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ chrec2 = chrec_convert (sizetype, chrec2, at_stmt);
+ res = chrec_fold_plus (type, chrec1, chrec2);
+ break;
+
case PLUS_EXPR:
- opnd10 = TREE_OPERAND (opnd1, 0);
- opnd11 = TREE_OPERAND (opnd1, 1);
- chrec10 = analyze_scalar_evolution (loop, opnd10);
- chrec11 = analyze_scalar_evolution (loop, opnd11);
- chrec10 = chrec_convert (type, chrec10, at_stmt);
- chrec11 = chrec_convert (type, chrec11, at_stmt);
- res = chrec_fold_plus (type, chrec10, chrec11);
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec2 = analyze_scalar_evolution (loop, rhs2);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ chrec2 = chrec_convert (type, chrec2, at_stmt);
+ res = chrec_fold_plus (type, chrec1, chrec2);
break;
case MINUS_EXPR:
- opnd10 = TREE_OPERAND (opnd1, 0);
- opnd11 = TREE_OPERAND (opnd1, 1);
- chrec10 = analyze_scalar_evolution (loop, opnd10);
- chrec11 = analyze_scalar_evolution (loop, opnd11);
- chrec10 = chrec_convert (type, chrec10, at_stmt);
- chrec11 = chrec_convert (type, chrec11, at_stmt);
- res = chrec_fold_minus (type, chrec10, chrec11);
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec2 = analyze_scalar_evolution (loop, rhs2);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ chrec2 = chrec_convert (type, chrec2, at_stmt);
+ res = chrec_fold_minus (type, chrec1, chrec2);
break;
case NEGATE_EXPR:
- opnd10 = TREE_OPERAND (opnd1, 0);
- chrec10 = analyze_scalar_evolution (loop, opnd10);
- chrec10 = chrec_convert (type, chrec10, at_stmt);
- res = chrec_fold_multiply (type, chrec10, SCALAR_FLOAT_TYPE_P (type)
- ? build_real (type, dconstm1)
- : build_int_cst_type (type, -1));
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ /* TYPE may be integer, real or complex, so use fold_convert. */
+ res = chrec_fold_multiply (type, chrec1,
+ fold_convert (type, integer_minus_one_node));
break;
- case MULT_EXPR:
- opnd10 = TREE_OPERAND (opnd1, 0);
- opnd11 = TREE_OPERAND (opnd1, 1);
- chrec10 = analyze_scalar_evolution (loop, opnd10);
- chrec11 = analyze_scalar_evolution (loop, opnd11);
- chrec10 = chrec_convert (type, chrec10, at_stmt);
- chrec11 = chrec_convert (type, chrec11, at_stmt);
- res = chrec_fold_multiply (type, chrec10, chrec11);
- break;
-
- case SSA_NAME:
- res = chrec_convert (type, analyze_scalar_evolution (loop, opnd1),
- at_stmt);
+ case BIT_NOT_EXPR:
+ /* Handle ~X as -1 - X. */
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ res = chrec_fold_minus (type,
+ fold_convert (type, integer_minus_one_node),
+ chrec1);
break;
- case ASSERT_EXPR:
- opnd10 = ASSERT_EXPR_VAR (opnd1);
- res = chrec_convert (type, analyze_scalar_evolution (loop, opnd10),
- at_stmt);
+ case MULT_EXPR:
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ chrec2 = analyze_scalar_evolution (loop, rhs2);
+ chrec1 = chrec_convert (type, chrec1, at_stmt);
+ chrec2 = chrec_convert (type, chrec2, at_stmt);
+ res = chrec_fold_multiply (type, chrec1, chrec2);
break;
- case NOP_EXPR:
- case CONVERT_EXPR:
- opnd10 = TREE_OPERAND (opnd1, 0);
- chrec10 = analyze_scalar_evolution (loop, opnd10);
- res = chrec_convert (type, chrec10, at_stmt);
+ CASE_CONVERT:
+ chrec1 = analyze_scalar_evolution (loop, rhs1);
+ res = chrec_convert (type, chrec1, at_stmt);
break;
default:
return res;
}
+/* Interpret the expression EXPR. */
+
+static tree
+interpret_expr (struct loop *loop, gimple at_stmt, tree expr)
+{
+ enum tree_code code;
+ tree type = TREE_TYPE (expr), op0, op1;
+
+ if (automatically_generated_chrec_p (expr))
+ return expr;
+
+ if (TREE_CODE (expr) == POLYNOMIAL_CHREC)
+ return chrec_dont_know;
+
+ extract_ops_from_tree (expr, &code, &op0, &op1);
+
+ return interpret_rhs_expr (loop, at_stmt, type,
+ op0, code, op1);
+}
+
+/* Interpret the rhs of the assignment STMT. */
+
+static tree
+interpret_gimple_assign (struct loop *loop, gimple stmt)
+{
+ tree type = TREE_TYPE (gimple_assign_lhs (stmt));
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+
+ return interpret_rhs_expr (loop, stmt, type,
+ gimple_assign_rhs1 (stmt), code,
+ gimple_assign_rhs2 (stmt));
+}
+
\f
/* This section contains all the entry points:
if (def_loop == wrto_loop)
return ev;
- def_loop = superloop_at_depth (def_loop, wrto_loop->depth + 1);
+ def_loop = superloop_at_depth (def_loop, loop_depth (wrto_loop) + 1);
res = compute_overall_effect_of_inner_loop (def_loop, ev);
return analyze_scalar_evolution_1 (wrto_loop, res, chrec_not_analyzed_yet);
static tree
analyze_scalar_evolution_1 (struct loop *loop, tree var, tree res)
{
- tree def, type = TREE_TYPE (var);
+ tree type = TREE_TYPE (var);
+ gimple def;
basic_block bb;
struct loop *def_loop;
- if (loop == NULL)
+ if (loop == NULL || TREE_CODE (type) == VECTOR_TYPE)
return chrec_dont_know;
if (TREE_CODE (var) != SSA_NAME)
- return interpret_rhs_modify_expr (loop, NULL_TREE, var, type);
+ return interpret_expr (loop, NULL, var);
def = SSA_NAME_DEF_STMT (var);
- bb = bb_for_stmt (def);
+ bb = gimple_bb (def);
def_loop = bb ? bb->loop_father : NULL;
if (bb == NULL
goto set_and_end;
}
- switch (TREE_CODE (def))
+ switch (gimple_code (def))
{
- case MODIFY_EXPR:
- res = interpret_rhs_modify_expr (loop, def, TREE_OPERAND (def, 1), type);
+ case GIMPLE_ASSIGN:
+ res = interpret_gimple_assign (loop, def);
break;
- case PHI_NODE:
+ case GIMPLE_PHI:
if (loop_phi_node_p (def))
res = interpret_loop_phi (loop, def);
else
res = var;
if (loop == def_loop)
- set_scalar_evolution (var, res);
+ set_scalar_evolution (block_before_loop (loop), var, res);
return res;
}
-/* Entry point for the scalar evolution analyzer.
