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gnu / gcc / 926d9947847a0683cf34de6fc231209747576088 / . / gcc / tree-ssa-sccvn.c
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/* SCC value numbering for trees
Copyright (C) 2006-2015 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "hash-set.h"
#include "machmode.h"
#include "vec.h"
#include "double-int.h"
#include "input.h"
#include "alias.h"
#include "symtab.h"
#include "wide-int.h"
#include "inchash.h"
#include "tree.h"
#include "fold-const.h"
#include "stor-layout.h"
#include "predict.h"
#include "hard-reg-set.h"
#include "function.h"
#include "dominance.h"
#include "cfg.h"
#include "cfganal.h"
#include "basic-block.h"
#include "gimple-pretty-print.h"
#include "tree-inline.h"
#include "hash-table.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "gimple-fold.h"
#include "tree-eh.h"
#include "gimple-expr.h"
#include "is-a.h"
#include "gimple.h"
#include "gimplify.h"
#include "gimple-ssa.h"
#include "tree-phinodes.h"
#include "ssa-iterators.h"
#include "stringpool.h"
#include "tree-ssanames.h"
#include "hashtab.h"
#include "rtl.h"
#include "flags.h"
#include "statistics.h"
#include "real.h"
#include "fixed-value.h"
#include "insn-config.h"
#include "expmed.h"
#include "dojump.h"
#include "explow.h"
#include "calls.h"
#include "emit-rtl.h"
#include "varasm.h"
#include "stmt.h"
#include "expr.h"
#include "tree-dfa.h"
#include "tree-ssa.h"
#include "dumpfile.h"
#include "alloc-pool.h"
#include "cfgloop.h"
#include "params.h"
#include "tree-ssa-propagate.h"
#include "tree-ssa-sccvn.h"
#include "tree-cfg.h"
#include "domwalk.h"
#include "ipa-ref.h"
#include "plugin-api.h"
#include "cgraph.h"
/* This algorithm is based on the SCC algorithm presented by Keith
Cooper and L. Taylor Simpson in "SCC-Based Value numbering"
(http://citeseer.ist.psu.edu/41805.html). In
straight line code, it is equivalent to a regular hash based value
numbering that is performed in reverse postorder.
For code with cycles, there are two alternatives, both of which
require keeping the hashtables separate from the actual list of
value numbers for SSA names.
1. Iterate value numbering in an RPO walk of the blocks, removing
all the entries from the hashtable after each iteration (but
keeping the SSA name->value number mapping between iterations).
Iterate until it does not change.
2. Perform value numbering as part of an SCC walk on the SSA graph,
iterating only the cycles in the SSA graph until they do not change
(using a separate, optimistic hashtable for value numbering the SCC
operands).
The second is not just faster in practice (because most SSA graph
cycles do not involve all the variables in the graph), it also has
some nice properties.
One of these nice properties is that when we pop an SCC off the
stack, we are guaranteed to have processed all the operands coming from
*outside of that SCC*, so we do not need to do anything special to
ensure they have value numbers.
Another nice property is that the SCC walk is done as part of a DFS
of the SSA graph, which makes it easy to perform combining and
simplifying operations at the same time.
The code below is deliberately written in a way that makes it easy
to separate the SCC walk from the other work it does.
In order to propagate constants through the code, we track which
expressions contain constants, and use those while folding. In
theory, we could also track expressions whose value numbers are
replaced, in case we end up folding based on expression
identities.
In order to value number memory, we assign value numbers to vuses.
This enables us to note that, for example, stores to the same
address of the same value from the same starting memory states are
equivalent.
TODO:
1. We can iterate only the changing portions of the SCC's, but
I have not seen an SCC big enough for this to be a win.
2. If you differentiate between phi nodes for loops and phi nodes
for if-then-else, you can properly consider phi nodes in different
blocks for equivalence.
3. We could value number vuses in more cases, particularly, whole
structure copies.
*/
/* vn_nary_op hashtable helpers. */
struct vn_nary_op_hasher : typed_noop_remove <vn_nary_op_s>
{
typedef vn_nary_op_s value_type;
typedef vn_nary_op_s compare_type;
static inline hashval_t hash (const value_type *);
static inline bool equal (const value_type *, const compare_type *);
};
/* Return the computed hashcode for nary operation P1. */
inline hashval_t
vn_nary_op_hasher::hash (const value_type *vno1)
{
return vno1->hashcode;
}
/* Compare nary operations P1 and P2 and return true if they are
equivalent. */
inline bool
vn_nary_op_hasher::equal (const value_type *vno1, const compare_type *vno2)
{
return vn_nary_op_eq (vno1, vno2);
}
typedef hash_table<vn_nary_op_hasher> vn_nary_op_table_type;
typedef vn_nary_op_table_type::iterator vn_nary_op_iterator_type;
/* vn_phi hashtable helpers. */
static int
vn_phi_eq (const_vn_phi_t const vp1, const_vn_phi_t const vp2);
struct vn_phi_hasher
{
typedef vn_phi_s value_type;
typedef vn_phi_s compare_type;
static inline hashval_t hash (const value_type *);
static inline bool equal (const value_type *, const compare_type *);
static inline void remove (value_type *);
};
/* Return the computed hashcode for phi operation P1. */
inline hashval_t
vn_phi_hasher::hash (const value_type *vp1)
{
return vp1->hashcode;
}
/* Compare two phi entries for equality, ignoring VN_TOP arguments. */
inline bool
vn_phi_hasher::equal (const value_type *vp1, const compare_type *vp2)
{
return vn_phi_eq (vp1, vp2);
}
/* Free a phi operation structure VP. */
inline void
vn_phi_hasher::remove (value_type *phi)
{
phi->phiargs.release ();
}
typedef hash_table<vn_phi_hasher> vn_phi_table_type;
typedef vn_phi_table_type::iterator vn_phi_iterator_type;
/* Compare two reference operands P1 and P2 for equality. Return true if
they are equal, and false otherwise. */
static int
vn_reference_op_eq (const void *p1, const void *p2)
{
const_vn_reference_op_t const vro1 = (const_vn_reference_op_t) p1;
const_vn_reference_op_t const vro2 = (const_vn_reference_op_t) p2;
return (vro1->opcode == vro2->opcode
/* We do not care for differences in type qualification. */
&& (vro1->type == vro2->type
|| (vro1->type && vro2->type
&& types_compatible_p (TYPE_MAIN_VARIANT (vro1->type),
TYPE_MAIN_VARIANT (vro2->type))))
&& expressions_equal_p (vro1->op0, vro2->op0)
&& expressions_equal_p (vro1->op1, vro2->op1)
&& expressions_equal_p (vro1->op2, vro2->op2));
}
/* Free a reference operation structure VP. */
static inline void
free_reference (vn_reference_s *vr)
{
vr->operands.release ();
}
/* vn_reference hashtable helpers. */
struct vn_reference_hasher
{
typedef vn_reference_s value_type;
typedef vn_reference_s compare_type;
static inline hashval_t hash (const value_type *);
static inline bool equal (const value_type *, const compare_type *);
static inline void remove (value_type *);
};
/* Return the hashcode for a given reference operation P1. */
inline hashval_t
vn_reference_hasher::hash (const value_type *vr1)
{
return vr1->hashcode;
}
inline bool
vn_reference_hasher::equal (const value_type *v, const compare_type *c)
{
return vn_reference_eq (v, c);
}
inline void
vn_reference_hasher::remove (value_type *v)
{
free_reference (v);
}
typedef hash_table<vn_reference_hasher> vn_reference_table_type;
typedef vn_reference_table_type::iterator vn_reference_iterator_type;
/* The set of hashtables and alloc_pool's for their items. */
typedef struct vn_tables_s
{
vn_nary_op_table_type *nary;
vn_phi_table_type *phis;
vn_reference_table_type *references;
struct obstack nary_obstack;
alloc_pool phis_pool;
alloc_pool references_pool;
} *vn_tables_t;
/* vn_constant hashtable helpers. */
struct vn_constant_hasher : typed_free_remove <vn_constant_s>
{
typedef vn_constant_s value_type;
typedef vn_constant_s compare_type;
static inline hashval_t hash (const value_type *);
static inline bool equal (const value_type *, const compare_type *);
};
/* Hash table hash function for vn_constant_t. */
inline hashval_t
vn_constant_hasher::hash (const value_type *vc1)
{
return vc1->hashcode;
}
/* Hash table equality function for vn_constant_t. */
inline bool
vn_constant_hasher::equal (const value_type *vc1, const compare_type *vc2)
{
if (vc1->hashcode != vc2->hashcode)
return false;
return vn_constant_eq_with_type (vc1->constant, vc2->constant);
}
static hash_table<vn_constant_hasher> *constant_to_value_id;
static bitmap constant_value_ids;
/* Valid hashtables storing information we have proven to be
correct. */
static vn_tables_t valid_info;
/* Optimistic hashtables storing information we are making assumptions about
during iterations. */
static vn_tables_t optimistic_info;
/* Pointer to the set of hashtables that is currently being used.
Should always point to either the optimistic_info, or the
valid_info. */
static vn_tables_t current_info;
/* Reverse post order index for each basic block. */
static int *rpo_numbers;
#define SSA_VAL(x) (VN_INFO ((x))->valnum)
/* Return the SSA value of the VUSE x, supporting released VDEFs
during elimination which will value-number the VDEF to the
associated VUSE (but not substitute in the whole lattice). */
static inline tree
vuse_ssa_val (tree x)
{
if (!x)
return NULL_TREE;
do
{
x = SSA_VAL (x);
}
while (SSA_NAME_IN_FREE_LIST (x));
return x;
}
/* This represents the top of the VN lattice, which is the universal
value. */
tree VN_TOP;
/* Unique counter for our value ids. */
static unsigned int next_value_id;
/* Next DFS number and the stack for strongly connected component
detection. */
static unsigned int next_dfs_num;
static vec<tree> sccstack;
/* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
are allocated on an obstack for locality reasons, and to free them
without looping over the vec. */
static vec<vn_ssa_aux_t> vn_ssa_aux_table;
static struct obstack vn_ssa_aux_obstack;
/* Return the value numbering information for a given SSA name. */
vn_ssa_aux_t
VN_INFO (tree name)
{
vn_ssa_aux_t res = vn_ssa_aux_table[SSA_NAME_VERSION (name)];
gcc_checking_assert (res);
return res;
}
/* Set the value numbering info for a given SSA name to a given
value. */
static inline void
VN_INFO_SET (tree name, vn_ssa_aux_t value)
{
vn_ssa_aux_table[SSA_NAME_VERSION (name)] = value;
}
/* Initialize the value numbering info for a given SSA name.
