有符号除法运算

Signed Divide divides a signed integer register value by another signed integer register value, and writes the result to the destination register. The condition flags are not affected.

将一个有符号整数寄存器值除以另一个有符号整数寄存器值，并将结果写入目标寄存器。条件标志不受影响。

32-bit variant
    Applies when sf == 0.
    SDIV <Wd>, <Wn>, <Wm>

64-bit variant
    Applies when sf == 1.
    SDIV <Xd>, <Xn>, <Xm>

  403f14:    b9405a7a     ldr    w26, [x19, #88]
  403f18:    340002fa     cbz    w26, 403f74 <ferror@plt+0x2094>
  403f1c:    52800020     mov    w0, #0x1                       // #1
  403f20:    2a0003fb     mov    w27, w0
  403f24:    0b000800     add    w0, w0, w0, lsl #2
  403f28:    531f7800     lsl    w0, w0, #1
  403f2c:    1ac00f42     sdiv    w2, w26, w0
  403f30:    35ffff82     cbnz    w2, 403f20 <ferror@plt+0x2040>