/* Data flow functions for trees.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008 Free Software
- Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@redhat.com>
This file is part of GCC.
#include "function.h"
#include "diagnostic.h"
#include "tree-dump.h"
-#include "tree-gimple.h"
+#include "gimple.h"
#include "tree-flow.h"
#include "tree-inline.h"
#include "tree-pass.h"
/* Counters used to display DFA and SSA statistics. */
struct dfa_stats_d
{
- long num_stmt_anns;
long num_var_anns;
long num_defs;
long num_uses;
long num_phis;
long num_phi_args;
- int max_num_phi_args;
+ size_t max_num_phi_args;
long num_vdefs;
long num_vuses;
};
/* Local functions. */
static void collect_dfa_stats (struct dfa_stats_d *);
-static tree collect_dfa_stats_r (tree *, int *, void *);
static tree find_vars_r (tree *, int *, void *);
find_referenced_vars (void)
{
basic_block bb;
- block_stmt_iterator si;
- tree phi;
+ gimple_stmt_iterator si;
FOR_EACH_BB (bb)
{
- for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
- {
- tree *stmt_p = bsi_stmt_ptr (si);
- walk_tree (stmt_p, find_vars_r, NULL, NULL);
- }
-
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- {
- int len = PHI_NUM_ARGS (phi);
- int i;
-
- walk_tree (&phi, find_vars_r, NULL, NULL);
+ for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
+ find_referenced_vars_in (gsi_stmt (si));
- for (i = 0; i < len; i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- walk_tree (&arg, find_vars_r, NULL, NULL);
- }
- }
+ for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
+ find_referenced_vars_in (gsi_stmt (si));
}
return 0;
return ann;
}
-/* Create a new annotation for a FUNCTION_DECL node T. */
-
-function_ann_t
-create_function_ann (tree t)
-{
- function_ann_t ann;
-
- gcc_assert (t);
- gcc_assert (TREE_CODE (t) == FUNCTION_DECL);
- gcc_assert (!t->base.ann || t->base.ann->common.type == FUNCTION_ANN);
-
- ann = (function_ann_t) ggc_alloc (sizeof (*ann));
- memset ((void *) ann, 0, sizeof (*ann));
-
- ann->common.type = FUNCTION_ANN;
-
- t->base.ann = (tree_ann_t) ann;
-
- return ann;
-}
-
-/* Create a new annotation for a statement node T. */
-
-stmt_ann_t
-create_stmt_ann (tree t)
-{
- stmt_ann_t ann;
-
- gcc_assert (is_gimple_stmt (t));
- gcc_assert (!t->base.ann || t->base.ann->common.type == STMT_ANN);
-
- ann = GGC_CNEW (struct stmt_ann_d);
-
- ann->common.type = STMT_ANN;
-
- /* Since we just created the annotation, mark the statement modified. */
- ann->modified = true;
-
- ann->uid = inc_gimple_stmt_max_uid (cfun);
- t->base.ann = (tree_ann_t) ann;
-
- return ann;
-}
-
/* Renumber all of the gimple stmt uids. */
void
set_gimple_stmt_max_uid (cfun, 0);
FOR_ALL_BB (bb)
{
- block_stmt_iterator bsi;
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ gimple_stmt_iterator bsi;
+ for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
{
- tree stmt = bsi_stmt (bsi);
- /* If the stmt has an annotation, then overwrite it, if not,
- the process of getting it will set the number
- properly. */
- if (has_stmt_ann (stmt))
- set_gimple_stmt_uid (stmt, inc_gimple_stmt_max_uid (cfun));
- else
- get_stmt_ann (stmt);
+ gimple stmt = gsi_stmt (bsi);
+ gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
