Article ID: 39373
Article Last Modified on 10/22/2003
APPLIES TO
- Microsoft Macro Assembler 5.1 Standard Edition
This article was previously published under Q39373
SYMPTOMS
The code below is correctly flagged as an error in the Microsoft Macro Assembler (MASM) versions 5.0, 6.0, 6.0a, 6.0b, but MASM 5.1 generates a warning and incorrect code.
The following is the error generated by MASM 5.0
Macro Assembler Version 5.1 fails to generate an error on the MOV instruction using the 8-bit registers (AH, BH, CH, DH, AL, BL, CL, DL) with segment registers (CS, DS, ES, SS). Instead, the following warning is generated
The code generated is also in error. Each of the (8-bit) byte registers maps to the set (SP, DI, BP, SI, AX, BX, CX, DX).
The following is the error generated by MASM 6.0
STATUS
Microsoft has confirmed this to be a problem in MASM version 5.1. This problem was corrected in MASM version 6.0.
MORE INFORMATION
The following sample code demonstrates the problem:
Sample Code:
;Assemble options needed: none
_TEXT segment word public 'CODE'
; instruction in source Generated code shown in listing
mov ds, ah ; mov ds, sp
mov ds, bh ; mov ds, di
mov ds, ch ; mov ds, bp
mov ds, dh ; mov ds, si
mov ds, al ; mov ds, ax
mov ds, bl ; mov ds, bx
mov ds, cl ; mov ds, cx
mov ds, dl ; mov ds, dx
mov ah, 4ch
int 21h
_TEXT ends
end
Additional query words: 5.10 buglist5.10 fixlist6.00
Keywords: kbfix KB39373
