byte_value       = octal_byte_value | hex_byte_value .
octal_byte_value = `\` octal_digit octal_digit octal_digit .
hex_byte_value   = `\` "x" hex_digit hex_digit .
little_u_value   = `\` "u" hex_digit hex_digit hex_digit hex_digit .
big_u_value      = `\` "U" hex_digit hex_digit hex_digit hex_digit
                           hex_digit hex_digit hex_digit hex_digit .
escaped_char     = `\` ( "a" | "b" | "f" | "n" | "r" | "t" | "v" | `\` | "'" | `"` ) .

about Go pointers applies not just to pointer types, but also to other
types that include Go pointers.

All Go pointers passed to C must point to pinned Go memory. Go pointers
passed as function arguments to C functions have the memory they point to
implicitly pinned for the duration of the call. Go memory reachable from
these function arguments must be pinned as long as the C code has access

For the remaining programs,
we define a new GODEBUG setting that
allows individual programs to opt back in to the old behavior.
A GODEBUG setting may not be added if doing so is infeasible,
but that should be extremely rare.

GODEBUG settings added for compatibility will be maintained
for a minimum of two years (four Go releases).
Some, such as `http2client` and `http2server`,

byte_value       = octal_byte_value | hex_byte_value .
octal_byte_value = `\` octal_digit octal_digit octal_digit .
hex_byte_value   = `\` "x" hex_digit hex_digit .
little_u_value   = `\` "u" hex_digit hex_digit hex_digit hex_digit .
big_u_value      = `\` "U" hex_digit hex_digit hex_digit hex_digit
                           hex_digit hex_digit hex_digit hex_digit .
escaped_char     = `\` ( "a" | "b" | "f" | "n" | "r" | "t" | "v" | `\` | "'" | `"` ) .

// It returns the byte index in s of the first Unicode
// code point satisfying f(c), or -1 if none do.
func IndexFunc(s []byte, f func(r rune) bool) int {
	return indexFunc(s, f, true)
}

// LastIndexFunc interprets s as a sequence of UTF-8-encoded code points.
// It returns the byte index in s of the last Unicode
// code point satisfying f(c), or -1 if none do.
func LastIndexFunc(s []byte, f func(r rune) bool) int {

// Range: -9223372036854775808 through 9223372036854775807.
type int64 int64

// float32 is the set of all IEEE 754 32-bit floating-point numbers.
type float32 float32

// float64 is the set of all IEEE 754 64-bit floating-point numbers.
type float64 float64

// complex64 is the set of all complex numbers with float32 real and
// imaginary parts.
type complex64 complex64

		if !haveConstant {
			p.back() // Put back the '('.
		}
	}
	if haveConstant {
		p.back()
		if p.have(scanner.Float) {
			if prefix != '$' {
				p.errorf("floating-point constant must be an immediate")
			}
			a.Type = obj.TYPE_FCONST
			a.Val = p.floatExpr()
			// fmt.Printf("FCONST %s\n", obj.Dconv(&emptyProg, 0, a))
			p.expectOperandEnd()
			return
		}

	// 11.6: Single-Precision Floating-Point Computational Instructions
	FADDS	F1, F0, F2				// 53011000
	FSUBS	F1, F0, F2				// 53011008
	FMULS	F1, F0, F2				// 53011010
	FDIVS	F1, F0, F2				// 53011018
	FMINS	F1, F0, F2				// 53011028
	FMAXS	F1, F0, F2				// 53111028
	FSQRTS	F0, F1					// d3000058

	// 11.7: Single-Precision Floating-Point Conversion and Move Instructions
	FCVTWS	F0, X5					// d31200c0

The build time overhead to building with [Profile Guided Optimization](/doc/pgo) has been reduced significantly.
Previously, large builds could see 100%+ build time increase from enabling PGO.
In Go 1.23, overhead should be in the single digit percentages.

## Assembler {#assembler}