devtools-docs

ictable. Now you might suggest that a "sufficiently advanced compiler" wouldn't do that, but such a thing is a fiction. In practice, the compiler is never sufficiently advanced to optimize in all cases effectively. --- Consider Javascript, where exactly the same thing happens. Your definition of a "high level language" may not include JS, but it's hard to argue it's not higher than ASM. Modern day JS engines do a pretty good job of optimizing code JIT. However, you make some innocuous code change and suddenly your function is running in the interpreter instead of being optimized (see https://github.com/GoogleChrome/devtools-docs/issues/53 for examples) If you were using a lower-level language, your chances of falling off mysterious performance cliffs is significantly reduced. Further, you have the capacity to do low level optimizations that your compiler literally cannot do. So what if your high level language can now do parallel-maps, if it ignores cache thrashing, or hits load-hit-stores or any one of myriad actual performance holes that real code can fall into? Or you add a field to the objects you're iterating over and the parallel map implementation hits a weird memory stride and perf drops through the floor. How do you even debug something like this in a high level language where all you see is "map()"? --- I also think your compiling-ASM-to-JS example is a bit of a strawman, FWIW. The parent was talking about how high-level languages yield higher performance than lower-level ones, not about the portability or transpilability of ASM->JS. (A "suitably advanced transpiler" would handle this problem perfectly anyway)