/* Data references and dependences detectors. | |

Copyright (C) 2003-2020 Free Software Foundation, Inc. | |

Contributed by Sebastian Pop <pop@cri.ensmp.fr> | |

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/>. */ | |

#ifndef GCC_TREE_DATA_REF_H | |

#define GCC_TREE_DATA_REF_H | |

#include "graphds.h" | |

#include "tree-chrec.h" | |

#include "opt-problem.h" | |

/* | |

innermost_loop_behavior describes the evolution of the address of the memory | |

reference in the innermost enclosing loop. The address is expressed as | |

BASE + STEP * # of iteration, and base is further decomposed as the base | |

pointer (BASE_ADDRESS), loop invariant offset (OFFSET) and | |

constant offset (INIT). Examples, in loop nest | |

for (i = 0; i < 100; i++) | |

for (j = 3; j < 100; j++) | |

Example 1 Example 2 | |

data-ref a[j].b[i][j] *(p + x + 16B + 4B * j) | |

innermost_loop_behavior | |

base_address &a p | |

offset i * D_i x | |

init 3 * D_j + offsetof (b) 28 | |

step D_j 4 | |

*/ | |

struct innermost_loop_behavior | |

{ | |

tree base_address; | |

tree offset; | |

tree init; | |

tree step; | |

/* BASE_ADDRESS is known to be misaligned by BASE_MISALIGNMENT bytes | |

from an alignment boundary of BASE_ALIGNMENT bytes. For example, | |

if we had: | |

struct S __attribute__((aligned(16))) { ... }; | |

char *ptr; | |

... *(struct S *) (ptr - 4) ...; | |

the information would be: | |

base_address: ptr | |

base_aligment: 16 | |

base_misalignment: 4 | |

init: -4 | |

where init cancels the base misalignment. If instead we had a | |

reference to a particular field: | |

struct S __attribute__((aligned(16))) { ... int f; ... }; | |

char *ptr; | |

... ((struct S *) (ptr - 4))->f ...; | |

the information would be: | |

base_address: ptr | |

base_aligment: 16 | |

base_misalignment: 4 | |

init: -4 + offsetof (S, f) | |

where base_address + init might also be misaligned, and by a different | |

amount from base_address. */ | |

unsigned int base_alignment; | |

unsigned int base_misalignment; | |

/* The largest power of two that divides OFFSET, capped to a suitably | |

high value if the offset is zero. This is a byte rather than a bit | |

quantity. */ | |

unsigned int offset_alignment; | |

/* Likewise for STEP. */ | |

unsigned int step_alignment; | |

}; | |

/* Describes the evolutions of indices of the memory reference. The indices | |

are indices of the ARRAY_REFs, indexes in artificial dimensions | |

added for member selection of records and the operands of MEM_REFs. | |

BASE_OBJECT is the part of the reference that is loop-invariant | |

(note that this reference does not have to cover the whole object | |

being accessed, in which case UNCONSTRAINED_BASE is set; hence it is | |

not recommended to use BASE_OBJECT in any code generation). | |

For the examples above, | |

base_object: a *(p + x + 4B * j_0) | |

indices: {j_0, +, 1}_2 {16, +, 4}_2 | |

4 | |

{i_0, +, 1}_1 | |

{j_0, +, 1}_2 | |

*/ | |

struct indices | |

{ | |

/* The object. */ | |

tree base_object; | |

/* A list of chrecs. Access functions of the indices. */ | |

vec<tree> access_fns; | |

/* Whether BASE_OBJECT is an access representing the whole object | |

or whether the access could not be constrained. */ | |

bool unconstrained_base; | |

}; | |

struct dr_alias | |

{ | |

/* The alias information that should be used for new pointers to this | |

location. */ | |

struct ptr_info_def *ptr_info; | |

}; | |

/* An integer vector. A vector formally consists of an element of a vector | |

