2 docs tagged with "code-size"

Raising the optimization level is the one build change that routinely alters what a firmware does. Not what it does more quickly — what it does. A delay loop disappears. A register write that was there at -O0 is gone at -O2. Code that worked for two years starts failing, and nothing in the source changed.

Every firmware project reaches the same afternoon. The build that fitted last week does not fit this week, or it fits but the RAM figure has doubled, and nobody changed anything that should have cost 12 KB. The instinct is to start deleting features. The correct move is to ask the toolchain, which has known the answer the whole time and wrote it down.