See, for instance: https://github.com/D-Programming-GDC/GDC/pull/217

Though the use of COMPOUND_EXPR  seems to make the matter look worse, it should be investigated why we create so many temporaries (SAVE_EXPRs).

Having a single pass after generating the code is not ideal.  If it is indeed simply COMPOUND_EXPRs with side effects, then we should make all codegen helpers COMPOUND_EXPR-aware.

e.g:

  build_deref(build_nop(type, build_address(expr)));

Should not result in:

  *((TYPE *)&(foo(), bar));

Instead always apply the action to the right-most result.

  (foo(), *(TYPE *)&bar);

This should simplify inspecting expressions in order-sensitive parts, where the question "Do we need a temporary?" in maybe_make_temp could three possible answers - Yes; No; and No, but the left hand side (normally construction) needs to be executed first.

Creating temporaries at every step also blocks bug42.