void
backprop::optimize_phi (gphi *phi, tree var, const usage_info *info)
{
/* If the sign of the result doesn't matter, try to strip sign operations
from arguments. */
if (info->flags.ignore_sign)
{
basic_block bb = gimple_bb (phi);
use_operand_p use;
ssa_op_iter oi;
bool replaced = false;
FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
{
/* Propagating along abnormal edges is delicate, punt for now. */
const int index = PHI_ARG_INDEX_FROM_USE (use);
if (EDGE_PRED (bb, index)->flags & EDGE_ABNORMAL)
continue;
tree new_arg = strip_sign_op (USE_FROM_PTR (use));
if (new_arg)
{
if (!replaced)
prepare_change (var);
if (dump_file && (dump_flags & TDF_DETAILS))
note_replacement (phi, USE_FROM_PTR (use), new_arg);
replace_exp (use, new_arg);
replaced = true;
}
}
}
static basic_block
nearest_common_dominator_of_uses (def_operand_p def_p, bool *debug_stmts)
{
tree var = DEF_FROM_PTR (def_p);
bitmap blocks = BITMAP_ALLOC (NULL);
basic_block commondom;
unsigned int j;
bitmap_iterator bi;
imm_use_iterator imm_iter;
use_operand_p use_p;
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
gimple *usestmt = USE_STMT (use_p);
basic_block useblock;
if (gphi *phi = dyn_cast <gphi *> (usestmt))
{
int idx = PHI_ARG_INDEX_FROM_USE (use_p);
useblock = gimple_phi_arg_edge (phi, idx)->src;
}
else if (is_gimple_debug (usestmt))
{
*debug_stmts = true;
continue;
}
else
{
useblock = gimple_bb (usestmt);
}
/* Short circuit. Nothing dominates the entry block. */
if (useblock == ENTRY_BLOCK_PTR_FOR_FN (cfun))
{
BITMAP_FREE (blocks);
return NULL;
}
bitmap_set_bit (blocks, useblock->index);
}