This should be called just once for every SSA name. */
vn_ssa_aux_t
VN_INFO_GET (tree name)
{
vn_ssa_aux_t newinfo;
newinfo = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
memset (newinfo, 0, sizeof (struct vn_ssa_aux));
if (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ())
vn_ssa_aux_table.safe_grow (SSA_NAME_VERSION (name) + 1);
vn_ssa_aux_table[SSA_NAME_VERSION (name)] = newinfo;
return newinfo;
}
/* Get the representative expression for the SSA_NAME NAME. Returns
the representative SSA_NAME if there is no expression associated with it. */
tree
vn_get_expr_for (tree name)
{
vn_ssa_aux_t vn = VN_INFO (name);
gimple def_stmt;
tree expr = NULL_TREE;
enum tree_code code;
if (vn->valnum == VN_TOP)
return name;
/* If the value-number is a constant it is the representative
expression. */
if (TREE_CODE (vn->valnum) != SSA_NAME)
return vn->valnum;
/* Get to the information of the value of this SSA_NAME. */
vn = VN_INFO (vn->valnum);
/* If the value-number is a constant it is the representative
expression. */
if (TREE_CODE (vn->valnum) != SSA_NAME)
return vn->valnum;
/* Else if we have an expression, return it. */
if (vn->expr != NULL_TREE)
return vn->expr;
/* Otherwise use the defining statement to build the expression. */
def_stmt = SSA_NAME_DEF_STMT (vn->valnum);
/* If the value number is not an assignment use it directly. */
if (!is_gimple_assign (def_stmt))
return vn->valnum;
/* Note that we can valueize here because we clear the cached
simplified expressions after each optimistic iteration. */
code = gimple_assign_rhs_code (def_stmt);
switch (TREE_CODE_CLASS (code))
{
case tcc_reference:
if ((code == REALPART_EXPR
|| code == IMAGPART_EXPR
|| code == VIEW_CONVERT_EXPR)
&& TREE_CODE (TREE_OPERAND (gimple_assign_rhs1 (def_stmt),
0)) == SSA_NAME)
expr = fold_build1 (code,
gimple_expr_type (def_stmt),
vn_valueize (TREE_OPERAND
(gimple_assign_rhs1 (def_stmt), 0)));
break;
case tcc_unary:
expr = fold_build1 (code,
gimple_expr_type (def_stmt),
vn_valueize (gimple_assign_rhs1 (def_stmt)));
break;
case tcc_binary:
expr = fold_build2 (code,
gimple_expr_type (def_stmt),
vn_valueize (gimple_assign_rhs1 (def_stmt)),
vn_valueize (gimple_assign_rhs2 (def_stmt)));
break;
case tcc_exceptional:
if (code == CONSTRUCTOR
&& TREE_CODE
(TREE_TYPE (gimple_assign_rhs1 (def_stmt))) == VECTOR_TYPE)
expr = gimple_assign_rhs1 (def_stmt);
break;
default:;
}
if (expr == NULL_TREE)
return vn->valnum;
/* Cache the expression. */
vn->expr = expr;
return expr;
}
/* Return the vn_kind the expression computed by the stmt should be
associated with. */
enum vn_kind
vn_get_stmt_kind (gimple stmt)
{
switch (gimple_code (stmt))
{
case GIMPLE_CALL:
return VN_REFERENCE;
case GIMPLE_PHI:
return VN_PHI;
case GIMPLE_ASSIGN:
{
enum tree_code code = gimple_assign_rhs_code (stmt);
tree rhs1 = gimple_assign_rhs1 (stmt);
switch (get_gimple_rhs_class (code))
{
case GIMPLE_UNARY_RHS:
case GIMPLE_BINARY_RHS:
case GIMPLE_TERNARY_RHS:
return VN_NARY;
case GIMPLE_SINGLE_RHS:
switch (TREE_CODE_CLASS (code))
{
case tcc_reference:
/* VOP-less references can go through unary case. */
if ((code == REALPART_EXPR
|| code == IMAGPART_EXPR
|| code == VIEW_CONVERT_EXPR
|| code == BIT_FIELD_REF)
&& TREE_CODE (TREE_OPERAND (rhs1, 0)) == SSA_NAME)
return VN_NARY;
/* Fallthrough. */
case tcc_declaration:
return VN_REFERENCE;
case tcc_constant:
return VN_CONSTANT;
default:
if (code == ADDR_EXPR)
return (is_gimple_min_invariant (rhs1)
? VN_CONSTANT : VN_REFERENCE);
else if (code == CONSTRUCTOR)
return VN_NARY;
return VN_NONE;
}
default:
return VN_NONE;
}
}
default:
return VN_NONE;
}
}
/* Lookup a value id for CONSTANT and return it. If it does not
exist returns 0. */
unsigned int
get_constant_value_id (tree constant)
{
vn_constant_s **slot;
struct vn_constant_s vc;
vc.hashcode = vn_hash_constant_with_type (constant);
vc.constant = constant;
slot = constant_to_value_id->find_slot (&vc, NO_INSERT);
if (slot)
return (*slot)->value_id;
return 0;
}
/* Lookup a value id for CONSTANT, and if it does not exist, create a
new one and return it. If it does exist, return it. */
unsigned int
get_or_alloc_constant_value_id (tree constant)
{
vn_constant_s **slot;
struct vn_constant_s vc;
vn_constant_t vcp;
vc.hashcode = vn_hash_constant_with_type (constant);
vc.constant = constant;
slot = constant_to_value_id->find_slot (&vc, INSERT);
if (*slot)
return (*slot)->value_id;
vcp = XNEW (struct vn_constant_s);
vcp->hashcode = vc.hashcode;
vcp->constant = constant;
vcp->value_id = get_next_value_id ();
*slot = vcp;
bitmap_set_bit (constant_value_ids, vcp->value_id);
return vcp->value_id;
}
/* Return true if V is a value id for a constant. */
bool
value_id_constant_p (unsigned int v)
{
return bitmap_bit_p (constant_value_ids, v);
}
/* Compute the hash for a reference operand VRO1. */
static void
vn_reference_op_compute_hash (const vn_reference_op_t vro1, inchash::hash &hstate)
{
hstate.add_int (vro1->opcode);
if (vro1->op0)
inchash::add_expr (vro1->op0, hstate);
if (vro1->op1)
inchash::add_expr (vro1->op1, hstate);
if (vro1->op2)
inchash::add_expr (vro1->op2, hstate);
}
/* Compute a hash for the reference operation VR1 and return it. */
static hashval_t
vn_reference_compute_hash (const vn_reference_t vr1)
{
inchash::hash hstate;
hashval_t result;
int i;
vn_reference_op_t vro;
HOST_WIDE_INT off = -1;
bool deref = false;
FOR_EACH_VEC_ELT (vr1->operands, i, vro)
{
if (vro->opcode == MEM_REF)
deref = true;
else if (vro->opcode != ADDR_EXPR)
deref = false;
if (vro->off != -1)
{
if (off == -1)
off = 0;
off += vro->off;
}
else
{
if (off != -1
&& off != 0)
hstate.add_int (off);
off = -1;
if (deref
&& vro->opcode == ADDR_EXPR)
{
if (vro->op0)
{
tree op = TREE_OPERAND (vro->op0, 0);
hstate.add_int (TREE_CODE (op));
inchash::add_expr (op, hstate);
}
}
else
vn_reference_op_compute_hash (vro, hstate);
}
}
result = hstate.end ();
/* ??? We would ICE later if we hash instead of adding that in. */
if (vr1->vuse)
result += SSA_NAME_VERSION (vr1->vuse);
return result;
}
/* Return true if reference operations VR1 and VR2 are equivalent. This
means they have the same set of operands and vuses. */
bool
vn_reference_eq (const_vn_reference_t const vr1, const_vn_reference_t const vr2)
{
unsigned i, j;
/* Early out if this is not a hash collision. */
if (vr1->hashcode != vr2->hashcode)
return false;
/* The VOP needs to be the same. */
if (vr1->vuse != vr2->vuse)
return false;
/* If the operands are the same we are done. */
if (vr1->operands == vr2->operands)
return true;
if (!expressions_equal_p (TYPE_SIZE (vr1->type), TYPE_SIZE (vr2->type)))
return false;
if (INTEGRAL_TYPE_P (vr1->type)
&& INTEGRAL_TYPE_P (vr2->type))
{
if (TYPE_PRECISION (vr1->type) != TYPE_PRECISION (vr2->type))
return false;
}
else if (INTEGRAL_TYPE_P (vr1->type)
&& (TYPE_PRECISION (vr1->type)
!= TREE_INT_CST_LOW (TYPE_SIZE (vr1->type))))
return false;
else if (INTEGRAL_TYPE_P (vr2->type)
&& (TYPE_PRECISION (vr2->type)
!= TREE_INT_CST_LOW (TYPE_SIZE (vr2->type))))
return false;
i = 0;
j = 0;
do
{
HOST_WIDE_INT off1 = 0, off2 = 0;
vn_reference_op_t vro1, vro2;
vn_reference_op_s tem1, tem2;
bool deref1 = false, deref2 = false;
for (; vr1->operands.iterate (i, &vro1); i++)
{
if (vro1->opcode == MEM_REF)
deref1 = true;
if (vro1->off == -1)
break;
off1 += vro1->off;
}
for (; vr2->operands.iterate (j, &vro2); j++)
{
if (vro2->opcode == MEM_REF)
deref2 = true;
if (vro2->off == -1)
break;
off2 += vro2->off;
}
if (off1 != off2)
return false;
if (deref1 && vro1->opcode == ADDR_EXPR)
{
memset (&tem1, 0, sizeof (tem1));
tem1.op0 = TREE_OPERAND (vro1->op0, 0);
tem1.type = TREE_TYPE (tem1.op0);
tem1.opcode = TREE_CODE (tem1.op0);
vro1 = &tem1;
deref1 = false;
}
if (deref2 && vro2->opcode == ADDR_EXPR)
{
memset (&tem2, 0, sizeof (tem2));
tem2.op0 = TREE_OPERAND (vro2->op0, 0);
tem2.type = TREE_TYPE (tem2.op0);
tem2.opcode = TREE_CODE (tem2.op0);
vro2 = &tem2;
deref2 = false;
}
if (deref1 != deref2)
return false;
if (!vn_reference_op_eq (vro1, vro2))
return false;
++j;
++i;
}
while (vr1->operands.length () != i
|| vr2->operands.length () != j);
return true;
}
/* Copy the operations present in load/store REF into RESULT, a vector of
vn_reference_op_s's. */
static void
copy_reference_ops_from_ref (tree ref, vec<vn_reference_op_s> *result)
{
if (TREE_CODE (ref) == TARGET_MEM_REF)
{
vn_reference_op_s temp;
result->reserve (3);
memset (&temp, 0, sizeof (temp));
temp.type = TREE_TYPE (ref);
temp.opcode = TREE_CODE (ref);
temp.op0 = TMR_INDEX (ref);
temp.op1 = TMR_STEP (ref);
temp.op2 = TMR_OFFSET (ref);
temp.off = -1;
result->quick_push (temp);
memset (&temp, 0, sizeof (temp));
temp.type = NULL_TREE;
temp.opcode = ERROR_MARK;
temp.op0 = TMR_INDEX2 (ref);
temp.off = -1;
result->quick_push (temp);
memset (&temp, 0, sizeof (temp));
temp.type = NULL_TREE;
temp.opcode = TREE_CODE (TMR_BASE (ref));
temp.op0 = TMR_BASE (ref);