- Analyzes and returns the scalar evolution of the ssa_name VAR.
- LOOP_NB is the identifier number of the loop in which the variable
- is used.
+/* Analyzes and returns the scalar evolution of the ssa_name VAR in
+ LOOP. LOOP is the loop in which the variable is used.
Example of use: having a pointer VAR to a SSA_NAME node, STMT a
pointer to the statement that uses this variable, in order to
determine the evolution function of the variable, use the following
calls:
- unsigned loop_nb = loop_containing_stmt (stmt)->num;
- tree chrec_with_symbols = analyze_scalar_evolution (loop_nb, var);
- tree chrec_instantiated = instantiate_parameters
- (loop_nb, chrec_with_symbols);
+ loop_p loop = loop_containing_stmt (stmt);
+ tree chrec_with_symbols = analyze_scalar_evolution (loop, var);
+ tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols);
*/
tree
fprintf (dump_file, ")\n");
}
- res = analyze_scalar_evolution_1 (loop, var, get_scalar_evolution (var));
-
- if (TREE_CODE (var) == SSA_NAME && res == chrec_dont_know)
- res = var;
+ res = get_scalar_evolution (block_before_loop (loop), var);
+ res = analyze_scalar_evolution_1 (loop, var, res);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, ")\n");
}
/* Analyze scalar evolution of use of VERSION in USE_LOOP with respect to
- WRTO_LOOP (which should be a superloop of both USE_LOOP and definition
- of VERSION). */
+ WRTO_LOOP (which should be a superloop of USE_LOOP)
+
+ FOLDED_CASTS is set to true if resolve_mixers used
+ chrec_convert_aggressive (TODO -- not really, we are way too conservative
+ at the moment in order to keep things simple).
+
+ To illustrate the meaning of USE_LOOP and WRTO_LOOP, consider the following
+ example:
+
+ for (i = 0; i < 100; i++) -- loop 1
+ {
+ for (j = 0; j < 100; j++) -- loop 2
+ {
+ k1 = i;
+ k2 = j;
+
+ use2 (k1, k2);
+
+ for (t = 0; t < 100; t++) -- loop 3
+ use3 (k1, k2);
+
+ }
+ use1 (k1, k2);
+ }
+
+ Both k1 and k2 are invariants in loop3, thus
+ analyze_scalar_evolution_in_loop (loop3, loop3, k1) = k1
+ analyze_scalar_evolution_in_loop (loop3, loop3, k2) = k2
+
+ As they are invariant, it does not matter whether we consider their
+ usage in loop 3 or loop 2, hence
+ analyze_scalar_evolution_in_loop (loop2, loop3, k1) =
+ analyze_scalar_evolution_in_loop (loop2, loop2, k1) = i
+ analyze_scalar_evolution_in_loop (loop2, loop3, k2) =
+ analyze_scalar_evolution_in_loop (loop2, loop2, k2) = [0,+,1]_2
+
+ Similarly for their evolutions with respect to loop 1. The values of K2
+ in the use in loop 2 vary independently on loop 1, thus we cannot express
+ the evolution with respect to loop 1:
+ analyze_scalar_evolution_in_loop (loop1, loop3, k1) =
+ analyze_scalar_evolution_in_loop (loop1, loop2, k1) = [0,+,1]_1
+ analyze_scalar_evolution_in_loop (loop1, loop3, k2) =
+ analyze_scalar_evolution_in_loop (loop1, loop2, k2) = dont_know
+
+ The value of k2 in the use in loop 1 is known, though:
+ analyze_scalar_evolution_in_loop (loop1, loop1, k1) = [0,+,1]_1
+ analyze_scalar_evolution_in_loop (loop1, loop1, k2) = 100
+ */
static tree
analyze_scalar_evolution_in_loop (struct loop *wrto_loop, struct loop *use_loop,
- tree version)
+ tree version, bool *folded_casts)
{
bool val = false;
- tree ev = version;
+ tree ev = version, tmp;
+
+ /* We cannot just do
+
+ tmp = analyze_scalar_evolution (use_loop, version);
+ ev = resolve_mixers (wrto_loop, tmp);
+ as resolve_mixers would query the scalar evolution with respect to
+ wrto_loop. For example, in the situation described in the function
+ comment, suppose that wrto_loop = loop1, use_loop = loop3 and
+ version = k2. Then
+
+ analyze_scalar_evolution (use_loop, version) = k2
+
+ and resolve_mixers (loop1, k2) finds that the value of k2 in loop 1
+ is 100, which is a wrong result, since we are interested in the
+ value in loop 3.
