{name: "PanicExtend", argLength: 4, aux: "Int64", typ: "Mem", call: true}, // arg0=idxHi, arg1=idxLo, arg2=len, arg3=mem, returns memory.

	// Function calls. Arguments to the call have already been written to the stack.
	// Return values appear on the stack. The method receiver, if any, is treated
	// as a phantom first argument.
	// TODO(josharian): ClosureCall and InterCall should have Int32 aux
	// to match StaticCall's 32 bit arg size limit.

// with RFC 8032. RFC 8032's private keys correspond to seeds in this
// package.
func NewKeyFromSeed(seed []byte) PrivateKey {
	// Outline the function body so that the returned key can be stack-allocated.
	privateKey := make([]byte, PrivateKeySize)
	newKeyFromSeed(privateKey, seed)
	return privateKey
}

func newKeyFromSeed(privateKey, seed []byte) {
	if l := len(seed); l != SeedSize {

func popDefer(gp *g) {
	d := gp._defer
	d.fn = nil // Can in theory point to the stack
	// We must not copy the stack between the updating gp._defer and setting
	// d.link to nil. Between these two steps, d is not on any defer list, so
	// stack copying won't adjust stack pointers in it (namely, d.link). Hence,
	// if we were to copy the stack, d could then contain a stale pointer.
	gp._defer = d.link
	d.link = nil

			fmt.Fprintf(os.Stderr, "%s: %d bytes of stack space saved via stack slot merging (%d nonpointer %d pointer)\n", ir.FuncName(fn), savedNP+savedP, savedNP, savedP)
			if base.Debug.MergeLocalsTrace > 1 {
				fmt.Fprintf(os.Stderr, "=-= merge locals state for %v:\n%v",
					fn, mls)
			}
		}
		leaders = make(map[*ir.Name]int64)
	}

	// Use sort.SliceStable instead of sort.Slice so stack layout (and thus

	execution tracer to double-check stack ownership before taking a stack trace.

	asyncpreemptoff: asyncpreemptoff=1 disables signal-based
	asynchronous goroutine preemption. This makes some loops
	non-preemptible for long periods, which may delay GC and
	goroutine scheduling. This is useful for debugging GC issues
	because it also disables the conservative stack scanning used
	for asynchronously preempted goroutines.

	asmArchMipsLE   = asmArch{name: "mipsle", bigEndian: false, stack: "R29", lr: true}
	asmArchMips64   = asmArch{name: "mips64", bigEndian: true, stack: "R29", lr: true}
	asmArchMips64LE = asmArch{name: "mips64le", bigEndian: false, stack: "R29", lr: true}
	asmArchPpc64    = asmArch{name: "ppc64", bigEndian: true, stack: "R1", lr: true, retRegs: []string{"R3", "F1"}}

	// further move the stack.
	new2 := uintptr(unsafe.Pointer(new))

	t.Logf("old stack pointer %x, new stack pointer %x", old, new2)
	if new2 == old {
		// Check that we didn't screw up the test's escape analysis.
		if cls := runtime.GCTestPointerClass(unsafe.Pointer(new)); cls != "stack" {
			t.Fatalf("test bug: new (%#x) should be a stack pointer, not %s", new2, cls)
		}
		// This was a real failure.
		return false
	}

	// There are unlocked sudogs that point into gp's stack. Stack
	// copying must lock the channels of those sudogs.
	// Set activeStackChans here instead of before we try parking
	// because we could self-deadlock in stack growth on the
	// channel lock.
	gp.activeStackChans = true
	// Mark that it's safe for stack shrinking to occur now,
	// because any thread acquiring this G's stack for shrinking

	EvGoSleep           event.Type = 19 // goroutine calls Sleep [timestamp, stack]
	EvGoBlock           event.Type = 20 // goroutine blocks [timestamp, stack]
	EvGoUnblock         event.Type = 21 // goroutine is unblocked [timestamp, goroutine id, seq, stack]
	EvGoBlockSend       event.Type = 22 // goroutine blocks on chan send [timestamp, stack]
	EvGoBlockRecv       event.Type = 23 // goroutine blocks on chan recv [timestamp, stack]

	stw := stopTheWorld(stwWriteHeapDump)

	// Keep m on this G's stack instead of the system stack.
	// Both readmemstats_m and writeheapdump_m have pretty large
	// peak stack depths and we risk blowing the system stack.
	// This is safe because the world is stopped, so we don't
	// need to worry about anyone shrinking and therefore moving
	// our stack.
	var m MemStats
	systemstack(func() {