}
}
}
ann = GGC_CNEW (struct tree_ann_common_d);
ann->type = TREE_ANN_COMMON;
+ ann->rn = -1;
t->base.ann = (tree_ann_t) ann;
return ann;
{
fprintf (file, "Variable: ");
dump_variable (file, var);
- fprintf (file, "\n");
}
+
+ fprintf (file, "\n");
}
fprintf (file, ", ");
print_generic_expr (file, TREE_TYPE (var), dump_flags);
- if (ann && ann->symbol_mem_tag)
- {
- fprintf (file, ", symbol memory tag: ");
- print_generic_expr (file, ann->symbol_mem_tag, dump_flags);
- }
-
if (TREE_ADDRESSABLE (var))
fprintf (file, ", is addressable");
if (TREE_THIS_VOLATILE (var))
fprintf (file, ", is volatile");
- dump_mem_sym_stats_for_var (file, var);
-
if (is_call_clobbered (var))
- {
- const char *s = "";
- var_ann_t va = var_ann (var);
- unsigned int escape_mask = va->escape_mask;
-
- fprintf (file, ", call clobbered");
- fprintf (file, " (");
- if (escape_mask & ESCAPE_STORED_IN_GLOBAL)
- { fprintf (file, "%sstored in global", s); s = ", "; }
- if (escape_mask & ESCAPE_TO_ASM)
- { fprintf (file, "%sgoes through ASM", s); s = ", "; }
- if (escape_mask & ESCAPE_TO_CALL)
- { fprintf (file, "%spassed to call", s); s = ", "; }
- if (escape_mask & ESCAPE_BAD_CAST)
- { fprintf (file, "%sbad cast", s); s = ", "; }
- if (escape_mask & ESCAPE_TO_RETURN)
- { fprintf (file, "%sreturned from func", s); s = ", "; }
- if (escape_mask & ESCAPE_TO_PURE_CONST)
- { fprintf (file, "%spassed to pure/const", s); s = ", "; }
- if (escape_mask & ESCAPE_IS_GLOBAL)
- { fprintf (file, "%sis global var", s); s = ", "; }
- if (escape_mask & ESCAPE_IS_PARM)
- { fprintf (file, "%sis incoming pointer", s); s = ", "; }
- if (escape_mask & ESCAPE_UNKNOWN)
- { fprintf (file, "%sunknown escape", s); s = ", "; }
- fprintf (file, ")");
- }
+ fprintf (file, ", call clobbered");
+ else if (is_call_used (var))
+ fprintf (file, ", call used");
- if (ann->noalias_state == NO_ALIAS)
+ if (ann && ann->noalias_state == NO_ALIAS)
fprintf (file, ", NO_ALIAS (does not alias other NO_ALIAS symbols)");
- else if (ann->noalias_state == NO_ALIAS_GLOBAL)
+ else if (ann && ann->noalias_state == NO_ALIAS_GLOBAL)
fprintf (file, ", NO_ALIAS_GLOBAL (does not alias other NO_ALIAS symbols"
" and global vars)");
- else if (ann->noalias_state == NO_ALIAS_ANYTHING)
+ else if (ann && ann->noalias_state == NO_ALIAS_ANYTHING)
fprintf (file, ", NO_ALIAS_ANYTHING (does not alias any other symbols)");
- if (gimple_default_def (cfun, var))
+ if (cfun && gimple_default_def (cfun, var))
{
fprintf (file, ", default def: ");
print_generic_expr (file, gimple_default_def (cfun, var), dump_flags);
}
- if (MTAG_P (var) && may_aliases (var))
+ if (DECL_INITIAL (var))
{
- fprintf (file, ", may aliases: ");
- dump_may_aliases_for (file, var);
- }
-
- if (!is_gimple_reg (var))
- {
- if (memory_partition (var))
- {
- fprintf (file, ", belongs to partition: ");
- print_generic_expr (file, memory_partition (var), dump_flags);
- }
-
- if (TREE_CODE (var) == MEMORY_PARTITION_TAG)
- {
- fprintf (file, ", partition symbols: ");
- dump_decl_set (file, MPT_SYMBOLS (var));
- }
+ fprintf (file, ", initial: ");
+ print_generic_expr (file, DECL_INITIAL (var), dump_flags);
}
fprintf (file, "\n");
