see https://golang.org/pkg/go/build/#hdr-Build_Constraints).

When cross-compiling, you must specify a C cross-compiler for cgo to
use. You can do this by setting the generic CC_FOR_TARGET or the
more specific CC_FOR_${GOOS}_${GOARCH} (for example, CC_FOR_linux_arm)
environment variable when building the toolchain using make.bash,
or you can set the CC environment variable any time you run the go tool.

pkg debug/macho, const GENERIC_RELOC_LOCAL_SECTDIFF = 4
pkg debug/macho, const GENERIC_RELOC_LOCAL_SECTDIFF RelocTypeGeneric
pkg debug/macho, const GENERIC_RELOC_PAIR = 1
pkg debug/macho, const GENERIC_RELOC_PAIR RelocTypeGeneric
pkg debug/macho, const GENERIC_RELOC_PB_LA_PTR = 3
pkg debug/macho, const GENERIC_RELOC_PB_LA_PTR RelocTypeGeneric
pkg debug/macho, const GENERIC_RELOC_SECTDIFF = 2

					return i
				}
				continue
			}
		}
		for _, ch := range chars {
			if r == ch {
				return i
			}
		}
	}
	return -1
}

// Generic split: splits after each instance of sep,
// including sepSave bytes of sep in the subslices.
func genSplit(s, sep []byte, sepSave, n int) [][]byte {
	if n == 0 {
		return nil
	}
	if len(sep) == 0 {

what the toolchain actually generates for that operation might
not be a move instruction at all, perhaps a clear or load.
Or it might correspond exactly to the machine instruction with that name.
In general, machine-specific operations tend to appear as themselves, while more general concepts like
memory move and subroutine call and return are more abstract.
The details vary with architecture, and we apologize for the imprecision; the situation is not well-defined.
</p>

		register[name] = int16(i)
	}
	for i := riscv.REG_F0; i <= riscv.REG_F31; i++ {
		name := fmt.Sprintf("F%d", i-riscv.REG_F0)
		register[name] = int16(i)
	}

	// General registers with ABI names.
	register["ZERO"] = riscv.REG_ZERO
	register["RA"] = riscv.REG_RA
	register["SP"] = riscv.REG_SP
	register["GP"] = riscv.REG_GP
	register["TP"] = riscv.REG_TP
	register["T0"] = riscv.REG_T0

		return int8(s[0] - '0')
	}
	p.errorf("bad scale: %s", s)
	return 0
}

// operand parses a general operand and stores the result in *a.
func (p *Parser) operand(a *obj.Addr) {
	//fmt.Printf("Operand: %v\n", p.input)
	if len(p.input) == 0 {
		p.errorf("empty operand: cannot happen")
		return
	}
	// General address (with a few exceptions) looks like
	//	$sym±offset(SB)(reg)(index*scale)
	// Exceptions are:
	//

	}
	return 0, false
}

// ARM64RegisterShift constructs an ARM64 register with shift operation.
func ARM64RegisterShift(reg, op, count int16) (int64, error) {
	// the base register of shift operations must be general register.
	if reg > arm64.REG_R31 || reg < arm64.REG_R0 {
		return 0, errors.New("invalid register for shift operation")
	}
	return int64(reg&31)<<16 | int64(op)<<22 | int64(uint16(count)), nil
}

</p>

<h3 id="overview">Informal Overview</h3>

<p>
Go approaches its memory model in much the same way as the rest of the language,
aiming to keep the semantics simple, understandable, and useful.
This section gives a general overview of the approach and should suffice for most programmers.
The memory model is specified more formally in the next section.
</p>

<p>
A data race is defined as

// to avoid misleading negative results.
// This makes all the references to os.FileInfo in go1.txt
// be read as if they said fs.FileInfo, since os.FileInfo is now an alias.
// If there are many of these, we could do a more general solution,
// but for now the replacer is fine.
var aliasReplacer = strings.NewReplacer(
	"os.FileInfo", "fs.FileInfo",
	"os.FileMode", "fs.FileMode",
	"os.PathError", "fs.PathError",
)

// DATA masks<>+0x00(SB)/4, $0x00000000
func (p *Parser) asmData(operands [][]lex.Token) {
	if len(operands) != 2 {
		p.errorf("expect two operands for DATA")
		return
	}

	// Operand 0 has the general form foo<>+0x04(SB)/4.
	op := operands[0]
	n := len(op)
	if n < 3 || op[n-2].ScanToken != '/' || op[n-1].ScanToken != scanner.Int {
		p.errorf("expect /size for DATA argument")
		return
	}