for i, tt := range dumpTests {
		if tt.Req != nil && tt.GetReq != nil || tt.Req == nil && tt.GetReq == nil {
			t.Errorf("#%d: either .Req(%p) or .GetReq(%p) can be set/nil but not both", i, tt.Req, tt.GetReq)
			continue
		}

		freshReq := func(ti dumpTest) *http.Request {
			req := ti.Req
			if req == nil {
				req = ti.GetReq()
			}

			if req.Header == nil {
				req.Header = make(http.Header)

	frontendClient := frontend.Client()

	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
	getReq.Host = "some-name"
	getReq.Header.Set("Connection", "close, TE")
	getReq.Header.Add("Te", "foo")
	getReq.Header.Add("Te", "bar, trailers")
	getReq.Header.Set("Proxy-Connection", "should be deleted")
	getReq.Header.Set("Upgrade", "foo")
	getReq.Close = true
	res, err := frontendClient.Do(getReq)
	if err != nil {

	MOVL	new+12(FP), CX
	LOCK
	CMPXCHGL	CX, 0(BX)
	SETEQ	ret+16(FP)
	RET

// bool	·Cas64(uint64 *val, uint64 old, uint64 new)
// Atomically:
//	if(*val == old){
//		*val = new;
//		return 1;
//	} else {
//		return 0;
//	}
TEXT ·Cas64(SB), NOSPLIT, $0-25
	MOVQ	ptr+0(FP), BX
	MOVQ	old+8(FP), AX
	MOVQ	new+16(FP), CX
	LOCK
	CMPXCHGQ	CX, 0(BX)
	SETEQ	ret+24(FP)
	RET

	ADDQ	$8, DI
	SUBQ	$8, BX
	CMPQ	CX, DX
	JEQ	bigloop
	XORQ	AX, AX	// return 0
	RET

	// remaining 0-8 bytes
leftover:
	MOVQ	-8(SI)(BX*1), CX
	MOVQ	-8(DI)(BX*1), DX
	CMPQ	CX, DX
	SETEQ	AX
	RET

small:
	CMPQ	BX, $0
	JEQ	equal

	LEAQ	0(BX*8), CX
	NEGQ	CX

	CMPB	SI, $0xf8
	JA	si_high

	// load at SI won't cross a page boundary.
	MOVQ	(SI), SI
	JMP	si_finish

	MOVL	new_hi+16(FP), CX
	LOCK
	CMPXCHG8B	0(BP)
	SETEQ	ret+20(FP)
	RET

// bool Casp1(void **p, void *old, void *new)
// Atomically:
//	if(*p == old){
//		*p = new;
//		return 1;
//	}else
//		return 0;
TEXT ·Casp1(SB), NOSPLIT, $0-13
	MOVL	ptr+0(FP), BX
	MOVL	old+4(FP), AX
	MOVL	new+8(FP), CX
	LOCK
	CMPXCHGL	CX, 0(BX)
	SETEQ	ret+12(FP)
	RET

// Absorb flag constants into SETxx ops.
((SETEQ|SETLE|SETGE|SETBE|SETAE) (FlagEQ))     => (MOVLconst [1])
((SETNE|SETL|SETG|SETB|SETA)     (FlagEQ))     => (MOVLconst [0])
((SETNE|SETL|SETLE|SETB|SETBE)   (FlagLT_ULT)) => (MOVLconst [1])
((SETEQ|SETG|SETGE|SETA|SETAE)   (FlagLT_ULT)) => (MOVLconst [0])
((SETNE|SETL|SETLE|SETA|SETAE)   (FlagLT_UGT)) => (MOVLconst [1])
((SETEQ|SETG|SETGE|SETB|SETBE)   (FlagLT_UGT)) => (MOVLconst [0])

	SHRQ	CX, SI	// move a's bit to bottom
	ANDQ	$1, SI	// mask bit
	LEAQ	-1(SI*2), AX // 1/0 => +1/-1
	RET

allsame:
	XORQ	AX, AX
	XORQ	CX, CX
	CMPQ	BX, DX
	SETGT	AX	// 1 if alen > blen
	SETEQ	CX	// 1 if alen == blen
	LEAQ	-1(CX)(AX*2), AX	// 1,0,-1 result
	RET

	// this works for >= 64 bytes of data.
#ifndef hasAVX2
big_loop:
	MOVOU	(SI), X0
	MOVOU	(DI), X1
	PCMPEQB X0, X1

	"SARB",
	"SARL",
	"SARQ",
	"SARW",
	"SARXL",
	"SARXQ",
	"SBBB",
	"SBBL",
	"SBBQ",
	"SBBW",
	"SCASB",
	"SCASL",
	"SCASQ",
	"SCASW",
	"SETCC",
	"SETCS",
	"SETEQ",
	"SETGE",
	"SETGT",
	"SETHI",
	"SETLE",
	"SETLS",
	"SETLT",
	"SETMI",
	"SETNE",
	"SETOC",
	"SETOS",
	"SETPC",
	"SETPL",
	"SETPS",
	"SFENCE",
	"SGDT",
	"SHA1MSG1",

		{name: "SBBLcarrymask", argLength: 1, reg: flagsgp, asm: "SBBL"}, // (int32)(-1) if carry is set, 0 if carry is clear.
		// Note: SBBW and SBBB are subsumed by SBBL

		{name: "SETEQ", argLength: 1, reg: readflags, asm: "SETEQ"}, // extract == condition from arg0
		{name: "SETNE", argLength: 1, reg: readflags, asm: "SETNE"}, // extract != condition from arg0

		{name: "SBBLcarrymask", argLength: 1, reg: flagsgp, asm: "SBBL"}, // (int32)(-1) if carry is set, 0 if carry is clear.
		// Note: SBBW and SBBB are subsumed by SBBL

		{name: "SETEQ", argLength: 1, reg: readflags, asm: "SETEQ"}, // extract == condition from arg0
		{name: "SETNE", argLength: 1, reg: readflags, asm: "SETNE"}, // extract != condition from arg0