Hello. I'm compiling C software for an embedded ARM system with -mcpu=cortex-a8 Currently my build system uses GCC version 12.2.1. I've been investigating the effects of -falign-functions=n:m "Align the start of functions to the next power-of-two greater than or equal to n, skipping up to m-1 bytes." I've set n=64 and I'm trying different values for m... -falign-functions=64:5 -falign-functions=64:6 -falign-functions=64:7 -falign-functions=64:8 etc. m=5,6,7,8 all give similar output. The same for m=9,10,11,12. This is what I'd expect since all ARM32 instructions are 4 bytes long, so would be aligned at a minimum on 4-byte boundaries. However I'm confused by m=1,2,3,4. m=1 gives a very different result to 2,3,4 (and in my case performance is considerably worse for m=1). What is -falign-functions=64:1 doing here? Also, what does it even mean when m=2, 3 or 4? If instructions are 4 bytes long, then I thought this wouldn't actually be doing any alignment. But it gives a different result to specifying -fno-align-functions, so presumably there is something I'm misunderstanding? Thanks in advance for your help, Tim
