/* Forward propagation of expressions for single use variables.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+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,
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 COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tree-dump.h"
#include "langhooks.h"
#include "flags.h"
+#include "gimple.h"
/* This pass propagates the RHS of assignment statements into use
sites of the LHS of the assignment. It's basically a specialized
form of tree combination. It is hoped all of this can disappear
when we have a generalized tree combiner.
- Note carefully that after propagation the resulting statement
- must still be a proper gimple statement. Right now we simply
- only perform propagations we know will result in valid gimple
- code. One day we'll want to generalize this code.
-
One class of common cases we handle is forward propagating a single use
- variable into a COND_EXPR.
+ variable into a COND_EXPR.
bb0:
x = a COND b;
bb0:
if (a COND b) goto ... else goto ...
-
+
Similarly for the tests (x == 0), (x != 0), (x == 1) and (x != 1).
Or (assuming c1 and c2 are constants):
bb0:
- x = a + c1;
+ x = a + c1;
if (x EQ/NEQ c2) goto ... else goto ...
Will be transformed into:
if (a EQ/NEQ (c2 - c1)) goto ... else goto ...
Similarly for x = a - c1.
-
+
Or
bb0:
res = x->y->z;
Or
+ ptr = (type1*)&type2var;
+ res = *ptr
+
+ Will get turned into (if type1 and type2 are the same size
+ and neither have volatile on them):
+ res = VIEW_CONVERT_EXPR<type1>(type2var)
+
+ Or
ptr = &x[0];
ptr2 = ptr + <constant>;
ptr2 = &x[index];
+ Or
+ ssa = (int) decl
+ res = ssa & 1
+
+ Provided that decl has known alignment >= 2, will get turned into
+
+ res = 0
+
We also propagate casts into SWITCH_EXPR and COND_EXPR conditions to
allow us to remove the cast and {NOT_EXPR,NEG_EXPR} into a subsequent
{NOT_EXPR,NEG_EXPR}.
/* Set to true if we delete EH edges during the optimization. */
static bool cfg_changed;
+static tree rhs_to_tree (tree type, gimple stmt);
/* Get the next statement we can propagate NAME's value into skipping
trivial copies. Returns the statement that is suitable as a
This only returns destinations in a single-use chain. FINAL_NAME_P
if non-NULL is written to the ssa name that represents the use. */
-static tree
+static gimple
get_prop_dest_stmt (tree name, tree *final_name_p)
{
use_operand_p use;
- tree use_stmt;
+ gimple use_stmt;
do {
/* If name has multiple uses, bail out. */
if (!single_imm_use (name, &use, &use_stmt))
- return NULL_TREE;
+ return NULL;
/* If this is not a trivial copy, we found it. */
- if (TREE_CODE (use_stmt) != GIMPLE_MODIFY_STMT
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) != SSA_NAME
- || GIMPLE_STMT_OPERAND (use_stmt, 1) != name)
+ if (!gimple_assign_ssa_name_copy_p (use_stmt)
+ || gimple_assign_rhs1 (use_stmt) != name)
break;
/* Continue searching uses of the copy destination. */
- name = GIMPLE_STMT_OPERAND (use_stmt, 0);
+ name = gimple_assign_lhs (use_stmt);
} while (1);
if (final_name_p)
it is set to whether the chain to NAME is a single use chain
or not. SINGLE_USE_P is not written to if SINGLE_USE_ONLY is set. */
-static tree
+static gimple
get_prop_source_stmt (tree name, bool single_use_only, bool *single_use_p)
{
bool single_use = true;
do {
- tree def_stmt = SSA_NAME_DEF_STMT (name);
+ gimple def_stmt = SSA_NAME_DEF_STMT (name);
if (!has_single_use (name))
{
single_use = false;
if (single_use_only)
- return NULL_TREE;
+ return NULL;
}
/* If name is defined by a PHI node or is the default def, bail out. */
- if (TREE_CODE (def_stmt) != GIMPLE_MODIFY_STMT)
- return NULL_TREE;
+ if (!is_gimple_assign (def_stmt))
+ return NULL;
- /* If name is not a simple copy destination, we found it. */
- if (TREE_CODE (GIMPLE_STMT_OPERAND (def_stmt, 1)) != SSA_NAME)
+ /* If def_stmt is not a simple copy, we possibly found it. */
+ if (!gimple_assign_ssa_name_copy_p (def_stmt))
{
+ tree rhs;
+
if (!single_use_only && single_use_p)
*single_use_p = single_use;
- return def_stmt;
+ /* We can look through pointer conversions in the search
+ for a useful stmt for the comparison folding. */
+ rhs = gimple_assign_rhs1 (def_stmt);
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
+ && TREE_CODE (rhs) == SSA_NAME
+ && POINTER_TYPE_P (TREE_TYPE (gimple_assign_lhs (def_stmt)))
+ && POINTER_TYPE_P (TREE_TYPE (rhs)))
+ name = rhs;
+ else
+ return def_stmt;
+ }
+ else
+ {
+ /* Continue searching the def of the copy source name. */
+ name = gimple_assign_rhs1 (def_stmt);
}
-
- /* Continue searching the def of the copy source name. */
- name = GIMPLE_STMT_OPERAND (def_stmt, 1);
} while (1);
}
propagation source. Returns true if so, otherwise false. */
static bool
-can_propagate_from (tree def_stmt)
+can_propagate_from (gimple def_stmt)
{
- tree rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
+ use_operand_p use_p;
+ ssa_op_iter iter;
- /* We cannot propagate ssa names that occur in abnormal phi nodes. */
- switch (TREE_CODE_LENGTH (TREE_CODE (rhs)))
- {
- case 3:
- if (TREE_OPERAND (rhs, 2) != NULL_TREE
- && TREE_CODE (TREE_OPERAND (rhs, 2)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (rhs, 2)))
- return false;
- case 2:
- if (TREE_OPERAND (rhs, 1) != NULL_TREE
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (rhs, 1)))
- return false;
- case 1:
- if (TREE_OPERAND (rhs, 0) != NULL_TREE
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (rhs, 0)))
- return false;
- break;
+ gcc_assert (is_gimple_assign (def_stmt));
+
+ /* If the rhs has side-effects we cannot propagate from it. */
+ if (gimple_has_volatile_ops (def_stmt))
+ return false;
- default:
+ /* If the rhs is a load we cannot propagate from it. */
+ if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_reference
+ || TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt)) == tcc_declaration)
+ return false;
+
+ /* Constants can be always propagated. */
+ if (gimple_assign_single_p (def_stmt)
+ && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
+ return true;
+
+ /* We cannot propagate ssa names that occur in abnormal phi nodes. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_USE)
+ if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p)))
return false;
- }
/* If the definition is a conversion of a pointer to a function type,
- then we can not apply optimizations as some targets require function
- pointers to be canonicalized and in this case this optimization could
- eliminate a necessary canonicalization. */
- if ((TREE_CODE (rhs) == NOP_EXPR
- || TREE_CODE (rhs) == CONVERT_EXPR)
- && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (rhs, 0)))
- && TREE_CODE (TREE_TYPE (TREE_TYPE
- (TREE_OPERAND (rhs, 0)))) == FUNCTION_TYPE)
- return false;
+ then we can not apply optimizations as some targets require
+ function pointers to be canonicalized and in this case this
+ optimization could eliminate a necessary canonicalization. */
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
+ {
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ if (POINTER_TYPE_P (TREE_TYPE (rhs))
+ && TREE_CODE (TREE_TYPE (TREE_TYPE (rhs))) == FUNCTION_TYPE)
+ return false;
+ }
return true;
}
as well, otherwise false. */
static bool
-remove_prop_source_from_use (tree name, tree up_to_stmt)
+remove_prop_source_from_use (tree name, gimple up_to_stmt)
{
- block_stmt_iterator bsi;
- tree stmt;
+ gimple_stmt_iterator gsi;
+ gimple stmt;
do {
if (!has_zero_uses (name))
if (stmt == up_to_stmt)
return true;
- bsi = bsi_for_stmt (stmt);
+ gsi = gsi_for_stmt (stmt);
release_defs (stmt);
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
- name = GIMPLE_STMT_OPERAND (stmt, 1);
- } while (TREE_CODE (name) == SSA_NAME);
+ name = (gimple_assign_copy_p (stmt)) ? gimple_assign_rhs1 (stmt) : NULL;
+ } while (name && TREE_CODE (name) == SSA_NAME);
return false;
}
+/* Return the rhs of a gimple_assign STMT in a form of a single tree,
+ converted to type TYPE.
