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PO(Bitwise Logic) What does AND'ing something with 0x7F accomplish?
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2013-03-13T19:15:16.290
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2013-03-13T19:54:11.127
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I'm trying to understand a program that I have disassembled. I'm understanding it so far. However, I do not understand why the program is AND'ing an integer with 0x7F. It also likes to AND an integer with 0xFF. The program is somewhat of a random number generator. What does this accomplish? I think AND'ing with 0xFF takes the lower byte (of a register) and discards the rest? Specifically in MIPS ASM: <pre><code>## r2 = 0xfd r3 = 0x10 ## andi r2,r2,0x00ff # What? Why? andi r3,r3,0x007f # What? Why? </code></pre>
Tags
<bit-manipulation><bitwise-and>
Title
(Bitwise Logic) What does AND'ing something with 0x7F accomplish?
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