}
	// R1 op R2 or r1 op constant.
	// op is:
	//	"<<" == 0
	//	">>" == 1
	//	"->" == 2
	//	"@>" == 3
	r1, ok := p.registerReference(name)
	if !ok {
		return 0
	}
	var op int16
	switch p.next().ScanToken {
	case lex.LSH:
		op = 0
	case lex.RSH:
		op = 1
	case lex.ARR:
		op = 2
	case lex.ROT:

<pre class="ebnf">
Expression = UnaryExpr | Expression binary_op Expression .
UnaryExpr  = PrimaryExpr | unary_op UnaryExpr .

binary_op  = "||" | "&amp;&amp;" | rel_op | add_op | mul_op .
rel_op     = "==" | "!=" | "&lt;" | "&lt;=" | ">" | ">=" .
add_op     = "+" | "-" | "|" | "^" .
mul_op     = "*" | "/" | "%" | "&lt;&lt;" | "&gt;&gt;" | "&amp;" | "&amp;^" .

unary_op   = "+" | "-" | "!" | "^" | "*" | "&amp;" | "&lt;-" .
</pre>

	// Parse left to right.
	op := operands[next]
	if len(op) < 2 || op[0].ScanToken != '$' {
		p.errorf("TEXT %s: frame size must be an immediate constant", name)
		return
	}
	op = op[1:]
	negative := false
	if op[0].ScanToken == '-' {
		negative = true
		op = op[1:]
	}
	if len(op) == 0 || op[0].ScanToken != scanner.Int {

// len(src) and len(dst).
func copy(dst, src []Type) int

// The delete built-in function deletes the element with the specified key
// (m[key]) from the map. If m is nil or there is no such element, delete
// is a no-op.
func delete(m map[Type]Type1, key Type)

// The len built-in function returns the length of v, according to its type:
//
//	Array: the number of elements in v.

<pre class="ebnf">
Expression = UnaryExpr | Expression binary_op Expression .
UnaryExpr  = PrimaryExpr | unary_op UnaryExpr .

binary_op  = "||" | "&amp;&amp;" | rel_op | add_op | mul_op .
rel_op     = "==" | "!=" | "&lt;" | "&lt;=" | ">" | ">=" .
add_op     = "+" | "-" | "|" | "^" .
mul_op     = "*" | "/" | "%" | "&lt;&lt;" | "&gt;&gt;" | "&amp;" | "&amp;^" .

unary_op   = "+" | "-" | "!" | "^" | "*" | "&amp;" | "&lt;-" .
</pre>