Hi Richard, > I'm just concerned that here we're using the same explanation but with > different numbers. Why are the new numbers more right than the old ones > (especially when it comes to code size, where the trade-off hasn't > really changed)?
Like all tuning/costing parameters, these values are never fixed but change over time due to optimizations, micro architectures and workloads. The previous values were out of date so that's why I retuned them by benchmarking different values and choosing the best combinations. > It would be good to have more discussion of why certain numbers are > too small or too high, and why 8 is the right pivot point for -Os. You mean add more discussion in the comment? That comment is already overly large and too specific - it would be better to reduce it. The -Os value was never tuned, and 8 turns out to be faster and smaller than GCC's default. Cheers, Wilco