temp.off = -1;
result->quick_push (temp);
return;
}
/* For non-calls, store the information that makes up the address. */
tree orig = ref;
while (ref)
{
vn_reference_op_s temp;
memset (&temp, 0, sizeof (temp));
temp.type = TREE_TYPE (ref);
temp.opcode = TREE_CODE (ref);
temp.off = -1;
switch (temp.opcode)
{
case MODIFY_EXPR:
temp.op0 = TREE_OPERAND (ref, 1);
break;
case WITH_SIZE_EXPR:
temp.op0 = TREE_OPERAND (ref, 1);
temp.off = 0;
break;
case MEM_REF:
/* The base address gets its own vn_reference_op_s structure. */
temp.op0 = TREE_OPERAND (ref, 1);
{
offset_int off = mem_ref_offset (ref);
if (wi::fits_shwi_p (off))
temp.off = off.to_shwi ();
}
break;
case BIT_FIELD_REF:
/* Record bits and position. */
temp.op0 = TREE_OPERAND (ref, 1);
temp.op1 = TREE_OPERAND (ref, 2);
break;
case COMPONENT_REF:
/* The field decl is enough to unambiguously specify the field,
a matching type is not necessary and a mismatching type
is always a spurious difference. */
temp.type = NULL_TREE;
temp.op0 = TREE_OPERAND (ref, 1);
temp.op1 = TREE_OPERAND (ref, 2);
{
tree this_offset = component_ref_field_offset (ref);
if (this_offset
&& TREE_CODE (this_offset) == INTEGER_CST)
{
tree bit_offset = DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref, 1));
if (TREE_INT_CST_LOW (bit_offset) % BITS_PER_UNIT == 0)
{
offset_int off
= (wi::to_offset (this_offset)
+ wi::lrshift (wi::to_offset (bit_offset),
LOG2_BITS_PER_UNIT));
if (wi::fits_shwi_p (off)
/* Probibit value-numbering zero offset components
of addresses the same before the pass folding
__builtin_object_size had a chance to run
(checking cfun->after_inlining does the
trick here). */
&& (TREE_CODE (orig) != ADDR_EXPR
|| off != 0
|| cfun->after_inlining))
temp.off = off.to_shwi ();
}
}
}
break;
case ARRAY_RANGE_REF:
case ARRAY_REF:
/* Record index as operand. */
temp.op0 = TREE_OPERAND (ref, 1);
/* Always record lower bounds and element size. */
temp.op1 = array_ref_low_bound (ref);
temp.op2 = array_ref_element_size (ref);
if (TREE_CODE (temp.op0) == INTEGER_CST
&& TREE_CODE (temp.op1) == INTEGER_CST
&& TREE_CODE (temp.op2) == INTEGER_CST)
{
offset_int off = ((wi::to_offset (temp.op0)
- wi::to_offset (temp.op1))
* wi::to_offset (temp.op2));
if (wi::fits_shwi_p (off))
temp.off = off.to_shwi();
}
break;
case VAR_DECL:
if (DECL_HARD_REGISTER (ref))
{
temp.op0 = ref;
break;
}
/* Fallthru. */
case PARM_DECL:
case CONST_DECL:
case RESULT_DECL:
/* Canonicalize decls to MEM[&decl] which is what we end up with
when valueizing MEM[ptr] with ptr = &decl. */
temp.opcode = MEM_REF;
temp.op0 = build_int_cst (build_pointer_type (TREE_TYPE (ref)), 0);
temp.off = 0;
result->safe_push (temp);
temp.opcode = ADDR_EXPR;
temp.op0 = build1 (ADDR_EXPR, TREE_TYPE (temp.op0), ref);
temp.type = TREE_TYPE (temp.op0);
temp.off = -1;
break;
case STRING_CST:
case INTEGER_CST:
case COMPLEX_CST:
case VECTOR_CST:
case REAL_CST:
case FIXED_CST:
case CONSTRUCTOR:
case SSA_NAME:
temp.op0 = ref;
break;
case ADDR_EXPR:
if (is_gimple_min_invariant (ref))
{
temp.op0 = ref;
break;
}
break;
/* These are only interesting for their operands, their
existence, and their type. They will never be the last
ref in the chain of references (IE they require an
operand), so we don't have to put anything
for op* as it will be handled by the iteration */
case REALPART_EXPR:
case VIEW_CONVERT_EXPR:
temp.off = 0;
break;
case IMAGPART_EXPR:
/* This is only interesting for its constant offset. */
temp.off = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (ref)));
break;
default:
gcc_unreachable ();
}
result->safe_push (temp);
if (REFERENCE_CLASS_P (ref)
|| TREE_CODE (ref) == MODIFY_EXPR
|| TREE_CODE (ref) == WITH_SIZE_EXPR
|| (TREE_CODE (ref) == ADDR_EXPR
&& !is_gimple_min_invariant (ref)))
ref = TREE_OPERAND (ref, 0);
else
ref = NULL_TREE;
}
}
/* Build a alias-oracle reference abstraction in *REF from the vn_reference
operands in *OPS, the reference alias set SET and the reference type TYPE.
Return true if something useful was produced. */
bool
ao_ref_init_from_vn_reference (ao_ref *ref,
alias_set_type set, tree type,
vec<vn_reference_op_s> ops)
{
vn_reference_op_t op;
unsigned i;
tree base = NULL_TREE;
tree *op0_p = &base;
HOST_WIDE_INT offset = 0;
HOST_WIDE_INT max_size;
HOST_WIDE_INT size = -1;
tree size_tree = NULL_TREE;
alias_set_type base_alias_set = -1;
/* First get the final access size from just the outermost expression. */
op = &ops[0];
if (op->opcode == COMPONENT_REF)
size_tree = DECL_SIZE (op->op0);
else if (op->opcode == BIT_FIELD_REF)
size_tree = op->op0;
else
{
machine_mode mode = TYPE_MODE (type);
if (mode == BLKmode)
size_tree = TYPE_SIZE (type);
else
size = GET_MODE_BITSIZE (mode);
}
if (size_tree != NULL_TREE)
{
if (!tree_fits_uhwi_p (size_tree))
size = -1;
else
size = tree_to_uhwi (size_tree);
}
/* Initially, maxsize is the same as the accessed element size.
In the following it will only grow (or become -1). */
max_size = size;
/* Compute cumulative bit-offset for nested component-refs and array-refs,
and find the ultimate containing object. */
FOR_EACH_VEC_ELT (ops, i, op)
{
switch (op->opcode)
{
/* These may be in the reference ops, but we cannot do anything
sensible with them here. */
case ADDR_EXPR:
/* Apart from ADDR_EXPR arguments to MEM_REF. */
if (base != NULL_TREE
&& TREE_CODE (base) == MEM_REF
&& op->op0
&& DECL_P (TREE_OPERAND (op->op0, 0)))
{
vn_reference_op_t pop = &ops[i-1];
base = TREE_OPERAND (op->op0, 0);
if (pop->off == -1)
{
max_size = -1;
offset = 0;
}
else
offset += pop->off * BITS_PER_UNIT;
op0_p = NULL;
break;
}
/* Fallthru. */
case CALL_EXPR:
return false;
/* Record the base objects. */
case MEM_REF:
base_alias_set = get_deref_alias_set (op->op0);
*op0_p = build2 (MEM_REF, op->type,
NULL_TREE, op->op0);
op0_p = &TREE_OPERAND (*op0_p, 0);
break;
case VAR_DECL:
case PARM_DECL:
case RESULT_DECL:
case SSA_NAME:
*op0_p = op->op0;
op0_p = NULL;
break;
/* And now the usual component-reference style ops. */
case BIT_FIELD_REF:
offset += tree_to_shwi (op->op1);
break;
case COMPONENT_REF:
{
tree field = op->op0;
/* We do not have a complete COMPONENT_REF tree here so we
cannot use component_ref_field_offset. Do the interesting
parts manually. */
if (op->op1
|| !tree_fits_uhwi_p (DECL_FIELD_OFFSET (field)))
max_size = -1;
else
{
offset += (tree_to_uhwi (DECL_FIELD_OFFSET (field))
* BITS_PER_UNIT);
offset += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
}
break;
}
case ARRAY_RANGE_REF:
case ARRAY_REF:
/* We recorded the lower bound and the element size. */
if (!tree_fits_shwi_p (op->op0)
|| !tree_fits_shwi_p (op->op1)
|| !tree_fits_shwi_p (op->op2))
max_size = -1;
else
{
HOST_WIDE_INT hindex = tree_to_shwi (op->op0);
hindex -= tree_to_shwi (op->op1);
hindex *= tree_to_shwi (op->op2);
hindex *= BITS_PER_UNIT;
offset += hindex;
}
break;
case REALPART_EXPR:
break;
case IMAGPART_EXPR:
offset += size;
break;
case VIEW_CONVERT_EXPR:
break;
case STRING_CST:
case INTEGER_CST:
case COMPLEX_CST:
case VECTOR_CST:
case REAL_CST:
case CONSTRUCTOR:
case CONST_DECL:
return false;
default:
return false;
}
}
if (base == NULL_TREE)
return false;
ref->ref = NULL_TREE;
ref->base = base;
ref->offset = offset;
ref->size = size;
ref->max_size = max_size;
ref->ref_alias_set = set;
if (base_alias_set != -1)
ref->base_alias_set = base_alias_set;
else
ref->base_alias_set = get_alias_set (base);
/* We discount volatiles from value-numbering elsewhere. */
ref->volatile_p = false;
return true;
}
/* Copy the operations present in load/store/call REF into RESULT, a vector of
vn_reference_op_s's. */
static void
copy_reference_ops_from_call (gcall *call,
vec<vn_reference_op_s> *result)
{
vn_reference_op_s temp;
unsigned i;
tree lhs = gimple_call_lhs (call);
int lr;
/* If 2 calls have a different non-ssa lhs, vdef value numbers should be
different. By adding the lhs here in the vector, we ensure that the
hashcode is different, guaranteeing a different value number. */
if (lhs && TREE_CODE (lhs) != SSA_NAME)
{
memset (&temp, 0, sizeof (temp));
temp.opcode = MODIFY_EXPR;
temp.type = TREE_TYPE (lhs);
temp.op0 = lhs;
temp.off = -1;
result->safe_push (temp);
}
/* Copy the type, opcode, function, static chain and EH region, if any. */
memset (&temp, 0, sizeof (temp));
temp.type = gimple_call_return_type (call);
temp.opcode = CALL_EXPR;
temp.op0 = gimple_call_fn (call);
temp.op1 = gimple_call_chain (call);
if (stmt_could_throw_p (call) && (lr = lookup_stmt_eh_lp (call)) > 0)
temp.op2 = size_int (lr);
temp.off = -1;
if (gimple_call_with_bounds_p (call))
temp.with_bounds = 1;
result->safe_push (temp);
/* Copy the call arguments. As they can be references as well,
just chain them together. */
for (i = 0; i < gimple_call_num_args (call); ++i)
{
tree callarg = gimple_call_arg (call, i);
copy_reference_ops_from_ref (callarg, result);
}
}
/* Fold *& at position *I_P in a vn_reference_op_s vector *OPS. Updates
