Microsoft KB Archive/26805

Incorrect Encoding of SAR Instruction ID Number: Q26805

5.00 MS-DOS buglist5.00 fixlist5.00a

Summary:

MASM encodes two similar instructions differently, as follows:

D1 7C 02 SAR word ptr +[si],1

D0 7C 02 SAR word ptr +1*2[si],1

The * operator causes the “word” size to be dropped, but not the sized attribute; as a result, that instruction has bogus byte size instead of the operator.

Microsoft has confirmed this to be a problem in Version 5.00. This problem was corrected in MASM Version 5.00a. Please call Microsoft Product Support Services at (206) 646-5109 and request an update to MASM Version 5.00a.