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Question about some x86 opcodes (Developers)

posted by mht , Wroclaw, Poland, 22.11.2008, 13:59

By the way:

Am186(TM) and Am188(TM) Family Instruction Set Manual from February 1997 (i.e., after Intel documented the "short" opcodes for 80386) explicitly documents the "short" opcodes on pages 57, 209 and 291:

AND r/m16,imm8   83 /4 ib   AND sign-extended immediate byte with r/m word
OR  r/m16,imm8   83 /1 ib   OR immediate byte with r/m word
XOR r/m16,imm8   83 /6 ib   XOR sign-extended immediate byte with r/m word

Note that the phrase "sign-extended" is missing in the description of OR intruction -- just an omission?

Complete thread:

• Question about some x86 opcodes - mht, 02.11.2008, 14:02 (Developers)
  • Question about some x86 opcodes - Japheth, 02.11.2008, 17:51
  • Question about some x86 opcodes - DOS386, 03.11.2008, 10:04
    • Question about some x86 opcodes - mht, 05.11.2008, 19:54
      • Question about some x86 opcodes - Rugxulo, 06.11.2008, 21:06
        • Question about some x86 opcodes - mht, 08.11.2008, 08:46
          • Question about some x86 opcodes - Rugxulo, 12.11.2008, 00:43
            • Question about some x86 opcodes - mht, 12.11.2008, 16:54
              • Question about some x86 opcodes - mht, 22.11.2008, 13:59