+
+ This should disappear, but is needed so we can combine expressions and use
+ the fold() interfaces. Long term, we need to develop folding and combine
+ routines that deal with gimple exclusively . */
+
+static tree
+rhs_to_tree (tree type, gimple stmt)
+{
+ location_t loc = gimple_location (stmt);
+ enum tree_code code = gimple_assign_rhs_code (stmt);
+ if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS)
+ return fold_build2_loc (loc, code, type, gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+ else if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS)
+ return build1 (code, type, gimple_assign_rhs1 (stmt));
+ else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ return gimple_assign_rhs1 (stmt);
+ else
+ gcc_unreachable ();
+}
+
/* Combine OP0 CODE OP1 in the context of a COND_EXPR. Returns
the folded result in a form suitable for COND_EXPR_COND or
NULL_TREE, if there is no suitable simplified form. If
considered simplified. */
static tree
-combine_cond_expr_cond (enum tree_code code, tree type,
+combine_cond_expr_cond (location_t loc, enum tree_code code, tree type,
tree op0, tree op1, bool invariant_only)
{
tree t;
gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
- t = fold_binary (code, type, op0, op1);
+ t = fold_binary_loc (loc, code, type, op0, op1);
if (!t)
return NULL_TREE;
/* Require that we got a boolean type out if we put one in. */
gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type));
- /* For (bool)x use x != 0. */
- if (TREE_CODE (t) == NOP_EXPR
- && TREE_TYPE (t) == boolean_type_node)
- {
- tree top0 = TREE_OPERAND (t, 0);
- t = build2 (NE_EXPR, type,
- top0, build_int_cst (TREE_TYPE (top0), 0));
- }
- /* For !x use x == 0. */
- else if (TREE_CODE (t) == TRUTH_NOT_EXPR)
- {
- tree top0 = TREE_OPERAND (t, 0);
- t = build2 (EQ_EXPR, type,
- top0, build_int_cst (TREE_TYPE (top0), 0));
- }
- /* For cmp ? 1 : 0 use cmp. */
- else if (TREE_CODE (t) == COND_EXPR
- && COMPARISON_CLASS_P (TREE_OPERAND (t, 0))
- && integer_onep (TREE_OPERAND (t, 1))
- && integer_zerop (TREE_OPERAND (t, 2)))
- {
- tree top0 = TREE_OPERAND (t, 0);
- t = build2 (TREE_CODE (top0), type,
- TREE_OPERAND (top0, 0), TREE_OPERAND (top0, 1));
- }
+ /* Canonicalize the combined condition for use in a COND_EXPR. */
+ t = canonicalize_cond_expr_cond (t);
/* Bail out if we required an invariant but didn't get one. */
- if (invariant_only
- && !is_gimple_min_invariant (t))
+ if (!t || (invariant_only && !is_gimple_min_invariant (t)))
return NULL_TREE;
- /* A valid conditional for a COND_EXPR is either a gimple value
- or a comparison with two gimple value operands. */
- if (is_gimple_val (t)
- || (COMPARISON_CLASS_P (t)
- && is_gimple_val (TREE_OPERAND (t, 0))
- && is_gimple_val (TREE_OPERAND (t, 1))))
- return t;
+ return t;
+}
+
+/* Propagate from the ssa name definition statements of COND_EXPR
+ in GIMPLE_COND statement STMT into the conditional if that simplifies it.
+ Returns zero if no statement was changed, one if there were
+ changes and two if cfg_cleanup needs to run.
+
+ This must be kept in sync with forward_propagate_into_cond. */
+
+static int
+forward_propagate_into_gimple_cond (gimple stmt)
+{
+ int did_something = 0;
+ location_t loc = gimple_location (stmt);
+
+ do {
+ tree tmp = NULL_TREE;
+ tree name = NULL_TREE, rhs0 = NULL_TREE, rhs1 = NULL_TREE;
+ gimple def_stmt;
+ bool single_use0_p = false, single_use1_p = false;
+ enum tree_code code = gimple_cond_code (stmt);
+
+ /* We can do tree combining on SSA_NAME and comparison expressions. */
+ if (TREE_CODE_CLASS (gimple_cond_code (stmt)) == tcc_comparison)
+ {
+ /* For comparisons use the first operand, that is likely to
+ simplify comparisons against constants. */
+ if (TREE_CODE (gimple_cond_lhs (stmt)) == SSA_NAME)
+ {
+ name = gimple_cond_lhs (stmt);
+ def_stmt = get_prop_source_stmt (name, false, &single_use0_p);
+ if (def_stmt && can_propagate_from (def_stmt))
+ {
+ tree op1 = gimple_cond_rhs (stmt);
+ rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
+ tmp = combine_cond_expr_cond (loc, code, boolean_type_node,
+ rhs0, op1, !single_use0_p);
+ }
+ }
+ /* If that wasn't successful, try the second operand. */
+ if (tmp == NULL_TREE
+ && TREE_CODE (gimple_cond_rhs (stmt)) == SSA_NAME)
+ {
+ tree op0 = gimple_cond_lhs (stmt);
+ name = gimple_cond_rhs (stmt);
+ def_stmt = get_prop_source_stmt (name, false, &single_use1_p);
+ if (!def_stmt || !can_propagate_from (def_stmt))
+ return did_something;
+
+ rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
+ tmp = combine_cond_expr_cond (loc, code, boolean_type_node, op0,
+ rhs1, !single_use1_p);
+ }
+ /* If that wasn't successful either, try both operands. */
+ if (tmp == NULL_TREE
+ && rhs0 != NULL_TREE
+ && rhs1 != NULL_TREE)
+ tmp = combine_cond_expr_cond (loc, code, boolean_type_node, rhs0,
+ fold_convert_loc (loc,
+ TREE_TYPE (rhs0),
+ rhs1),
+ !(single_use0_p && single_use1_p));
+ }
+
+ if (tmp)
+ {
+ if (dump_file && tmp)
+ {
+ tree cond = build2 (gimple_cond_code (stmt),
+ boolean_type_node,
+ gimple_cond_lhs (stmt),
+ gimple_cond_rhs (stmt));
+ fprintf (dump_file, " Replaced '");
+ print_generic_expr (dump_file, cond, 0);
+ fprintf (dump_file, "' with '");
+ print_generic_expr (dump_file, tmp, 0);
+ fprintf (dump_file, "'\n");
+ }
+
+ gimple_cond_set_condition_from_tree (stmt, unshare_expr (tmp));
+ update_stmt (stmt);
+
+ /* Remove defining statements. */
+ remove_prop_source_from_use (name, NULL);
- return NULL_TREE;
+ if (is_gimple_min_invariant (tmp))
+ did_something = 2;
+ else if (did_something == 0)
+ did_something = 1;
+
+ /* Continue combining. */
+ continue;
+ }
+
+ break;
+ } while (1);
+
+ return did_something;
}
+
/* Propagate from the ssa name definition statements of COND_EXPR
- in statement STMT into the conditional if that simplifies it. */
+ in the rhs of statement STMT into the conditional if that simplifies it.
+ Returns zero if no statement was changed, one if there were
+ changes and two if cfg_cleanup needs to run.