fprintf (file, fmt_str_1, "Referenced variables", (unsigned long)num_referenced_vars,
SCALE (size), LABEL (size));
- size = dfa_stats.num_stmt_anns * sizeof (struct stmt_ann_d);
- total += size;
- fprintf (file, fmt_str_1, "Statements annotated", dfa_stats.num_stmt_anns,
- SCALE (size), LABEL (size));
-
size = dfa_stats.num_var_anns * sizeof (struct var_ann_d);
total += size;
fprintf (file, fmt_str_1, "Variables annotated", dfa_stats.num_var_anns,
fprintf (file, fmt_str_1, "VDEF operands", dfa_stats.num_vdefs,
SCALE (size), LABEL (size));
- size = dfa_stats.num_phis * sizeof (struct tree_phi_node);
+ size = dfa_stats.num_phis * sizeof (struct gimple_statement_phi);
total += size;
fprintf (file, fmt_str_1, "PHI nodes", dfa_stats.num_phis,
SCALE (size), LABEL (size));
fprintf (file, "\n");
if (dfa_stats.num_phis)
- fprintf (file, "Average number of arguments per PHI node: %.1f (max: %d)\n",
+ fprintf (file, "Average number of arguments per PHI node: %.1f (max: %ld)\n",
(float) dfa_stats.num_phi_args / (float) dfa_stats.num_phis,
- dfa_stats.max_num_phi_args);
+ (long) dfa_stats.max_num_phi_args);
fprintf (file, "\n");
}
DFA_STATS_P. */
static void
-collect_dfa_stats (struct dfa_stats_d *dfa_stats_p)
+collect_dfa_stats (struct dfa_stats_d *dfa_stats_p ATTRIBUTE_UNUSED)
{
- struct pointer_set_t *pset;
basic_block bb;
- block_stmt_iterator i;
+ referenced_var_iterator vi;
+ tree var;
gcc_assert (dfa_stats_p);
memset ((void *)dfa_stats_p, 0, sizeof (struct dfa_stats_d));
- /* Walk all the trees in the function counting references. Start at
- basic block NUM_FIXED_BLOCKS, but don't stop at block boundaries. */
- pset = pointer_set_create ();
-
- for (i = bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
- !bsi_end_p (i); bsi_next (&i))
- walk_tree (bsi_stmt_ptr (i), collect_dfa_stats_r, (void *) dfa_stats_p,
- pset);
-
- pointer_set_destroy (pset);
+ /* Count all the variable annotations. */
+ FOR_EACH_REFERENCED_VAR (var, vi)
+ if (var_ann (var))
+ dfa_stats_p->num_var_anns++;
+ /* Walk all the statements in the function counting references. */
FOR_EACH_BB (bb)
{
- tree phi;
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ gimple_stmt_iterator si;
+
+ for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
{
+ gimple phi = gsi_stmt (si);
dfa_stats_p->num_phis++;
- dfa_stats_p->num_phi_args += PHI_NUM_ARGS (phi);
- if (PHI_NUM_ARGS (phi) > dfa_stats_p->max_num_phi_args)
- dfa_stats_p->max_num_phi_args = PHI_NUM_ARGS (phi);
+ dfa_stats_p->num_phi_args += gimple_phi_num_args (phi);
+ if (gimple_phi_num_args (phi) > dfa_stats_p->max_num_phi_args)
+ dfa_stats_p->max_num_phi_args = gimple_phi_num_args (phi);
}
- }
-}
-
-
-/* Callback for walk_tree to collect DFA statistics for a tree and its
- children. */
-static tree
-collect_dfa_stats_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
- void *data)
-{
- tree t = *tp;
- struct dfa_stats_d *dfa_stats_p = (struct dfa_stats_d *)data;
-
- if (t->base.ann)
- {
- switch (ann_type (t->base.ann))
+ for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
{
- case STMT_ANN:
- {
- dfa_stats_p->num_stmt_anns++;
- dfa_stats_p->num_defs += NUM_SSA_OPERANDS (t, SSA_OP_DEF);
