DOCUMENT:Q38027 23-JAN-2002 [visualc] TITLE :INFO: Negative Values Use Two's Complement PRODUCT :Microsoft C Compiler PROD/VER:MS-DOS:6.0,6.00a,6.00ax,7.0; OS/2:6.0,6.00a; WINDOWS:1.0,1.5; WINDOWS:1.0,2.0,4.0,5.0 OPER/SYS: KEYWORDS:kbCompiler kbVC kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - The C/C++ Compiler (CL.EXE), included with: - Microsoft C for MS-DOS, versions 6.0, 6.0a, 6.0ax - Microsoft C for OS/2, versions 6.0, 6.0a - Microsoft C/C++ for MS-DOS, version 7.0 - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5 - Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 4.0, 5.0, 6.0 ------------------------------------------------------------------------------- SUMMARY ======= In most C compilers, including the Microsoft C Compiler, negative values are represented internally in two's complement format. Two's complement can be obtained by negating each bit of the value, then adding 1. Performing two's complement twice generates the original value. The following is an example: Original Value Two's Complement -------------- ---------------- (dec) (hex) (binary) (dec) (hex) (binary) 127 0x7f 01111111 -127 0x81 10000001 111 0x6f 01101111 -111 0x91 10010001 -111 0x91 10010001 111 0x6f 01101111 Additional query words: 8.00 8.00c 9.00 ====================================================================== Keywords : kbCompiler kbVC kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 Technology : kbVCsearch kbAudDeveloper kbCVCComp Version : MS-DOS:6.0,6.00a,6.00ax,7.0; OS/2:6.0,6.00a; WINDOWS:1.0,1.5; WINDOWS:1.0,2.0,4.0,5.0 Issue type : kbinfo ============================================================================= 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 2002.