-static bool
-forward_propagate_into_cond (tree cond_expr, tree stmt)
+ This must be kept in sync with forward_propagate_into_gimple_cond. */
+
+static int
+forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
- bool did_something = false;
+ gimple stmt = gsi_stmt (*gsi_p);
+ location_t loc = gimple_location (stmt);
+ int did_something = 0;
do {
tree tmp = NULL_TREE;
- tree cond = COND_EXPR_COND (cond_expr);
- tree name, def_stmt, rhs;
- bool single_use_p;
+ tree cond = gimple_assign_rhs1 (stmt);
+ tree name, rhs0 = NULL_TREE, rhs1 = NULL_TREE;
+ gimple def_stmt;
+ bool single_use0_p = false, single_use1_p = false;
/* We can do tree combining on SSA_NAME and comparison expressions. */
if (COMPARISON_CLASS_P (cond)
/* For comparisons use the first operand, that is likely to
simplify comparisons against constants. */
name = TREE_OPERAND (cond, 0);
- def_stmt = get_prop_source_stmt (name, false, &single_use_p);
- if (def_stmt != NULL_TREE
- && can_propagate_from (def_stmt))
+ def_stmt = get_prop_source_stmt (name, false, &single_use0_p);
+ if (def_stmt && can_propagate_from (def_stmt))
{
tree op1 = TREE_OPERAND (cond, 1);
- rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
- tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
- fold_convert (TREE_TYPE (op1), rhs),
- op1, !single_use_p);
+ rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
+ tmp = combine_cond_expr_cond (loc, TREE_CODE (cond),
+ boolean_type_node,
+ rhs0, op1, !single_use0_p);
}
/* If that wasn't successful, try the second operand. */
if (tmp == NULL_TREE
{
tree op0 = TREE_OPERAND (cond, 0);
name = TREE_OPERAND (cond, 1);
- def_stmt = get_prop_source_stmt (name, false, &single_use_p);
- if (def_stmt == NULL_TREE
- || !can_propagate_from (def_stmt))
+ def_stmt = get_prop_source_stmt (name, false, &single_use1_p);
+ if (!def_stmt || !can_propagate_from (def_stmt))
return did_something;
- rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
- tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node,
- op0,
- fold_convert (TREE_TYPE (op0), rhs),
- !single_use_p);
+ rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
+ tmp = combine_cond_expr_cond (loc, TREE_CODE (cond),
+ boolean_type_node,
+ op0, rhs1, !single_use1_p);
}
+ /* If that wasn't successful either, try both operands. */
+ if (tmp == NULL_TREE
+ && rhs0 != NULL_TREE
+ && rhs1 != NULL_TREE)
+ tmp = combine_cond_expr_cond (loc, TREE_CODE (cond),
+ boolean_type_node,
+ rhs0,
+ fold_convert_loc (loc,
+ TREE_TYPE (rhs0),
+ rhs1),
+ !(single_use0_p && single_use1_p));
}
else if (TREE_CODE (cond) == SSA_NAME)
{
name = cond;
def_stmt = get_prop_source_stmt (name, true, NULL);
- if (def_stmt == NULL_TREE
- || !can_propagate_from (def_stmt))
+ if (def_stmt || !can_propagate_from (def_stmt))
return did_something;
- rhs = GIMPLE_STMT_OPERAND (def_stmt, 1);
- tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs,
- build_int_cst (TREE_TYPE (rhs), 0),
+ rhs0 = gimple_assign_rhs1 (def_stmt);
+ tmp = combine_cond_expr_cond (loc, NE_EXPR, boolean_type_node, rhs0,
+ build_int_cst (TREE_TYPE (rhs0), 0),
false);
}
fprintf (dump_file, "'\n");
}
- COND_EXPR_COND (cond_expr) = unshare_expr (tmp);
+ gimple_assign_set_rhs_from_tree (gsi_p, unshare_expr (tmp));
+ stmt = gsi_stmt (*gsi_p);
update_stmt (stmt);
/* Remove defining statements. */
remove_prop_source_from_use (name, NULL);
- did_something = true;
+ if (is_gimple_min_invariant (tmp))
+ did_something = 2;
+ else if (did_something == 0)
+ did_something = 1;
/* Continue combining. */
continue;
return did_something;
}
-/* We've just substituted an ADDR_EXPR into stmt. Update all the
+/* We've just substituted an ADDR_EXPR into stmt. Update all the
relevant data structures to match. */
static void
-tidy_after_forward_propagate_addr (tree stmt)
+tidy_after_forward_propagate_addr (gimple stmt)
{
/* We may have turned a trapping insn into a non-trapping insn. */
if (maybe_clean_or_replace_eh_stmt (stmt, stmt)
- && tree_purge_dead_eh_edges (bb_for_stmt (stmt)))
+ && gimple_purge_dead_eh_edges (gimple_bb (stmt)))
cfg_changed = true;
- if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == ADDR_EXPR)
- recompute_tree_invariant_for_addr_expr (GIMPLE_STMT_OPERAND (stmt, 1));
-
- mark_symbols_for_renaming (stmt);
+ if (TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
}
-/* DEF_RHS defines LHS which is contains the address of the 0th element
- in an array. USE_STMT uses LHS to compute the address of an
+/* DEF_RHS contains the address of the 0th element in an array.
+ USE_STMT uses type of DEF_RHS to compute the address of an
arbitrary element within the array. The (variable) byte offset
of the element is contained in OFFSET.
with the new address computation. */
static bool
-forward_propagate_addr_into_variable_array_index (tree offset, tree lhs,
- tree def_rhs, tree use_stmt)
+forward_propagate_addr_into_variable_array_index (tree offset,
+ tree def_rhs,
+ gimple_stmt_iterator *use_stmt_gsi)
{
- tree index;
-
- /* The offset must be defined by a simple GIMPLE_MODIFY_STMT statement. */
- if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
- return false;
+ tree index, tunit;
+ gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);
+ tree tmp;
- /* The RHS of the statement which defines OFFSET must be a gimple
- cast of another SSA_NAME. */
- offset = GIMPLE_STMT_OPERAND (offset, 1);
- if (!is_gimple_cast (offset))
+ tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)));
+ if (!host_integerp (tunit, 1))
return false;
- offset = TREE_OPERAND (offset, 0);
- if (TREE_CODE (offset) != SSA_NAME)
- return false;
-
- /* Get the defining statement of the offset before type
- conversion. */
- offset = SSA_NAME_DEF_STMT (offset);
+ /* Get the offset's defining statement. */
+ offset_def = SSA_NAME_DEF_STMT (offset);
- /* The statement which defines OFFSET before type conversion
- must be a simple GIMPLE_MODIFY_STMT. */
- if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
- return false;
+ /* Try to find an expression for a proper index. This is either a
+ multiplication expression by the element size or just the ssa name we came
+ along in case the element size is one. In that case, however, we do not
+ allow multiplications because they can be computing index to a higher
+ level dimension (PR 37861). */
+ if (integer_onep (tunit))
+ {
+ if (is_gimple_assign (offset_def)
+ && gimple_assign_rhs_code (offset_def) == MULT_EXPR)
+ return false;
- /* The RHS of the statement which defines OFFSET must be a
- multiplication of an object by the size of the array elements.
- This implicitly verifies that the size of the array elements
- is constant. */
- offset = GIMPLE_STMT_OPERAND (offset, 1);
- if (TREE_CODE (offset) != MULT_EXPR
- || TREE_CODE (TREE_OPERAND (offset, 1)) != INTEGER_CST
- || !simple_cst_equal (TREE_OPERAND (offset, 1),
- TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (lhs)))))
- return false;
+ index = offset;
+ }
+ else
+ {
+ /* The statement which defines OFFSET before type conversion
+ must be a simple GIMPLE_ASSIGN. */
+ if (!is_gimple_assign (offset_def))
+ return false;
- /* The first operand to the MULT_EXPR is the desired index. */
- index = TREE_OPERAND (offset, 0);
+ /* The RHS of the statement which defines OFFSET must be a
+ multiplication of an object by the size of the array elements.
+ This implicitly verifies that the size of the array elements
+ is constant. */
+ if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), tunit))
+ {
+ /* The first operand to the MULT_EXPR is the desired index. */
+ index = gimple_assign_rhs1 (offset_def);
+ }
+ /* If we have idx * tunit + CST * tunit re-associate that. */
+ else if ((gimple_assign_rhs_code (offset_def) == PLUS_EXPR
+ || gimple_assign_rhs_code (offset_def) == MINUS_EXPR)
+ && TREE_CODE (gimple_assign_rhs1 (offset_def)) == SSA_NAME
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && (tmp = div_if_zero_remainder (EXACT_DIV_EXPR,
+ gimple_assign_rhs2 (offset_def),
+ tunit)) != NULL_TREE)
+ {
+ gimple offset_def2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (offset_def));
+ if (is_gimple_assign (offset_def2)
+ && gimple_assign_rhs_code (offset_def2) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def2)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def2), tunit))
+ {
+ index = fold_build2 (gimple_assign_rhs_code (offset_def),
+ TREE_TYPE (offset),
+ gimple_assign_rhs1 (offset_def2), tmp);
+ }
+ else
+ return false;
+ }
+ else
+ return false;
+ }
/* Replace the pointer addition with array indexing. */
- GIMPLE_STMT_OPERAND (use_stmt, 1) = unshare_expr (def_rhs);
- TREE_OPERAND (TREE_OPERAND (GIMPLE_STMT_OPERAND (use_stmt, 1), 0), 1)
+ index = force_gimple_operand_gsi (use_stmt_gsi, index, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ gimple_assign_set_rhs_from_tree (use_stmt_gsi, unshare_expr (def_rhs));
+ use_stmt = gsi_stmt (*use_stmt_gsi);
+ TREE_OPERAND (TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0), 1)
= index;
/* That should have created gimple, so there is no need to
Try to forward propagate the ADDR_EXPR into the use USE_STMT.
Often this will allow for removal of an ADDR_EXPR and INDIRECT_REF
node or for recovery of array indexing from pointer arithmetic.