+
+ Instead, we need to proceed from use_loop to wrto_loop loop by loop,
+ each time checking that there is no evolution in the inner loop. */
+
+ if (folded_casts)
+ *folded_casts = false;
while (1)
{
- ev = analyze_scalar_evolution (use_loop, ev);
- ev = resolve_mixers (use_loop, ev);
+ tmp = analyze_scalar_evolution (use_loop, ev);
+ ev = resolve_mixers (use_loop, tmp);
+
+ if (folded_casts && tmp != ev)
+ *folded_casts = true;
if (use_loop == wrto_loop)
return ev;
|| !val)
return chrec_dont_know;
- use_loop = use_loop->outer;
+ use_loop = loop_outer (use_loop);
}
}
-/* Returns instantiated value for VERSION in CACHE. */
+/* Returns from CACHE the value for VERSION instantiated below
+ INSTANTIATED_BELOW block. */
static tree
-get_instantiated_value (htab_t cache, tree version)
+get_instantiated_value (htab_t cache, basic_block instantiated_below,
+ tree version)
{
struct scev_info_str *info, pattern;
pattern.var = version;
- info = htab_find (cache, &pattern);
+ pattern.instantiated_below = instantiated_below;
+ info = (struct scev_info_str *) htab_find (cache, &pattern);
if (info)
return info->chrec;
return NULL_TREE;
}
-/* Sets instantiated value for VERSION to VAL in CACHE. */
+/* Sets in CACHE the value of VERSION instantiated below basic block
+ INSTANTIATED_BELOW to VAL. */
static void
-set_instantiated_value (htab_t cache, tree version, tree val)
+set_instantiated_value (htab_t cache, basic_block instantiated_below,
+ tree version, tree val)
{
struct scev_info_str *info, pattern;
PTR *slot;
pattern.var = version;
+ pattern.instantiated_below = instantiated_below;
slot = htab_find_slot (cache, &pattern, INSERT);
if (!*slot)
- *slot = new_scev_info_str (version);
+ *slot = new_scev_info_str (instantiated_below, version);
info = (struct scev_info_str *) *slot;
info->chrec = val;
}
{
struct loop *loop;
edge exit;
- tree phi;
+ gimple phi;
+ gimple_stmt_iterator psi;
if (var == NULL_TREE
|| TREE_CODE (var) != SSA_NAME)
return NULL_TREE;
loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var));
- exit = loop->single_exit;
+ exit = single_exit (loop);
if (!exit)
return NULL_TREE;
- for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi))
- if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var)
- return PHI_RESULT (phi);
+ for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi))
+ {
+ phi = gsi_stmt (psi);
+ if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var)
+ return PHI_RESULT (phi);
+ }
return NULL_TREE;
}
-/* Analyze all the parameters of the chrec that were left under a symbolic form,
- with respect to LOOP. CHREC is the chrec to instantiate. CACHE is the cache
- of already instantiated values. FLAGS modify the way chrecs are
- instantiated. SIZE_EXPR is used for computing the size of the expression to
- be instantiated, and to stop if it exceeds some limit. */
+/* Analyze all the parameters of the chrec, between INSTANTIATE_BELOW
+ and EVOLUTION_LOOP, that were left under a symbolic form.
-/* Values for FLAGS. */
-enum
-{
- INSERT_SUPERLOOP_CHRECS = 1, /* Loop invariants are replaced with chrecs
- in outer loops. */
- FOLD_CONVERSIONS = 2 /* The conversions that may wrap in
- signed/pointer type are folded, as long as the
- value of the chrec is preserved. */
-};
+ CHREC is the scalar evolution to instantiate.
+
+ CACHE is the cache of already instantiated values.
+
+ FOLD_CONVERSIONS should be set to true when the conversions that
+ may wrap in signed/pointer type are folded, as long as the value of
+ the chrec is preserved.
+
+ SIZE_EXPR is used for computing the size of the expression to be
+ instantiated, and to stop if it exceeds some limit. */
static tree
-instantiate_parameters_1 (struct loop *loop, tree chrec, int flags, htab_t cache,
- int size_expr)
+instantiate_scev_1 (basic_block instantiate_below,
+ struct loop *evolution_loop, tree chrec,
+ bool fold_conversions, htab_t cache, int size_expr)
{
tree res, op0, op1, op2;
basic_block def_bb;
struct loop *def_loop;
+ tree type = chrec_type (chrec);
/* Give up if the expression is larger than the MAX that we allow. */
if (size_expr++ > PARAM_VALUE (PARAM_SCEV_MAX_EXPR_SIZE))
switch (TREE_CODE (chrec))
{
case SSA_NAME:
- def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (chrec));
+ def_bb = gimple_bb (SSA_NAME_DEF_STMT (chrec));
/* A parameter (or loop invariant and we do not want to include
evolutions in outer loops), nothing to do. */
if (!def_bb
- || (!(flags & INSERT_SUPERLOOP_CHRECS)
- && !flow_bb_inside_loop_p (loop, def_bb)))
+ || loop_depth (def_bb->loop_father) == 0
+ || dominated_by_p (CDI_DOMINATORS, instantiate_below, def_bb))
return chrec;
/* We cache the value of instantiated variable to avoid exponential
| a_2 -> {0, +, 1, +, a_2}_1 */
- res = get_instantiated_value (cache, chrec);
+ res = get_instantiated_value (cache, instantiate_below, chrec);
if (res)
return res;
- /* Store the convenient value for chrec in the structure. If it
- is defined outside of the loop, we may just leave it in symbolic
- form, otherwise we need to admit that we do not know its behavior
- inside the loop. */
- res = !flow_bb_inside_loop_p (loop, def_bb) ? chrec : chrec_dont_know;
- set_instantiated_value (cache, chrec, res);
-
- /* To make things even more complicated, instantiate_parameters_1
- calls analyze_scalar_evolution that may call # of iterations
- analysis that may in turn call instantiate_parameters_1 again.
