On Thu, Sep 08, 2016 at 09:43:53AM -0700, Stephane Eranian wrote: > I like the idea and yes, branch stack can be used for this, but I have > a hard time understanding the colored output.
> What is the explanation for the color changes? In general, or the changes acme made? I can only answer the first. For code: NORMAL <1%, BLUE otherwise, quickly shows you the code in a function that's not ran at all. This quickly eliminated a big chunk of the function I was looking at at the time, since the benchmark in question simply didn't touch most of it. For address: NORMAL <1%, RED > 75%, MAGENTA otherwise. Quickly shows the hottest blocks in a function. The 75% is a random number otherwise. Not sure if we can do better. > How do I interpret the percentages in the comments of the assembly: > -54.50% (p: 42%) -54.50% is 54.40% of the coverage is leaving here, aka 54.40% take this branch. p: 42% mean the branch is predicted 42% of the time. Similarly, +50.46% is a branch target and means that of all the times this instruction gets executed, 50.46% of those joined at this instruction. > Why not have dedicated columns before the assembly with proper column headers? I found it too noisy, you only want to annotate branch instructions and branch targets. Adding columns just adds a whole heap of whitespace (wasted screen-estate) on the left. Something I did want to look at was attempting to align the # comments, but I never did bother. But to each their own I suppose.