-
+
Return true if the propagation was successful (the propagation can
be not totally successful, yet things may have been changed). */
static bool
-forward_propagate_addr_expr_1 (tree name, tree def_rhs, tree use_stmt,
+forward_propagate_addr_expr_1 (tree name, tree def_rhs,
+ gimple_stmt_iterator *use_stmt_gsi,
bool single_use_p)
{
- tree lhs, rhs, array_ref;
-
- /* Strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
- ADDR_EXPR will not appear on the LHS. */
- lhs = GIMPLE_STMT_OPERAND (use_stmt, 0);
- while (handled_component_p (lhs))
- lhs = TREE_OPERAND (lhs, 0);
+ tree lhs, rhs, rhs2, array_ref;
+ tree *rhsp, *lhsp;
+ gimple use_stmt = gsi_stmt (*use_stmt_gsi);
+ enum tree_code rhs_code;
+ bool res = true;
- rhs = GIMPLE_STMT_OPERAND (use_stmt, 1);
+ gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR);
- /* Now see if the LHS node is an INDIRECT_REF using NAME. If so,
- propagate the ADDR_EXPR into the use of NAME and fold the result. */
- if (TREE_CODE (lhs) == INDIRECT_REF && TREE_OPERAND (lhs, 0) == name)
- {
- /* This should always succeed in creating gimple, so there is
- no need to save enough state to undo this propagation. */
- TREE_OPERAND (lhs, 0) = unshare_expr (def_rhs);
- fold_stmt_inplace (use_stmt);
- tidy_after_forward_propagate_addr (use_stmt);
-
- /* Continue propagating into the RHS. */
- }
+ lhs = gimple_assign_lhs (use_stmt);
+ rhs_code = gimple_assign_rhs_code (use_stmt);
+ rhs = gimple_assign_rhs1 (use_stmt);
/* Trivial cases. The use statement could be a trivial copy or a
useless conversion. Recurse to the uses of the lhs as copyprop does
- not copy through differen variant pointers and FRE does not catch
+ not copy through different variant pointers and FRE does not catch
all useless conversions. Treat the case of a single-use name and
a conversion to def_rhs type separate, though. */
- else if (TREE_CODE (lhs) == SSA_NAME
- && (TREE_CODE (rhs) == NOP_EXPR
- || TREE_CODE (rhs) == CONVERT_EXPR)
- && TREE_TYPE (rhs) == TREE_TYPE (def_rhs)
- && single_use_p)
+ if (TREE_CODE (lhs) == SSA_NAME
+ && ((rhs_code == SSA_NAME && rhs == name)
+ || CONVERT_EXPR_CODE_P (rhs_code)))
{
- GIMPLE_STMT_OPERAND (use_stmt, 1) = unshare_expr (def_rhs);
+ /* Only recurse if we don't deal with a single use or we cannot
+ do the propagation to the current statement. In particular
+ we can end up with a conversion needed for a non-invariant
+ address which we cannot do in a single statement. */
+ if (!single_use_p
+ || (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs))
+ && (!is_gimple_min_invariant (def_rhs)
+ || (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ && POINTER_TYPE_P (TREE_TYPE (def_rhs))
+ && (TYPE_PRECISION (TREE_TYPE (lhs))
+ > TYPE_PRECISION (TREE_TYPE (def_rhs)))))))
+ return forward_propagate_addr_expr (lhs, def_rhs);
+
+ gimple_assign_set_rhs1 (use_stmt, unshare_expr (def_rhs));
+ if (useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))
+ gimple_assign_set_rhs_code (use_stmt, TREE_CODE (def_rhs));
+ else
+ gimple_assign_set_rhs_code (use_stmt, NOP_EXPR);
return true;
}
- else if ((TREE_CODE (lhs) == SSA_NAME
- && rhs == name)
- || ((TREE_CODE (rhs) == NOP_EXPR
- || TREE_CODE (rhs) == CONVERT_EXPR)
- && tree_ssa_useless_type_conversion_1 (TREE_TYPE (rhs),
- TREE_TYPE (def_rhs))))
- return forward_propagate_addr_expr (lhs, def_rhs);
+
+ /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
+ ADDR_EXPR will not appear on the LHS. */
+ lhsp = gimple_assign_lhs_ptr (use_stmt);
+ while (handled_component_p (*lhsp))
+ lhsp = &TREE_OPERAND (*lhsp, 0);
+ lhs = *lhsp;
+
+ /* Now see if the LHS node is an INDIRECT_REF using NAME. If so,
+ propagate the ADDR_EXPR into the use of NAME and fold the result. */
+ if (TREE_CODE (lhs) == INDIRECT_REF
+ && TREE_OPERAND (lhs, 0) == name)
+ {
+ if (may_propagate_address_into_dereference (def_rhs, lhs)
+ && (lhsp != gimple_assign_lhs_ptr (use_stmt)
+ || useless_type_conversion_p
+ (TREE_TYPE (TREE_OPERAND (def_rhs, 0)), TREE_TYPE (rhs))))
+ {
+ *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
+ fold_stmt_inplace (use_stmt);
+ tidy_after_forward_propagate_addr (use_stmt);
+
+ /* Continue propagating into the RHS if this was not the only use. */
+ if (single_use_p)
+ return true;
+ }
+ else
+ /* We can have a struct assignment dereferencing our name twice.
+ Note that we didn't propagate into the lhs to not falsely
+ claim we did when propagating into the rhs. */
+ res = false;
+ }
/* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
nodes from the RHS. */
- while (handled_component_p (rhs)
- || TREE_CODE (rhs) == ADDR_EXPR)
- rhs = TREE_OPERAND (rhs, 0);
+ rhsp = gimple_assign_rhs1_ptr (use_stmt);
+ while (handled_component_p (*rhsp)
+ || TREE_CODE (*rhsp) == ADDR_EXPR)
+ rhsp = &TREE_OPERAND (*rhsp, 0);
+ rhs = *rhsp;
- /* Now see if the RHS node is an INDIRECT_REF using NAME. If so,
+ /* Now see if the RHS node is an INDIRECT_REF using NAME. If so,
propagate the ADDR_EXPR into the use of NAME and fold the result. */
- if (TREE_CODE (rhs) == INDIRECT_REF && TREE_OPERAND (rhs, 0) == name)
+ if (TREE_CODE (rhs) == INDIRECT_REF
+ && TREE_OPERAND (rhs, 0) == name
+ && may_propagate_address_into_dereference (def_rhs, rhs))
{
- /* This should always succeed in creating gimple, so there is
- no need to save enough state to undo this propagation. */
- TREE_OPERAND (rhs, 0) = unshare_expr (def_rhs);
+ *rhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
- return true;
+ return res;
}
+ /* Now see if the RHS node is an INDIRECT_REF using NAME. If so,
+ propagate the ADDR_EXPR into the use of NAME and try to
+ create a VCE and fold the result. */
+ if (TREE_CODE (rhs) == INDIRECT_REF
+ && TREE_OPERAND (rhs, 0) == name
+ && TYPE_SIZE (TREE_TYPE (rhs))
+ && TYPE_SIZE (TREE_TYPE (TREE_OPERAND (def_rhs, 0)))
+ /* Function decls should not be used for VCE either as it could be a
+ function descriptor that we want and not the actual function code. */
+ && TREE_CODE (TREE_OPERAND (def_rhs, 0)) != FUNCTION_DECL
+ /* We should not convert volatile loads to non volatile loads. */
+ && !TYPE_VOLATILE (TREE_TYPE (rhs))
+ && !TYPE_VOLATILE (TREE_TYPE (TREE_OPERAND (def_rhs, 0)))
+ && operand_equal_p (TYPE_SIZE (TREE_TYPE (rhs)),
+ TYPE_SIZE (TREE_TYPE (TREE_OPERAND (def_rhs, 0))), 0)
+ /* Make sure we only do TBAA compatible replacements. */
+ && get_alias_set (TREE_OPERAND (def_rhs, 0)) == get_alias_set (rhs))
+ {
+ tree def_rhs_base, new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
+ new_rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (rhs), new_rhs);
+ if (TREE_CODE (new_rhs) != VIEW_CONVERT_EXPR)
+ {
+ /* If we have folded the VIEW_CONVERT_EXPR then the result is only
+ valid if we can replace the whole rhs of the use statement. */
+ if (rhs != gimple_assign_rhs1 (use_stmt))
+ return false;
+ new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs, true, NULL,
+ true, GSI_NEW_STMT);
+ gimple_assign_set_rhs1 (use_stmt, new_rhs);
+ tidy_after_forward_propagate_addr (use_stmt);
+ return res;
+ }
+ /* If the defining rhs comes from an indirect reference, then do not
+ convert into a VIEW_CONVERT_EXPR. */
+ def_rhs_base = TREE_OPERAND (def_rhs, 0);
+ while (handled_component_p (def_rhs_base))
+ def_rhs_base = TREE_OPERAND (def_rhs_base, 0);
+ if (!INDIRECT_REF_P (def_rhs_base))
+ {
+ /* We may have arbitrary VIEW_CONVERT_EXPRs in a nested component