*I_P to point to the last element of the replacement. */
void
vn_reference_fold_indirect (vec<vn_reference_op_s> *ops,
unsigned int *i_p)
{
unsigned int i = *i_p;
vn_reference_op_t op = &(*ops)[i];
vn_reference_op_t mem_op = &(*ops)[i - 1];
tree addr_base;
HOST_WIDE_INT addr_offset = 0;
/* The only thing we have to do is from &OBJ.foo.bar add the offset
from .foo.bar to the preceding MEM_REF offset and replace the
address with &OBJ. */
addr_base = get_addr_base_and_unit_offset (TREE_OPERAND (op->op0, 0),
&addr_offset);
gcc_checking_assert (addr_base && TREE_CODE (addr_base) != MEM_REF);
if (addr_base != TREE_OPERAND (op->op0, 0))
{
offset_int off = offset_int::from (mem_op->op0, SIGNED);
off += addr_offset;
mem_op->op0 = wide_int_to_tree (TREE_TYPE (mem_op->op0), off);
op->op0 = build_fold_addr_expr (addr_base);
if (tree_fits_shwi_p (mem_op->op0))
mem_op->off = tree_to_shwi (mem_op->op0);
else
mem_op->off = -1;
}
}
/* Fold *& at position *I_P in a vn_reference_op_s vector *OPS. Updates
*I_P to point to the last element of the replacement. */
static void
vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops,
unsigned int *i_p)
{
unsigned int i = *i_p;
vn_reference_op_t op = &(*ops)[i];
vn_reference_op_t mem_op = &(*ops)[i - 1];
gimple def_stmt;
enum tree_code code;
offset_int off;
def_stmt = SSA_NAME_DEF_STMT (op->op0);
if (!is_gimple_assign (def_stmt))
return;
code = gimple_assign_rhs_code (def_stmt);
if (code != ADDR_EXPR
&& code != POINTER_PLUS_EXPR)
return;
off = offset_int::from (mem_op->op0, SIGNED);
/* The only thing we have to do is from &OBJ.foo.bar add the offset
from .foo.bar to the preceding MEM_REF offset and replace the
address with &OBJ. */
if (code == ADDR_EXPR)
{
tree addr, addr_base;
HOST_WIDE_INT addr_offset;
addr = gimple_assign_rhs1 (def_stmt);
addr_base = get_addr_base_and_unit_offset (TREE_OPERAND (addr, 0),
&addr_offset);
if (!addr_base
|| TREE_CODE (addr_base) != MEM_REF)
return;
off += addr_offset;
off += mem_ref_offset (addr_base);
op->op0 = TREE_OPERAND (addr_base, 0);
}
else
{
tree ptr, ptroff;
ptr = gimple_assign_rhs1 (def_stmt);
ptroff = gimple_assign_rhs2 (def_stmt);
if (TREE_CODE (ptr) != SSA_NAME
|| TREE_CODE (ptroff) != INTEGER_CST)
return;
off += wi::to_offset (ptroff);
op->op0 = ptr;
}
mem_op->op0 = wide_int_to_tree (TREE_TYPE (mem_op->op0), off);
if (tree_fits_shwi_p (mem_op->op0))
mem_op->off = tree_to_shwi (mem_op->op0);
else
mem_op->off = -1;
if (TREE_CODE (op->op0) == SSA_NAME)
op->op0 = SSA_VAL (op->op0);
if (TREE_CODE (op->op0) != SSA_NAME)
op->opcode = TREE_CODE (op->op0);
/* And recurse. */
if (TREE_CODE (op->op0) == SSA_NAME)
vn_reference_maybe_forwprop_address (ops, i_p);
else if (TREE_CODE (op->op0) == ADDR_EXPR)
vn_reference_fold_indirect (ops, i_p);
}
/* Optimize the reference REF to a constant if possible or return
NULL_TREE if not. */
tree
fully_constant_vn_reference_p (vn_reference_t ref)
{
vec<vn_reference_op_s> operands = ref->operands;
vn_reference_op_t op;
/* Try to simplify the translated expression if it is
a call to a builtin function with at most two arguments. */
op = &operands[0];
if (op->opcode == CALL_EXPR
&& TREE_CODE (op->op0) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (op->op0, 0)) == FUNCTION_DECL
&& DECL_BUILT_IN (TREE_OPERAND (op->op0, 0))
&& operands.length () >= 2
&& operands.length () <= 3)
{
vn_reference_op_t arg0, arg1 = NULL;
bool anyconst = false;
arg0 = &operands[1];
if (operands.length () > 2)
arg1 = &operands[2];
if (TREE_CODE_CLASS (arg0->opcode) == tcc_constant
|| (arg0->opcode == ADDR_EXPR
&& is_gimple_min_invariant (arg0->op0)))
anyconst = true;
if (arg1
&& (TREE_CODE_CLASS (arg1->opcode) == tcc_constant
|| (arg1->opcode == ADDR_EXPR
&& is_gimple_min_invariant (arg1->op0))))
anyconst = true;
if (anyconst)
{
tree folded = build_call_expr (TREE_OPERAND (op->op0, 0),
arg1 ? 2 : 1,
arg0->op0,
arg1 ? arg1->op0 : NULL);
if (folded
&& TREE_CODE (folded) == NOP_EXPR)
folded = TREE_OPERAND (folded, 0);
if (folded
&& is_gimple_min_invariant (folded))
return folded;
}
}
/* Simplify reads from constants or constant initializers. */
else if (BITS_PER_UNIT == 8
&& is_gimple_reg_type (ref->type)
&& (!INTEGRAL_TYPE_P (ref->type)
|| TYPE_PRECISION (ref->type) % BITS_PER_UNIT == 0))
{
HOST_WIDE_INT off = 0;
HOST_WIDE_INT size;
if (INTEGRAL_TYPE_P (ref->type))
size = TYPE_PRECISION (ref->type);
else
size = tree_to_shwi (TYPE_SIZE (ref->type));
if (size % BITS_PER_UNIT != 0
|| size > MAX_BITSIZE_MODE_ANY_MODE)
return NULL_TREE;
size /= BITS_PER_UNIT;
unsigned i;
for (i = 0; i < operands.length (); ++i)
{
if (operands[i].off == -1)
return NULL_TREE;
off += operands[i].off;
if (operands[i].opcode == MEM_REF)
{
++i;
break;
}
}
vn_reference_op_t base = &operands[--i];
tree ctor = error_mark_node;
tree decl = NULL_TREE;
if (TREE_CODE_CLASS (base->opcode) == tcc_constant)
ctor = base->op0;
else if (base->opcode == MEM_REF
&& base[1].opcode == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (base[1].op0, 0)) == VAR_DECL
|| TREE_CODE (TREE_OPERAND (base[1].op0, 0)) == CONST_DECL))
{
decl = TREE_OPERAND (base[1].op0, 0);
ctor = ctor_for_folding (decl);
}
if (ctor == NULL_TREE)
return build_zero_cst (ref->type);
else if (ctor != error_mark_node)
{
if (decl)
{
tree res = fold_ctor_reference (ref->type, ctor,
off * BITS_PER_UNIT,
size * BITS_PER_UNIT, decl);
if (res)
{
STRIP_USELESS_TYPE_CONVERSION (res);
if (is_gimple_min_invariant (res))
return res;
}
}
else
{
unsigned char buf[MAX_BITSIZE_MODE_ANY_MODE / BITS_PER_UNIT];
if (native_encode_expr (ctor, buf, size, off) > 0)
return native_interpret_expr (ref->type, buf, size);
}
}
}
return NULL_TREE;
}
/* Transform any SSA_NAME's in a vector of vn_reference_op_s
structures into their value numbers. This is done in-place, and
the vector passed in is returned. *VALUEIZED_ANYTHING will specify
whether any operands were valueized. */
static vec<vn_reference_op_s>
valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
{
vn_reference_op_t vro;
unsigned int i;
*valueized_anything = false;
FOR_EACH_VEC_ELT (orig, i, vro)
{
if (vro->opcode == SSA_NAME
|| (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
{
tree tem = SSA_VAL (vro->op0);
if (tem != vro->op0)
{
*valueized_anything = true;
vro->op0 = tem;
}
/* If it transforms from an SSA_NAME to a constant, update
the opcode. */
if (TREE_CODE (vro->op0) != SSA_NAME && vro->opcode == SSA_NAME)
vro->opcode = TREE_CODE (vro->op0);
}
if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
{
tree tem = SSA_VAL (vro->op1);
if (tem != vro->op1)
{
*valueized_anything = true;
vro->op1 = tem;
}
}
if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
{
tree tem = SSA_VAL (vro->op2);
if (tem != vro->op2)
{
*valueized_anything = true;
vro->op2 = tem;
}
}
/* If it transforms from an SSA_NAME to an address, fold with
a preceding indirect reference. */
if (i > 0
&& vro->op0
&& TREE_CODE (vro->op0) == ADDR_EXPR
&& orig[i - 1].opcode == MEM_REF)
vn_reference_fold_indirect (&orig, &i);
else if (i > 0
&& vro->opcode == SSA_NAME
&& orig[i - 1].opcode == MEM_REF)
vn_reference_maybe_forwprop_address (&orig, &i);
/* If it transforms a non-constant ARRAY_REF into a constant
one, adjust the constant offset. */
else if (vro->opcode == ARRAY_REF
&& vro->off == -1
&& TREE_CODE (vro->op0) == INTEGER_CST
&& TREE_CODE (vro->op1) == INTEGER_CST
&& TREE_CODE (vro->op2) == INTEGER_CST)
{
offset_int off = ((wi::to_offset (vro->op0)
- wi::to_offset (vro->op1))
* wi::to_offset (vro->op2));
if (wi::fits_shwi_p (off))
vro->off = off.to_shwi ();
}
}
return orig;
}
static vec<vn_reference_op_s>
valueize_refs (vec<vn_reference_op_s> orig)
{
bool tem;
return valueize_refs_1 (orig, &tem);
}
static vec<vn_reference_op_s> shared_lookup_references;
/* Create a vector of vn_reference_op_s structures from REF, a
REFERENCE_CLASS_P tree. The vector is shared among all callers of
this function. *VALUEIZED_ANYTHING will specify whether any
operands were valueized. */
static vec<vn_reference_op_s>
valueize_shared_reference_ops_from_ref (tree ref, bool *valueized_anything)
{
if (!ref)
return vNULL;
shared_lookup_references.truncate (0);
copy_reference_ops_from_ref (ref, &shared_lookup_references);
shared_lookup_references = valueize_refs_1 (shared_lookup_references,
valueized_anything);
return shared_lookup_references;
}
/* Create a vector of vn_reference_op_s structures from CALL, a
call statement. The vector is shared among all callers of
this function. */
static vec<vn_reference_op_s>
valueize_shared_reference_ops_from_call (gcall *call)
{
if (!call)
return vNULL;
shared_lookup_references.truncate (0);
copy_reference_ops_from_call (call, &shared_lookup_references);
shared_lookup_references = valueize_refs (shared_lookup_references);
return shared_lookup_references;
}
/* Lookup a SCCVN reference operation VR in the current hash table.
