On: What you get is what you C: Controlling side effects in mainstream C compilers [pdf]

[quacker]

"portable" in the sense that the compiler will produce the proper assembly for the platform - choice of x86, ARM, MIPS, 32/64 bit, etc. Whether the "tricks" behave identically across all platforms depends on the trick, I think.

[pjmlp → quacker]

Usually those tricks are not even portable across compilers on the same platform.

It suffices a change on compiler version with optimizer improvements, or using another vendor's compiler for the tricks to fall apart.

In a gigantic code base, with rotating developers, it becomes a very "fun" thing to debug.

[coldtea → pjmlp]

>Usually those tricks are not even portable across compilers on the same platform.

That's much less of an issue. If it can work on GCC for example or Clang across platforms, you're OK for tons of platforms, even if you can't change compilers intra-platform.