+ reference. Place it there and fold the thing. */
+ *rhsp = new_rhs;
+ fold_stmt_inplace (use_stmt);
+ tidy_after_forward_propagate_addr (use_stmt);
+ return res;
+ }
+ }
+
+ /* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there
+ is nothing to do. */
+ if (gimple_assign_rhs_code (use_stmt) != POINTER_PLUS_EXPR
+ || gimple_assign_rhs1 (use_stmt) != name)
+ return false;
+
/* The remaining cases are all for turning pointer arithmetic into
array indexing. They only apply when we have the address of
element zero in an array. If that is not the case then there
array_ref = TREE_OPERAND (def_rhs, 0);
if (TREE_CODE (array_ref) != ARRAY_REF
|| TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE
- || !integer_zerop (TREE_OPERAND (array_ref, 1)))
- return false;
-
- /* If the use of the ADDR_EXPR must be a PLUS_EXPR, or else there
- is nothing to do. */
- if (TREE_CODE (rhs) != PLUS_EXPR)
+ || TREE_CODE (TREE_OPERAND (array_ref, 1)) != INTEGER_CST)
return false;
- /* Try to optimize &x[0] + C where C is a multiple of the size
- of the elements in X into &x[C/element size]. */
- if (TREE_OPERAND (rhs, 0) == name
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == INTEGER_CST)
+ rhs2 = gimple_assign_rhs2 (use_stmt);
+ /* Try to optimize &x[C1] p+ C2 where C2 is a multiple of the size
+ of the elements in X into &x[C1 + C2/element size]. */
+ if (TREE_CODE (rhs2) == INTEGER_CST)
{
- tree orig = unshare_expr (rhs);
- TREE_OPERAND (rhs, 0) = unshare_expr (def_rhs);
-
- /* If folding succeeds, then we have just exposed new variables
- in USE_STMT which will need to be renamed. If folding fails,
- then we need to put everything back the way it was. */
- if (fold_stmt_inplace (use_stmt))
+ tree new_rhs = maybe_fold_stmt_addition (gimple_location (use_stmt),
+ TREE_TYPE (def_rhs),
+ def_rhs, rhs2);
+ if (new_rhs)
{
+ tree type = TREE_TYPE (gimple_assign_lhs (use_stmt));
+ new_rhs = unshare_expr (new_rhs);
+ if (!useless_type_conversion_p (type, TREE_TYPE (new_rhs)))
+ {
+ if (!is_gimple_min_invariant (new_rhs))
+ new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs,
+ true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ new_rhs = fold_convert (type, new_rhs);
+ }
+ gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);
+ use_stmt = gsi_stmt (*use_stmt_gsi);
+ update_stmt (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
- else
- {
- GIMPLE_STMT_OPERAND (use_stmt, 1) = orig;
- update_stmt (use_stmt);
- return false;
- }
}
- /* Try to optimize &x[0] + OFFSET where OFFSET is defined by
+ /* Try to optimize &x[0] p+ OFFSET where OFFSET is defined by
converting a multiplication of an index by the size of the
array elements, then the result is converted into the proper
type for the arithmetic. */
- if (TREE_OPERAND (rhs, 0) == name
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == SSA_NAME
+ if (TREE_CODE (rhs2) == SSA_NAME
+ && integer_zerop (TREE_OPERAND (array_ref, 1))
+ && useless_type_conversion_p (TREE_TYPE (name), TREE_TYPE (def_rhs))
/* Avoid problems with IVopts creating PLUS_EXPRs with a
different type than their operands. */
- && lang_hooks.types_compatible_p (TREE_TYPE (name), TREE_TYPE (rhs)))
- {
- bool res;
- tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 1));
-
- res = forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
- def_rhs, use_stmt);
- return res;
- }
-
- /* Same as the previous case, except the operands of the PLUS_EXPR
- were reversed. */
- if (TREE_OPERAND (rhs, 1) == name
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
- /* Avoid problems with IVopts creating PLUS_EXPRs with a
- different type than their operands. */
- && lang_hooks.types_compatible_p (TREE_TYPE (name), TREE_TYPE (rhs)))
- {
- bool res;
- tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
- res = forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
- def_rhs, use_stmt);
- return res;
- }
+ && useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))
+ return forward_propagate_addr_into_variable_array_index (rhs2, def_rhs,
+ use_stmt_gsi);
return false;
}
static bool
forward_propagate_addr_expr (tree name, tree rhs)
{
- int stmt_loop_depth = bb_for_stmt (SSA_NAME_DEF_STMT (name))->loop_depth;
+ int stmt_loop_depth = gimple_bb (SSA_NAME_DEF_STMT (name))->loop_depth;
imm_use_iterator iter;
- tree use_stmt;
+ gimple use_stmt;
bool all = true;
bool single_use_p = has_single_use (name);
FOR_EACH_IMM_USE_STMT (use_stmt, iter, name)
{
bool result;
+ tree use_rhs;
/* If the use is not in a simple assignment statement, then
there is nothing we can do. */
- if (TREE_CODE (use_stmt) != GIMPLE_MODIFY_STMT)
+ if (gimple_code (use_stmt) != GIMPLE_ASSIGN)
{
- all = false;
+ if (!is_gimple_debug (use_stmt))
+ all = false;
continue;
}
/* If the use is in a deeper loop nest, then we do not want
- to propagate the ADDR_EXPR into the loop as that is likely
- adding expression evaluations into the loop. */
- if (bb_for_stmt (use_stmt)->loop_depth > stmt_loop_depth)
- {
- all = false;
- continue;
- }
-
- /* If the use_stmt has side-effects, don't propagate into it. */
- if (stmt_ann (use_stmt)->has_volatile_ops)
+ to propagate non-invariant ADDR_EXPRs into the loop as that
+ is likely adding expression evaluations into the loop. */
+ if (gimple_bb (use_stmt)->loop_depth > stmt_loop_depth
+ && !is_gimple_min_invariant (rhs))
{
all = false;
continue;
}
- push_stmt_changes (&use_stmt);
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
+ result = forward_propagate_addr_expr_1 (name, rhs, &gsi,
+ single_use_p);
+ /* If the use has moved to a different statement adjust
+ the update machinery for the old statement too. */
+ if (use_stmt != gsi_stmt (gsi))
+ {
+ update_stmt (use_stmt);
+ use_stmt = gsi_stmt (gsi);
+ }
- result = forward_propagate_addr_expr_1 (name, rhs, use_stmt,
- single_use_p);
+ update_stmt (use_stmt);
+ }
all &= result;
- pop_stmt_changes (&use_stmt);
-
/* Remove intermediate now unused copy and conversion chains. */
+ use_rhs = gimple_assign_rhs1 (use_stmt);
if (result
- && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) == SSA_NAME
- && (TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == SSA_NAME
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == NOP_EXPR
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == CONVERT_EXPR))
+ && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME
+ && TREE_CODE (use_rhs) == SSA_NAME
+ && has_zero_uses (gimple_assign_lhs (use_stmt)))
{
- block_stmt_iterator bsi = bsi_for_stmt (use_stmt);
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
release_defs (use_stmt);
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
}
}
return all;
}
-/* Forward propagate the comparison COND defined in STMT like
+/* Forward propagate the comparison defined in STMT like
cond_1 = x CMP y to uses of the form
a_1 = (T')cond_1
a_1 = !cond_1
Returns true if stmt is now unused. */
static bool
-forward_propagate_comparison (tree cond, tree stmt)
+forward_propagate_comparison (gimple stmt)
{
- tree name = GIMPLE_STMT_OPERAND (stmt, 0);
- tree use_stmt, tmp = NULL_TREE;
+ tree name = gimple_assign_lhs (stmt);
+ gimple use_stmt;
+ tree tmp = NULL_TREE;
/* Don't propagate ssa names that occur in abnormal phis. */
- if ((TREE_CODE (TREE_OPERAND (cond, 0)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (cond, 0)))