Returns the resulting value number if it exists in the hash table,
NULL_TREE otherwise. VNRESULT will be filled in with the actual
vn_reference_t stored in the hashtable if something is found. */
static tree
vn_reference_lookup_1 (vn_reference_t vr, vn_reference_t *vnresult)
{
vn_reference_s **slot;
hashval_t hash;
hash = vr->hashcode;
slot = current_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (!slot && current_info == optimistic_info)
slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (slot)
{
if (vnresult)
*vnresult = (vn_reference_t)*slot;
return ((vn_reference_t)*slot)->result;
}
return NULL_TREE;
}
static tree *last_vuse_ptr;
static vn_lookup_kind vn_walk_kind;
static vn_lookup_kind default_vn_walk_kind;
/* Callback for walk_non_aliased_vuses. Adjusts the vn_reference_t VR_
with the current VUSE and performs the expression lookup. */
static void *
vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse,
unsigned int cnt, void *vr_)
{
vn_reference_t vr = (vn_reference_t)vr_;
vn_reference_s **slot;
hashval_t hash;
/* This bounds the stmt walks we perform on reference lookups
to O(1) instead of O(N) where N is the number of dominating
stores. */
if (cnt > (unsigned) PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS))
return (void *)-1;
if (last_vuse_ptr)
*last_vuse_ptr = vuse;
/* Fixup vuse and hash. */
if (vr->vuse)
vr->hashcode = vr->hashcode - SSA_NAME_VERSION (vr->vuse);
vr->vuse = vuse_ssa_val (vuse);
if (vr->vuse)
vr->hashcode = vr->hashcode + SSA_NAME_VERSION (vr->vuse);
hash = vr->hashcode;
slot = current_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (!slot && current_info == optimistic_info)
slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (slot)
return *slot;
return NULL;
}
/* Lookup an existing or insert a new vn_reference entry into the
value table for the VUSE, SET, TYPE, OPERANDS reference which
has the value VALUE which is either a constant or an SSA name. */
static vn_reference_t
vn_reference_lookup_or_insert_for_pieces (tree vuse,
alias_set_type set,
tree type,
vec<vn_reference_op_s,
va_heap> operands,
tree value)
{
vn_reference_s vr1;
vn_reference_t result;
unsigned value_id;
vr1.vuse = vuse;
vr1.operands = operands;
vr1.type = type;
vr1.set = set;
vr1.hashcode = vn_reference_compute_hash (&vr1);
if (vn_reference_lookup_1 (&vr1, &result))
return result;
if (TREE_CODE (value) == SSA_NAME)
value_id = VN_INFO (value)->value_id;
else
value_id = get_or_alloc_constant_value_id (value);
return vn_reference_insert_pieces (vuse, set, type,
operands.copy (), value, value_id);
}
/* Callback for walk_non_aliased_vuses. Tries to perform a lookup
from the statement defining VUSE and if not successful tries to
translate *REFP and VR_ through an aggregate copy at the definition
of VUSE. */
static void *
vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
bool disambiguate_only)
{
vn_reference_t vr = (vn_reference_t)vr_;
gimple def_stmt = SSA_NAME_DEF_STMT (vuse);
tree base;
HOST_WIDE_INT offset, maxsize;
static vec<vn_reference_op_s>
lhs_ops = vNULL;
ao_ref lhs_ref;
bool lhs_ref_ok = false;
/* First try to disambiguate after value-replacing in the definitions LHS. */
if (is_gimple_assign (def_stmt))
{
vec<vn_reference_op_s> tem;
tree lhs = gimple_assign_lhs (def_stmt);
bool valueized_anything = false;
/* Avoid re-allocation overhead. */
lhs_ops.truncate (0);
copy_reference_ops_from_ref (lhs, &lhs_ops);
tem = lhs_ops;
lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything);
gcc_assert (lhs_ops == tem);
if (valueized_anything)
{
lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref,
get_alias_set (lhs),
TREE_TYPE (lhs), lhs_ops);
if (lhs_ref_ok
&& !refs_may_alias_p_1 (ref, &lhs_ref, true))
return NULL;
}
else
{
ao_ref_init (&lhs_ref, lhs);
lhs_ref_ok = true;
}
}
else if (gimple_call_builtin_p (def_stmt, BUILT_IN_NORMAL)
&& gimple_call_num_args (def_stmt) <= 4)
{
/* For builtin calls valueize its arguments and call the
alias oracle again. Valueization may improve points-to
info of pointers and constify size and position arguments.
Originally this was motivated by PR61034 which has
conditional calls to free falsely clobbering ref because
of imprecise points-to info of the argument. */
tree oldargs[4];
bool valueized_anything = false;
for (unsigned i = 0; i < gimple_call_num_args (def_stmt); ++i)
{
oldargs[i] = gimple_call_arg (def_stmt, i);
if (TREE_CODE (oldargs[i]) == SSA_NAME
&& VN_INFO (oldargs[i])->valnum != oldargs[i])
{
gimple_call_set_arg (def_stmt, i, VN_INFO (oldargs[i])->valnum);
valueized_anything = true;
}
}
if (valueized_anything)
{
bool res = call_may_clobber_ref_p_1 (as_a <gcall *> (def_stmt),
ref);
for (unsigned i = 0; i < gimple_call_num_args (def_stmt); ++i)
gimple_call_set_arg (def_stmt, i, oldargs[i]);
if (!res)
return NULL;
}
}
if (disambiguate_only)
return (void *)-1;
base = ao_ref_base (ref);
offset = ref->offset;
maxsize = ref->max_size;
/* If we cannot constrain the size of the reference we cannot
test if anything kills it. */
if (maxsize == -1)
return (void *)-1;
/* We can't deduce anything useful from clobbers. */
if (gimple_clobber_p (def_stmt))
return (void *)-1;
/* def_stmt may-defs *ref. See if we can derive a value for *ref
from that definition.
1) Memset. */
if (is_gimple_reg_type (vr->type)
&& gimple_call_builtin_p (def_stmt, BUILT_IN_MEMSET)
&& integer_zerop (gimple_call_arg (def_stmt, 1))
&& tree_fits_uhwi_p (gimple_call_arg (def_stmt, 2))
&& TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR)
{
tree ref2 = TREE_OPERAND (gimple_call_arg (def_stmt, 0), 0);
tree base2;
HOST_WIDE_INT offset2, size2, maxsize2;
base2 = get_ref_base_and_extent (ref2, &offset2, &size2, &maxsize2);
size2 = tree_to_uhwi (gimple_call_arg (def_stmt, 2)) * 8;
if ((unsigned HOST_WIDE_INT)size2 / 8
== tree_to_uhwi (gimple_call_arg (def_stmt, 2))
&& maxsize2 != -1
&& operand_equal_p (base, base2, 0)
&& offset2 <= offset
&& offset2 + size2 >= offset + maxsize)
{
tree val = build_zero_cst (vr->type);
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
}
}
/* 2) Assignment from an empty CONSTRUCTOR. */
else if (is_gimple_reg_type (vr->type)
&& gimple_assign_single_p (def_stmt)
&& gimple_assign_rhs_code (def_stmt) == CONSTRUCTOR
&& CONSTRUCTOR_NELTS (gimple_assign_rhs1 (def_stmt)) == 0)
{
tree base2;
HOST_WIDE_INT offset2, size2, maxsize2;
base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
&offset2, &size2, &maxsize2);
if (maxsize2 != -1
&& operand_equal_p (base, base2, 0)
&& offset2 <= offset
&& offset2 + size2 >= offset + maxsize)
{
tree val = build_zero_cst (vr->type);
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
}
}
/* 3) Assignment from a constant. We can use folds native encode/interpret
routines to extract the assigned bits. */
else if (vn_walk_kind == VN_WALKREWRITE
&& CHAR_BIT == 8 && BITS_PER_UNIT == 8
&& ref->size == maxsize
&& maxsize % BITS_PER_UNIT == 0
&& offset % BITS_PER_UNIT == 0
&& is_gimple_reg_type (vr->type)
&& gimple_assign_single_p (def_stmt)
&& is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
{
tree base2;
HOST_WIDE_INT offset2, size2, maxsize2;
base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
&offset2, &size2, &maxsize2);
if (maxsize2 != -1
&& maxsize2 == size2
&& size2 % BITS_PER_UNIT == 0
&& offset2 % BITS_PER_UNIT == 0
&& operand_equal_p (base, base2, 0)
&& offset2 <= offset
&& offset2 + size2 >= offset + maxsize)
{
/* We support up to 512-bit values (for V8DFmode). */
unsigned char buffer[64];
int len;
len = native_encode_expr (gimple_assign_rhs1 (def_stmt),
buffer, sizeof (buffer));
if (len > 0)
{
tree val = native_interpret_expr (vr->type,
buffer
+ ((offset - offset2)
/ BITS_PER_UNIT),
ref->size / BITS_PER_UNIT);
if (val)
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
}
}
}
/* 4) Assignment from an SSA name which definition we may be able
to access pieces from. */
else if (ref->size == maxsize
&& is_gimple_reg_type (vr->type)
&& gimple_assign_single_p (def_stmt)
&& TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME)
{
tree rhs1 = gimple_assign_rhs1 (def_stmt);
gimple def_stmt2 = SSA_NAME_DEF_STMT (rhs1);
if (is_gimple_assign (def_stmt2)
&& (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR
|| gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR)
&& types_compatible_p (vr->type, TREE_TYPE (TREE_TYPE (rhs1))))
{
tree base2;
HOST_WIDE_INT offset2, size2, maxsize2, off;
base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
&offset2, &size2, &maxsize2);
off = offset - offset2;
if (maxsize2 != -1
&& maxsize2 == size2
&& operand_equal_p (base, base2, 0)
&& offset2 <= offset
&& offset2 + size2 >= offset + maxsize)
{
tree val = NULL_TREE;
HOST_WIDE_INT elsz
= TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (TREE_TYPE (rhs1))));
if (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR)
{
if (off == 0)
val = gimple_assign_rhs1 (def_stmt2);
else if (off == elsz)
val = gimple_assign_rhs2 (def_stmt2);
}
else if (gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR
&& off % elsz == 0)
{
tree ctor = gimple_assign_rhs1 (def_stmt2);
unsigned i = off / elsz;
if (i < CONSTRUCTOR_NELTS (ctor))
{
constructor_elt *elt = CONSTRUCTOR_ELT (ctor, i);
if (TREE_CODE (TREE_TYPE (rhs1)) == VECTOR_TYPE)
{
if (TREE_CODE (TREE_TYPE (elt->value))
!= VECTOR_TYPE)
val = elt->value;
}
}
}
if (val)
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
}
}
}
/* 5) For aggregate copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& gimple_assign_single_p (def_stmt)
&& (DECL_P (gimple_assign_rhs1 (def_stmt))
|| TREE_CODE (gimple_assign_rhs1 (def_stmt)) == MEM_REF
|| handled_component_p (gimple_assign_rhs1 (def_stmt))))
{
tree base2;
HOST_WIDE_INT offset2, size2, maxsize2;
int i, j;
auto_vec<vn_reference_op_s> rhs;
vn_reference_op_t vro;
ao_ref r;
if (!lhs_ref_ok)
return (void *)-1;
/* See if the assignment kills REF. */
base2 = ao_ref_base (&lhs_ref);
offset2 = lhs_ref.offset;
size2 = lhs_ref.size;
maxsize2 = lhs_ref.max_size;
if (maxsize2 == -1
|| (base != base2 && !operand_equal_p (base, base2, 0))
|| offset2 > offset
|| offset2 + size2 < offset + maxsize)
return (void *)-1;
/* Find the common base of ref and the lhs. lhs_ops already
contains valueized operands for the lhs. */
i = vr->operands.length () - 1;
j = lhs_ops.length () - 1;
while (j >= 0 && i >= 0
&& vn_reference_op_eq (&vr->operands[i], &lhs_ops[j]))
{
i--;
j--;
}
/* ??? The innermost op should always be a MEM_REF and we already
checked that the assignment to the lhs kills vr. Thus for
aggregate copies using char[] types the vn_reference_op_eq
may fail when comparing types for compatibility. But we really
don't care here - further lookups with the rewritten operands
will simply fail if we messed up types too badly. */
HOST_WIDE_INT extra_off = 0;
if (j == 0 && i >= 0
&& lhs_ops[0].opcode == MEM_REF
&& lhs_ops[0].off != -1)
{
if (lhs_ops[0].off == vr->operands[i].off)
i--, j--;
else if (vr->operands[i].opcode == MEM_REF
&& vr->operands[i].off != -1)
{
extra_off = vr->operands[i].off - lhs_ops[0].off;
i--, j--;
}
}
/* i now points to the first additional op.
