On: Make LLVM Fast Again

[jeffbee]

Pretty cool improvements. For any large project profiling it, making it faster, and preventing or reverting regressions can be a full-time job. Perhaps LLVM project needs such a person in such a role. Still, I question the utility of timing optimized builds. Usually when I have to wait for the compiler it's an incremental fastbuild to execute unit tests. Optimized builds usually happen while I'm busy doing something else.

[tbodt → jeffbee]

The problem with that is LLVM non-optimized codegen is so bad that many projects build with -O2 even in debug mode.

[jeffbee → tbodt]

Really? It's good enough that Google used clang for fastbuild (tests) for many years before switching release builds off GCC.