- || (TREE_CODE (TREE_OPERAND (cond, 1)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (cond, 1))))
+ if ((TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs1 (stmt)))
+ || (TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_assign_rhs2 (stmt))))
return false;
/* Do not un-cse comparisons. But propagate through copies. */
use_stmt = get_prop_dest_stmt (name, &name);
- if (use_stmt == NULL_TREE)
+ if (!use_stmt)
return false;
/* Conversion of the condition result to another integral type. */
- if (TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
- && (TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == CONVERT_EXPR
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == NOP_EXPR
- || COMPARISON_CLASS_P (GIMPLE_STMT_OPERAND (use_stmt, 1))
- || TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == TRUTH_NOT_EXPR)
- && INTEGRAL_TYPE_P (TREE_TYPE (GIMPLE_STMT_OPERAND (use_stmt, 0))))
+ if (is_gimple_assign (use_stmt)
+ && (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt))
+ || TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
+ == tcc_comparison
+ || gimple_assign_rhs_code (use_stmt) == TRUTH_NOT_EXPR)
+ && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (use_stmt))))
{
- tree lhs = GIMPLE_STMT_OPERAND (use_stmt, 0);
- tree rhs = GIMPLE_STMT_OPERAND (use_stmt, 1);
+ tree lhs = gimple_assign_lhs (use_stmt);
/* We can propagate the condition into a conversion. */
- if (TREE_CODE (rhs) == CONVERT_EXPR
- || TREE_CODE (rhs) == NOP_EXPR)
+ if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt)))
{
/* Avoid using fold here as that may create a COND_EXPR with
non-boolean condition as canonical form. */
- tmp = build2 (TREE_CODE (cond), TREE_TYPE (lhs),
- TREE_OPERAND (cond, 0), TREE_OPERAND (cond, 1));
+ tmp = build2 (gimple_assign_rhs_code (stmt), TREE_TYPE (lhs),
+ gimple_assign_rhs1 (stmt), gimple_assign_rhs2 (stmt));
}
/* We can propagate the condition into X op CST where op
- is EQ_EXRP or NE_EXPR and CST is either one or zero. */
- else if (COMPARISON_CLASS_P (rhs)
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
- && TREE_CODE (TREE_OPERAND (rhs, 1)) == INTEGER_CST)
- {
- enum tree_code code = TREE_CODE (rhs);
- tree cst = TREE_OPERAND (rhs, 1);
-
- tmp = combine_cond_expr_cond (code, TREE_TYPE (lhs),
- fold_convert (TREE_TYPE (cst), cond),
- cst, false);
- if (tmp == NULL_TREE)
- return false;
- }
+ is EQ_EXPR or NE_EXPR and CST is either one or zero. */
+ else if (TREE_CODE_CLASS (gimple_assign_rhs_code (use_stmt))
+ == tcc_comparison
+ && TREE_CODE (gimple_assign_rhs1 (use_stmt)) == SSA_NAME
+ && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST)
+ {
+ enum tree_code code = gimple_assign_rhs_code (use_stmt);
+ tree cst = gimple_assign_rhs2 (use_stmt);
+ tree cond;
+
+ cond = build2 (gimple_assign_rhs_code (stmt),
+ TREE_TYPE (cst),
+ gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
+
+ tmp = combine_cond_expr_cond (gimple_location (use_stmt),
+ code, TREE_TYPE (lhs),
+ cond, cst, false);
+ if (tmp == NULL_TREE)
+ return false;
+ }
/* We can propagate the condition into a statement that
computes the logical negation of the comparison result. */
- else if (TREE_CODE (rhs) == TRUTH_NOT_EXPR)
+ else if (gimple_assign_rhs_code (use_stmt) == TRUTH_NOT_EXPR)
{
- tree type = TREE_TYPE (TREE_OPERAND (cond, 0));
+ tree type = TREE_TYPE (gimple_assign_rhs1 (stmt));
bool nans = HONOR_NANS (TYPE_MODE (type));
enum tree_code code;
- code = invert_tree_comparison (TREE_CODE (cond), nans);
+ code = invert_tree_comparison (gimple_assign_rhs_code (stmt), nans);
if (code == ERROR_MARK)
return false;
- tmp = build2 (code, TREE_TYPE (lhs), TREE_OPERAND (cond, 0),
- TREE_OPERAND (cond, 1));
+ tmp = build2 (code, TREE_TYPE (lhs), gimple_assign_rhs1 (stmt),
+ gimple_assign_rhs2 (stmt));
}
else
return false;
- GIMPLE_STMT_OPERAND (use_stmt, 1) = unshare_expr (tmp);
- update_stmt (use_stmt);
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
+ gimple_assign_set_rhs_from_tree (&gsi, unshare_expr (tmp));
+ use_stmt = gsi_stmt (gsi);
+ update_stmt (use_stmt);
+ }
/* Remove defining statements. */
remove_prop_source_from_use (name, stmt);
if (dump_file && (dump_flags & TDF_DETAILS))
{
+ tree old_rhs = rhs_to_tree (TREE_TYPE (gimple_assign_lhs (stmt)),
+ stmt);
fprintf (dump_file, " Replaced '");
- print_generic_expr (dump_file, rhs, dump_flags);
+ print_generic_expr (dump_file, old_rhs, dump_flags);
fprintf (dump_file, "' with '");
print_generic_expr (dump_file, tmp, dump_flags);
fprintf (dump_file, "'\n");
/* If we have lhs = ~x (STMT), look and see if earlier we had x = ~y.
If so, we can change STMT into lhs = y which can later be copy
- propagated. Similarly for negation.
+ propagated. Similarly for negation.
- This could trivially be formulated as a forward propagation
+ This could trivially be formulated as a forward propagation
to immediate uses. However, we already had an implementation
from DOM which used backward propagation via the use-def links.
than one forward link. */
static void
-simplify_not_neg_expr (tree stmt)
+simplify_not_neg_expr (gimple_stmt_iterator *gsi_p)
{
- tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
- tree rhs_def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
+ gimple stmt = gsi_stmt (*gsi_p);
+ tree rhs = gimple_assign_rhs1 (stmt);
+ gimple rhs_def_stmt = SSA_NAME_DEF_STMT (rhs);
/* See if the RHS_DEF_STMT has the same form as our statement. */
- if (TREE_CODE (rhs_def_stmt) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (rhs_def_stmt, 1)) == TREE_CODE (rhs))
+ if (is_gimple_assign (rhs_def_stmt)
+ && gimple_assign_rhs_code (rhs_def_stmt) == gimple_assign_rhs_code (stmt))
{
- tree rhs_def_operand =
- TREE_OPERAND (GIMPLE_STMT_OPERAND (rhs_def_stmt, 1), 0);
+ tree rhs_def_operand = gimple_assign_rhs1 (rhs_def_stmt);
/* Verify that RHS_DEF_OPERAND is a suitable SSA_NAME. */
if (TREE_CODE (rhs_def_operand) == SSA_NAME
&& ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs_def_operand))
{
- GIMPLE_STMT_OPERAND (stmt, 1) = rhs_def_operand;
+ gimple_assign_set_rhs_from_tree (gsi_p, rhs_def_operand);
+ stmt = gsi_stmt (*gsi_p);
update_stmt (stmt);
}
}
the condition which we may be able to optimize better. */
static void
-simplify_switch_expr (tree stmt)
+simplify_gimple_switch (gimple stmt)
{
- tree cond = SWITCH_COND (stmt);
+ tree cond = gimple_switch_index (stmt);
tree def, to, ti;
+ gimple def_stmt;
/* The optimization that we really care about is removing unnecessary
casts. That will let us do much better in propagating the inferred
constant at the switch target. */
if (TREE_CODE (cond) == SSA_NAME)
{
- def = SSA_NAME_DEF_STMT (cond);
- if (TREE_CODE (def) == GIMPLE_MODIFY_STMT)
+ def_stmt = SSA_NAME_DEF_STMT (cond);
+ if (is_gimple_assign (def_stmt))
{
- def = GIMPLE_STMT_OPERAND (def, 1);
- if (TREE_CODE (def) == NOP_EXPR)
+ if (gimple_assign_rhs_code (def_stmt) == NOP_EXPR)
{
int need_precision;
bool fail;
- def = TREE_OPERAND (def, 0);
+ def = gimple_assign_rhs1 (def_stmt);
#ifdef ENABLE_CHECKING
/* ??? Why was Jeff testing this? We are gimple... */
if (!fail)
{
- SWITCH_COND (stmt) = def;
+ gimple_switch_set_index (stmt, def);
update_stmt (stmt);
}
}
}
}
+/* Run bitwise and assignments throug the folder. If the first argument is an
+ ssa name that is itself a result of a typecast of an ADDR_EXPR to an
+ integer, feed the ADDR_EXPR to the folder rather than the ssa name.
