Online HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens
IMUL - Signed Multiply
Usage: IMUL src
IMUL src,immed (286+ only)
IMUL dest,src,immed8 (286+ only)
IMUL dest,src (386+ only)
Modifies flags: CF OF (AF,PF,SF,ZF undefined)
Signed multiplication of accumulator by "src" with result placed
in the accumulator. If the source operand is a byte value, it
is multiplied by AL and the result stored in AX. If the source
operand is a word value it is multiplied by AX and the result is
stored in DX:AX. Other variations of this instruction allow
specification of source and destination registers as well as a
third immediate factor.
Clocks Size
Operands 808x 286 386 486 Bytes
reg8 80-98 13 9-14 13-18 2
reg16 128-154 21 9-22 13-26 2
reg32 - - 9-38 12-42 2
mem8 86-104 16 12-17 13-18 2-4
mem16 134-160 24 12-25 13-26 2-4
mem32 - - 12-41 13-42 2-4
reg16,reg16 - - 9-22 13-26 3-5
reg32,reg32 - - 9-38 13-42 3-5
reg16,mem16 - - 12-25 13-26 3-5
reg32,mem32 - - 12-41 13-42 3-5
reg16,immed - 21 9-22 13-26 3
reg32,immed - 21 9-38 13-42 3-6
reg16,reg16,immed - 2 9-22 13-26 3-6
reg32,reg32,immed - 21 9-38 13-42 3-6
reg16,mem16,immed - 24 12-25 13-26 3-6
reg32,mem32,immed - 24 12-41 13-42 3-6
- see Instruction Timing
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