- To prevent the infinite recursion, keep also the bitmap of
- ssa names that are being instantiated globally. */
- if (bitmap_bit_p (already_instantiated, SSA_NAME_VERSION (chrec)))
- return res;
+ res = chrec_dont_know;
+ set_instantiated_value (cache, instantiate_below, chrec, res);
- def_loop = find_common_loop (loop, def_bb->loop_father);
+ def_loop = find_common_loop (evolution_loop, def_bb->loop_father);
/* If the analysis yields a parametric chrec, instantiate the
result again. */
- bitmap_set_bit (already_instantiated, SSA_NAME_VERSION (chrec));
res = analyze_scalar_evolution (def_loop, chrec);
/* Don't instantiate loop-closed-ssa phi nodes. */
if (TREE_CODE (res) == SSA_NAME
&& (loop_containing_stmt (SSA_NAME_DEF_STMT (res)) == NULL
- || (loop_containing_stmt (SSA_NAME_DEF_STMT (res))->depth
- > def_loop->depth)))
+ || (loop_depth (loop_containing_stmt (SSA_NAME_DEF_STMT (res)))
+ > loop_depth (def_loop))))
{
if (res == chrec)
res = loop_closed_phi_def (chrec);
else
res = chrec;
- if (res == NULL_TREE)
+ if (res == NULL_TREE
+ || !dominated_by_p (CDI_DOMINATORS, instantiate_below,
+ gimple_bb (SSA_NAME_DEF_STMT (res))))
res = chrec_dont_know;
}
else if (res != chrec_dont_know)
- res = instantiate_parameters_1 (loop, res, flags, cache, size_expr);
-
- bitmap_clear_bit (already_instantiated, SSA_NAME_VERSION (chrec));
+ res = instantiate_scev_1 (instantiate_below, evolution_loop, res,
+ fold_conversions, cache, size_expr);
/* Store the correct value to the cache. */
- set_instantiated_value (cache, chrec, res);
+ set_instantiated_value (cache, instantiate_below, chrec, res);
return res;
case POLYNOMIAL_CHREC:
- op0 = instantiate_parameters_1 (loop, CHREC_LEFT (chrec),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ CHREC_LEFT (chrec), fold_conversions, cache,
+ size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, CHREC_RIGHT (chrec),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ CHREC_RIGHT (chrec), fold_conversions, cache,
+ size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
if (CHREC_LEFT (chrec) != op0
|| CHREC_RIGHT (chrec) != op1)
- chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1);
+ {
+ op1 = chrec_convert_rhs (chrec_type (op0), op1, NULL);
+ chrec = build_polynomial_chrec (CHREC_VARIABLE (chrec), op0, op1);
+ }
return chrec;
+ case POINTER_PLUS_EXPR:
case PLUS_EXPR:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0), fold_conversions, cache,
+ size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 1),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 1), fold_conversions, cache,
+ size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
if (TREE_OPERAND (chrec, 0) != op0
|| TREE_OPERAND (chrec, 1) != op1)
- chrec = chrec_fold_plus (TREE_TYPE (chrec), op0, op1);
+ {
+ op0 = chrec_convert (type, op0, NULL);
+ op1 = chrec_convert_rhs (type, op1, NULL);
+ chrec = chrec_fold_plus (type, op0, op1);
+ }
return chrec;
case MINUS_EXPR:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0), fold_conversions, cache,
+ size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 1),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 1),
+ fold_conversions, cache, size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
if (TREE_OPERAND (chrec, 0) != op0
|| TREE_OPERAND (chrec, 1) != op1)
- chrec = chrec_fold_minus (TREE_TYPE (chrec), op0, op1);
+ {
+ op0 = chrec_convert (type, op0, NULL);
+ op1 = chrec_convert (type, op1, NULL);
+ chrec = chrec_fold_minus (type, op0, op1);
+ }
return chrec;
case MULT_EXPR:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 1),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 1),
+ fold_conversions, cache, size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
if (TREE_OPERAND (chrec, 0) != op0
|| TREE_OPERAND (chrec, 1) != op1)
- chrec = chrec_fold_multiply (TREE_TYPE (chrec), op0, op1);
+ {
+ op0 = chrec_convert (type, op0, NULL);
+ op1 = chrec_convert (type, op1, NULL);
+ chrec = chrec_fold_multiply (type, op0, op1);
+ }
return chrec;
- case NOP_EXPR:
- case CONVERT_EXPR:
- case NON_LVALUE_EXPR:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ CASE_CONVERT:
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- if (flags & FOLD_CONVERSIONS)
+ if (fold_conversions)
{
tree tmp = chrec_convert_aggressive (TREE_TYPE (chrec), op0);
if (tmp)
if (op0 == TREE_OPERAND (chrec, 0))
return chrec;
- return chrec_convert (TREE_TYPE (chrec), op0, NULL_TREE);
+ /* If we used chrec_convert_aggressive, we can no longer assume that
+ signed chrecs do not overflow, as chrec_convert does, so avoid
+ calling it in that case. */
+ if (fold_conversions)
+ return fold_convert (TREE_TYPE (chrec), op0);
+
+ return chrec_convert (TREE_TYPE (chrec), op0, NULL);
+
+ case BIT_NOT_EXPR:
+ /* Handle ~X as -1 - X. */