+*/
+
+static void
+simplify_bitwise_and (gimple_stmt_iterator *gsi, gimple stmt)
+{
+ tree res;
+ tree arg1 = gimple_assign_rhs1 (stmt);
+ tree arg2 = gimple_assign_rhs2 (stmt);
+
+ if (TREE_CODE (arg2) != INTEGER_CST)
+ return;
+
+ if (TREE_CODE (arg1) == SSA_NAME && !SSA_NAME_IS_DEFAULT_DEF (arg1))
+ {
+ gimple def = SSA_NAME_DEF_STMT (arg1);
+
+ if (gimple_assign_cast_p (def)
+ && INTEGRAL_TYPE_P (gimple_expr_type (def)))
+ {
+ tree op = gimple_assign_rhs1 (def);
+
+ if (TREE_CODE (op) == ADDR_EXPR)
+ arg1 = op;
+ }
+ }
+
+ res = fold_binary_loc (gimple_location (stmt),
+ BIT_AND_EXPR, TREE_TYPE (gimple_assign_lhs (stmt)),
+ arg1, arg2);
+ if (res && is_gimple_min_invariant (res))
+ {
+ gimple_assign_set_rhs_from_tree (gsi, res);
+ update_stmt (stmt);
+ }
+ return;
+}
+
/* Main entry point for the forward propagation optimizer. */
static unsigned int
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
+ gimple_stmt_iterator gsi;
- /* Note we update BSI within the loop as necessary. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+ /* Note we update GSI within the loop as necessary. */
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
{
- tree stmt = bsi_stmt (bsi);
+ gimple stmt = gsi_stmt (gsi);
/* If this statement sets an SSA_NAME to an address,
try to propagate the address into the uses of the SSA_NAME. */
- if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+ if (is_gimple_assign (stmt))
{
- tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
- tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
-
+ tree lhs = gimple_assign_lhs (stmt);
+ tree rhs = gimple_assign_rhs1 (stmt);
if (TREE_CODE (lhs) != SSA_NAME)
{
- bsi_next (&bsi);
+ gsi_next (&gsi);
continue;
}
- if (TREE_CODE (rhs) == ADDR_EXPR)
+ if (gimple_assign_rhs_code (stmt) == ADDR_EXPR
+ /* Handle pointer conversions on invariant addresses
+ as well, as this is valid gimple. */
+ || (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
+ && TREE_CODE (rhs) == ADDR_EXPR
+ && POINTER_TYPE_P (TREE_TYPE (lhs))))
{
- if (forward_propagate_addr_expr (lhs, rhs))
+ STRIP_NOPS (rhs);
+ if (!stmt_references_abnormal_ssa_name (stmt)
+ && forward_propagate_addr_expr (lhs, rhs))
{
release_defs (stmt);
todoflags |= TODO_remove_unused_locals;
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
}
else
- bsi_next (&bsi);
+ gsi_next (&gsi);
+ }
+ else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
+ && is_gimple_min_invariant (rhs))
+ {
+ /* Make sure to fold &a[0] + off_1 here. */
+ fold_stmt_inplace (stmt);
+ update_stmt (stmt);
+ if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
+ gsi_next (&gsi);
}
- else if ((TREE_CODE (rhs) == BIT_NOT_EXPR
- || TREE_CODE (rhs) == NEGATE_EXPR)
- && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ else if ((gimple_assign_rhs_code (stmt) == BIT_NOT_EXPR
+ || gimple_assign_rhs_code (stmt) == NEGATE_EXPR)
+ && TREE_CODE (rhs) == SSA_NAME)
{
- simplify_not_neg_expr (stmt);
- bsi_next (&bsi);
+ simplify_not_neg_expr (&gsi);
+ gsi_next (&gsi);
}
- else if (TREE_CODE (rhs) == COND_EXPR)
+ else if (gimple_assign_rhs_code (stmt) == COND_EXPR)
{
- bool did_something;
+ /* In this case the entire COND_EXPR is in rhs1. */
+ int did_something;
fold_defer_overflow_warnings ();
- did_something = forward_propagate_into_cond (rhs, stmt);
+ did_something = forward_propagate_into_cond (&gsi);
+ stmt = gsi_stmt (gsi);
+ if (did_something == 2)
+ cfg_changed = true;
fold_undefer_overflow_warnings (!TREE_NO_WARNING (rhs)
&& did_something, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
- else if (COMPARISON_CLASS_P (rhs))
+ else if (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt))
+ == tcc_comparison)
{
- if (forward_propagate_comparison (rhs, stmt))
+ if (forward_propagate_comparison (stmt))
{
release_defs (stmt);
todoflags |= TODO_remove_unused_locals;
- bsi_remove (&bsi, true);
+ gsi_remove (&gsi, true);
}
else
- bsi_next (&bsi);
+ gsi_next (&gsi);
+ }
+ else if (gimple_assign_rhs_code (stmt) == BIT_AND_EXPR)
+ {
+ simplify_bitwise_and (&gsi, stmt);
+ gsi_next (&gsi);
}
else
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
- else if (TREE_CODE (stmt) == SWITCH_EXPR)
+ else if (gimple_code (stmt) == GIMPLE_SWITCH)
{
- simplify_switch_expr (stmt);
- bsi_next (&bsi);
+ simplify_gimple_switch (stmt);
+ gsi_next (&gsi);
}
- else if (TREE_CODE (stmt) == COND_EXPR)
+ else if (gimple_code (stmt) == GIMPLE_COND)
{
- bool did_something;
+ int did_something;
fold_defer_overflow_warnings ();
- did_something = forward_propagate_into_cond (stmt, stmt);
- fold_undefer_overflow_warnings (!TREE_NO_WARNING (stmt)
- && did_something, stmt,
+ did_something = forward_propagate_into_gimple_cond (stmt);
+ if (did_something == 2)
+ cfg_changed = true;
+ fold_undefer_overflow_warnings (did_something, stmt,
WARN_STRICT_OVERFLOW_CONDITIONAL);
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
else
- bsi_next (&bsi);
+ gsi_next (&gsi);
}
}
static bool
gate_forwprop (void)
{
- return 1;
+ return flag_tree_forwprop;
}
-struct tree_opt_pass pass_forwprop = {
+struct gimple_opt_pass pass_forwprop =
+{
+ {
+ GIMPLE_PASS,
"forwprop", /* name */
gate_forwprop, /* gate */
tree_ssa_forward_propagate_single_use_vars, /* execute */
TODO_dump_func
| TODO_ggc_collect
| TODO_update_ssa
- | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
};
-
-/* Structure to keep track of the value of a dereferenced PHI result
- and the set of virtual operands used for that dereference. */
-
-struct phiprop_d
-{
- tree value;
- tree vop_stmt;
-};
-
-/* Verify if the value recorded for NAME in PHIVN is still valid at
- the start of basic block BB. */
-
-static bool
-phivn_valid_p (struct phiprop_d *phivn, tree name, basic_block bb)
-{
- tree vop_stmt = phivn[SSA_NAME_VERSION (name)].vop_stmt;
- ssa_op_iter ui;
- tree vuse;
-
- /* The def stmts of all virtual uses need to be post-dominated
- by bb. */
- FOR_EACH_SSA_TREE_OPERAND (vuse, vop_stmt, ui, SSA_OP_VUSE)
- {
- tree use_stmt;
- imm_use_iterator ui2;
- bool ok = true;
-
- FOR_EACH_IMM_USE_STMT (use_stmt, ui2, vuse)
- {
- /* If BB does not dominate a VDEF, the value is invalid. */
- if (((TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
- && !ZERO_SSA_OPERANDS (use_stmt, SSA_OP_VDEF))
- || TREE_CODE (use_stmt) == PHI_NODE)
- && !dominated_by_p (CDI_DOMINATORS, bb_for_stmt (use_stmt), bb))
- {
- ok = false;
- BREAK_FROM_IMM_USE_STMT (ui2);
- }
- }
- if (!ok)
- return false;
- }
-
- return true;
-}
-
-/* Insert a new phi node for the dereference of PHI at basic_block
- BB with the virtual operands from USE_STMT. */
-
-static tree
-phiprop_insert_phi (basic_block bb, tree phi, tree use_stmt,
- struct phiprop_d *phivn, size_t n)
-{
- tree res, new_phi;
- edge_iterator ei;
- edge e;
-
- /* Build a new PHI node to replace the definition of