space. A vector space is a set that is closed under vector addition | |

and scalar multiplication. In this vector space, an element is a list of | |

integers. */ | |

typedef HOST_WIDE_INT lambda_int; | |

typedef lambda_int *lambda_vector; | |

/* An integer matrix. A matrix consists of m vectors of length n (IE | |

all vectors are the same length). */ | |

typedef lambda_vector *lambda_matrix; | |

struct data_reference | |

{ | |

/* A pointer to the statement that contains this DR. */ | |

gimple *stmt; | |

/* A pointer to the memory reference. */ | |

tree ref; | |

/* Auxiliary info specific to a pass. */ | |

void *aux; | |

/* True when the data reference is in RHS of a stmt. */ | |

bool is_read; | |

/* True when the data reference is conditional within STMT, | |

i.e. if it might not occur even when the statement is executed | |

and runs to completion. */ | |

bool is_conditional_in_stmt; | |

/* Behavior of the memory reference in the innermost loop. */ | |

struct innermost_loop_behavior innermost; | |

/* Subscripts of this data reference. */ | |

struct indices indices; | |

/* Alias information for the data reference. */ | |

struct dr_alias alias; | |

}; | |

#define DR_STMT(DR) (DR)->stmt | |

#define DR_REF(DR) (DR)->ref | |

#define DR_BASE_OBJECT(DR) (DR)->indices.base_object | |

#define DR_UNCONSTRAINED_BASE(DR) (DR)->indices.unconstrained_base | |

#define DR_ACCESS_FNS(DR) (DR)->indices.access_fns | |

#define DR_ACCESS_FN(DR, I) DR_ACCESS_FNS (DR)[I] | |

#define DR_NUM_DIMENSIONS(DR) DR_ACCESS_FNS (DR).length () | |

#define DR_IS_READ(DR) (DR)->is_read | |

#define DR_IS_WRITE(DR) (!DR_IS_READ (DR)) | |

#define DR_IS_CONDITIONAL_IN_STMT(DR) (DR)->is_conditional_in_stmt | |

#define DR_BASE_ADDRESS(DR) (DR)->innermost.base_address | |

#define DR_OFFSET(DR) (DR)->innermost.offset | |

#define DR_INIT(DR) (DR)->innermost.init | |

#define DR_STEP(DR) (DR)->innermost.step | |

#define DR_PTR_INFO(DR) (DR)->alias.ptr_info | |

#define DR_BASE_ALIGNMENT(DR) (DR)->innermost.base_alignment | |

#define DR_BASE_MISALIGNMENT(DR) (DR)->innermost.base_misalignment | |

#define DR_OFFSET_ALIGNMENT(DR) (DR)->innermost.offset_alignment | |

#define DR_STEP_ALIGNMENT(DR) (DR)->innermost.step_alignment | |

#define DR_INNERMOST(DR) (DR)->innermost | |

typedef struct data_reference *data_reference_p; | |

/* This struct is used to store the information of a data reference, | |

including the data ref itself and the segment length for aliasing | |

checks. This is used to merge alias checks. */ | |

class dr_with_seg_len | |

{ | |

public: | |

dr_with_seg_len (data_reference_p d, tree len, unsigned HOST_WIDE_INT size, | |

unsigned int a) | |

: dr (d), seg_len (len), access_size (size), align (a) {} | |

data_reference_p dr; | |

/* The offset of the last access that needs to be checked minus | |

the offset of the first. */ | |

tree seg_len; | |

/* A value that, when added to abs (SEG_LEN), gives the total number of | |

bytes in the segment. */ | |

poly_uint64 access_size; | |

/* The minimum common alignment of DR's start address, SEG_LEN and | |

ACCESS_SIZE. */ | |

unsigned int align; | |

}; | |

/* Flags that describe a potential alias between two dr_with_seg_lens. | |

In general, each pair of dr_with_seg_lens represents a composite of | |

multiple access pairs P, so testing flags like DR_IS_READ on the DRs | |

does not give meaningful information. | |

DR_ALIAS_RAW: | |

There is a pair in P for which the second reference is a read | |

