actually, it wasn't a bug; the compiler just optimized a statement away until it was declared volatile. inserting a no-op assembler instruction to make it more obvious what's going on
========================= EFM32-TG-STK3300 Examples ========================= Examples in this directory are designed to be run on the Energy Micro EFM32 Tiny Gecko Starter Kit, which is based on the EFM32TG840F32 MCU, has an onboard USB debug and power management interface, and a bunch of peripherials built in that demonstrate the chip's low power capabilities (LED, LCD display, light sensor, touch slider, LC sensor, push buttons).