</p>

<p>
<code>R10</code> points to the <code>g</code> (goroutine) structure.
Within assembler source code, this pointer must be referred to as <code>g</code>;
the name <code>R10</code> is not recognized.
</p>

<p>
To make it easier for people and compilers to write assembly, the ARM linker
allows general addressing forms and pseudo-operations like <code>DIV</code> or <code>MOD</code>

func nilRegisterNumber(name string, n int16) (int16, bool) {
	return 0, false
}

// Set configures the architecture specified by GOARCH and returns its representation.
// It returns nil if GOARCH is not recognized.
func Set(GOARCH string, shared bool) *Arch {
	switch GOARCH {
	case "386":
		return archX86(&x86.Link386)
	case "amd64":
		return archX86(&x86.Linkamd64)
	case "arm":
		return archArm()
	case "arm64":

			}
		}
	}
}

func TestNewReaderSizeIdempotent(t *testing.T) {
	const BufSize = 1000
	b := NewReaderSize(strings.NewReader("hello world"), BufSize)
	// Does it recognize itself?
	b1 := NewReaderSize(b, BufSize)
	if b1 != b {
		t.Error("NewReaderSize did not detect underlying Reader")
	}
	// Does it wrap if existing buffer is too small?
	b2 := NewReaderSize(b, 2*BufSize)

	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
	buildcfg.GOARCH = goarch
	architecture := arch.Set(goarch, false)
	if architecture == nil {
		panic("asm: unrecognized architecture " + goarch)
	}
	ctxt := obj.Linknew(architecture.LinkArch)
	ctxt.Pkgpath = "pkg"
	return architecture, ctxt
}

func newParser(goarch string) *Parser {
	architecture, ctxt := setArch(goarch)

// white space characters while taking into account quotes and escaping, and
// returns an array of substrings of s or an empty list if s contains only white space.
// Single quotes and double quotes are recognized to prevent splitting within the
// quoted region, and are removed from the resulting substrings. If a quote in s
// isn't closed err will be set and r will have the unclosed argument as the

	arm.ABLT,
	arm.ABGT,
	arm.ABLE,
	arm.AB,
	obj.ANOP,
}

// ARMConditionCodes handles the special condition code situation for the ARM.
// It returns a boolean to indicate success; failure means cond was unrecognized.
func ARMConditionCodes(prog *obj.Prog, cond string) bool {
	if cond == "" {
		return true
	}
	bits, ok := ParseARMCondition(cond)
	if !ok {
		return false
	}

	log.SetPrefix("asm: ")

	buildcfg.Check()
	GOARCH := buildcfg.GOARCH

	flags.Parse()

	architecture := arch.Set(GOARCH, *flags.Shared || *flags.Dynlink)
	if architecture == nil {
		log.Fatalf("unrecognized architecture %s", GOARCH)
	}
	ctxt := obj.Linknew(architecture.LinkArch)
	ctxt.Debugasm = flags.PrintOut
	ctxt.Debugvlog = flags.DebugV
	ctxt.Flag_dynlink = *flags.Dynlink
	ctxt.Flag_linkshared = *flags.Linkshared

to say `go` `1.21`, the program can opt back into the old `panic(nil)`
behavior by including this directive:

	//go:debug panicnil=1

Starting in Go 1.21, the Go toolchain treats a `//go:debug` directive
with an unrecognized GODEBUG setting as an invalid program.
Programs with more than one `//go:debug` line for a given setting
are also treated as invalid.
(Older toolchains ignore `//go:debug` directives entirely.)

		{"VADDPD.SAE.SAE X0, X1, X2", `duplicate suffix "SAE"`},
		{"VADDPD.RZ_SAE.SAE X0, X1, X2", `bad suffix combination`},

		// BSWAP on 16-bit registers is undefined. See #29167,
		{"BSWAPW DX", `unrecognized instruction`},
		{"BSWAPW R11", `unrecognized instruction`},
	})
}

func testBadInstParser(t *testing.T, goarch string, tests []badInstTest) {
	for i, test := range tests {
		arch, ctxt := setArch(goarch)

'\000'
'\007'
'\377'
'\x07'
'\xff'
'\u12e4'
'\U00101234'
'\''         // rune literal containing single quote character
'aa'         // illegal: too many characters
'\k'         // illegal: k is not recognized after a backslash
'\xa'        // illegal: too few hexadecimal digits
'\0'         // illegal: too few octal digits
'\400'       // illegal: octal value over 255
'\uDFFF'     // illegal: surrogate half