// result = t4 ^ t5            -- (d,   c,   b,   a  )
// using shifted ops this can be done in 4 instructions.
(Bswap32 <t> x) && buildcfg.GOARM.Version==5 =>
	(XOR <t>
		(SRLconst <t> (BICconst <t> (XOR <t> x (SRRconst <t> [16] x)) [0xff0000]) [8])
		(SRRconst <t> x [8]))

// byte swap for ARMv6 and above
(Bswap32 x) && buildcfg.GOARM.Version>=6 => (REV x)

// boolean ops -- booleans are represented with 0=false, 1=true

func readUintptr(p *byte) uintptr {
	x := *(*uintptr)(unsafe.Pointer(p))
	if goarch.BigEndian {
		if goarch.PtrSize == 8 {
			return uintptr(sys.Bswap64(uint64(x)))
		}
		return uintptr(sys.Bswap32(uint32(x)))
	}
	return x
}

var debugPtrmask struct {
	lock mutex
	data *byte
}

// progToPointerMask returns the 1-bit pointer mask output by the GC program prog.

(SumBytes4 x) => (SumBytes2 (ADDW <typ.UInt16> (SRWconst <typ.UInt16> x [16]) x))
(SumBytes8 x) => (SumBytes4 (ADDW <typ.UInt32> (SRDconst <typ.UInt32> x [32]) x))

(Bswap64 ...) => (MOVDBR ...)
(Bswap32 ...) => (MOVWBR ...)

// add with carry
(Select0 (Add64carry x y c))
  => (Select0 <typ.UInt64> (ADDE x y (Select1 <types.TypeFlags> (ADDCconst c [-1]))))
(Select1 (Add64carry x y c))