- dfa_stats_p->num_uses += NUM_SSA_OPERANDS (t, SSA_OP_USE);
- dfa_stats_p->num_vdefs += NUM_SSA_OPERANDS (t, SSA_OP_VDEF);
- dfa_stats_p->num_vuses += NUM_SSA_OPERANDS (t, SSA_OP_VUSE);
- break;
- }
-
- case VAR_ANN:
- dfa_stats_p->num_var_anns++;
- break;
-
- default:
- break;
+ gimple stmt = gsi_stmt (si);
+ dfa_stats_p->num_defs += NUM_SSA_OPERANDS (stmt, SSA_OP_DEF);
+ dfa_stats_p->num_uses += NUM_SSA_OPERANDS (stmt, SSA_OP_USE);
+ dfa_stats_p->num_vdefs += gimple_vdef (stmt) ? 1 : 0;
+ dfa_stats_p->num_vuses += gimple_vuse (stmt) ? 1 : 0;
}
}
-
- return NULL;
}
return NULL_TREE;
}
+/* Find referenced variables in STMT. In contrast with
+ find_new_referenced_vars, this function will not mark newly found
+ variables for renaming. */
+
+void
+find_referenced_vars_in (gimple stmt)
+{
+ size_t i;
+
+ if (gimple_code (stmt) != GIMPLE_PHI)
+ {
+ for (i = 0; i < gimple_num_ops (stmt); i++)
+ walk_tree (gimple_op_ptr (stmt, i), find_vars_r, NULL, NULL);
+ }
+ else
+ {
+ walk_tree (gimple_phi_result_ptr (stmt), find_vars_r, NULL, NULL);
+
+ for (i = 0; i < gimple_phi_num_args (stmt); i++)
+ {
+ tree arg = gimple_phi_arg_def (stmt, i);
+ walk_tree (&arg, find_vars_r, NULL, NULL);
+ }
+ }
+}
+
+
/* Lookup UID in the referenced_vars hashtable and return the associated
variable. */
/* Add VAR to the list of referenced variables if it isn't already there. */
-void
+bool
add_referenced_var (tree var)
{
var_ann_t v_ann;
/* Insert VAR into the referenced_vars has table if it isn't present. */
if (referenced_var_check_and_insert (var))
{
- /* This is the first time we found this variable, annotate it with
- attributes that are intrinsic to the variable. */
-
- /* Tag's don't have DECL_INITIAL. */
- if (MTAG_P (var))
- return;
-
/* Scan DECL_INITIAL for pointer variables as they may contain
address arithmetic referencing the address of other
- variables.
- Even non-constant initializers need to be walked, because
- IPA passes might prove that their are invariant later on. */
+ variables. As we are only interested in directly referenced
+ globals or referenced locals restrict this to initializers
+ than can refer to local variables. */
if (DECL_INITIAL (var)
- /* Initializers of external variables are not useful to the
- optimizers. */
- && !DECL_EXTERNAL (var))
+ && DECL_CONTEXT (var) == current_function_decl)
walk_tree (&DECL_INITIAL (var), find_vars_r, NULL, 0);
+
+ return true;
}
+
+ return false;
}
/* Remove VAR from the list. */
void **loc;
unsigned int uid = DECL_UID (var);
- clear_call_clobbered (var);
- bitmap_clear_bit (gimple_call_used_vars (cfun), uid);
- if ((v_ann = var_ann (var)))
+ /* Preserve var_anns of globals. */
+ if (!is_global_var (var)
+ && (v_ann = var_ann (var)))
{
- /* Preserve var_anns of globals, but clear their alias info. */
- if (MTAG_P (var)
- || (!TREE_STATIC (var) && !DECL_EXTERNAL (var)))
- {
- ggc_free (v_ann);
- var->base.ann = NULL;
- }
- else
- {
- v_ann->mpt = NULL_TREE;
- v_ann->symbol_mem_tag = NULL_TREE;
- }
+ ggc_free (v_ann);
+ var->base.ann = NULL;
}
gcc_assert (DECL_P (var));
in.uid = uid;
return var;
}
-/* Mark all the naked symbols in STMT for SSA renaming.
-
- NOTE: This function should only be used for brand new statements.