??? LHS may not be completely contained in VR, one or more
VIEW_CONVERT_EXPRs could be in its way. We could at least
try handling outermost VIEW_CONVERT_EXPRs. */
if (j != -1)
return (void *)-1;
/* Now re-write REF to be based on the rhs of the assignment. */
copy_reference_ops_from_ref (gimple_assign_rhs1 (def_stmt), &rhs);
/* Apply an extra offset to the inner MEM_REF of the RHS. */
if (extra_off != 0)
{
if (rhs.length () < 2
|| rhs[0].opcode != MEM_REF
|| rhs[0].off == -1)
return (void *)-1;
rhs[0].off += extra_off;
rhs[0].op0 = int_const_binop (PLUS_EXPR, rhs[0].op0,
build_int_cst (TREE_TYPE (rhs[0].op0),
extra_off));
}
/* We need to pre-pend vr->operands[0..i] to rhs. */
vec<vn_reference_op_s> old = vr->operands;
if (i + 1 + rhs.length () > vr->operands.length ())
{
vr->operands.safe_grow (i + 1 + rhs.length ());
if (old == shared_lookup_references)
shared_lookup_references = vr->operands;
}
else
vr->operands.truncate (i + 1 + rhs.length ());
FOR_EACH_VEC_ELT (rhs, j, vro)
vr->operands[i + 1 + j] = *vro;
vr->operands = valueize_refs (vr->operands);
if (old == shared_lookup_references)
shared_lookup_references = vr->operands;
vr->hashcode = vn_reference_compute_hash (vr);
/* Try folding the new reference to a constant. */
tree val = fully_constant_vn_reference_p (vr);
if (val)
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
/* Adjust *ref from the new operands. */
if (!ao_ref_init_from_vn_reference (&r, vr->set, vr->type, vr->operands))
return (void *)-1;
/* This can happen with bitfields. */
if (ref->size != r.size)
return (void *)-1;
*ref = r;
/* Do not update last seen VUSE after translating. */
last_vuse_ptr = NULL;
/* Keep looking for the adjusted *REF / VR pair. */
return NULL;
}
/* 6) For memcpy copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& is_gimple_reg_type (vr->type)
/* ??? Handle BCOPY as well. */
&& (gimple_call_builtin_p (def_stmt, BUILT_IN_MEMCPY)
|| gimple_call_builtin_p (def_stmt, BUILT_IN_MEMPCPY)
|| gimple_call_builtin_p (def_stmt, BUILT_IN_MEMMOVE))
&& (TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR
|| TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME)
&& (TREE_CODE (gimple_call_arg (def_stmt, 1)) == ADDR_EXPR
|| TREE_CODE (gimple_call_arg (def_stmt, 1)) == SSA_NAME)
&& tree_fits_uhwi_p (gimple_call_arg (def_stmt, 2)))
{
tree lhs, rhs;
ao_ref r;
HOST_WIDE_INT rhs_offset, copy_size, lhs_offset;
vn_reference_op_s op;
HOST_WIDE_INT at;
/* Only handle non-variable, addressable refs. */
if (ref->size != maxsize
|| offset % BITS_PER_UNIT != 0
|| ref->size % BITS_PER_UNIT != 0)
return (void *)-1;
/* Extract a pointer base and an offset for the destination. */
lhs = gimple_call_arg (def_stmt, 0);
lhs_offset = 0;
if (TREE_CODE (lhs) == SSA_NAME)
lhs = SSA_VAL (lhs);
if (TREE_CODE (lhs) == ADDR_EXPR)
{
tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (lhs, 0),
&lhs_offset);
if (!tem)
return (void *)-1;
if (TREE_CODE (tem) == MEM_REF
&& tree_fits_uhwi_p (TREE_OPERAND (tem, 1)))
{
lhs = TREE_OPERAND (tem, 0);
lhs_offset += tree_to_uhwi (TREE_OPERAND (tem, 1));
}
else if (DECL_P (tem))
lhs = build_fold_addr_expr (tem);
else
return (void *)-1;
}
if (TREE_CODE (lhs) != SSA_NAME
&& TREE_CODE (lhs) != ADDR_EXPR)
return (void *)-1;
/* Extract a pointer base and an offset for the source. */
rhs = gimple_call_arg (def_stmt, 1);
rhs_offset = 0;
if (TREE_CODE (rhs) == SSA_NAME)
rhs = SSA_VAL (rhs);
if (TREE_CODE (rhs) == ADDR_EXPR)
{
tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs, 0),
&rhs_offset);
if (!tem)
return (void *)-1;
if (TREE_CODE (tem) == MEM_REF
&& tree_fits_uhwi_p (TREE_OPERAND (tem, 1)))
{
rhs = TREE_OPERAND (tem, 0);
rhs_offset += tree_to_uhwi (TREE_OPERAND (tem, 1));
}
else if (DECL_P (tem))
rhs = build_fold_addr_expr (tem);
else
return (void *)-1;
}
if (TREE_CODE (rhs) != SSA_NAME
&& TREE_CODE (rhs) != ADDR_EXPR)
return (void *)-1;
copy_size = tree_to_uhwi (gimple_call_arg (def_stmt, 2));
/* The bases of the destination and the references have to agree. */
if ((TREE_CODE (base) != MEM_REF
&& !DECL_P (base))
|| (TREE_CODE (base) == MEM_REF
&& (TREE_OPERAND (base, 0) != lhs
|| !tree_fits_uhwi_p (TREE_OPERAND (base, 1))))
|| (DECL_P (base)
&& (TREE_CODE (lhs) != ADDR_EXPR
|| TREE_OPERAND (lhs, 0) != base)))
return (void *)-1;
/* And the access has to be contained within the memcpy destination. */
at = offset / BITS_PER_UNIT;
if (TREE_CODE (base) == MEM_REF)
at += tree_to_uhwi (TREE_OPERAND (base, 1));
if (lhs_offset > at
|| lhs_offset + copy_size < at + maxsize / BITS_PER_UNIT)
return (void *)-1;
/* Make room for 2 operands in the new reference. */
if (vr->operands.length () < 2)
{
vec<vn_reference_op_s> old = vr->operands;
vr->operands.safe_grow_cleared (2);
if (old == shared_lookup_references
&& vr->operands != old)
shared_lookup_references = vr->operands;
}
else
vr->operands.truncate (2);
/* The looked-through reference is a simple MEM_REF. */
memset (&op, 0, sizeof (op));
op.type = vr->type;
op.opcode = MEM_REF;
op.op0 = build_int_cst (ptr_type_node, at - rhs_offset);
op.off = at - lhs_offset + rhs_offset;
vr->operands[0] = op;
op.type = TREE_TYPE (rhs);
op.opcode = TREE_CODE (rhs);
op.op0 = rhs;
op.off = -1;
vr->operands[1] = op;
vr->hashcode = vn_reference_compute_hash (vr);
/* Adjust *ref from the new operands. */
if (!ao_ref_init_from_vn_reference (&r, vr->set, vr->type, vr->operands))
return (void *)-1;
/* This can happen with bitfields. */
if (ref->size != r.size)
return (void *)-1;
*ref = r;
/* Do not update last seen VUSE after translating. */
last_vuse_ptr = NULL;
/* Keep looking for the adjusted *REF / VR pair. */
return NULL;
}
/* Bail out and stop walking. */
return (void *)-1;
}
/* Lookup a reference operation by it's parts, in the current hash table.
Returns the resulting value number if it exists in the hash table,
NULL_TREE otherwise. VNRESULT will be filled in with the actual
vn_reference_t stored in the hashtable if something is found. */
tree
vn_reference_lookup_pieces (tree vuse, alias_set_type set, tree type,
vec<vn_reference_op_s> operands,
vn_reference_t *vnresult, vn_lookup_kind kind)
{
struct vn_reference_s vr1;
vn_reference_t tmp;
tree cst;
if (!vnresult)
vnresult = &tmp;
*vnresult = NULL;
vr1.vuse = vuse_ssa_val (vuse);
shared_lookup_references.truncate (0);
shared_lookup_references.safe_grow (operands.length ());
memcpy (shared_lookup_references.address (),
operands.address (),
sizeof (vn_reference_op_s)
* operands.length ());
vr1.operands = operands = shared_lookup_references
= valueize_refs (shared_lookup_references);
vr1.type = type;
vr1.set = set;
vr1.hashcode = vn_reference_compute_hash (&vr1);
if ((cst = fully_constant_vn_reference_p (&vr1)))
return cst;
vn_reference_lookup_1 (&vr1, vnresult);
if (!*vnresult
&& kind != VN_NOWALK
&& vr1.vuse)
{
ao_ref r;
vn_walk_kind = kind;
if (ao_ref_init_from_vn_reference (&r, set, type, vr1.operands))
*vnresult =
(vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse,
vn_reference_lookup_2,
vn_reference_lookup_3,
vuse_ssa_val, &vr1);
gcc_checking_assert (vr1.operands == shared_lookup_references);
}
if (*vnresult)
return (*vnresult)->result;
return NULL_TREE;
}
/* Lookup OP in the current hash table, and return the resulting value
number if it exists in the hash table. Return NULL_TREE if it does
not exist in the hash table or if the result field of the structure
was NULL.. VNRESULT will be filled in with the vn_reference_t
stored in the hashtable if one exists. When TBAA_P is false assume
we are looking up a store and treat it as having alias-set zero. */
tree
vn_reference_lookup (tree op, tree vuse, vn_lookup_kind kind,
vn_reference_t *vnresult, bool tbaa_p)
{
vec<vn_reference_op_s> operands;
struct vn_reference_s vr1;
tree cst;
bool valuezied_anything;
if (vnresult)
*vnresult = NULL;
vr1.vuse = vuse_ssa_val (vuse);
vr1.operands = operands
= valueize_shared_reference_ops_from_ref (op, &valuezied_anything);
vr1.type = TREE_TYPE (op);
vr1.set = tbaa_p ? get_alias_set (op) : 0;
vr1.hashcode = vn_reference_compute_hash (&vr1);
if ((cst = fully_constant_vn_reference_p (&vr1)))
return cst;
if (kind != VN_NOWALK
&& vr1.vuse)
{
vn_reference_t wvnresult;
ao_ref r;
/* Make sure to use a valueized reference if we valueized anything.