and the first is a write. | |

DR_ALIAS_WAR: | |

There is a pair in P for which the second reference is a write | |

and the first is a read. | |

DR_ALIAS_WAW: | |

There is a pair in P for which both references are writes. | |

DR_ALIAS_ARBITRARY: | |

Either | |

(a) it isn't possible to classify one pair in P as RAW, WAW or WAR; or | |

(b) there is a pair in P that breaks the ordering assumption below. | |

This flag overrides the RAW, WAR and WAW flags above. | |

DR_ALIAS_UNSWAPPED: | |

DR_ALIAS_SWAPPED: | |

Temporary flags that indicate whether there is a pair P whose | |

DRs have or haven't been swapped around. | |

DR_ALIAS_MIXED_STEPS: | |

The DR_STEP for one of the data references in the pair does not | |

accurately describe that reference for all members of P. (Note | |

that the flag does not say anything about whether the DR_STEPs | |

of the two references in the pair are the same.) | |

The ordering assumption mentioned above is that for every pair | |

(DR_A, DR_B) in P: | |

(1) The original code accesses n elements for DR_A and n elements for DR_B, | |

interleaved as follows: | |

one access of size DR_A.access_size at DR_A.dr | |

one access of size DR_B.access_size at DR_B.dr | |

one access of size DR_A.access_size at DR_A.dr + STEP_A | |

one access of size DR_B.access_size at DR_B.dr + STEP_B | |

one access of size DR_A.access_size at DR_A.dr + STEP_A * 2 | |

one access of size DR_B.access_size at DR_B.dr + STEP_B * 2 | |

... | |

(2) The new code accesses the same data in exactly two chunks: | |

one group of accesses spanning |DR_A.seg_len| + DR_A.access_size | |

one group of accesses spanning |DR_B.seg_len| + DR_B.access_size | |

A pair might break this assumption if the DR_A and DR_B accesses | |

in the original or the new code are mingled in some way. For example, | |

if DR_A.access_size represents the effect of two individual writes | |

to nearby locations, the pair breaks the assumption if those writes | |

occur either side of the access for DR_B. | |

Note that DR_ALIAS_ARBITRARY describes whether the ordering assumption | |

fails to hold for any individual pair in P. If the assumption *does* | |

hold for every pair in P, it doesn't matter whether it holds for the | |

composite pair or not. In other words, P should represent the complete | |

set of pairs that the composite pair is testing, so only the ordering | |

of two accesses in the same member of P matters. */ | |

const unsigned int DR_ALIAS_RAW = 1U << 0; | |

const unsigned int DR_ALIAS_WAR = 1U << 1; | |

const unsigned int DR_ALIAS_WAW = 1U << 2; | |

const unsigned int DR_ALIAS_ARBITRARY = 1U << 3; | |

const unsigned int DR_ALIAS_SWAPPED = 1U << 4; | |

const unsigned int DR_ALIAS_UNSWAPPED = 1U << 5; | |

const unsigned int DR_ALIAS_MIXED_STEPS = 1U << 6; | |

/* This struct contains two dr_with_seg_len objects with aliasing data | |

refs. Two comparisons are generated from them. */ | |

class dr_with_seg_len_pair_t | |

{ | |

public: | |

/* WELL_ORDERED indicates that the ordering assumption described above | |

DR_ALIAS_ARBITRARY holds. REORDERED indicates that it doesn't. */ | |

enum sequencing { WELL_ORDERED, REORDERED }; | |

dr_with_seg_len_pair_t (const dr_with_seg_len &, | |

const dr_with_seg_len &, sequencing); | |

dr_with_seg_len first; | |

dr_with_seg_len second; | |

unsigned int flags; | |

}; | |

inline dr_with_seg_len_pair_t:: | |

dr_with_seg_len_pair_t (const dr_with_seg_len &d1, const dr_with_seg_len &d2, | |