- If the caller is modifying an existing statement, it should use the
- combination push_stmt_changes/pop_stmt_changes. */
+/* Mark all the naked symbols in STMT for SSA renaming. */
void
-mark_symbols_for_renaming (tree stmt)
+mark_symbols_for_renaming (gimple stmt)
{
tree op;
ssa_op_iter iter;
}
-/* Find all variables within the gimplified statement that were not previously
- visible to the function and add them to the referenced variables list. */
+/* Find all variables within the gimplified statement that were not
+ previously visible to the function and add them to the referenced
+ variables list. */
static tree
find_new_referenced_vars_1 (tree *tp, int *walk_subtrees,
return NULL;
}
+
+/* Find any new referenced variables in STMT. */
+
void
-find_new_referenced_vars (tree *stmt_p)
+find_new_referenced_vars (gimple stmt)
{
- walk_tree (stmt_p, find_new_referenced_vars_1, NULL, NULL);
+ walk_gimple_op (stmt, find_new_referenced_vars_1, NULL);
}
tree size_tree = NULL_TREE;
HOST_WIDE_INT bit_offset = 0;
bool seen_variable_array_ref = false;
-
- gcc_assert (!SSA_VAR_P (exp));
+ bool seen_union = false;
/* First get the final access size from just the outermost expression. */
if (TREE_CODE (exp) == COMPONENT_REF)
switch (TREE_CODE (exp))
{
case BIT_FIELD_REF:
- bit_offset += tree_low_cst (TREE_OPERAND (exp, 2), 0);
+ bit_offset += TREE_INT_CST_LOW (TREE_OPERAND (exp, 2));
break;
case COMPONENT_REF:
tree field = TREE_OPERAND (exp, 1);
tree this_offset = component_ref_field_offset (exp);
- if (this_offset && TREE_CODE (this_offset) == INTEGER_CST)
- {
- HOST_WIDE_INT hthis_offset = tree_low_cst (this_offset, 0);
+ if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == UNION_TYPE)
+ seen_union = true;
+ if (this_offset
+ && TREE_CODE (this_offset) == INTEGER_CST
+ && host_integerp (this_offset, 0))
+ {
+ HOST_WIDE_INT hthis_offset = TREE_INT_CST_LOW (this_offset);
hthis_offset *= BITS_PER_UNIT;
bit_offset += hthis_offset;
- bit_offset += tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 0);
+ bit_offset += TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field));
}
else
{
case ARRAY_RANGE_REF:
{
tree index = TREE_OPERAND (exp, 1);
- tree low_bound = array_ref_low_bound (exp);
- tree unit_size = array_ref_element_size (exp);
+ tree low_bound, unit_size;
/* If the resulting bit-offset is constant, track it. */
- if (host_integerp (index, 0)
- && host_integerp (low_bound, 0)
- && host_integerp (unit_size, 1))
+ if (TREE_CODE (index) == INTEGER_CST
+ && host_integerp (index, 0)
+ && (low_bound = array_ref_low_bound (exp),
+ host_integerp (low_bound, 0))
+ && (unit_size = array_ref_element_size (exp),
+ host_integerp (unit_size, 1)))
{
- HOST_WIDE_INT hindex = tree_low_cst (index, 0);
+ HOST_WIDE_INT hindex = TREE_INT_CST_LOW (index);
- hindex -= tree_low_cst (low_bound, 0);
- hindex *= tree_low_cst (unit_size, 1);
+ hindex -= TREE_INT_CST_LOW (low_bound);
+ hindex *= TREE_INT_CST_LOW (unit_size);
hindex *= BITS_PER_UNIT;
bit_offset += hindex;
where we do not know maxsize for variable index accesses to
the array. The simplest way to conservatively deal with this
is to punt in the case that offset + maxsize reaches the
- base type boundary. */
+ base type boundary.
+
+ Unfortunately this is difficult to determine reliably when unions are
+ involved and so we are conservative in such cases.
+
+ FIXME: This approach may be too conservative, we probably want to at least
+ check that the union is the last field/element at its level or even
+ propagate the calculated offsets back up the access chain and check
+ there. */
+
if (seen_variable_array_ref
- && maxsize != -1
- && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)
- && bit_offset + maxsize
- == (signed)TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))
+ && (seen_union
+ || (maxsize != -1
+ && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)
+ && bit_offset + maxsize
+ == (signed) TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))))
maxsize = -1;
/* ??? Due to negative offsets in ARRAY_REF we can end up with
SSA_NAME_OCCURS_IN_ABNORMAL_PHI set, otherwise false. */
bool
-stmt_references_abnormal_ssa_name (tree stmt)
+stmt_references_abnormal_ssa_name (gimple stmt)
{
ssa_op_iter oi;
use_operand_p use_p;
return false;
}
-/* Return true, if the two memory references REF1 and REF2 may alias. */
-
-bool
-refs_may_alias_p (tree ref1, tree ref2)
-{
- tree base1, base2;
- HOST_WIDE_INT offset1 = 0, offset2 = 0;
- HOST_WIDE_INT size1 = -1, size2 = -1;
- HOST_WIDE_INT max_size1 = -1, max_size2 = -1;
- bool strict_aliasing_applies;
-
- gcc_assert ((SSA_VAR_P (ref1)
- || handled_component_p (ref1)
- || INDIRECT_REF_P (ref1)
- || TREE_CODE (ref1) == TARGET_MEM_REF)
- && (SSA_VAR_P (ref2)
- || handled_component_p (ref2)
- || INDIRECT_REF_P (ref2)
- || TREE_CODE (ref2) == TARGET_MEM_REF));
-
- /* Defer to TBAA if possible. */
- if (flag_strict_aliasing
- && !alias_sets_conflict_p (get_alias_set (ref1), get_alias_set (ref2)))
- return false;
-
- /* Decompose the references into their base objects and the access. */
- base1 = ref1;
- if (handled_component_p (ref1))
- base1 = get_ref_base_and_extent (ref1, &offset1, &size1, &max_size1);
- base2 = ref2;
- if (handled_component_p (ref2))
- base2 = get_ref_base_and_extent (ref2, &offset2, &size2, &max_size2);
-
- /* If both references are based on different variables, they cannot alias.
