Operation

IF (instruction = MOVSD) OR (instruction has doubleword operands)
THEN OperandSize  32;
ELSE OperandSize  16;
IF AddressSize = 16
THEN use SI for source-index and DI for destination-index;
ELSE (* AddressSize = 32 *)
use ESI for source-index and EDI for destination-index;
FI;
IF byte type of instruction
THEN
[destination-index]  [source-index]; (* byte assignment *)
IF DF = 0 THEN IncDec  1 ELSE IncDec  -1; FI;
ELSE
IF OperandSize = 16
THEN
[destination-index]  [source-index]; (* word assignment *)
IF DF = 0 THEN IncDec  2 ELSE IncDec  -2; FI;
ELSE (* OperandSize = 32 *)
[destination-index]  [source-index]; (* doubleword assignment *)
IF DF = 0 THEN IncDec  4 ELSE IncDec  -4; FI;
FI;
FI;
source-index  source-index + IncDec;
destination-index  destination-index + IncDec;

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