A friend recently asked me for “the sim­plest opti­miza­tion prob­lem I could think of”. This led to a fun dis­cus­sion of low-level opti­miza­tion and how the CPU exe­cutes your code. And so I decided to share it here. (more…)

Ouch. These last few days, I’ve been fix­ing a few lin­ger­ing bugs in my STM sys­tem, and last night, I finally nailed them. Specif­i­cally, it is now pos­si­ble to open vari­ables within a trans­ac­tion as read-only. An obvi­ous opti­miza­tion, right? At least that’s the idea. Less work is required by the STM sys­tem if we can trust that the vari­able isn’t mod­i­fied by this trans­ac­tion. (more…)