var intelReg = [...]string{
	F0:  "st0",
	F1:  "st1",
	F2:  "st2",
	F3:  "st3",
	F4:  "st4",
	F5:  "st5",
	F6:  "st6",
	F7:  "st7",
	M0:  "mmx0",
	M1:  "mmx1",
	M2:  "mmx2",
	M3:  "mmx3",
	M4:  "mmx4",
	M5:  "mmx5",
	M6:  "mmx6",
	M7:  "mmx7",
	X0:  "xmm0",
	X1:  "xmm1",
	X2:  "xmm2",
	X3:  "xmm3",
	X4:  "xmm4",
	X5:  "xmm5",
	X6:  "xmm6",
	X7:  "xmm7",
	X8:  "xmm8",

	R14
	R15

	// Instruction pointer.
	IP  // 16-bit
	EIP // 32-bit
	RIP // 64-bit

	// 387 floating point registers.
	F0
	F1
	F2
	F3
	F4
	F5
	F6
	F7

	// MMX registers.
	M0
	M1
	M2
	M3
	M4
	M5
	M6
	M7

	// XMM registers.
	X0
	X1
	X2
	X3
	X4
	X5
	X6
	X7
	X8
	X9
	X10
	X11
	X12
	X13

notintel:

	// Load EAX=1 cpuid flags
	MOVL	$1, AX
	CPUID
	MOVL	CX, DI // Move to global variable clobbers CX when generating PIC
	MOVL	AX, runtime·processorVersionInfo(SB)

	// Check for MMX support
	TESTL	$(1<<23), DX // MMX
	JZ	bad_proc

nocpuinfo:
	// if there is an _cgo_init, call it to let it
	// initialize and to set up GS.  if not,
	// we set up GS ourselves.
	MOVL	_cgo_init(SB), AX
	TESTL	AX, AX

//
// [the Go memory model]: https://go.dev/ref/mem
package atomic

import (
	"unsafe"
)

// BUG(rsc): On 386, the 64-bit functions use instructions unavailable before the Pentium MMX.
//
// On non-Linux ARM, the 64-bit functions use instructions unavailable before the ARMv6k core.
//
// On ARM, 386, and 32-bit MIPS, it is the caller's responsibility to arrange

	HasFPA      bool // Floating point arithmetic support
	HasVFP      bool // Vector floating point support
	HasEDSP     bool // DSP Extensions support
	HasJAVA     bool // Java instruction set
	HasIWMMXT   bool // Intel Wireless MMX technology support
	HasCRUNCH   bool // MaverickCrunch context switching and handling
	HasTHUMBEE  bool // Thumb EE instruction set
	HasNEON     bool // NEON instruction set

	F4:   "%st(4)",
	F5:   "%st(5)",
	F6:   "%st(6)",
	F7:   "%st(7)",
	M0:   "%mm0",
	M1:   "%mm1",
	M2:   "%mm2",
	M3:   "%mm3",
	M4:   "%mm4",
	M5:   "%mm5",
	M6:   "%mm6",
	M7:   "%mm7",
	X0:   "%xmm0",
	X1:   "%xmm1",
	X2:   "%xmm2",
	X3:   "%xmm3",
	X4:   "%xmm4",
	X5:   "%xmm5",
	X6:   "%xmm6",
	X7:   "%xmm7",
	X8:   "%xmm8",
	X9:   "%xmm9",
	X10:  "%xmm10",

					inst.PCRelOff = dispoff
				}
			} else {
				base := baseReg[x]
				index := Reg(rm)
				switch decodeOp(x) {
				case xArgMmM32, xArgMmM64, xArgMm2M64:
					// There are only 8 MMX registers, so these ignore the REX.X bit.
					index &= 7
				case xArgRM8:
					if rex != 0 && index >= 4 {
						rexUsed |= PrefixREX
						index -= 4
						base = SPB
					}
				case xArgYmm2M256: