(RotateLeft(32|64) ...) => ((ROTLW|ROTL) ...)

// Constant rotate generation
(ROTLW  x (MOVDconst [c])) => (ROTLWconst  x [c&31])
(ROTL   x (MOVDconst [c])) => (ROTLconst   x [c&63])

// Combine rotate and mask operations
(ANDconst [m] (ROTLWconst [r] x)) && isPPC64WordRotateMask(m) => (RLWINM [encodePPC64RotateMask(r,m,32)] x)
(AND (MOVDconst [m]) (ROTLWconst [r] x)) && isPPC64WordRotateMask(m) => (RLWINM [encodePPC64RotateMask(r,m,32)] x)

	AESENC	runtime·aeskeysched+16(SB), X0
	AESENC	runtime·aeskeysched+32(SB), X0
	MOVQ	X0, AX	// return X0
	RET
noaes:
	JMP	runtime·memhash64Fallback<ABIInternal>(SB)

// simple mask to get rid of data in the high part of the register.
DATA masks<>+0x00(SB)/8, $0x0000000000000000
DATA masks<>+0x08(SB)/8, $0x0000000000000000
DATA masks<>+0x10(SB)/8, $0x00000000000000ff

	// the parsing of the AST, only the conversion of the AST
	// to a string.
	LLVMStyle
)

// maxLengthShift is how we shift the MaxLength value.
const maxLengthShift = 16

// maxLengthMask is a mask for the maxLength value.
const maxLengthMask = 0x1f << maxLengthShift

// MaxLength returns an Option that limits the maximum length of a
// demangled string. The maximum length is expressed as a power of 2,

// generic.rules changes ANDs of high-part/low-part masks into a couple of shifts,
// for instance:
//    x & 0xFFFF0000 -> (x >> 16) << 16
//    x & 0x80000000 -> (x >> 31) << 31
//
// In case the mask is just one bit (like second example above), it conflicts
// with the above rules to detect bit-testing / bit-clearing of first/last bit.
// We thus special-case them, by detecting the shift patterns.