name: "client prefers AES-GCM, server doesn't have hardware AES (pick ChaCha)",
			clientCiphers: []uint16{
				TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
				TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
				TLS_RSA_WITH_AES_128_CBC_SHA,
			},
			serverHasAESGCM: false,
			expectedCipher:  TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
		},
		{
			name: "client prefers AES-GCM, server has hardware AES (pick AES-GCM)",
			clientCiphers: []uint16{

	// amd64, addresses are sign-extended beyond heapAddrBits. On
	// other arches, they are zero-extended.
	//
	// On most 64-bit platforms, we limit this to 48 bits based on a
	// combination of hardware and OS limitations.
	//
	// amd64 hardware limits addresses to 48 bits, sign-extended
	// to 64 bits. Addresses where the top 16 bits are not either
	// all 0 or all 1 are "non-canonical" and invalid. Because of

	// server's preference. Servers now select the best mutually supported
	// cipher suite based on logic that takes into account inferred client
	// hardware, server hardware, and security.
	//
	// Deprecated: PreferServerCipherSuites is ignored.
	PreferServerCipherSuites bool

	// SessionTicketsDisabled may be set to true to disable session ticket and

// that difference will be visible when printing t.String() and u.String().
//
// # Timer Resolution
//
// [Timer] resolution varies depending on the Go runtime, the operating system
// and the underlying hardware.
// On Unix, the resolution is ~1ms.
// On Windows version 1803 and newer, the resolution is ~0.5ms.
// On older Windows versions, the default resolution is ~16ms, but

	aCache |= uint64(bytes[7]) << (7 * 8)
	s.allocCache = ^aCache
}

// nextFreeIndex returns the index of the next free object in s at
// or after s.freeindex.
// There are hardware instructions that can be used to make this
// faster if profiling warrants it.
func (s *mspan) nextFreeIndex() uint16 {
	sfreeindex := s.freeindex
	snelems := s.nelems
	if sfreeindex == snelems {

	// runtime detection of CPU manufacturer.
	MFENCE
	LFENCE
	RDTSC
	JMP done

// func memhash(p unsafe.Pointer, h, s uintptr) uintptr
// hash function using AES hardware instructions
TEXT runtime·memhash<ABIInternal>(SB),NOSPLIT,$0-32
	// AX = ptr to data
	// BX = seed
	// CX = size
	CMPB	runtime·useAeshash(SB), $0
	JEQ	noaes
	JMP	aeshashbody<>(SB)
noaes:

			if goarch == "arm64" {
				for i := range symtab {
					if symtab[i].Name == "__hwasan_init" {
						// -fsanitize=hwaddress on ARM
						// uses the upper byte of a
						// memory address as a hardware
						// tag. Remove it so that
						// we can find the associated
						// data.
						removeTag = func(v uint64) uint64 { return v &^ (0xff << (64 - 8)) }
						break
					}
				}
			}

		return true
	}
	return false
}

// flagConstant represents the result of a compile-time comparison.
// The sense of these flags does not necessarily represent the hardware's notion
// of a flags register - these are just a compile-time construct.
// We happen to match the semantics to those of arm/arm64.
// Note that these semantics differ from x86: the carry flag has the opposite