Are there any programming languages which change the data layout beyond naively sorting struct members by alignment? (which at best helps with reducing padding bytes but can be either good or bad for performance, depending on the code which accesses the data).
replyOne simple optimization is to change arrays of struts into struts of arrays. To my knowledge, nothing even makes those changes, despite them being safe and having a huge potential performance benefit.
replyNow that you mention it... :)
replyZig has MultiArrayList in the stdlib which does the SoA transform via comptime:
https://ziglang.org/documentation/master/std/#std.multi_arra...
Zig also sorts struct members by size/alignment, but has two escape hatches ('extern struct' which is for C compatibility, and 'packed struct' which offers an explicit bit-by-bit memory layout).
AFAIK Odin and Jai offer the SoA transform as specialized language features, e.g. in Odin:
https://odin-lang.org/docs/overview/#soa-data-types
I'd still always want such data layout transforms as an explicit language feature though, not the compiler making this decision for me.
Halide comes to mind (though it a DSL and not a full independent language).
replyI wonder if Futhark does? Eg https://futhark-lang.org/student-projects/pedersen-nelin-msc...
various SQLs and APLs come to mind :) the industry still has a lot to learn from them both
replyFORTRAN is used for a lot of numerical algorithms - today! installed on your computer right now in some library! - because it optimizes better than C because it doesn't have pointers.
replyAs I understand it most of the difference can be made up by adding the restrict qualifier to everything in C.
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