static bool
forward_propagate_addr_into_variable_array_index (tree offset,
tree def_rhs,
gimple_stmt_iterator *use_stmt_gsi)
{
tree index;
gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);
/* Get the offset's defining statement. */
offset_def = SSA_NAME_DEF_STMT (offset);
/* 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 (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)))))
{
if (is_gimple_assign (offset_def)
&& gimple_assign_rhs_code (offset_def) == MULT_EXPR)
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 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_assign_rhs1 (offset_def);
if (gimple_assign_rhs_code (offset_def) != MULT_EXPR
|| TREE_CODE (gimple_assign_rhs2 (offset_def)) != INTEGER_CST
|| !simple_cst_equal (gimple_assign_rhs2 (offset_def),
TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)))))
return false;
/* The first operand to the MULT_EXPR is the desired index. */
index = offset;
}
/* Replace the pointer addition with array indexing. */
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
record information to undo the propagation. */
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
static bool
forward_propagate_addr_into_variable_array_index (tree offset, tree lhs,
tree stmt, tree use_stmt)
{
tree index;
/* The offset must be defined by a simple MODIFY_EXPR statement. */
if (TREE_CODE (offset) != MODIFY_EXPR)
return false;
/* The RHS of the statement which defines OFFSET must be a gimple
cast of another SSA_NAME. */
offset = TREE_OPERAND (offset, 1);
if (!is_gimple_cast (offset))
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);
/* The statement which defines OFFSET before type conversion
must be a simple MODIFY_EXPR. */
if (TREE_CODE (offset) != MODIFY_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 = TREE_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;
/* The first operand to the MULT_EXPR is the desired index. */
index = TREE_OPERAND (offset, 0);
/* Replace the pointer addition with array indexing. */
TREE_OPERAND (use_stmt, 1) = unshare_expr (TREE_OPERAND (stmt, 1));
TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (use_stmt, 1), 0), 1) = index;
/* That should have created gimple, so there is no need to
record information to undo the propagation. */
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
static bool
forward_propagate_addr_expr_1 (tree name, tree def_rhs,
gimple_stmt_iterator *use_stmt_gsi,
bool single_use_p)
{
tree lhs, rhs, rhs2, array_ref;
tree *rhsp, *lhsp;
gimple use_stmt = gsi_stmt (*use_stmt_gsi);
enum tree_code rhs_code;
gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR);
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 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. */
if (TREE_CODE (lhs) == SSA_NAME
&& ((rhs_code == SSA_NAME && rhs == name)
|| CONVERT_EXPR_CODE_P (rhs_code)))
{
/* 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)))
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;
}
/* 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
&& 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;
}
/* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
nodes from the RHS. */
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,
propagate the ADDR_EXPR into the use of NAME and fold the result. */
if (TREE_CODE (rhs) == INDIRECT_REF
&& TREE_OPERAND (rhs, 0) == name
&& may_propagate_address_into_dereference (def_rhs, rhs))
{
*rhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
/* 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))
{
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 true;
}
/* 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 true;
}
}
/* 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
is nothing to do. */
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;
rhs2 = gimple_assign_rhs2 (use_stmt);
/* Try to optimize &x[0] p+ C where C is a multiple of the size
of the elements in X into &x[C/element size]. */
if (TREE_CODE (rhs2) == INTEGER_CST)
{
tree new_rhs = maybe_fold_stmt_addition (gimple_expr_type (use_stmt),
array_ref, rhs2);
if (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;
}
}
/* 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_CODE (rhs2) == SSA_NAME
/* Avoid problems with IVopts creating PLUS_EXPRs with a
different type than their operands. */
&& 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_into_variable_array_index (tree offset,
tree def_rhs,
gimple_stmt_iterator *use_stmt_gsi)
{
tree index, tunit;
gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);
tree tmp;
tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)));
if (!host_integerp (tunit, 1))
return false;
/* Get the offset's defining statement. */
offset_def = SSA_NAME_DEF_STMT (offset);
/* 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;
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 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. */
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
record information to undo the propagation. */
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
static bool
forward_propagate_addr_expr (tree stmt)
{
int stmt_loop_depth = bb_for_stmt (stmt)->loop_depth;
tree name = TREE_OPERAND (stmt, 0);
use_operand_p imm_use;
tree use_stmt, lhs, rhs, array_ref;
/* We require that the SSA_NAME holding the result of the ADDR_EXPR
be used only once. That may be overly conservative in that we
could propagate into multiple uses. However, that would effectively
be un-cseing the ADDR_EXPR, which is probably not what we want. */
single_imm_use (name, &imm_use, &use_stmt);
if (!use_stmt)
return false;
/* If the use is not in a simple assignment statement, then
there is nothing we can do. */
if (TREE_CODE (use_stmt) != MODIFY_EXPR)
return false;
/* 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)
return false;
/* Strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
ADDR_EXPR will not appear on the LHS. */
lhs = TREE_OPERAND (use_stmt, 0);
while (TREE_CODE (lhs) == COMPONENT_REF || TREE_CODE (lhs) == ARRAY_REF)
lhs = TREE_OPERAND (lhs, 0);
/* 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 (TREE_OPERAND (stmt, 1));
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
/* Trivial case. The use statement could be a trivial copy. We
go ahead and handle that case here since it's trivial and
removes the need to run copy-prop before this pass to get
the best results. Also note that by handling this case here
we can catch some cascading effects, ie the single use is
in a copy, and the copy is used later by a single INDIRECT_REF
for example. */
if (TREE_CODE (lhs) == SSA_NAME && TREE_OPERAND (use_stmt, 1) == name)
{
TREE_OPERAND (use_stmt, 1) = unshare_expr (TREE_OPERAND (stmt, 1));
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
/* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
nodes from the RHS. */
rhs = TREE_OPERAND (use_stmt, 1);
while (TREE_CODE (rhs) == COMPONENT_REF
|| TREE_CODE (rhs) == ARRAY_REF
|| TREE_CODE (rhs) == ADDR_EXPR)
rhs = TREE_OPERAND (rhs, 0);
/* 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)
{
/* 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 (TREE_OPERAND (stmt, 1));
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
/* 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
is nothing to do. */
array_ref = TREE_OPERAND (TREE_OPERAND (stmt, 1), 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)
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)
{
tree orig = unshare_expr (rhs);
TREE_OPERAND (rhs, 0) = unshare_expr (TREE_OPERAND (stmt, 1));
/* 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))
{
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
else
{
TREE_OPERAND (use_stmt, 1) = orig;
update_stmt (use_stmt);
return false;
}
}
/* Try to optimize &x[0] + 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
/* 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)))
{
tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 1));
return forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
stmt, use_stmt);
}
/* 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)))
{
tree offset_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
return forward_propagate_addr_into_variable_array_index (offset_stmt, lhs,
stmt, use_stmt);
}
return false;
}
