tracefpunwindoff: setting tracefpunwindoff=1 forces the execution tracer to
	use the runtime's default stack unwinder instead of frame pointer unwinding.
	This increases tracer overhead, but could be helpful as a workaround or for
	debugging unexpected regressions caused by frame pointer unwinding.

	traceadvanceperiod: the approximate period in nanoseconds between trace generations. Only

	MOVQ	AX, DX	// DX = fn

	// Save state in g->sched. The caller's SP and PC are restored by gogo to
	// resume execution in the caller's frame (implicit return). The caller's BP
	// is also restored to support frame pointer unwinding.
	MOVQ	SP, BX	// hide (SP) reads from vet
	MOVQ	8(BX), BX	// caller's PC
	MOVQ	BX, (g_sched+gobuf_pc)(R14)
	LEAQ	fn+0(FP), BX	// caller's SP
	MOVQ	BX, (g_sched+gobuf_sp)(R14)

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register (R3), and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOVV	R29, R29

	MOVV	R0, REGCTXT
	JMP	runtime·morestack(SB)

// reflectcall: call a function with the given argument list

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register, and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOV	X2, X2

	MOV	ZERO, CTXT
	JMP	runtime·morestack(SB)

// AES hashing not implemented for riscv64
TEXT runtime·memhash<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-32

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register (R5), and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOVD	R15, R15

	MOVD	$0, R12
	BR	runtime·morestack(SB)

// reflectcall: call a function with the given argument list

	WasmPtr
)

type InlMark struct {
	// When unwinding from an instruction in an inlined body, mark
	// where we should unwind to.
	// id records the global inlining id of the inlined body.
	// p records the location of an instruction in the parent (inliner) frame.
	p  *Prog
	id int32
}

// Mark p as the instruction to set as the pc when
// "unwinding" the inlining global frame id. Usually it should be

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register (R3), and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOVW	R29, R29

	MOVW	R0, REGCTXT
	JMP	runtime·morestack(SB)

// reflectcall: call a function with the given argument list

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register (R5), and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOVV    R3, R3

	MOVV	R0, REGCTXT
	JMP	runtime·morestack(SB)

// reflectcall: call a function with the given argument list

	// but it is called with a special calling convention where
	// the caller doesn't save LR on stack but passes it as a
	// register (R3), and the unwinder currently doesn't understand.
	// Make it SPWRITE to stop unwinding. (See issue 54332)
	MOVW	R13, R13

	MOVW	$0, R7
	B runtime·morestack(SB)

// reflectcall: call a function with the given argument list

	memProfile bucketType = 1 + iota
	blockProfile
	mutexProfile

	// size of bucket hash table
	buckHashSize = 179999

	// maxSkip is to account for deferred inline expansion
	// when using frame pointer unwinding. We record the stack
	// with "physical" frame pointers but handle skipping "logical"
	// frames at some point after collecting the stack. So
	// we need extra space in order to avoid getting fewer than the