PRB: Error A2032 Using Indexed Addressing (119872)

The information in this article applies to:

Microsoft Macro Assembler (MASM) 6.0
Microsoft Macro Assembler (MASM) 6.0a
Microsoft Macro Assembler (MASM) 6.0b
Microsoft Macro Assembler (MASM) 6.1
Microsoft Macro Assembler (MASM) 6.1a
Microsoft Macro Assembler (MASM) 6.11

This article was previously published under Q119872

SYMPTOMS

Assembling a line of code that performs indexed addressing, such as the following:

mov dx,mylabel-2[bx]

produces the following error:

error A2032: invalid use of register

The same line of code assembles without error under MASM version 5.1.

CAUSE

The index operator '[]' is now at the very top of the MASM operator precedence list, while the binary "+" and "-" operators are in the lower half. So, for example, if the expression

2 - 3[bx]

is no longer equivalent to

2 - 3 + bx

but rather to

2 - (3 + bx) ; or 2 - 3 - bx

then it is the "- bx" that is causing the A2032 error.

RESOLUTION

Assemble using the OPTION M510 directive, the /Zm switch (which implies the OPTION M510), or use one of the following syntaxes:

mov dx, (mylabel-2)[bx]
mov dx, mylabel-2+[bx]
mov dx, mylabel[bx]-2

NOTE: The OPTION M510 is used for compilation with maximum MASM version 5.10 compatibility.

Modification Type:	Minor	Last Reviewed:	2/11/2004
Keywords:	KB119872