/* Tree SCC value numbering | |

Copyright (C) 2007-2021 Free Software Foundation, Inc. | |

Contributed by Daniel Berlin <dberlin@dberlin.org> | |

This file is part of GCC. | |

GCC is free software; you can redistribute it and/or modify | |

under the terms of the GNU General Public License as published by | |

the Free Software Foundation; either version 3 of the License, 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 TREE_SSA_SCCVN_H | |

#define TREE_SSA_SCCVN_H | |

/* In tree-ssa-sccvn.c */ | |

bool expressions_equal_p (tree, tree, bool = true); | |

/* TOP of the VN lattice. */ | |

extern tree VN_TOP; | |

/* A predicated value. */ | |

struct vn_pval | |

{ | |

vn_pval *next; | |

/* The value of the expression this is attached to is RESULT in | |

case the expression is computed dominated by one of the blocks | |

in valid_dominated_by_p. */ | |

tree result; | |

unsigned n; | |

int valid_dominated_by_p[1]; | |

}; | |

/* N-ary operations in the hashtable consist of length operands, an | |

opcode, and a type. Result is the value number of the operation, | |

and hashcode is stored to avoid having to calculate it | |

repeatedly. */ | |

typedef struct vn_nary_op_s | |

{ | |

vn_nary_op_s *next; | |

vn_nary_op_s *unwind_to; | |

/* Unique identify that all expressions with the same value have. */ | |

unsigned int value_id; | |

ENUM_BITFIELD(tree_code) opcode : 16; | |

unsigned length : 16; | |

hashval_t hashcode; | |

unsigned predicated_values : 1; | |

union { | |

/* If ! predicated_values this is the value of the expression. */ | |

tree result; | |

/* If predicated_values this is a list of values of the expression. */ | |

vn_pval *values; | |

} u; | |

tree type; | |

tree op[1]; | |

} *vn_nary_op_t; | |

typedef const struct vn_nary_op_s *const_vn_nary_op_t; | |

/* Return the size of a vn_nary_op_t with LENGTH operands. */ | |

static inline size_t | |

sizeof_vn_nary_op (unsigned int length) | |

{ | |

return sizeof (struct vn_nary_op_s) + sizeof (tree) * length - sizeof (tree); | |

