RBIT

Reverse bits

This instruction reverses the bit order in a register.

Encoding: Integer

313029282726252423222120191817161514131211109876543210
101101011000000000000
sfSopcode2opcodeRnRd

32-bit (sf == 0)

RBIT <Wd>, <Wn>

64-bit (sf == 1)

RBIT <Xd>, <Xn>

Decoding algorithm

constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer datasize = 32 << UInt(sf);

Operation

constant bits(datasize) operand = X[n, datasize];
bits(datasize) result;

for i = 0 to datasize-1
    result<(datasize-1)-i> = operand;

X[d, datasize] = result;

Explanations

<Wd>: Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Wn>: Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field.
<Xd>: Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Xn>: Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field.

Operational Notes

If PSTATE.DIT is 1: