例えば 5 倍の書き方

  4b 8d 34 9b             lea    (%r11,%r11,4),%rsi

=> r11 + r11*4

lea == load effective address

• REX: 0x4b == 0100_1_0_1_1
• lea: 0x8d
• Mod R/M: 0x34 == 00_110_100 (110=RSI, 100=SIB)
• SIB: 0x9b == 10_011_011 (scale=10, 011=R11)