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
+ if (op0 == chrec_dont_know)
+ return chrec_dont_know;
+
+ if (TREE_OPERAND (chrec, 0) != op0)
+ {
+ op0 = chrec_convert (type, op0, NULL);
+ chrec = chrec_fold_minus (type,
+ fold_convert (type,
+ integer_minus_one_node),
+ op0);
+ }
+ return chrec;
case SCEV_NOT_KNOWN:
return chrec_dont_know;
break;
}
+ if (VL_EXP_CLASS_P (chrec))
+ return chrec_dont_know;
+
switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
{
case 3:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 1),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 1),
+ fold_conversions, cache, size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
- op2 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 2),
- flags, cache, size_expr);
+ op2 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 2),
+ fold_conversions, cache, size_expr);
if (op2 == chrec_dont_know)
return chrec_dont_know;
TREE_TYPE (chrec), op0, op1, op2);
case 2:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
- op1 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 1),
- flags, cache, size_expr);
+ op1 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 1),
+ fold_conversions, cache, size_expr);
if (op1 == chrec_dont_know)
return chrec_dont_know;
return fold_build2 (TREE_CODE (chrec), TREE_TYPE (chrec), op0, op1);
case 1:
- op0 = instantiate_parameters_1 (loop, TREE_OPERAND (chrec, 0),
- flags, cache, size_expr);
+ op0 = instantiate_scev_1 (instantiate_below, evolution_loop,
+ TREE_OPERAND (chrec, 0),
+ fold_conversions, cache, size_expr);
if (op0 == chrec_dont_know)
return chrec_dont_know;
if (op0 == TREE_OPERAND (chrec, 0))
}
/* Analyze all the parameters of the chrec that were left under a
- symbolic form. LOOP is the loop in which symbolic names have to
- be analyzed and instantiated. */
+ symbolic form. INSTANTIATE_BELOW is the basic block that stops the
+ recursive instantiation of parameters: a parameter is a variable
+ that is defined in a basic block that dominates INSTANTIATE_BELOW or
+ a function parameter. */
tree
-instantiate_parameters (struct loop *loop,
- tree chrec)
+instantiate_scev (basic_block instantiate_below, struct loop *evolution_loop,
+ tree chrec)
{
tree res;
htab_t cache = htab_create (10, hash_scev_info, eq_scev_info, del_scev_info);
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "(instantiate_parameters \n");
- fprintf (dump_file, " (loop_nb = %d)\n", loop->num);
+ fprintf (dump_file, "(instantiate_scev \n");
+ fprintf (dump_file, " (instantiate_below = %d)\n", instantiate_below->index);
+ fprintf (dump_file, " (evolution_loop = %d)\n", evolution_loop->num);
fprintf (dump_file, " (chrec = ");
print_generic_expr (dump_file, chrec, 0);
fprintf (dump_file, ")\n");
}
- res = instantiate_parameters_1 (loop, chrec, INSERT_SUPERLOOP_CHRECS, cache,
- 0);
+ res = instantiate_scev_1 (instantiate_below, evolution_loop, chrec, false,
+ cache, 0);
if (dump_file && (dump_flags & TDF_DETAILS))
{
care about causing overflows, as long as they do not affect value
of an expression. */
-static tree
+tree
resolve_mixers (struct loop *loop, tree chrec)
{
htab_t cache = htab_create (10, hash_scev_info, eq_scev_info, del_scev_info);
- tree ret = instantiate_parameters_1 (loop, chrec, FOLD_CONVERSIONS, cache, 0);
+ tree ret = instantiate_scev_1 (block_before_loop (loop), loop, chrec, true,
+ cache, 0);
htab_delete (cache);
return ret;
}
the loop body has been executed 6 times. */
tree
-number_of_iterations_in_loop (struct loop *loop)
+number_of_latch_executions (struct loop *loop)
{
tree res, type;
edge exit;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(number_of_iterations_in_loop\n");
- exit = loop->single_exit;
+ exit = single_exit (loop);
if (!exit)
goto end;
return set_nb_iterations_in_loop (loop, res);
}
+/* Returns the number of executions of the exit condition of LOOP,
+ i.e., the number by one higher than number_of_latch_executions.
+ Note that unlike number_of_latch_executions, this number does
+ not necessarily fit in the unsigned variant of the type of
+ the control variable -- if the number of iterations is a constant,
+ we return chrec_dont_know if adding one to number_of_latch_executions
+ overflows; however, in case the number of iterations is symbolic
+ expression, the caller is responsible for dealing with this
+ the possible overflow. */
+
+tree
+number_of_exit_cond_executions (struct loop *loop)
+{
+ tree ret = number_of_latch_executions (loop);
+ tree type = chrec_type (ret);
+
+ if (chrec_contains_undetermined (ret))
+ return ret;
+
+ ret = chrec_fold_plus (type, ret, build_int_cst (type, 1));
+ if (TREE_CODE (ret) == INTEGER_CST
+ && TREE_OVERFLOW (ret))
+ return chrec_dont_know;
+
+ return ret;
+}
+
/* One of the drivers for testing the scalar evolutions analysis.