- If both references are based on the same variable, they cannot alias if
- the accesses do not overlap. */
- if (SSA_VAR_P (base1)
- && SSA_VAR_P (base2))
- {
- if (!operand_equal_p (base1, base2, 0))
- return false;
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
- }
-
- /* If one base is a ref-all pointer weird things are allowed. */
- strict_aliasing_applies = (flag_strict_aliasing
- && (!INDIRECT_REF_P (base1)
- || get_alias_set (base1) != 0)
- && (!INDIRECT_REF_P (base2)
- || get_alias_set (base2) != 0));
-
- /* If strict aliasing applies the only way to access a scalar variable
- is through a pointer dereference or through a union (gcc extension). */
- if (strict_aliasing_applies
- && ((SSA_VAR_P (ref2)
- && !AGGREGATE_TYPE_P (TREE_TYPE (ref2))
- && !INDIRECT_REF_P (ref1)
- && TREE_CODE (TREE_TYPE (base1)) != UNION_TYPE)
- || (SSA_VAR_P (ref1)
- && !AGGREGATE_TYPE_P (TREE_TYPE (ref1))
- && !INDIRECT_REF_P (ref2)
- && TREE_CODE (TREE_TYPE (base2)) != UNION_TYPE)))
- return false;
-
- /* If both references are through the same type, or if strict aliasing
- doesn't apply they are through two same pointers, they do not alias
- if the accesses do not overlap. */
- if ((strict_aliasing_applies
- && (TYPE_MAIN_VARIANT (TREE_TYPE (base1))
- == TYPE_MAIN_VARIANT (TREE_TYPE (base2))))
- || (TREE_CODE (base1) == INDIRECT_REF
- && TREE_CODE (base2) == INDIRECT_REF
- && operand_equal_p (TREE_OPERAND (base1, 0),
- TREE_OPERAND (base2, 0), 0)))
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
-
- /* If both are component references through pointers try to find a
- common base and apply offset based disambiguation. This handles
- for example
- struct A { int i; int j; } *q;
- struct B { struct A a; int k; } *p;
- disambiguating q->i and p->a.j. */
- if (strict_aliasing_applies
- && (TREE_CODE (base1) == INDIRECT_REF
- || TREE_CODE (base2) == INDIRECT_REF)
- && handled_component_p (ref1)
- && handled_component_p (ref2))
- {
- tree *refp;
- /* Now search for the type of base1 in the access path of ref2. This
- would be a common base for doing offset based disambiguation on. */
- refp = &ref2;
- while (handled_component_p (*refp)
- /* Note that the following is only conservative if there are
- never copies of types appearing as sub-structures. */
- && (TYPE_MAIN_VARIANT (TREE_TYPE (*refp))
- != TYPE_MAIN_VARIANT (TREE_TYPE (base1))))
- refp = &TREE_OPERAND (*refp, 0);
- if (TYPE_MAIN_VARIANT (TREE_TYPE (*refp))
- == TYPE_MAIN_VARIANT (TREE_TYPE (base1)))
- {
- HOST_WIDE_INT offadj, sztmp, msztmp;
- get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
- offset2 -= offadj;
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
- }
- /* The other way around. */
- refp = &ref1;
- while (handled_component_p (*refp)
- && (TYPE_MAIN_VARIANT (TREE_TYPE (*refp))
- != TYPE_MAIN_VARIANT (TREE_TYPE (base2))))
- refp = &TREE_OPERAND (*refp, 0);
- if (TYPE_MAIN_VARIANT (TREE_TYPE (*refp))
- == TYPE_MAIN_VARIANT (TREE_TYPE (base2)))
- {
- HOST_WIDE_INT offadj, sztmp, msztmp;
- get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
- offset1 -= offadj;
- return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
- }
- /* If we can be sure to catch all equivalent types in the search
- for the common base then we could return false here. In that
- case we would be able to disambiguate q->i and p->k. */
- }
-
- return true;
-}
-
-/* Given a stmt STMT that references memory, return the single stmt
- that is reached by following the VUSE -> VDEF link. Returns
- NULL_TREE, if there is no single stmt that defines all VUSEs of
- STMT.
