ARM base instruction -- csetm

Conditional Set Mask sets all bits of the destination register to 1 if the condition is TRUE, and otherwise sets all bits to 0.

如果条件为TRUE，则条件设置掩码将目标寄存器的所有位设置为1，否则将所有位设为0。

32-bit variant
    Applies when sf == 0.
    CSETM <Wd>, <cond>

64-bit variant
    Applies when sf == 1.
    CSETM <Xd>, <cond>

  411c64:    f100001f     cmp    x0, #0x0
  411c68:    a94363f7     ldp    x23, x24, [sp, #48]
  411c6c:    f900b680     str    x0, [x20, #360]
  411c70:    5a9f13e0     csetm    w0, eq  // if (x0 == 0x0) w0=0xffffffff, else w0 = 0