This function computes the number of iterations for all the loops
from the EXIT_CONDITIONS array. */
static void
-number_of_iterations_for_all_loops (VEC(tree,heap) **exit_conditions)
+number_of_iterations_for_all_loops (VEC(gimple,heap) **exit_conditions)
{
unsigned int i;
unsigned nb_chrec_dont_know_loops = 0;
unsigned nb_static_loops = 0;
- tree cond;
+ gimple cond;
- for (i = 0; VEC_iterate (tree, *exit_conditions, i, cond); i++)
+ for (i = 0; VEC_iterate (gimple, *exit_conditions, i, cond); i++)
{
- tree res = number_of_iterations_in_loop (loop_containing_stmt (cond));
+ tree res = number_of_latch_executions (loop_containing_stmt (cond));
if (chrec_contains_undetermined (res))
nb_chrec_dont_know_loops++;
else
fprintf (dump_file, "-----------------------------------------\n");
fprintf (dump_file, "%d\tnb_chrec_dont_know_loops\n", nb_chrec_dont_know_loops);
fprintf (dump_file, "%d\tnb_static_loops\n", nb_static_loops);
- fprintf (dump_file, "%d\tnb_total_loops\n", current_loops->num);
+ fprintf (dump_file, "%d\tnb_total_loops\n", number_of_loops ());
fprintf (dump_file, "-----------------------------------------\n");
fprintf (dump_file, ")\n\n");
- print_loop_ir (dump_file);
+ print_loops (dump_file, 3);
}
}
fprintf (dump_file, " affine_univariate\n");
stats->nb_affine++;
}
- else if (evolution_function_is_affine_multivariate_p (chrec))
+ else if (evolution_function_is_affine_multivariate_p (chrec, 0))
{
if (dump_file && (dump_flags & TDF_STATS))
fprintf (dump_file, " affine_multivariate\n");
index. This allows the parallelization of the loop. */
static void
-analyze_scalar_evolution_for_all_loop_phi_nodes (VEC(tree,heap) **exit_conditions)
+analyze_scalar_evolution_for_all_loop_phi_nodes (VEC(gimple,heap) **exit_conditions)
{
unsigned int i;
struct chrec_stats stats;
- tree cond;
+ gimple cond, phi;
+ gimple_stmt_iterator psi;
reset_chrecs_counters (&stats);
- for (i = 0; VEC_iterate (tree, *exit_conditions, i, cond); i++)
+ for (i = 0; VEC_iterate (gimple, *exit_conditions, i, cond); i++)
{
struct loop *loop;
basic_block bb;
- tree phi, chrec;
+ tree chrec;
loop = loop_containing_stmt (cond);
bb = loop->header;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- if (is_gimple_reg (PHI_RESULT (phi)))
- {
- chrec = instantiate_parameters
- (loop,
- analyze_scalar_evolution (loop, PHI_RESULT (phi)));
+ for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
+ {
+ phi = gsi_stmt (psi);
+ if (is_gimple_reg (PHI_RESULT (phi)))
+ {
+ chrec = instantiate_parameters
+ (loop,
+ analyze_scalar_evolution (loop, PHI_RESULT (phi)));
- if (dump_file && (dump_flags & TDF_STATS))
- gather_chrec_stats (chrec, &stats);
- }
+ if (dump_file && (dump_flags & TDF_STATS))
+ gather_chrec_stats (chrec, &stats);
+ }
+ }
}
if (dump_file && (dump_flags & TDF_STATS))
/* Initialize the analysis of scalar evolutions for LOOPS. */
void
-scev_initialize (struct loops *loops)
+scev_initialize (void)
{
- unsigned i;
- current_loops = loops;
+ loop_iterator li;
+ struct loop *loop;
- scalar_evolution_info = htab_create (100, hash_scev_info,
- eq_scev_info, del_scev_info);
- already_instantiated = BITMAP_ALLOC (NULL);
+ scalar_evolution_info = htab_create_alloc (100,
+ hash_scev_info,
+ eq_scev_info,
+ del_scev_info,
+ ggc_calloc,
+ ggc_free);
initialize_scalar_evolutions_analyzer ();
- for (i = 1; i < loops->num; i++)
- if (loops->parray[i])
- loops->parray[i]->nb_iterations = NULL_TREE;
+ FOR_EACH_LOOP (li, loop, 0)
+ {
+ loop->nb_iterations = NULL_TREE;
+ }
}
/* Cleans up the information cached by the scalar evolutions analysis. */
void
scev_reset (void)
{
- unsigned i;
+ loop_iterator li;
struct loop *loop;
if (!scalar_evolution_info || !current_loops)
return;
htab_empty (scalar_evolution_info);
- for (i = 1; i < current_loops->num; i++)
+ FOR_EACH_LOOP (li, loop, 0)
{
- loop = current_loops->parray[i];
- if (loop)
- loop->nb_iterations = NULL_TREE;
+ loop->nb_iterations = NULL_TREE;
}
}
-/* Checks whether OP behaves as a simple affine iv of LOOP in STMT and returns
- its BASE and STEP if possible. If ALLOW_NONCONSTANT_STEP is true, we
- want STEP to be invariant in LOOP. Otherwise we require it to be an
- integer constant. */
+/* Checks whether use of OP in USE_LOOP behaves as a simple affine iv with
+ respect to WRTO_LOOP and returns its base and step in IV if possible
+ (see analyze_scalar_evolution_in_loop for more details on USE_LOOP
+ and WRTO_LOOP). If ALLOW_NONCONSTANT_STEP is true, we want step to be
+ invariant in LOOP. Otherwise we require it to be an integer constant.
+
+ IV->no_overflow is set to true if we are sure the iv cannot overflow (e.g.