Otherwise preserve the full reference for advanced TBAA. */
if (!valuezied_anything
|| !ao_ref_init_from_vn_reference (&r, vr1.set, vr1.type,
vr1.operands))
ao_ref_init (&r, op);
if (! tbaa_p)
r.ref_alias_set = r.base_alias_set = 0;
vn_walk_kind = kind;
wvnresult =
(vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse,
vn_reference_lookup_2,
vn_reference_lookup_3,
vuse_ssa_val, &vr1);
gcc_checking_assert (vr1.operands == shared_lookup_references);
if (wvnresult)
{
if (vnresult)
*vnresult = wvnresult;
return wvnresult->result;
}
return NULL_TREE;
}
return vn_reference_lookup_1 (&vr1, vnresult);
}
/* Lookup CALL in the current hash table and return the entry in
*VNRESULT if found. Populates *VR for the hashtable lookup. */
void
vn_reference_lookup_call (gcall *call, vn_reference_t *vnresult,
vn_reference_t vr)
{
if (vnresult)
*vnresult = NULL;
tree vuse = gimple_vuse (call);
vr->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
vr->operands = valueize_shared_reference_ops_from_call (call);
vr->type = gimple_expr_type (call);
vr->set = 0;
vr->hashcode = vn_reference_compute_hash (vr);
vn_reference_lookup_1 (vr, vnresult);
}
/* Insert OP into the current hash table with a value number of
RESULT, and return the resulting reference structure we created. */
static vn_reference_t
vn_reference_insert (tree op, tree result, tree vuse, tree vdef)
{
vn_reference_s **slot;
vn_reference_t vr1;
bool tem;
vr1 = (vn_reference_t) pool_alloc (current_info->references_pool);
if (TREE_CODE (result) == SSA_NAME)
vr1->value_id = VN_INFO (result)->value_id;
else
vr1->value_id = get_or_alloc_constant_value_id (result);
vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
vr1->operands = valueize_shared_reference_ops_from_ref (op, &tem).copy ();
vr1->type = TREE_TYPE (op);
vr1->set = get_alias_set (op);
vr1->hashcode = vn_reference_compute_hash (vr1);
vr1->result = TREE_CODE (result) == SSA_NAME ? SSA_VAL (result) : result;
vr1->result_vdef = vdef;
slot = current_info->references->find_slot_with_hash (vr1, vr1->hashcode,
INSERT);
/* Because we lookup stores using vuses, and value number failures
using the vdefs (see visit_reference_op_store for how and why),
it's possible that on failure we may try to insert an already
inserted store. This is not wrong, there is no ssa name for a
store that we could use as a differentiator anyway. Thus, unlike
the other lookup functions, you cannot gcc_assert (!*slot)
here. */
/* But free the old slot in case of a collision. */
if (*slot)
free_reference (*slot);
*slot = vr1;
return vr1;
}
/* Insert a reference by it's pieces into the current hash table with
a value number of RESULT. Return the resulting reference
structure we created. */
vn_reference_t
vn_reference_insert_pieces (tree vuse, alias_set_type set, tree type,
vec<vn_reference_op_s> operands,
tree result, unsigned int value_id)
{
vn_reference_s **slot;
vn_reference_t vr1;
vr1 = (vn_reference_t) pool_alloc (current_info->references_pool);
vr1->value_id = value_id;
vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
vr1->operands = valueize_refs (operands);
vr1->type = type;
vr1->set = set;
vr1->hashcode = vn_reference_compute_hash (vr1);
if (result && TREE_CODE (result) == SSA_NAME)
result = SSA_VAL (result);
vr1->result = result;
slot = current_info->references->find_slot_with_hash (vr1, vr1->hashcode,
INSERT);
/* At this point we should have all the things inserted that we have
seen before, and we should never try inserting something that
already exists. */
gcc_assert (!*slot);
if (*slot)
free_reference (*slot);
*slot = vr1;
return vr1;
}
/* Compute and return the hash value for nary operation VBO1. */
static hashval_t
vn_nary_op_compute_hash (const vn_nary_op_t vno1)
{
inchash::hash hstate;
unsigned i;
for (i = 0; i < vno1->length; ++i)
if (TREE_CODE (vno1->op[i]) == SSA_NAME)
vno1->op[i] = SSA_VAL (vno1->op[i]);
if (vno1->length == 2
&& commutative_tree_code (vno1->opcode)
&& tree_swap_operands_p (vno1->op[0], vno1->op[1], false))
{
tree temp = vno1->op[0];
vno1->op[0] = vno1->op[1];
vno1->op[1] = temp;
}
hstate.add_int (vno1->opcode);
for (i = 0; i < vno1->length; ++i)
inchash::add_expr (vno1->op[i], hstate);
return hstate.end ();
}
/* Compare nary operations VNO1 and VNO2 and return true if they are
equivalent. */
bool
vn_nary_op_eq (const_vn_nary_op_t const vno1, const_vn_nary_op_t const vno2)
{
unsigned i;
if (vno1->hashcode != vno2->hashcode)
return false;
if (vno1->length != vno2->length)
return false;
if (vno1->opcode != vno2->opcode
|| !types_compatible_p (vno1->type, vno2->type))
return false;
for (i = 0; i < vno1->length; ++i)
if (!expressions_equal_p (vno1->op[i], vno2->op[i]))
return false;
return true;
}
/* Initialize VNO from the pieces provided. */
static void
init_vn_nary_op_from_pieces (vn_nary_op_t vno, unsigned int length,
enum tree_code code, tree type, tree *ops)
{
vno->opcode = code;
vno->length = length;
vno->type = type;
memcpy (&vno->op[0], ops, sizeof (tree) * length);
}
/* Initialize VNO from OP. */
static void
init_vn_nary_op_from_op (vn_nary_op_t vno, tree op)
{
unsigned i;
vno->opcode = TREE_CODE (op);
vno->length = TREE_CODE_LENGTH (TREE_CODE (op));
vno->type = TREE_TYPE (op);
for (i = 0; i < vno->length; ++i)
vno->op[i] = TREE_OPERAND (op, i);
}
/* Return the number of operands for a vn_nary ops structure from STMT. */
static unsigned int
vn_nary_length_from_stmt (gimple stmt)
{
switch (gimple_assign_rhs_code (stmt))
{
case REALPART_EXPR:
case IMAGPART_EXPR:
case VIEW_CONVERT_EXPR:
return 1;
case BIT_FIELD_REF:
return 3;
case CONSTRUCTOR:
return CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt));
default:
return gimple_num_ops (stmt) - 1;
}
}
/* Initialize VNO from STMT. */
static void
init_vn_nary_op_from_stmt (vn_nary_op_t vno, gimple stmt)
{
unsigned i;
vno->opcode = gimple_assign_rhs_code (stmt);
vno->type = gimple_expr_type (stmt);
switch (vno->opcode)
{
case REALPART_EXPR:
case IMAGPART_EXPR:
case VIEW_CONVERT_EXPR:
vno->length = 1;
vno->op[0] = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
break;
case BIT_FIELD_REF:
vno->length = 3;
vno->op[0] = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
vno->op[1] = TREE_OPERAND (gimple_assign_rhs1 (stmt), 1);
vno->op[2] = TREE_OPERAND (gimple_assign_rhs1 (stmt), 2);
break;
case CONSTRUCTOR:
vno->length = CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt));
for (i = 0; i < vno->length; ++i)
vno->op[i] = CONSTRUCTOR_ELT (gimple_assign_rhs1 (stmt), i)->value;
break;
default:
gcc_checking_assert (!gimple_assign_single_p (stmt));
vno->length = gimple_num_ops (stmt) - 1;
for (i = 0; i < vno->length; ++i)
vno->op[i] = gimple_op (stmt, i + 1);
}
}
/* Compute the hashcode for VNO and look for it in the hash table;
return the resulting value number if it exists in the hash table.
Return NULL_TREE if it does not exist in the hash table or if the
result field of the operation is NULL. VNRESULT will contain the
vn_nary_op_t from the hashtable if it exists. */
static tree
vn_nary_op_lookup_1 (vn_nary_op_t vno, vn_nary_op_t *vnresult)
{
vn_nary_op_s **slot;
if (vnresult)
*vnresult = NULL;
vno->hashcode = vn_nary_op_compute_hash (vno);
slot = current_info->nary->find_slot_with_hash (vno, vno->hashcode,
NO_INSERT);
if (!slot && current_info == optimistic_info)
slot = valid_info->nary->find_slot_with_hash (vno, vno->hashcode,
NO_INSERT);
if (!slot)
return NULL_TREE;
if (vnresult)
*vnresult = *slot;
return (*slot)->result;
}
/* Lookup a n-ary operation by its pieces and return the resulting value
number if it exists in the hash table. Return NULL_TREE if it does
not exist in the hash table or if the result field of the operation
is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
if it exists. */
tree
vn_nary_op_lookup_pieces (unsigned int length, enum tree_code code,
tree type, tree *ops, vn_nary_op_t *vnresult)
{
vn_nary_op_t vno1 = XALLOCAVAR (struct vn_nary_op_s,
sizeof_vn_nary_op (length));
init_vn_nary_op_from_pieces (vno1, length, code, type, ops);
return vn_nary_op_lookup_1 (vno1, vnresult);
}
/* Lookup OP in the current hash table, and return the resulting value
number if it exists in the hash table. Return NULL_TREE if it does
not exist in the hash table or if the result field of the operation
is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
if it exists. */
tree
vn_nary_op_lookup (tree op, vn_nary_op_t *vnresult)
{
vn_nary_op_t vno1
= XALLOCAVAR (struct vn_nary_op_s,
sizeof_vn_nary_op (TREE_CODE_LENGTH (TREE_CODE (op))));
init_vn_nary_op_from_op (vno1, op);
return vn_nary_op_lookup_1 (vno1, vnresult);
}
/* Lookup the rhs of STMT in the current hash table, and return the resulting
value number if it exists in the hash table. Return NULL_TREE if
it does not exist in the hash table. VNRESULT will contain the
vn_nary_op_t from the hashtable if it exists. */
tree
vn_nary_op_lookup_stmt (gimple stmt, vn_nary_op_t *vnresult)
{
vn_nary_op_t vno1
= XALLOCAVAR (struct vn_nary_op_s,
sizeof_vn_nary_op (vn_nary_length_from_stmt (stmt)));
init_vn_nary_op_from_stmt (vno1, stmt);
return vn_nary_op_lookup_1 (vno1, vnresult);
}
/* Allocate a vn_nary_op_t with LENGTH operands on STACK. */
static vn_nary_op_t
alloc_vn_nary_op_noinit (unsigned int length, struct obstack *stack)
{
return (vn_nary_op_t) obstack_alloc (stack, sizeof_vn_nary_op (length));
}
/* Allocate and initialize a vn_nary_op_t on CURRENT_INFO's
obstack. */
static vn_nary_op_t
alloc_vn_nary_op (unsigned int length, tree result, unsigned int value_id)
{
vn_nary_op_t vno1 = alloc_vn_nary_op_noinit (length,
&current_info->nary_obstack);
vno1->value_id = value_id;
vno1->length = length;
vno1->result = result;
return vno1;
}
/* Insert VNO into TABLE. If COMPUTE_HASH is true, then compute
VNO->HASHCODE first. */
static vn_nary_op_t
vn_nary_op_insert_into (vn_nary_op_t vno, vn_nary_op_table_type *table,
bool compute_hash)
{
vn_nary_op_s **slot;
if (compute_hash)
vno->hashcode = vn_nary_op_compute_hash (vno);
slot = table->find_slot_with_hash (vno, vno->hashcode, INSERT);
gcc_assert (!*slot);
*slot = vno;
return vno;
}
/* Insert a n-ary operation into the current hash table using it's
pieces. Return the vn_nary_op_t structure we created and put in
the hashtable. */
vn_nary_op_t
vn_nary_op_insert_pieces (unsigned int length, enum tree_code code,
tree type, tree *ops,
tree result, unsigned int value_id)
{
vn_nary_op_t vno1 = alloc_vn_nary_op (length, result, value_id);
init_vn_nary_op_from_pieces (vno1, length, code, type, ops);
return vn_nary_op_insert_into (vno1, current_info->nary, true);
}
/* Insert OP into the current hash table with a value number of
RESULT. Return the vn_nary_op_t structure we created and put in
the hashtable. */
vn_nary_op_t
vn_nary_op_insert (tree op, tree result)
{
unsigned length = TREE_CODE_LENGTH (TREE_CODE (op));
vn_nary_op_t vno1;
vno1 = alloc_vn_nary_op (length, result, VN_INFO (result)->value_id);
init_vn_nary_op_from_op (vno1, op);
return vn_nary_op_insert_into (vno1, current_info->nary, true);
}
/* Insert the rhs of STMT into the current hash table with a value number of
RESULT. */
vn_nary_op_t
vn_nary_op_insert_stmt (gimple stmt, tree result)
{
vn_nary_op_t vno1
= alloc_vn_nary_op (vn_nary_length_from_stmt (stmt),
result, VN_INFO (result)->value_id);
init_vn_nary_op_from_stmt (vno1, stmt);
return vn_nary_op_insert_into (vno1, current_info->nary, true);
}
/* Compute a hashcode for PHI operation VP1 and return it. */
static inline hashval_t
vn_phi_compute_hash (vn_phi_t vp1)
{
inchash::hash hstate (vp1->block->index);
int i;
tree phi1op;
tree type;
/* If all PHI arguments are constants we need to distinguish
the PHI node via its type. */
type = vp1->type;
hstate.merge_hash (vn_hash_type (type));
FOR_EACH_VEC_ELT (vp1->phiargs, i, phi1op)
{
if (phi1op == VN_TOP)
continue;
inchash::add_expr (phi1op, hstate);
}
return hstate.end ();
}
/* Compare two phi entries for equality, ignoring VN_TOP arguments. */
static int
vn_phi_eq (const_vn_phi_t const vp1, const_vn_phi_t const vp2)
{
if (vp1->hashcode != vp2->hashcode)
return false;
if (vp1->block == vp2->block)
{
int i;
tree phi1op;
/* If the PHI nodes do not have compatible types
they are not the same. */
if (!types_compatible_p (vp1->type, vp2->type))
return false;
/* Any phi in the same block will have it's arguments in the
same edge order, because of how we store phi nodes. */
FOR_EACH_VEC_ELT (vp1->phiargs, i, phi1op)
{
tree phi2op = vp2->phiargs[i];
if (phi1op == VN_TOP || phi2op == VN_TOP)
continue;
if (!expressions_equal_p (phi1op, phi2op))
return false;
}
return true;
}
return false;
}
static vec<tree> shared_lookup_phiargs;
/* Lookup PHI in the current hash table, and return the resulting
value number if it exists in the hash table. Return NULL_TREE if
it does not exist in the hash table. */
static tree
vn_phi_lookup (gimple phi)
{
vn_phi_s **slot;
struct vn_phi_s vp1;
unsigned i;
shared_lookup_phiargs.truncate (0);
/* Canonicalize the SSA_NAME's to their value number. */
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree def = PHI_ARG_DEF (phi, i);
def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
shared_lookup_phiargs.safe_push (def);
}
vp1.type = TREE_TYPE (gimple_phi_result (phi));
vp1.phiargs = shared_lookup_phiargs;
vp1.block = gimple_bb (phi);
vp1.hashcode = vn_phi_compute_hash (&vp1);
slot = current_info->phis->find_slot_with_hash (&vp1, vp1.hashcode,
NO_INSERT);
if (!slot && current_info == optimistic_info)
slot = valid_info->phis->find_slot_with_hash (&vp1, vp1.hashcode,
NO_INSERT);
if (!slot)
return NULL_TREE;
return (*slot)->result;
}
/* Insert PHI into the current hash table with a value number of
RESULT. */
static vn_phi_t
vn_phi_insert (gimple phi, tree result)
{
vn_phi_s **slot;
vn_phi_t vp1 = (vn_phi_t) pool_alloc (current_info->phis_pool);
unsigned i;
vec<tree> args = vNULL;
/* Canonicalize the SSA_NAME's to their value number. */
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree def = PHI_ARG_DEF (phi, i);
def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
args.safe_push (def);
}
vp1->value_id = VN_INFO (result)->value_id;
vp1->type = TREE_TYPE (gimple_phi_result (phi));
vp1->phiargs = args;
vp1->block = gimple_bb (phi);
vp1->result = result;
vp1->hashcode = vn_phi_compute_hash (vp1);
slot = current_info->phis->find_slot_with_hash (vp1, vp1->hashcode, INSERT);
/* Because we iterate over phi operations more than once, it's
possible the slot might already exist here, hence no assert.*/
*slot = vp1;
return vp1;
}
/* Print set of components in strongly connected component SCC to OUT. */
static void
print_scc (FILE *out, vec<tree> scc)
{
tree var;
unsigned int i;
fprintf (out, "SCC consists of:");
FOR_EACH_VEC_ELT (scc, i, var)
{
fprintf (out, " ");
print_generic_expr (out, var, 0);
}
fprintf (out, "\n");
}
/* Set the value number of FROM to TO, return true if it has changed
as a result. */
static inline bool
set_ssa_val_to (tree from, tree to)
{
tree currval = SSA_VAL (from);
HOST_WIDE_INT toff, coff;
/* The only thing we allow as value numbers are ssa_names
and invariants. So assert that here. We don't allow VN_TOP
as visiting a stmt should produce a value-number other than
that.
