// See RFC 7231, section 7.1.2
		if u.Scheme == "" && u.Host == "" {
			oldpath := r.URL.Path
			if oldpath == "" { // should not happen, but avoid a crash if it does
				oldpath = "/"
			}

			// no leading http://server
			if url == "" || url[0] != '/' {
				// make relative path absolute
				olddir, _ := path.Split(oldpath)
				url = olddir + url
			}

			var query string

		fpstore    = regInfo{inputs: []regMask{gpspsb, fp, 0}}
		fpstoreidx = regInfo{inputs: []regMask{gpspsb, gpsp, fp, 0}}

		prefreg = regInfo{inputs: []regMask{gpspsbg}}
	)

	var AMD64ops = []opData{
		// {ADD,SUB,MUL,DIV}Sx: floating-point arithmetic
		// x==S for float32, x==D for float64
		// computes arg0 OP arg1
		{name: "ADDSS", argLength: 2, reg: fp21, asm: "ADDSS", commutative: true, resultInArg0: true},