sequencing seq) | |

: first (d1), second (d2), flags (0) | |

{ | |

if (DR_IS_READ (d1.dr) && DR_IS_WRITE (d2.dr)) | |

flags |= DR_ALIAS_WAR; | |

else if (DR_IS_WRITE (d1.dr) && DR_IS_READ (d2.dr)) | |

flags |= DR_ALIAS_RAW; | |

else if (DR_IS_WRITE (d1.dr) && DR_IS_WRITE (d2.dr)) | |

flags |= DR_ALIAS_WAW; | |

else | |

gcc_unreachable (); | |

if (seq == REORDERED) | |

flags |= DR_ALIAS_ARBITRARY; | |

} | |

enum data_dependence_direction { | |

dir_positive, | |

dir_negative, | |

dir_equal, | |

dir_positive_or_negative, | |

dir_positive_or_equal, | |

dir_negative_or_equal, | |

dir_star, | |

dir_independent | |

}; | |

/* The description of the grid of iterations that overlap. At most | |

two loops are considered at the same time just now, hence at most | |

two functions are needed. For each of the functions, we store | |

the vector of coefficients, f[0] + x * f[1] + y * f[2] + ..., | |

where x, y, ... are variables. */ | |

#define MAX_DIM 2 | |

/* Special values of N. */ | |

#define NO_DEPENDENCE 0 | |

#define NOT_KNOWN (MAX_DIM + 1) | |

#define CF_NONTRIVIAL_P(CF) ((CF)->n != NO_DEPENDENCE && (CF)->n != NOT_KNOWN) | |

#define CF_NOT_KNOWN_P(CF) ((CF)->n == NOT_KNOWN) | |

#define CF_NO_DEPENDENCE_P(CF) ((CF)->n == NO_DEPENDENCE) | |

typedef vec<tree> affine_fn; | |

struct conflict_function | |

{ | |

unsigned n; | |

affine_fn fns[MAX_DIM]; | |

}; | |

/* What is a subscript? Given two array accesses a subscript is the | |

tuple composed of the access functions for a given dimension. | |

Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three | |

subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts | |

are stored in the data_dependence_relation structure under the form | |

of an array of subscripts. */ | |

struct subscript | |

{ | |

/* The access functions of the two references. */ | |

tree access_fn[2]; | |

/* A description of the iterations for which the elements are | |

accessed twice. */ | |

conflict_function *conflicting_iterations_in_a; | |

conflict_function *conflicting_iterations_in_b; | |

/* This field stores the information about the iteration domain | |

validity of the dependence relation. */ | |

tree last_conflict; | |

/* Distance from the iteration that access a conflicting element in | |

A to the iteration that access this same conflicting element in | |

B. The distance is a tree scalar expression, i.e. a constant or a | |

symbolic expression, but certainly not a chrec function. */ | |

tree distance; | |

}; | |

typedef struct subscript *subscript_p; | |

#define SUB_ACCESS_FN(SUB, I) (SUB)->access_fn[I] | |

#define SUB_CONFLICTS_IN_A(SUB) (SUB)->conflicting_iterations_in_a | |

#define SUB_CONFLICTS_IN_B(SUB) (SUB)->conflicting_iterations_in_b | |

#define SUB_LAST_CONFLICT(SUB) (SUB)->last_conflict | |

#define SUB_DISTANCE(SUB) (SUB)->distance | |

/* A data_dependence_relation represents a relation between two | |

data_references A and B. */ | |

struct data_dependence_relation | |

{ | |

struct data_reference *a; | |

struct data_reference *b; | |

/* A "yes/no/maybe" field for the dependence relation: | |

- when "ARE_DEPENDENT == NULL_TREE", there exist a dependence | |

relation between A and B, and the description of this relation | |

is given in the SUBSCRIPTS array, | |

- when "ARE_DEPENDENT == chrec_known", there is no dependence and | |

SUBSCRIPTS is empty, | |

- when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence, | |

but the analyzer cannot be more specific. */ | |

tree are_dependent; | |

/* If nonnull, COULD_BE_INDEPENDENT_P is true and the accesses are | |

independent when the runtime addresses of OBJECT_A and OBJECT_B | |

are different. The addresses of both objects are invariant in the | |

