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mstorsjo / llvm-mingw

An LLVM/Clang/LLD based mingw-w64 toolchain
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Missing Polly? #351

Open ghost opened 1 year ago

ghost commented 1 year ago

libPolly.so does not seem to exist, which prevents Polly optimization from being enabled

mstorsjo commented 1 year ago

Indeed, polly isn't enabled in the builds here.

Overall, the philosophy of llvm-mingw isn't to enable everything that possibly could be useful, but a pragmatic tradeoff between effort/overhead and actual benefit.

For Polly, I'm not familiar with exactly what optimizations it brings and where they would make a difference, while it afaik adds some levels of complexity (including external dependencies) to the build.

ghost commented 1 year ago

Sorry for only replying now. polly needs to manually add CFLAGS to have an effect, so by default polly doesn't have a negative effect. Not sure what external dependencies are generated, Polly should be a built-in LLVM item, same as lld. Currently it is not possible to find any pre-compiled LLVM toolchain with Polly enabled (-DLLVM_POLLY_LINK_INTO_TOOLS=ON), and for that one has to spend hours compiling it, it would be convenient if llvm-mingw would provide Polly.