bool
cfg_layout_can_duplicate_bb_p (basic_block bb)
{
/* Do not attempt to duplicate tablejumps, as we need to unshare
the dispatch table. This is difficult to do, as the instructions
computing jump destination may be hoisted outside the basic block. */
if (tablejump_p (BB_END (bb), NULL, NULL))
return false;
/* Do not duplicate blocks containing insns that can't be copied. */
if (targetm.cannot_copy_insn_p)
{
rtx insn = BB_HEAD (bb);
while (1)
{
if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn))
return false;
if (insn == BB_END (bb))
break;
insn = NEXT_INSN (insn);
}
}
return true;
}
bool
cfg_layout_can_duplicate_bb_p (basic_block bb)
{
edge s;
if (bb == EXIT_BLOCK_PTR || bb == ENTRY_BLOCK_PTR)
return false;
/* Duplicating fallthru block to exit would require adding a jump
and splitting the real last BB. */
for (s = bb->succ; s; s = s->succ_next)
if (s->dest == EXIT_BLOCK_PTR && s->flags & EDGE_FALLTHRU)
return false;
/* Do not attempt to duplicate tablejumps, as we need to unshare
the dispatch table. This is difficult to do, as the instructions
computing jump destination may be hoisted outside the basic block. */
if (tablejump_p (BB_END (bb), NULL, NULL))
return false;
/* Do not duplicate blocks containing insns that can't be copied. */
if (targetm.cannot_copy_insn_p)
{
rtx insn = BB_HEAD (bb);
while (1)
{
if (INSN_P (insn) && (*targetm.cannot_copy_insn_p) (insn))
return false;
if (insn == BB_END (bb))
break;
insn = NEXT_INSN (insn);
}
}
return true;
}
