This repository provides a reproduction for LTO issue in GNU MCU Eclipse GCC toolchain.

Steps

1. Clone this repository to <Work>/src folder
2. Create directory for build: mkdir <Work>/build
3. Generate CMake build: cd <Work>/build && cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DENABLE_LTO=ON -DTOOLCHAIN=<toolchain_directory>/bin <Work>/src
4. Run build: make app.dump_bin
5. Check size for resulting binary: ls -l <Work>/bin/app/app.bin

Expected Result

app.bin should be around 1600 bytes

Actual Result

app.bin is around 3000 bytes and is binary identical to version without LTO.