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.MODEL (32-bit MASM)

Initializes the program memory model. (32-bit MASM only.)

Syntax

.MODEL memory-model, language-type⟧ ⟦, stack-option

Parameters

memory-model
Required parameter that determines the size of code and data pointers.

language-type
Optional parameter that sets the calling and naming conventions for procedures and public symbols.

stack-option
Optional parameter.

stack-option is not used if memory-model is FLAT.

Specifying NEARSTACK groups the stack segment into a single physical segment (DGROUP) along with data. The stack segment register (SS) is assumed to hold the same address as the data segment register (DS). FARSTACK does not group the stack with DGROUP; thus SS does not equal DS.

Remarks

.MODEL is not used in MASM for x64 (ml64.exe).

The following table lists the possible values for each parameter when targeting 16-bit and 32-bit platforms:

Parameter 32-bit values 16-bit values (support for earlier 16-bit development)
memory-model FLAT TINY, SMALL, COMPACT, MEDIUM, LARGE, HUGE, FLAT
language-type C, STDCALL C, BASIC, FORTRAN, PASCAL, SYSCALL, STDCALL
stack-option Not used NEARSTACK, FARSTACK

Code

For MASM-related samples, download the Compiler samples from Visual C++ Samples and Related Documentation for Visual Studio 2010.

The following example demonstrates the use of the .MODEL directive.

Example

; file simple.asm
; For x86 (32-bit), assemble with debug information:
;   ml -c -Zi simple.asm
; For x64 (64-bit), assemble with debug information:
;   ml64 -c -DX64 -Zi simple.asm
;
; In this sample, the 'X64' define excludes source not used
;  when targeting the x64 architecture

ifndef X64
.686p
.XMM
.model flat, C
endif

.data
; user data

.code
; user code

fxn PROC public
  xor eax, eax ; zero function return value
  ret
fxn ENDP

end

See also

Directives Reference
MASM BNF Grammar