+ because it is computed in signed arithmetics). Consequently, adding an
+ induction variable
+
+ for (i = IV->base; ; i += IV->step)
+
+ is only safe if IV->no_overflow is false, or TYPE_OVERFLOW_UNDEFINED is
+ false for the type of the induction variable, or you can prove that i does
+ not wrap by some other argument. Otherwise, this might introduce undefined
+ behavior, and
+
+ for (i = iv->base; ; i = (type) ((unsigned type) i + (unsigned type) iv->step))
+
+ must be used instead. */
bool
-simple_iv (struct loop *loop, tree stmt, tree op, tree *base, tree *step,
- bool allow_nonconstant_step)
+simple_iv (struct loop *wrto_loop, struct loop *use_loop, tree op,
+ affine_iv *iv, bool allow_nonconstant_step)
{
- basic_block bb = bb_for_stmt (stmt);
tree type, ev;
+ bool folded_casts;
- *base = NULL_TREE;
- *step = NULL_TREE;
+ iv->base = NULL_TREE;
+ iv->step = NULL_TREE;
+ iv->no_overflow = false;
type = TREE_TYPE (op);
if (TREE_CODE (type) != INTEGER_TYPE
&& TREE_CODE (type) != POINTER_TYPE)
return false;
- ev = analyze_scalar_evolution_in_loop (loop, bb->loop_father, op);
- if (chrec_contains_undetermined (ev))
+ ev = analyze_scalar_evolution_in_loop (wrto_loop, use_loop, op,
+ &folded_casts);
+ if (chrec_contains_undetermined (ev)
+ || chrec_contains_symbols_defined_in_loop (ev, wrto_loop->num))
return false;
- if (tree_does_not_contain_chrecs (ev)
- && !chrec_contains_symbols_defined_in_loop (ev, loop->num))
+ if (tree_does_not_contain_chrecs (ev))
{
- *base = ev;
+ iv->base = ev;
+ iv->step = build_int_cst (TREE_TYPE (ev), 0);
+ iv->no_overflow = true;
return true;
}
if (TREE_CODE (ev) != POLYNOMIAL_CHREC
- || CHREC_VARIABLE (ev) != (unsigned) loop->num)
+ || CHREC_VARIABLE (ev) != (unsigned) wrto_loop->num)
return false;
- *step = CHREC_RIGHT (ev);
- if (allow_nonconstant_step)
- {
- if (tree_contains_chrecs (*step, NULL)
- || chrec_contains_symbols_defined_in_loop (*step, loop->num))
- return false;
- }
- else if (TREE_CODE (*step) != INTEGER_CST)
+ iv->step = CHREC_RIGHT (ev);
+ if ((!allow_nonconstant_step && TREE_CODE (iv->step) != INTEGER_CST)
+ || tree_contains_chrecs (iv->step, NULL))
return false;
- *base = CHREC_LEFT (ev);
- if (tree_contains_chrecs (*base, NULL)
- || chrec_contains_symbols_defined_in_loop (*base, loop->num))
+ iv->base = CHREC_LEFT (ev);
+ if (tree_contains_chrecs (iv->base, NULL))
return false;
+ iv->no_overflow = !folded_casts && TYPE_OVERFLOW_UNDEFINED (type);
+
return true;
}
void
scev_analysis (void)
{
- VEC(tree,heap) *exit_conditions;
+ VEC(gimple,heap) *exit_conditions;
- exit_conditions = VEC_alloc (tree, heap, 37);
- select_loops_exit_conditions (current_loops, &exit_conditions);
+ exit_conditions = VEC_alloc (gimple, heap, 37);
+ select_loops_exit_conditions (&exit_conditions);
if (dump_file && (dump_flags & TDF_STATS))
analyze_scalar_evolution_for_all_loop_phi_nodes (&exit_conditions);
number_of_iterations_for_all_loops (&exit_conditions);
- VEC_free (tree, heap, exit_conditions);
+ VEC_free (gimple, heap, exit_conditions);
}
/* Finalize the scalar evolution analysis. */
void
scev_finalize (void)
{
+ if (!scalar_evolution_info)
+ return;
htab_delete (scalar_evolution_info);
- BITMAP_FREE (already_instantiated);
+ scalar_evolution_info = NULL;
}
-/* Returns true if EXPR looks expensive. */
+/* Returns true if the expression EXPR is considered to be too expensive
+ for scev_const_prop. */
-static bool
+bool
expression_expensive_p (tree expr)
{
- return force_expr_to_var_cost (expr) >= target_spill_cost;
+ enum tree_code code;
+
+ if (is_gimple_val (expr))
+ return false;
+
+ code = TREE_CODE (expr);
+ if (code == TRUNC_DIV_EXPR
+ || code == CEIL_DIV_EXPR
+ || code == FLOOR_DIV_EXPR
+ || code == ROUND_DIV_EXPR
+ || code == TRUNC_MOD_EXPR
+ || code == CEIL_MOD_EXPR
+ || code == FLOOR_MOD_EXPR
+ || code == ROUND_MOD_EXPR
+ || code == EXACT_DIV_EXPR)
+ {
+ /* Division by power of two is usually cheap, so we allow it.