??? Still VN_TOP can happen for unreachable code, so force
it to varying in that case. Not all code is prepared to
get VN_TOP on valueization. */
if (to == VN_TOP)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Forcing value number to varying on "
"receiving VN_TOP\n");
to = from;
}
gcc_assert (to != NULL_TREE
&& ((TREE_CODE (to) == SSA_NAME
&& (to == from || SSA_VAL (to) == to))
|| is_gimple_min_invariant (to)));
if (from != to)
{
if (currval == from)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Not changing value number of ");
print_generic_expr (dump_file, from, 0);
fprintf (dump_file, " from VARYING to ");
print_generic_expr (dump_file, to, 0);
fprintf (dump_file, "\n");
}
return false;
}
else if (TREE_CODE (to) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to))
to = from;
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Setting value number of ");
print_generic_expr (dump_file, from, 0);
fprintf (dump_file, " to ");
print_generic_expr (dump_file, to, 0);
}
if (currval != to
&& !operand_equal_p (currval, to, 0)
/* ??? For addresses involving volatile objects or types operand_equal_p
does not reliably detect ADDR_EXPRs as equal. We know we are only
getting invariant gimple addresses here, so can use
get_addr_base_and_unit_offset to do this comparison. */
&& !(TREE_CODE (currval) == ADDR_EXPR
&& TREE_CODE (to) == ADDR_EXPR
&& (get_addr_base_and_unit_offset (TREE_OPERAND (currval, 0), &coff)
== get_addr_base_and_unit_offset (TREE_OPERAND (to, 0), &toff))
&& coff == toff))
{
VN_INFO (from)->valnum = to;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " (changed)\n");
return true;
}
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "\n");
return false;
}
/* Mark as processed all the definitions in the defining stmt of USE, or
the USE itself. */
static void
mark_use_processed (tree use)
{
ssa_op_iter iter;
def_operand_p defp;
gimple stmt = SSA_NAME_DEF_STMT (use);
if (SSA_NAME_IS_DEFAULT_DEF (use) || gimple_code (stmt) == GIMPLE_PHI)
{
VN_INFO (use)->use_processed = true;
return;
}
FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_ALL_DEFS)
{
tree def = DEF_FROM_PTR (defp);
VN_INFO (def)->use_processed = true;
}
}
/* Set all definitions in STMT to value number to themselves.
Return true if a value number changed. */
static bool
defs_to_varying (gimple stmt)
{
bool changed = false;
ssa_op_iter iter;
def_operand_p defp;
FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_ALL_DEFS)
{
tree def = DEF_FROM_PTR (defp);
changed |= set_ssa_val_to (def, def);
}
return changed;
}
static bool expr_has_constants (tree expr);
/* Visit a copy between LHS and RHS, return true if the value number
changed. */
static bool
visit_copy (tree lhs, tree rhs)
{
/* The copy may have a more interesting constant filled expression
(we don't, since we know our RHS is just an SSA name). */
VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
/* And finally valueize. */
rhs = SSA_VAL (rhs);
return set_ssa_val_to (lhs, rhs);
}
/* Visit a nary operator RHS, value number it, and return true if the
value number of LHS has changed as a result. */
static bool
visit_nary_op (tree lhs, gimple stmt)
{
bool changed = false;
tree result = vn_nary_op_lookup_stmt (stmt, NULL);
if (result)
changed = set_ssa_val_to (lhs, result);
else
{
changed = set_ssa_val_to (lhs, lhs);
vn_nary_op_insert_stmt (stmt, lhs);
}
return changed;
}
/* Visit a call STMT storing into LHS. Return true if the value number
of the LHS has changed as a result. */
static bool
visit_reference_op_call (tree lhs, gcall *stmt)
{
bool changed = false;
struct vn_reference_s vr1;
vn_reference_t vnresult = NULL;
tree vdef = gimple_vdef (stmt);
/* Non-ssa lhs is handled in copy_reference_ops_from_call. */
if (lhs && TREE_CODE (lhs) != SSA_NAME)
lhs = NULL_TREE;
vn_reference_lookup_call (stmt, &vnresult, &vr1);
if (vnresult)
{
if (vnresult->result_vdef && vdef)
changed |= set_ssa_val_to (vdef, vnresult->result_vdef);
else if (vdef)
/* If the call was discovered to be pure or const reflect
that as far as possible. */
changed |= set_ssa_val_to (vdef, vuse_ssa_val (gimple_vuse (stmt)));
if (!vnresult->result && lhs)
vnresult->result = lhs;
if (vnresult->result && lhs)
{
changed |= set_ssa_val_to (lhs, vnresult->result);
if (VN_INFO (vnresult->result)->has_constants)
VN_INFO (lhs)->has_constants = true;
}
}
else
{
vn_reference_t vr2;
vn_reference_s **slot;
if (vdef)
changed |= set_ssa_val_to (vdef, vdef);
if (lhs)
changed |= set_ssa_val_to (lhs, lhs);
vr2 = (vn_reference_t) pool_alloc (current_info->references_pool);
vr2->vuse = vr1.vuse;
/* As we are not walking the virtual operand chain we know the
shared_lookup_references are still original so we can re-use
them here. */
vr2->operands = vr1.operands.copy ();
vr2->type = vr1.type;
vr2->set = vr1.set;
vr2->hashcode = vr1.hashcode;
vr2->result = lhs;
vr2->result_vdef = vdef;
slot = current_info->references->find_slot_with_hash (vr2, vr2->hashcode,
INSERT);
gcc_assert (!*slot);
*slot = vr2;
}
return changed;
}
/* Visit a load from a reference operator RHS, part of STMT, value number it,
and return true if the value number of the LHS has changed as a result. */
static bool
visit_reference_op_load (tree lhs, tree op, gimple stmt)
{
bool changed = false;
tree last_vuse;
tree result;
last_vuse = gimple_vuse (stmt);
last_vuse_ptr = &last_vuse;
result = vn_reference_lookup (op, gimple_vuse (stmt),
default_vn_walk_kind, NULL, true);
last_vuse_ptr = NULL;
/* We handle type-punning through unions by value-numbering based
on offset and size of the access. Be prepared to handle a
type-mismatch here via creating a VIEW_CONVERT_EXPR. */
if (result
&& !useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (op)))
{
/* We will be setting the value number of lhs to the value number
of VIEW_CONVERT_EXPR <TREE_TYPE (result)> (result).
So first simplify and lookup this expression to see if it
is already available. */
tree val = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (op), result);
if ((CONVERT_EXPR_P (val)
|| TREE_CODE (val) == VIEW_CONVERT_EXPR)
&& TREE_CODE (TREE_OPERAND (val, 0)) == SSA_NAME)
{
tree tem = vn_get_expr_for (TREE_OPERAND (val, 0));
if ((CONVERT_EXPR_P (tem)
|| TREE_CODE (tem) == VIEW_CONVERT_EXPR)
&& (tem = fold_unary_ignore_overflow (TREE_CODE (val),
TREE_TYPE (val), tem)))
val = tem;
}
result = val;
if (!is_gimple_min_invariant (val)
&& TREE_CODE (val) != SSA_NAME)
result = vn_nary_op_lookup (val, NULL);
/* If the expression is not yet available, value-number lhs to
a new SSA_NAME we create. */
if (!result)
{
result = make_temp_ssa_name (TREE_TYPE (lhs), gimple_build_nop (),
"vntemp");
/* Initialize value-number information properly. */
VN_INFO_GET (result)->valnum = result;
VN_INFO (result)->value_id = get_next_value_id ();
VN_INFO (result)->expr = val;
VN_INFO (result)->has_constants = expr_has_constants (val);
VN_INFO (result)->needs_insertion = true;
/* As all "inserted" statements are singleton SCCs, insert
to the valid table. This is strictly needed to
avoid re-generating new value SSA_NAMEs for the same
expression during SCC iteration over and over (the
optimistic table gets cleared after each iteration).
We do not need to insert into the optimistic table, as
lookups there will fall back to the valid table. */
if (current_info == optimistic_info)
{
current_info = valid_info;
vn_nary_op_insert (val, result);
current_info = optimistic_info;
}
else
vn_nary_op_insert (val, result);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Inserting name ");
print_generic_expr (dump_file, result, 0);
fprintf (dump_file, " for expression ");
print_generic_expr (dump_file, val, 0);
fprintf (dump_file, "\n");