[PATCH] D146352: Introduce `llvm-min-tblgen` to build public header files

Wed Apr 26 09:35:59 PDT 2023

chapuni added a comment.

In D146352#4296422 <https://reviews.llvm.org/D146352#4296422>, @mstorsjo wrote:

> I measured the benefit from this patch in another build case; where I just want to build a small set of executables (for testing compiller-rt) in a new build tree; building tools like `FileCheck` is quite quick in general, but `llvm-config` has got surprisingly large numbers of dependencies. With this patch, the number of build steps to build `llvm-config` drops from 248 to 188, and the total cpu time for compiling it drops from ~11 minutes to ~5 minutes.

I don't guess your background. Does it come from the bottleneck in the full version of `llvm-tblgen`?

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Comment at: llvm/cmake/modules/TableGen.cmake:185
+      add_custom_target(${target}-host DEPENDS ${${project}_TABLEGEN_EXE})
+      set(${project}_TABLEGEN_TARGET ${target}-host PARENT_SCOPE)

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mstorsjo wrote:
> I guess these two lines could be consider a standalone NFC refactoring/cleanup on top of the current code as well?
It is leftover in my attempts.
Would it be better to rewind it? I prefer this.

Repository:
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  https://reviews.llvm.org/D146352/new/

https://reviews.llvm.org/D146352