TRN1

Transpose vectors (primary). This instruction reads corresponding even-numbered vector elements from the two source SIMD&FP registers, starting at zero, places each result into consecutive elements of a vector, and writes the vector to the destination SIMD&FP register. Vector elements from the first source register are placed into even-numbered elements of the destination vector, starting at zero, while vector elements from the second source register are placed into odd-numbered elements of the destination vector.

By using this instruction with TRN2, a 2 x 2 matrix can be transposed.

The following figure shows an example of the operation of TRN1 and TRN2 halfword operations where Q = 0.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size:Q == '110' then UNDEFINED; integer esize = 8 << UInt(size); integer datasize = if Q == '1' then 128 else 64; integer elements = datasize DIV esize; integer part = UInt(op); integer pairs = elements DIV 2;