dest = source
The movaps instruction moves 4 single precision floating point values (32 bits each) from the source value (second operand) to the destination. The source and the destination can be an XMM register or a memory location. You can not use 2 memory addresses. The vmovaps instruction allows moving 8 floats between YMM registers and memory.
This version requires that any memory address used be aligned on a 16 byte boundary (bits 0:3 all 0). Using an unaligned address generates a general protection fault. In the original designs movaps was faster than than movups (move unaligned). When in doubt use movups instead.
movaps moves the values without inspection or conversion.
An XMM register is 128 bits total, while CPUs supporting AVX instructions have an additional 128 bits in each register accessible as YMM registers.
movaps xmm1, xmm2 ; moves 4 floats from xmm2 to xmm1 ; leaves the rest of xmm1 unchanged movaps xmm2, [x] ; moves 4 floats from variable x to xmm2 ; leaves the rest of xmm2 alone movaps [y], xmm0 ; moves 4 floats from xmm0 to variable y ; moves precisely 128 bits vmovaps xmm1, xmm2 ; moves 4 floats from xmm2 to xmm1 ; leaves the rest of xmm1 unchanged vmovaps ymm1, ymm2 ; moves 8 floats from ymm2 to ymm1 vmovaps ymm2, [x] ; moves 8 floats from variable x to ymm2 vmovaps [y], ymm0 ; moves 8 floats from ymm0 to variable y