I'm still waiting with interest for someone to pick up the ball and tell why they don't agree with my previous post.
as seen by the rating of your post, maybe you should start a new nthread.

Some architectures will be better to handle one C code construct while another architecture will better handle other constructs.
indeed very true.
HOWEVER, I will consider such, beyond "rules given" (e.g. do not use function pointers with the '51), "advanced C"

But to be able to know what maps well and what maps badly, we just have to be able to read assembler output. Even if not able to write code, we must be able to see the amount of instructions, and recognize which instructions are expensive (such as giving memory access/pipeline stalls or a multi-clockcycle divide) and which large set of assembler instructions that could be reduced to just one or two if the original C code had described the problem in another way potentially removing a C language standard forced requirement for the compiler.
again, "advanced C"

a true professional must have such knowledge, I doubt an amateur needs it beyound the often published 'rules'

The most glaring vioulations of the above are made by "professionals" the simply states "C is C, who cares which processor". this is, more or less, the mantra of university graduates that have not yet understood that the university has very little resemblance to the real world.

I have, on coccasion interviewed PhDs that were far less qualified than other applicants with no formal training.

Erik