// and corresponds to first matching byte (bit 6 is 0)
	PCMPESTRI $0x0c, (DI), X1
	// CX == 16 means no match,
	// CX > R9 means partial match at the end of the string,
	// otherwise sep is at offset CX from X1 start
	CMPQ CX, R9
	JBE sse42_success
	ADDQ R9, DI
	CMPQ DI, SI
	JB loop_sse42
	PCMPESTRI $0x0c, -1(SI), X1
	CMPQ CX, R9
	JA fail
	LEAQ -1(SI), DI
sse42_success:

	"PADDW",
	"PALIGNR",
	"PAND",
	"PANDN",
	"PAUSE",
	"PAVGB",
	"PAVGW",
	"PBLENDVB",
	"PBLENDW",
	"PCLMULQDQ",
	"PCMPEQB",
	"PCMPEQL",
	"PCMPEQQ",
	"PCMPEQW",
	"PCMPESTRI",
	"PCMPESTRM",
	"PCMPGTB",
	"PCMPGTL",
	"PCMPGTQ",
	"PCMPGTW",
	"PCMPISTRI",
	"PCMPISTRM",
	"PDEPL",
	"PDEPQ",
	"PEXTL",
	"PEXTQ",
	"PEXTRB",
	"PEXTRD",
	"PEXTRQ",