It's 2016 and COMPILERS ARE STILL STUPID

Just analysing a device driver for hardware few months old... as usual, it's as bloated as a week-old dead pig overall but then I come across pieces like this:

shl ecx, 4
mov edx, ecx
shr ecx, 2
xor eax, eax
rep stosd
mov ecx, edx
and ecx, 3
rep stosb

:facepalm:

>>87,88
The two pieces of code aren't equivalent since d, s and t can overlap; the SIMD code would be wrong for add4. This is why languages that require you to break down every operation on arrays into detailed loops are stupid by the way.