- the indirect reference lhs. */
- res = GIMPLE_STMT_OPERAND (use_stmt, 0);
- SSA_NAME_DEF_STMT (res) = new_phi = create_phi_node (res, bb);
-
- /* Add PHI arguments for each edge inserting loads of the
- addressable operands. */
- FOR_EACH_EDGE (e, ei, bb->preds)
- {
- tree old_arg, new_var, tmp;
-
- old_arg = PHI_ARG_DEF_FROM_EDGE (phi, e);
- while (TREE_CODE (old_arg) == SSA_NAME
- && (SSA_NAME_VERSION (old_arg) >= n
- || phivn[SSA_NAME_VERSION (old_arg)].value == NULL_TREE))
- {
- tree def_stmt = SSA_NAME_DEF_STMT (old_arg);
- old_arg = GIMPLE_STMT_OPERAND (def_stmt, 1);
- }
-
- if (TREE_CODE (old_arg) == SSA_NAME)
- /* Reuse a formely created dereference. */
- new_var = phivn[SSA_NAME_VERSION (old_arg)].value;
- else
- {
- old_arg = TREE_OPERAND (old_arg, 0);
- new_var = create_tmp_var (TREE_TYPE (old_arg), NULL);
- tmp = build2 (GIMPLE_MODIFY_STMT, void_type_node,
- NULL_TREE, unshare_expr (old_arg));
- if (TREE_CODE (TREE_TYPE (old_arg)) == COMPLEX_TYPE
- || TREE_CODE (TREE_TYPE (old_arg)) == VECTOR_TYPE)
- DECL_GIMPLE_REG_P (new_var) = 1;
- add_referenced_var (new_var);
- new_var = make_ssa_name (new_var, tmp);
- GIMPLE_STMT_OPERAND (tmp, 0) = new_var;
-
- bsi_insert_on_edge (e, tmp);
-
- update_stmt (tmp);
- mark_symbols_for_renaming (tmp);
- }
-
- add_phi_arg (new_phi, new_var, e);
- }
-
- update_stmt (new_phi);
-
- return res;
-}
-
-/* Propagate between the phi node arguments of PHI in BB and phi result
- users. For now this matches
- # p_2 = PHI <&x, &y>
- <Lx>:;
- p_3 = p_2;
- z_2 = *p_3;
- and converts it to
- # z_2 = PHI <x, y>
- <Lx>:;
- Returns true if a transformation was done and edge insertions
- need to be committed. Global data PHIVN and N is used to track
- past transformation results. We need to be especially careful here
- with aliasing issues as we are moving memory reads. */
-
-static bool
-propagate_with_phi (basic_block bb, tree phi, struct phiprop_d *phivn, size_t n)
-{
- tree ptr = PHI_RESULT (phi);
- tree use_stmt, res = NULL_TREE;
- block_stmt_iterator bsi;
- imm_use_iterator ui;
- use_operand_p arg_p, use;
- ssa_op_iter i;
- bool phi_inserted;
-
- if (MTAG_P (SSA_NAME_VAR (ptr))
- || !POINTER_TYPE_P (TREE_TYPE (ptr))
- || !is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr))))
- return false;
-
- /* Check if we can "cheaply" dereference all phi arguments. */
- FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE)
- {
- tree arg = USE_FROM_PTR (arg_p);
- /* Walk the ssa chain until we reach a ssa name we already
- created a value for or we reach a definition of the form
- ssa_name_n = &var; */
- while (TREE_CODE (arg) == SSA_NAME
- && !SSA_NAME_IS_DEFAULT_DEF (arg)
- && (SSA_NAME_VERSION (arg) >= n
- || phivn[SSA_NAME_VERSION (arg)].value == NULL_TREE))
- {
- tree def_stmt = SSA_NAME_DEF_STMT (arg);
- if (TREE_CODE (def_stmt) != GIMPLE_MODIFY_STMT)
- return false;
- arg = GIMPLE_STMT_OPERAND (def_stmt, 1);
- }
- if ((TREE_CODE (arg) != ADDR_EXPR
- /* Avoid to have to decay *&a to a[0] later. */
- || !is_gimple_reg_type (TREE_TYPE (TREE_OPERAND (arg, 0))))
- && !(TREE_CODE (arg) == SSA_NAME
- && phivn[SSA_NAME_VERSION (arg)].value != NULL_TREE
- && phivn_valid_p (phivn, arg, bb)))
- return false;
- }
-
- /* Find a dereferencing use. First follow (single use) ssa
- copy chains for ptr. */
- while (single_imm_use (ptr, &use, &use_stmt)
- && TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
- && GIMPLE_STMT_OPERAND (use_stmt, 1) == ptr
- && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) == SSA_NAME)
- ptr = GIMPLE_STMT_OPERAND (use_stmt, 0);
-
- /* Replace the first dereference of *ptr if there is one and if we
- can move the loads to the place of the ptr phi node. */
- phi_inserted = false;
- FOR_EACH_IMM_USE_STMT (use_stmt, ui, ptr)
- {
- ssa_op_iter ui2;
- tree vuse;
-
- /* Check whether this is a load of *ptr. */
- if (!(TREE_CODE (use_stmt) == GIMPLE_MODIFY_STMT
- && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 0)) == SSA_NAME
- && TREE_CODE (GIMPLE_STMT_OPERAND (use_stmt, 1)) == INDIRECT_REF
- && TREE_OPERAND (GIMPLE_STMT_OPERAND (use_stmt, 1), 0) == ptr
- /* We cannot replace a load that may throw or is volatile. */
- && !tree_can_throw_internal (use_stmt)))
- continue;
-
- /* Check if we can move the loads. The def stmts of all virtual uses
- need to be post-dominated by bb. */
- FOR_EACH_SSA_TREE_OPERAND (vuse, use_stmt, ui2, SSA_OP_VUSE)
- {
- tree def_stmt = SSA_NAME_DEF_STMT (vuse);
- if (!SSA_NAME_IS_DEFAULT_DEF (vuse)
- && (bb_for_stmt (def_stmt) == bb
- || !dominated_by_p (CDI_DOMINATORS,
- bb, bb_for_stmt (def_stmt))))
- goto next;
- }
-
- /* Found a proper dereference. Insert a phi node if this
- is the first load transformation. */
- if (!phi_inserted)
- {
- res = phiprop_insert_phi (bb, phi, use_stmt, phivn, n);
-
- /* Remember the value we created for *ptr. */
- phivn[SSA_NAME_VERSION (ptr)].value = res;
- phivn[SSA_NAME_VERSION (ptr)].vop_stmt = use_stmt;
-
- /* Remove old stmt. The phi is taken care of by DCE, if we
- want to delete it here we also have to delete all intermediate
- copies. */
- bsi = bsi_for_stmt (use_stmt);
- bsi_remove (&bsi, 0);
-
- phi_inserted = true;
- }
- else
- {
- /* Further replacements are easy, just make a copy out of the
- load. */
- GIMPLE_STMT_OPERAND (use_stmt, 1) = res;
- update_stmt (use_stmt);
- }
-
-next:;
- /* Continue searching for a proper dereference. */
- }
-
- return phi_inserted;
-}
-
-/* Helper walking the dominator tree starting from BB and processing
- phi nodes with global data PHIVN and N. */
-
-static bool
-tree_ssa_phiprop_1 (basic_block bb, struct phiprop_d *phivn, size_t n)
-{
- bool did_something = false;
- basic_block son;
- tree phi;
-
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- did_something |= propagate_with_phi (bb, phi, phivn, n);
-
- for (son = first_dom_son (CDI_DOMINATORS, bb);
- son;
- son = next_dom_son (CDI_DOMINATORS, son))
- did_something |= tree_ssa_phiprop_1 (son, phivn, n);
-
- return did_something;
-}
-
-/* Main entry for phiprop pass. */
-
-static unsigned int
-tree_ssa_phiprop (void)
-{
- struct phiprop_d *phivn;
-
- calculate_dominance_info (CDI_DOMINATORS);
-
- phivn = XCNEWVEC (struct phiprop_d, num_ssa_names);
-
- if (tree_ssa_phiprop_1 (ENTRY_BLOCK_PTR, phivn, num_ssa_names))
- bsi_commit_edge_inserts ();
-
- free (phivn);
-
- return 0;
-}
-
-static bool
-gate_phiprop (void)
-{
- return 1;
-}
-
-struct tree_opt_pass pass_phiprop = {
- "phiprop", /* name */
- gate_phiprop, /* gate */
- tree_ssa_phiprop, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TREE_FORWPROP, /* tv_id */
- PROP_cfg | PROP_ssa, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_dump_func
- | TODO_ggc_collect
- | TODO_update_ssa
- | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
-};
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