loop nest. */ | |

tree object_a; | |

tree object_b; | |

/* For each subscript in the dependence test, there is an element in | |

this array. This is the attribute that labels the edge A->B of | |

the data_dependence_relation. */ | |

vec<subscript_p> subscripts; | |

/* The analyzed loop nest. */ | |

vec<loop_p> loop_nest; | |

/* The classic direction vector. */ | |

vec<lambda_vector> dir_vects; | |

/* The classic distance vector. */ | |

vec<lambda_vector> dist_vects; | |

/* Is the dependence reversed with respect to the lexicographic order? */ | |

bool reversed_p; | |

/* When the dependence relation is affine, it can be represented by | |

a distance vector. */ | |

bool affine_p; | |

/* Set to true when the dependence relation is on the same data | |

access. */ | |

bool self_reference_p; | |

/* True if the dependence described is conservatively correct rather | |

than exact, and if it is still possible for the accesses to be | |

conditionally independent. For example, the a and b references in: | |

struct s *a, *b; | |

for (int i = 0; i < n; ++i) | |

a->f[i] += b->f[i]; | |

conservatively have a distance vector of (0), for the case in which | |

a == b, but the accesses are independent if a != b. Similarly, | |

the a and b references in: | |

struct s *a, *b; | |

for (int i = 0; i < n; ++i) | |

a[0].f[i] += b[i].f[i]; | |

conservatively have a distance vector of (0), but they are indepenent | |

when a != b + i. In contrast, the references in: | |

struct s *a; | |

for (int i = 0; i < n; ++i) | |

a->f[i] += a->f[i]; | |

have the same distance vector of (0), but the accesses can never be | |

independent. */ | |

bool could_be_independent_p; | |

}; | |

typedef struct data_dependence_relation *ddr_p; | |

#define DDR_A(DDR) (DDR)->a | |

#define DDR_B(DDR) (DDR)->b | |

#define DDR_AFFINE_P(DDR) (DDR)->affine_p | |

#define DDR_ARE_DEPENDENT(DDR) (DDR)->are_dependent | |

#define DDR_OBJECT_A(DDR) (DDR)->object_a | |

#define DDR_OBJECT_B(DDR) (DDR)->object_b | |

#define DDR_SUBSCRIPTS(DDR) (DDR)->subscripts | |

#define DDR_SUBSCRIPT(DDR, I) DDR_SUBSCRIPTS (DDR)[I] | |

#define DDR_NUM_SUBSCRIPTS(DDR) DDR_SUBSCRIPTS (DDR).length () | |

#define DDR_LOOP_NEST(DDR) (DDR)->loop_nest | |

/* The size of the direction/distance vectors: the number of loops in | |

the loop nest. */ | |

#define DDR_NB_LOOPS(DDR) (DDR_LOOP_NEST (DDR).length ()) | |

#define DDR_SELF_REFERENCE(DDR) (DDR)->self_reference_p | |

#define DDR_DIST_VECTS(DDR) ((DDR)->dist_vects) | |

#define DDR_DIR_VECTS(DDR) ((DDR)->dir_vects) | |

#define DDR_NUM_DIST_VECTS(DDR) \ | |

(DDR_DIST_VECTS (DDR).length ()) | |

#define DDR_NUM_DIR_VECTS(DDR) \ | |

(DDR_DIR_VECTS (DDR).length ()) | |

#define DDR_DIR_VECT(DDR, I) \ | |

DDR_DIR_VECTS (DDR)[I] | |

#define DDR_DIST_VECT(DDR, I) \ | |

DDR_DIST_VECTS (DDR)[I] | |

#define DDR_REVERSED_P(DDR) (DDR)->reversed_p | |

#define DDR_COULD_BE_INDEPENDENT_P(DDR) (DDR)->could_be_independent_p | |

opt_result dr_analyze_innermost (innermost_loop_behavior *, tree, | |

class loop *, const gimple *); | |

extern bool compute_data_dependences_for_loop (class loop *, bool, | |

vec<loop_p> *, | |

vec<data_reference_p> *, | |

vec<ddr_p> *); | |

extern void debug_ddrs (vec<ddr_p> ); | |

extern void dump_data_reference (FILE *, struct data_reference *); | |

extern void debug (data_reference &ref); | |

extern void debug (data_reference *ptr); | |

extern void debug_data_reference (struct data_reference *); | |

extern void debug_data_references (vec<data_reference_p> ); | |

extern void debug (vec<data_reference_p> &ref); | |

extern void debug (vec<data_reference_p> *ptr); | |

extern void debug_data_dependence_relation (struct data_dependence_relation *); | |