- Note that for a stmt with a single virtual operand this may return
- a PHI node as well. Note that if all VUSEs are default definitions
- this function will return an empty statement. */
-
-tree
-get_single_def_stmt (tree stmt)
-{
- tree def_stmt = NULL_TREE;
- tree use;
- ssa_op_iter iter;
-
- FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_VIRTUAL_USES)
- {
- tree tmp = SSA_NAME_DEF_STMT (use);
-
- /* ??? This is too simplistic for multiple virtual operands
- reaching different PHI nodes of the same basic blocks or for
- reaching all default definitions. */
- if (def_stmt
- && def_stmt != tmp
- && !(IS_EMPTY_STMT (def_stmt)
- && IS_EMPTY_STMT (tmp)))
- return NULL_TREE;
-
- def_stmt = tmp;
- }
-
- return def_stmt;
-}
-
-/* Given a PHI node of virtual operands, tries to eliminate cyclic
- reached definitions if they do not alias REF and returns the
- defining statement of the single virtual operand that flows in
- from a non-backedge. Returns NULL_TREE if such statement within
- the above conditions cannot be found. */
-
-tree
-get_single_def_stmt_from_phi (tree ref, tree phi)
-{
- tree def_arg = NULL_TREE;
- int i;
-
- /* Find the single PHI argument that is not flowing in from a
- back edge and verify that the loop-carried definitions do
- not alias the reference we look for. */
- for (i = 0; i < PHI_NUM_ARGS (phi); ++i)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- tree def_stmt;
-
- if (!(PHI_ARG_EDGE (phi, i)->flags & EDGE_DFS_BACK))
- {
- /* Multiple non-back edges? Do not try to handle this. */
- if (def_arg)
- return NULL_TREE;
- def_arg = arg;
- continue;
- }
-
- /* Follow the definitions back to the original PHI node. Bail
- out once a definition is found that may alias REF. */
- def_stmt = SSA_NAME_DEF_STMT (arg);
- do
- {
- if (TREE_CODE (def_stmt) != GIMPLE_MODIFY_STMT
- || refs_may_alias_p (ref, GIMPLE_STMT_OPERAND (def_stmt, 0)))
- return NULL_TREE;
- /* ??? This will only work, reaching the PHI node again if
- there is a single virtual operand on def_stmt. */
- def_stmt = get_single_def_stmt (def_stmt);
- if (!def_stmt)
- return NULL_TREE;
- }
- while (def_stmt != phi);
- }
-
- return SSA_NAME_DEF_STMT (def_arg);
-}
-
-/* Return the single reference statement defining all virtual uses
- on STMT or NULL_TREE, if there are multiple defining statements.
- Take into account only definitions that alias REF if following
- back-edges when looking through a loop PHI node. */
-
-tree
-get_single_def_stmt_with_phi (tree ref, tree stmt)
-{
- switch (NUM_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES))
- {
- case 0:
- gcc_unreachable ();
-
- case 1:
- {
- tree def_stmt = SSA_NAME_DEF_STMT (SINGLE_SSA_TREE_OPERAND
- (stmt, SSA_OP_VIRTUAL_USES));
- /* We can handle lookups over PHI nodes only for a single
- virtual operand. */
- if (TREE_CODE (def_stmt) == PHI_NODE)
- return get_single_def_stmt_from_phi (ref, def_stmt);
- return def_stmt;
- }
-
- default:
- return get_single_def_stmt (stmt);
- }
-}
OSDN Git Service
