Slide 8.5: SIZEOF operator and LABEL directive

Slide 8.4: TYPE and LENGTHOF operators
Slide 8.6: Addressing modes
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SIZEOF Operator and LABEL Directive

SIZEOF Operator
The SIZEOF operator returns a value that is equivalent to multiplying LENGTHOF by TYPE.

LABEL Directive
The LABEL directive lets you insert a label and give it a size attribute without allocating any storage.

One common use of LABEL is to provide an alternative name and size attribute for the variable declared next in the data segment.
The LABEL directive allows you to construct a larger integer from two smaller integers.

`SIZEOF` Array	`SIZEOF` Table	`LABEL WORD`
.data arr DWORD 12 DUP(?) .code mov eax, SIZEOF arr call WriteInt	.data tbl WORD \ 10 DUP(5 DUP(?)) .code mov eax, SIZEOF tbl call WriteInt	.data X LABEL WORD Y DWORD 12345678h .code mov eax, 0 mov ax, X+2 call WriteHex
Output	Output	Output

`LABEL BYTE`	`LABEL DWORD`	`LABEL DWORD`
.data S LABEL BYTE C1 BYTE 'a' C2 BYTE 'b' C3 BYTE 0 .code mov edx, OFFSET S call WriteString	.data X LABEL DWORD Y WORD 1234h Z WORD 5678h .code mov eax, X call WriteHex	.data X LABEL DWORD Y WORD 1234h Z DWORD 5678h .code mov eax, X call WriteHex
Output	Output	Output