// Save callee-saved registers (Go code won't respect that).
	// 8(RSP) and 16(RSP) are for args passed through racecallback
	SUB	$176, RSP
	MOVD	LR, 0(RSP)

	SAVE_R19_TO_R28(8*3)
	SAVE_F8_TO_F15(8*13)
	MOVD	R29, (8*21)(RSP)
	// Set g = g0.
	// load_g will clobber R0, Save R0
	MOVD	R0, R13
	load_g
	// restore R0
	MOVD	R13, R0
	MOVD	g_m(g), R13
	MOVD	m_g0(R13), R14
	CMP	R14, g

		// but may clobber anything else, including R31 (REGTMP).
		// Returns a pointer to a write barrier buffer in R29.
		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ buildReg("R0 R3 R4 R5 R6 R7 R8 R9 R10 R14 R15 R16 R17 R20 R21 g")) | buildReg("R31"), outputs: []regMask{buildReg("R29")}}, clobberFlags: true, aux: "Int64"},

	// On x86, the ABI is to save the frame pointer word at the
	// top of the stack frame, so we have to back down over it.
	// On arm64, the frame pointer should be at the bottom of
	// the stack (with R29 (aka FP) = RSP), in which case we would
	// not want to do the subtraction here. But we started out without
	// any frame pointer, and when we wanted to add it, we didn't

	"R15",
	"R16",
	"R17",
	"R18", // platform register, not used
	"R19",
	"R20",
	"R21",
	"R22",
	"R23",
	"R24",
	"R25",
	"R26",
	// R27 = REGTMP not used in regalloc
	"g",   // aka R28
	"R29", // frame pointer, not used
	"R30", // aka REGLINK
	"SP",  // aka R31

	"F0",
	"F1",
	"F2",
	"F3",
	"F4",
	"F5",
	"F6",
	"F7",
	"F8",
	"F9",
	"F10",
	"F11",
	"F12",
	"F13",