| Not a knock on LLVM. The conditions are just different. There is no software that is 100% great at every single thing - that's why Windows embedded CE failed while iOS and Android thrived on phone and mobile devices. VxWorks is great at driving martian rovers, but would be horrible at running Adobe Photoshop or Maya. Why does everything either need to be a snub or a boon? LLVM is great at generating compiled binaries - it just takes resources (time + memory) to do so - in practical terms, the compilation time only affects the programmers and developers running multiple compiles over a work day, working on the codebase itself. For consumers who are running the programs, LLVM makes great optimized binaries. In a JS engine, the compiler doesn't have access to the source code until a user loads up the page, so it's in essence doing "compilation" on the spot. And in this case compilation memory and time usage matters. Swift itself is a "compiled" lanugage - meaning that in development, a developer needs to hit that "compile" button in XCode to generate a binary file which is then distributed and run. In this case, LLVM can use all cores on that big honking Mac Pro or shiny MacBook Pro 15" retina all it wants - take all 16 cpus and 32 gigs of ram and crank it and make a nice binary that comes out optimized to run on a iPad Air. Of course things like Java conflates the two styles (source code compiled to bytecode and then to run on the JVM) - but in the Java ecosystem there are significant optimizations in both the compile phase (ie javac helloworld.java) as well as ahead of time compilation in the JVM itself. |