} | |

/* Phi nodes in the hashtable consist of their non-VN_TOP phi | |

arguments, and the basic block the phi is in. Result is the value | |

number of the operation, and hashcode is stored to avoid having to | |

calculate it repeatedly. Phi nodes not in the same block are never | |

considered equivalent. */ | |

typedef struct vn_phi_s | |

{ | |

vn_phi_s *next; | |

/* Unique identifier that all expressions with the same value have. */ | |

unsigned int value_id; | |

hashval_t hashcode; | |

basic_block block; | |

/* Controlling condition lhs/rhs. */ | |

tree cclhs; | |

tree ccrhs; | |

tree type; | |

tree result; | |

/* The number of args is determined by EDGE_COUT (block->preds). */ | |

tree phiargs[1]; | |

} *vn_phi_t; | |

typedef const struct vn_phi_s *const_vn_phi_t; | |

/* Reference operands only exist in reference operations structures. | |

They consist of an opcode, type, and some number of operands. For | |

a given opcode, some, all, or none of the operands may be used. | |

The operands are there to store the information that makes up the | |

portion of the addressing calculation that opcode performs. */ | |

typedef struct vn_reference_op_struct | |

{ | |

ENUM_BITFIELD(tree_code) opcode : 16; | |

/* Dependence info, used for [TARGET_]MEM_REF only. For internal | |

function calls clique is also used for the internal function code. */ | |

unsigned short clique; | |

unsigned short base; | |

unsigned reverse : 1; | |

/* For storing TYPE_ALIGN for array ref element size computation. */ | |

unsigned align : 6; | |

/* Constant offset this op adds or -1 if it is variable. */ | |

poly_int64_pod off; | |

tree type; | |

tree op0; | |

tree op1; | |

tree op2; | |

} vn_reference_op_s; | |

typedef vn_reference_op_s *vn_reference_op_t; | |

typedef const vn_reference_op_s *const_vn_reference_op_t; | |

inline unsigned | |

vn_ref_op_align_unit (vn_reference_op_t op) | |

{ | |

return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0; | |

} | |

/* A reference operation in the hashtable is representation as | |

the vuse, representing the memory state at the time of | |

the operation, and a collection of operands that make up the | |

addressing calculation. If two vn_reference_t's have the same set | |

of operands, they access the same memory location. We also store | |

the resulting value number, and the hashcode. */ | |

typedef struct vn_reference_s | |

{ | |

vn_reference_s *next; | |

/* Unique identifier that all expressions with the same value have. */ | |

unsigned int value_id; | |

hashval_t hashcode; | |

tree vuse; | |

alias_set_type set; | |

alias_set_type base_set; | |

tree type; | |

unsigned punned : 1; | |

vec<vn_reference_op_s> operands; | |

tree result; | |

tree result_vdef; | |

} *vn_reference_t; | |

typedef const struct vn_reference_s *const_vn_reference_t; | |

typedef struct vn_constant_s | |

{ | |

unsigned int value_id; | |

hashval_t hashcode; | |

tree constant; | |

} *vn_constant_t; | |

enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI }; | |

enum vn_kind vn_get_stmt_kind (gimple *); | |

/* Hash the type TYPE using bits that distinguishes it in the | |

types_compatible_p sense. */ | |

static inline hashval_t | |

vn_hash_type (tree type) | |

{ | |

return (INTEGRAL_TYPE_P (type) | |

+ (INTEGRAL_TYPE_P (type) | |

? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0)); | |

} | |

/* Hash the constant CONSTANT with distinguishing type incompatible | |

constants in the types_compatible_p sense. */ | |

static inline hashval_t | |

vn_hash_constant_with_type (tree constant) | |

{ | |

inchash::hash hstate; | |

inchash::add_expr (constant, hstate); | |

hstate.merge_hash (vn_hash_type (TREE_TYPE (constant))); | |

return hstate.end (); | |

} | |

/* Compare the constants C1 and C2 with distinguishing type incompatible | |

constants in the types_compatible_p sense. */ | |

static inline bool | |

vn_constant_eq_with_type (tree c1, tree c2) | |

{ | |

return (expressions_equal_p (c1, c2) | |

&& types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2))); | |

} | |

/* Instead of having a local availability lattice for each basic-block | |

and availability at X defined as union of the local availabilities | |

at X and its dominators we're turning this upside down and track | |

availability per value given values are usually made available at very | |

few points. | |

So we have a chain of LOCATION, LEADER entries where LOCATION is | |

specifying the basic-block LEADER is made available for VALUE. | |

We prepend to this chain in RPO order thus for iteration we can simply | |

remove the last entries. | |

LOCATION is the basic-block index and LEADER is its SSA name version. */ | |

struct vn_avail | |

{ | |

vn_avail *next; | |

/* The basic-block LEADER is made available. */ | |

int location; | |

/* The LEADER for the value we are chained on. */ | |

int leader; | |

/* The previous value we pushed a avail record to. */ | |

struct vn_ssa_aux *next_undo; | |

}; | |

typedef struct vn_ssa_aux | |

{ | |

/* SSA name this vn_ssa_aux is associated with in the lattice. */ | |

tree name; | |

/* Value number. This may be an SSA name or a constant. */ | |

tree valnum; | |

/* Statements to insert if needs_insertion is true. */ | |

gimple_seq expr; | |

/* AVAIL entries, last in RPO order is first. This is only tracked | |

for SSA names also serving as values (NAME == VALNUM). */ | |

vn_avail *avail; | |

/* Unique identifier that all expressions with the same value have. */ | |

unsigned int value_id; | |

/* Whether the SSA_NAME has been processed at least once. */ | |

unsigned visited : 1; | |

/* Whether the SSA_NAME has no defining statement and thus an | |

insertion of such with EXPR as definition is required before | |

a use can be created of it. */ | |

unsigned needs_insertion : 1; | |

} *vn_ssa_aux_t; | |

enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE }; | |

/* Return the value numbering info for an SSA_NAME. */ | |

bool has_VN_INFO (tree); | |

extern vn_ssa_aux_t VN_INFO (tree); | |

tree vn_get_expr_for (tree); | |

void scc_vn_restore_ssa_info (void); | |

tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *); | |

tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code, | |

tree, tree *, vn_nary_op_t *); | |

vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code, | |

tree, tree *, tree, unsigned int); | |

bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, alias_set_type, | |

tree, const vec<vn_reference_op_s> &); | |

vec<vn_reference_op_s> vn_reference_operands_for_lookup (tree); | |

tree vn_reference_lookup_pieces (tree, alias_set_type, alias_set_type, tree, | |

vec<vn_reference_op_s> , | |

vn_reference_t *, vn_lookup_kind); | |

tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool, | |

tree * = NULL, tree = NULL_TREE); | |

void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t); | |

vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, alias_set_type, | |

tree, vec<vn_reference_op_s>, | |

tree, unsigned int); | |

void print_vn_reference_ops (FILE *, const vec<vn_reference_op_s>); | |

bool vn_nary_op_eq (const_vn_nary_op_t const vno1, | |

const_vn_nary_op_t const vno2); | |

bool vn_nary_may_trap (vn_nary_op_t); | |

bool vn_reference_may_trap (vn_reference_t); | |

bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const); | |

unsigned int get_max_value_id (void); | |

unsigned int get_max_constant_value_id (void); | |

unsigned int get_next_value_id (void); | |

unsigned int get_next_constant_value_id (void); | |

unsigned int get_constant_value_id (tree); | |

unsigned int get_or_alloc_constant_value_id (tree); | |

/* Return true if V is a value id for a constant. */ | |

static inline bool | |

value_id_constant_p (unsigned int v) | |

{ | |

return (int)v < 0; | |

} | |

tree fully_constant_vn_reference_p (vn_reference_t); | |

tree vn_nary_simplify (vn_nary_op_t); | |

unsigned do_rpo_vn (function *, edge, bitmap); | |

void run_rpo_vn (vn_lookup_kind); | |

unsigned eliminate_with_rpo_vn (bitmap); | |

void free_rpo_vn (void); | |

/* Valueize NAME if it is an SSA name, otherwise just return it. This hook | |

is initialized by run_scc_vn. */ | |

extern tree (*vn_valueize) (tree); | |

/* Context that valueization should operate on. */ | |

extern basic_block vn_context_bb; | |

#endif /* TREE_SSA_SCCVN_H */ |