+ Forbid anything else. */
+ if (!integer_pow2p (TREE_OPERAND (expr, 1)))
+ return true;
+ }
+
+ switch (TREE_CODE_CLASS (code))
+ {
+ case tcc_binary:
+ case tcc_comparison:
+ if (expression_expensive_p (TREE_OPERAND (expr, 1)))
+ return true;
+
+ /* Fallthru. */
+ case tcc_unary:
+ return expression_expensive_p (TREE_OPERAND (expr, 0));
+
+ default:
+ return true;
+ }
}
/* Replace ssa names for that scev can prove they are constant by the
We only consider SSA names defined by phi nodes; rest is left to the
ordinary constant propagation pass. */
-void
+unsigned int
scev_const_prop (void)
{
basic_block bb;
- tree name, phi, next_phi, type, ev;
+ tree name, type, ev;
+ gimple phi, ass;
struct loop *loop, *ex_loop;
bitmap ssa_names_to_remove = NULL;
unsigned i;
+ loop_iterator li;
+ gimple_stmt_iterator psi;
- if (!current_loops)
- return;
+ if (number_of_loops () <= 1)
+ return 0;
FOR_EACH_BB (bb)
{
loop = bb->loop_father;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
{
+ phi = gsi_stmt (psi);
name = PHI_RESULT (phi);
if (!is_gimple_reg (name))
}
}
- /* Remove the ssa names that were replaced by constants. We do not remove them
- directly in the previous cycle, since this invalidates scev cache. */
+ /* Remove the ssa names that were replaced by constants. We do not
+ remove them directly in the previous cycle, since this
+ invalidates scev cache. */
if (ssa_names_to_remove)
{
bitmap_iterator bi;
- unsigned i;
EXECUTE_IF_SET_IN_BITMAP (ssa_names_to_remove, 0, i, bi)
{
+ gimple_stmt_iterator psi;
name = ssa_name (i);
phi = SSA_NAME_DEF_STMT (name);
- gcc_assert (TREE_CODE (phi) == PHI_NODE);
- remove_phi_node (phi, NULL);
+ gcc_assert (gimple_code (phi) == GIMPLE_PHI);
+ psi = gsi_for_stmt (phi);
+ remove_phi_node (&psi, true);
}
BITMAP_FREE (ssa_names_to_remove);
}
/* Now the regular final value replacement. */
- for (i = current_loops->num - 1; i > 0; i--)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
edge exit;
- tree def, rslt, ass;
- block_stmt_iterator bsi;
-
- loop = current_loops->parray[i];
- if (!loop)
- continue;
+ tree def, rslt, niter;
+ gimple_stmt_iterator bsi;
/* If we do not know exact number of iterations of the loop, we cannot
replace the final value. */
- exit = loop->single_exit;
- if (!exit
- || number_of_iterations_in_loop (loop) == chrec_dont_know)
+ exit = single_exit (loop);
+ if (!exit)
+ continue;
+
+ niter = number_of_latch_executions (loop);
+ if (niter == chrec_dont_know)
continue;
/* Ensure that it is possible to insert new statements somewhere. */
if (!single_pred_p (exit->dest))
split_loop_exit_edge (exit);
- tree_block_label (exit->dest);
- bsi = bsi_after_labels (exit->dest);
+ bsi = gsi_after_labels (exit->dest);
- ex_loop = superloop_at_depth (loop, exit->dest->loop_father->depth + 1);
+ ex_loop = superloop_at_depth (loop,
+ loop_depth (exit->dest->loop_father) + 1);
- for (phi = phi_nodes (exit->dest); phi; phi = next_phi)
+ for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); )
{
- next_phi = PHI_CHAIN (phi);
+ phi = gsi_stmt (psi);
rslt = PHI_RESULT (phi);
def = PHI_ARG_DEF_FROM_EDGE (phi, exit);
if (!is_gimple_reg (def))
- continue;
+ {
+ gsi_next (&psi);
+ continue;
+ }
if (!POINTER_TYPE_P (TREE_TYPE (def))
&& !INTEGRAL_TYPE_P (TREE_TYPE (def)))
- continue;
+ {
+ gsi_next (&psi);
+ continue;
+ }
- def = analyze_scalar_evolution_in_loop (ex_loop, loop, def);
+ def = analyze_scalar_evolution_in_loop (ex_loop, loop, def, NULL);
def = compute_overall_effect_of_inner_loop (ex_loop, def);
if (!tree_does_not_contain_chrecs (def)
- || chrec_contains_symbols_defined_in_loop (def, ex_loop->num))
- continue;
-
- /* If computing the expression is expensive, let it remain in the
- loop. */
- if (expression_expensive_p (def))
- continue;
+ || chrec_contains_symbols_defined_in_loop (def, ex_loop->num)
+ /* Moving the computation from the loop may prolong life range
+ of some ssa names, which may cause problems if they appear
+ on abnormal edges. */
+ || contains_abnormal_ssa_name_p (def)
+ /* Do not emit expensive expressions. The rationale is that
+ when someone writes a code like
+
+ while (n > 45) n -= 45;
+
+ he probably knows that n is not large, and does not want it
+ to be turned into n %= 45. */
+ || expression_expensive_p (def))
+ {
+ gsi_next (&psi);
+ continue;
+ }
- /* Eliminate the phi node and replace it by a computation outside
+ /* Eliminate the PHI node and replace it by a computation outside
the loop. */
def = unshare_expr (def);
- SET_PHI_RESULT (phi, NULL_TREE);
- remove_phi_node (phi, NULL_TREE);
-
- ass = build2 (MODIFY_EXPR, void_type_node, rslt, NULL_TREE);
- SSA_NAME_DEF_STMT (rslt) = ass;
- bsi_insert_after (&bsi, ass, BSI_NEW_STMT);
- def = force_gimple_operand_bsi (&bsi, def, false, NULL_TREE);
- TREE_OPERAND (ass, 1) = def;
- update_stmt (ass);
+ remove_phi_node (&psi, false);
+
+ def = force_gimple_operand_gsi (&bsi, def, false, NULL_TREE,
+ true, GSI_SAME_STMT);
+ ass = gimple_build_assign (rslt, def);
+ gsi_insert_before (&bsi, ass, GSI_SAME_STMT);
}
}
+ return 0;
}
+
+#include "gt-tree-scalar-evolution.h"
OSDN Git Service
