DOCUMENT:Q26822 06-MAY-2001 [masm] TITLE :FIX: Relational Operators Evaluate to Wrong Value PRODUCT :Microsoft Macro Assembler PROD/VER::5.0,5.1,5.1a OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Macro Assembler (MASM), versions 5.0, 5.1, 5.1a ------------------------------------------------------------------------------- SYMPTOMS ======== When used with a MOV instruction, some relational operators will evaluate to the wrong value. The following listing file sections are examples of this problem. It is important to note that FFFF = true, and 0000 = false. It is also important to note that when FFFFh is used with the GT, GE, or LT, LE operator, it is interpreted as the largest positive number and not as -1. STATUS ====== Microsoft has confirmed this to be a problem in Microsoft Macro Assembler (MASM) version 5.0, 5.1, and 5.1a. This problem was corrected in MASM version 6.0. MORE INFORMATION ================ Sample Code ----------- The following demonstrates this problem with MASM 5.0: .MODEL SMALL 0000 .CODE 0000 B8 0000 MOV AX, 0FFFFH GT -1 0003 B8 FFFF MOV AX, 0FFFFH LE -1 0006 .386 .MODEL SMALL 0000 .CODE 0000 66 | B8 FFFF MOV AX, -1 GE 0FFFFFFFFH 0004 66 | B8 FFFF MOV AX, 0FFFFFFFFH LE -1 0008 66 | B8 0000 MOV AX, 0FFFFFFFFH GT -1 000C 66 | B8 0000 MOV AX, -1 LT 0FFFFFFFFH 0010 END The following demonstrates the problem MASM 5.1: .MODEL SMALL 0000 .CODE 0000 B8 0000 MOV AX, 0FFFFH GT -1 0003 B8 FFFF MOV AX, 0FFFFH LE -1 0006 .386 .MODEL SMALL 0000 .CODE 0000 66 | B8 FFFF MOV AX, -1 GE 0FFFFFFFFH 0004 66 | B8 0000 MOV AX, 0FFFFFFFFH LE -1 0008 66 | B8 FFFF MOV AX, 0FFFFFFFFH GT -1 000C 66 | B8 0000 MOV AX, -1 LT 0FFFFFFFFH 0010 END Additional query words: 5.00 5.10 5.10a buglist5.00 buglist5.10 fixlist6.00 ====================================================================== Keywords : Technology : kbMASMsearch kbAudDeveloper kbMASM510 kbMASM500 kbMASM510a Version : :5.0,5.1,5.1a Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.