On Sep 16, 2018, at 5:59 PM, Filip Pizlo <fpizlo@apple.com> wrote:

Which offline assembler build step are you referring to?

The one that is the “Offline Assembler” target in Xcode, which runs this command:

ruby JavaScriptCore/offlineasm/asm.rb JavaScriptCore/llint/LowLevelInterpreter.asm "${BUILT_PRODUCTS_DIR}/JSCLLIntOffsetsExtractor” LLIntAssembly.h

For a “nothing rebuild” of all of WebKit and all of Safari for iOS on my iMac, it takes about 10 seconds out of a 30 second total “build" time.

Looking more carefully at the build log now, it seems that recompiling LLIntOffsetExtractor.cpp is also taking multiple seconds. Not executing generate_offset_extractor.rb, but compiling the output.

— Darin