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Q38027: INFO: Negative Values Use Two's Complement |
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Article: Q38027
Product(s): Microsoft C Compiler
Version(s): 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
Operating System(s):
Keyword(s): kbCompiler kbVC kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600
Last Modified: 23-JAN-2002
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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
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SUMMARY
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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
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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
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