Is there a instruction to implement bit reverse??

[yuyang]

or there is a cheap way to implement bit reverse？
current now I only can do this using iteration.

[Craig Topper]

You can use the Zbb rev8 from instruction to swap the bytes and then use shifts, ands, and ors to reverse the bits within each byte. https://godbolt.org/z/5onMsrq7r

Or you can use rev8 and brev8 from Zbkb to reverse bytes and bits within bytes. https://godbolt.org/z/5zh6dbjM7

[yuyang]

ok,thanks you.