extern void dump_data_dependence_relations (FILE *, vec<ddr_p> ); | |

extern void debug (vec<ddr_p> &ref); | |

extern void debug (vec<ddr_p> *ptr); | |

extern void debug_data_dependence_relations (vec<ddr_p> ); | |

extern void free_dependence_relation (struct data_dependence_relation *); | |

extern void free_dependence_relations (vec<ddr_p> ); | |

extern void free_data_ref (data_reference_p); | |

extern void free_data_refs (vec<data_reference_p> ); | |

extern opt_result find_data_references_in_stmt (class loop *, gimple *, | |

vec<data_reference_p> *); | |

extern bool graphite_find_data_references_in_stmt (edge, loop_p, gimple *, | |

vec<data_reference_p> *); | |

tree find_data_references_in_loop (class loop *, vec<data_reference_p> *); | |

bool loop_nest_has_data_refs (loop_p loop); | |

struct data_reference *create_data_ref (edge, loop_p, tree, gimple *, bool, | |

bool); | |

extern bool find_loop_nest (class loop *, vec<loop_p> *); | |

extern struct data_dependence_relation *initialize_data_dependence_relation | |

(struct data_reference *, struct data_reference *, vec<loop_p>); | |

extern void compute_affine_dependence (struct data_dependence_relation *, | |

loop_p); | |

extern void compute_self_dependence (struct data_dependence_relation *); | |

extern bool compute_all_dependences (vec<data_reference_p> , | |

vec<ddr_p> *, | |

vec<loop_p>, bool); | |

extern tree find_data_references_in_bb (class loop *, basic_block, | |

vec<data_reference_p> *); | |

extern unsigned int dr_alignment (innermost_loop_behavior *); | |

extern tree get_base_for_alignment (tree, unsigned int *); | |

/* Return the alignment in bytes that DR is guaranteed to have at all | |

times. */ | |

inline unsigned int | |

dr_alignment (data_reference *dr) | |

{ | |

return dr_alignment (&DR_INNERMOST (dr)); | |

} | |

extern bool dr_may_alias_p (const struct data_reference *, | |

const struct data_reference *, class loop *); | |

extern bool dr_equal_offsets_p (struct data_reference *, | |

struct data_reference *); | |

extern opt_result runtime_alias_check_p (ddr_p, class loop *, bool); | |

extern int data_ref_compare_tree (tree, tree); | |

extern void prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *, | |

poly_uint64); | |

extern void create_runtime_alias_checks (class loop *, | |

vec<dr_with_seg_len_pair_t> *, tree*); | |

extern tree dr_direction_indicator (struct data_reference *); | |

extern tree dr_zero_step_indicator (struct data_reference *); | |

extern bool dr_known_forward_stride_p (struct data_reference *); | |

/* Return true when the base objects of data references A and B are | |

the same memory object. */ | |

static inline bool | |

same_data_refs_base_objects (data_reference_p a, data_reference_p b) | |

{ | |

return DR_NUM_DIMENSIONS (a) == DR_NUM_DIMENSIONS (b) | |

&& operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), 0); | |

} | |

/* Return true when the data references A and B are accessing the same | |

memory object with the same access functions. */ | |

static inline bool | |

same_data_refs (data_reference_p a, data_reference_p b) | |

{ | |

unsigned int i; | |

/* The references are exactly the same. */ | |

if (operand_equal_p (DR_REF (a), DR_REF (b), 0)) | |

return true; | |

if (!same_data_refs_base_objects (a, b)) | |

return false; | |

for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) | |

if (!eq_evolutions_p (DR_ACCESS_FN (a, i), DR_ACCESS_FN (b, i))) | |

return false; | |

return true; | |

} | |

/* Returns true when all the dependences are computable. */ | |

inline bool | |

known_dependences_p (vec<ddr_p> dependence_relations) | |

{ | |

ddr_p ddr; | |

unsigned int i; | |

FOR_EACH_VEC_ELT (dependence_relations, i, ddr) | |

if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) | |

return false; | |

return true; | |

} | |

/* Returns the dependence level for a vector DIST of size LENGTH. | |

LEVEL = 0 means a lexicographic dependence, i.e. a dependence due | |

to the sequence of statements, not carried by any loop. */ | |

static inline unsigned | |

dependence_level (lambda_vector dist_vect, int length) | |

{ | |

int i; | |

for (i = 0; i < length; i++) | |

if (dist_vect[i] != 0) | |

return i + 1; | |

return 0; | |

} | |

/* Return the dependence level for the DDR relation. */ | |

static inline unsigned | |

ddr_dependence_level (ddr_p ddr) | |

{ | |

unsigned vector; | |

unsigned level = 0; | |

if (DDR_DIST_VECTS (ddr).exists ()) | |

level = dependence_level (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr)); | |

