// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ir

type bitset8 uint8

func (f *bitset8) set(mask uint8, b bool) {
	if b {
		*(*uint8)(f) |= mask
	} else {
		*(*uint8)(f) &^= mask
	}
}

func (f bitset8) get2(shift uint8) uint8 {
	return uint8(f>>shift) & 3
}

// set2 sets two bits in f using the bottom two bits of b.

//go:nosplit
//go:nowritebarrierrec
func sigaddset(mask *sigset, i int) {
	if i > 64 {
		throw("unexpected signal greater than 64")
	}
	*mask |= 1 << (uint(i) - 1)
}

func sigdelset(mask *sigset, i int) {
	if i > 64 {
		throw("unexpected signal greater than 64")
	}
	*mask &^= 1 << (uint(i) - 1)
}

//go:nosplit
func sigfillset(mask *uint64) {
	*mask = ^uint64(0)

						&net.IPNet{IP: netutils.ParseIPSloppy("1.2.3.4"), Mask: net.CIDRMask(30, 32)},
						&net.IPNet{IP: netutils.ParseIPSloppy("2001:db8::1"), Mask: net.CIDRMask(64, 128)},
					},
				},
				{
					itf: net.Interface{Index: 1, MTU: 0, Name: "lo", HardwareAddr: nil, Flags: 0},
					addrs: []net.Addr{
						&net.IPNet{IP: netutils.ParseIPSloppy("127.0.0.1"), Mask: net.CIDRMask(8, 32)},

    int hash = smearedHash(key);
    int mask = hashTableMask();
    int tableIndex = hash & mask;
    int next = CompactHashing.tableGet(requireTable(), tableIndex);
    if (next == UNSET) { // uninitialized bucket
      if (newSize > mask) {
        // Resize and add new entry
        mask = resizeTable(mask, CompactHashing.newCapacity(mask), hash, newEntryIndex);
      } else {

// Signal handler for SIGSEGV on a C thread.
static void segvHandler(int signo, siginfo_t* info, void* ctxt) {
	sigset_t mask;
	int i;

	if (sigemptyset(&mask) < 0) {
		die("sigemptyset");
	}
	if (sigaddset(&mask, SIGSEGV) < 0) {
		die("sigaddset");
	}
	i = sigprocmask(SIG_UNBLOCK, &mask, NULL);
	if (i != 0) {
		fprintf(stderr, "sigprocmask: %s\n", strerror(i));
		exit(EXIT_FAILURE);
	}

	// AVX2GATHER mask/index/dest #UD cases.
	VPGATHERQQ Y2, (BP)(X2*2), Y2   // ERROR "mask, index, and destination registers should be distinct"
	VPGATHERQQ Y2, (BP)(X2*2), Y7   // ERROR "mask, index, and destination registers should be distinct"
	VPGATHERQQ Y2, (BP)(X7*2), Y2   // ERROR "mask, index, and destination registers should be distinct"

						nmsa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(nmrsa))
						ip = make(IP, IPv6len)
						copy(ip, ipsa.Addr[:])
						mask = make(IPMask, IPv6len)
						copy(mask, nmsa.Addr[:])
					}
					ifa := &IPNet{IP: ip, Mask: mask}
					ifat = append(ifat, ifa)
				}
			}
		}
		tab = tab[ifm.Msglen:]
	}

	return ifat, nil
}

		sig.delivering.Add(-1)
		return false
	}

	// Add signal to outgoing queue.
	for {
		mask := sig.mask[s/32]
		if mask&bit != 0 {
			sig.delivering.Add(-1)
			return true // signal already in queue
		}
		if atomic.Cas(&sig.mask[s/32], mask, mask|bit) {
			break
		}
	}

	// Notify receiver that queue has new bit.
Send:
	for {
		switch sig.state.Load() {
		default:

	// features seem to contribute similar slowdowns (~1.4x each).

	mask := maskOf(types)
	for i := 0; i < len(in.events); {
		ev := in.events[i]
		if ev.index > i {
			// push
			if ev.typ&mask != 0 {
				f(ev.node)
			}
			pop := ev.index
			if in.events[pop].typ&mask == 0 {
				// Subtrees do not contain types: skip them and pop.
				i = pop + 1
				continue
			}
		}

	// Array of NCases elements.
	// Each case must be a non-empty interface type.
	Cases [1]*InterfaceType
}

type InterfaceSwitchCache struct {
	Mask    uintptr                      // mask for index. Must be a power of 2 minus 1
	Entries [1]InterfaceSwitchCacheEntry // Mask+1 entries total
}

type InterfaceSwitchCacheEntry struct {
	// type of source value (a *Type)
	Typ uintptr
	// case # to dispatch to
	Case int