static bool
should_replace_address (rtx old_rtx, rtx new_rtx, machine_mode mode,
addr_space_t as, bool speed)
{
int gain;
if (rtx_equal_p (old_rtx, new_rtx)
|| !memory_address_addr_space_p (mode, new_rtx, as))
return false;
/* Copy propagation is always ok. */
if (REG_P (old_rtx) && REG_P (new_rtx))
return true;
/* Prefer the new address if it is less expensive. */
gain = (address_cost (old_rtx, mode, as, speed)
- address_cost (new_rtx, mode, as, speed));
/* If the addresses have equivalent cost, prefer the new address
if it has the highest `set_src_cost'. That has the potential of
eliminating the most insns without additional costs, and it
is the same that cse.c used to do. */
if (gain == 0)
gain = (set_src_cost (new_rtx, VOIDmode, speed)
- set_src_cost (old_rtx, VOIDmode, speed));
return (gain > 0);
}
rtx
gen_lowpart_if_possible (machine_mode mode, rtx x)
{
rtx result = gen_lowpart_common (mode, x);
if (result)
return result;
else if (MEM_P (x))
{
/* This is the only other case we handle. */
poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
rtx new_rtx = adjust_address_nv (x, mode, offset);
if (! memory_address_addr_space_p (mode, XEXP (new_rtx, 0),
MEM_ADDR_SPACE (x)))
return 0;
return new_rtx;
}
else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode
&& validate_subreg (mode, GET_MODE (x), x,
subreg_lowpart_offset (mode, GET_MODE (x))))
return gen_lowpart_SUBREG (mode, x);
else
return 0;
}
static bool
valid_mem_ref_p (enum machine_mode mode, addr_space_t as,
struct mem_address *addr)
{
rtx address;
address = addr_for_mem_ref (addr, as, false);
if (!address)
return false;
return memory_address_addr_space_p (mode, address, as);
}