for (vector = 1; vector < DDR_NUM_DIST_VECTS (ddr); vector++) | |

level = MIN (level, dependence_level (DDR_DIST_VECT (ddr, vector), | |

DDR_NB_LOOPS (ddr))); | |

return level; | |

} | |

/* Return the index of the variable VAR in the LOOP_NEST array. */ | |

static inline int | |

index_in_loop_nest (int var, vec<loop_p> loop_nest) | |

{ | |

class loop *loopi; | |

int var_index; | |

for (var_index = 0; loop_nest.iterate (var_index, &loopi); var_index++) | |

if (loopi->num == var) | |

return var_index; | |

gcc_unreachable (); | |

} | |

/* Returns true when the data reference DR the form "A[i] = ..." | |

with a stride equal to its unit type size. */ | |

static inline bool | |

adjacent_dr_p (struct data_reference *dr) | |

{ | |

/* If this is a bitfield store bail out. */ | |

if (TREE_CODE (DR_REF (dr)) == COMPONENT_REF | |

&& DECL_BIT_FIELD (TREE_OPERAND (DR_REF (dr), 1))) | |

return false; | |

if (!DR_STEP (dr) | |

|| TREE_CODE (DR_STEP (dr)) != INTEGER_CST) | |

return false; | |

return tree_int_cst_equal (fold_unary (ABS_EXPR, TREE_TYPE (DR_STEP (dr)), | |

DR_STEP (dr)), | |

TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)))); | |

} | |

void split_constant_offset (tree , tree *, tree *); | |

/* Compute the greatest common divisor of a VECTOR of SIZE numbers. */ | |

static inline lambda_int | |

lambda_vector_gcd (lambda_vector vector, int size) | |

{ | |

int i; | |

lambda_int gcd1 = 0; | |

if (size > 0) | |

{ | |

gcd1 = vector[0]; | |

for (i = 1; i < size; i++) | |

gcd1 = gcd (gcd1, vector[i]); | |

} | |

return gcd1; | |

} | |

/* Allocate a new vector of given SIZE. */ | |

static inline lambda_vector | |

lambda_vector_new (int size) | |

{ | |

/* ??? We shouldn't abuse the GC allocator here. */ | |

return ggc_cleared_vec_alloc<lambda_int> (size); | |

} | |

/* Clear out vector VEC1 of length SIZE. */ | |

static inline void | |

lambda_vector_clear (lambda_vector vec1, int size) | |

{ | |

memset (vec1, 0, size * sizeof (*vec1)); | |

} | |

/* Returns true when the vector V is lexicographically positive, in | |

other words, when the first nonzero element is positive. */ | |

static inline bool | |

lambda_vector_lexico_pos (lambda_vector v, | |

unsigned n) | |

{ | |

unsigned i; | |

for (i = 0; i < n; i++) | |

{ | |

if (v[i] == 0) | |

continue; | |

if (v[i] < 0) | |

return false; | |

if (v[i] > 0) | |

return true; | |

} | |

return true; | |

} | |

/* Return true if vector VEC1 of length SIZE is the zero vector. */ | |

static inline bool | |

lambda_vector_zerop (lambda_vector vec1, int size) | |

{ | |

int i; | |

for (i = 0; i < size; i++) | |

if (vec1[i] != 0) | |

return false; | |

return true; | |

} | |

/* Allocate a matrix of M rows x N cols. */ | |

static inline lambda_matrix | |

lambda_matrix_new (int m, int n, struct obstack *lambda_obstack) | |

{ | |

lambda_matrix mat; | |

int i; | |

mat = XOBNEWVEC (lambda_obstack, lambda_vector, m); | |

for (i = 0; i < m; i++) | |

mat[i] = XOBNEWVEC (lambda_obstack, lambda_int, n); | |

return mat; | |

} | |

#endif /* GCC_TREE_DATA_REF_H */ |