AMD: Avoid stubs in favor of object libraries. #875
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Avoid the stub files that were used to build objects for the int64_t interface. Instead, use object libraries that build the same source files once with `DLONG` and once without it. This also avoids building all objects twice (for the shared and the static library), effectively reducing the build time approximately by a factor of two.
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I used this strategy long ago, before I had a cmake build system. Just Makefiles. However, I found it confusing. Where is the function amd_l_defaults ( ... ) defined? It was hard to find. Now it's simple: just look at Source/amd_l_defaults.c. Yes, that's just a simple 'C template' wrapped around amd_defaults.c, but you can find amd_l_defaults by just looking for the file of the same name, just add the ".c". I had a hard time navigating my own code in this old system, and so did others. So when I went to a cmake build system, I changed my codes to use this new mechanism. Yes, it might cut the build time in half for packages like AMD, COLAMD, UMFPACK, and CHOLMOD, but it makes the code easier (for me) to navigate, and that's more important. I don't use this strategy for my largest code, GraphBLAS, which takes the longest to compile, because that package doesn't have so many variants with different names (there is a single GrB_mxm for all matrices and all data types and all semirings, regardless of what they are). So it only impacts codes that compile pretty quickly anyway. So, while it does cut the build time, and I do appreciate the input, but I'd rather stick with the current code structure. |
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Thank you for the feedback and explaining your thought process. My original motivation for this PR was to remove the stub files. But I understand your motivation for preferring to keep them. I'll close this PR and potentially open a new one with the "side effect" only (if that works)... |
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That was simpler than I expected. See #876. |
Avoid the stub files that were used to build objects for the int64_t interface. Instead, use object libraries that build the same source files once with
DLONGand once without it.This also avoids building all objects twice (for the shared and the static library), effectively reducing the build time approximately by a factor of two.
Something similar could probably be done for most of the SuiteSparse libraries. So, build time could probably be reduced by a lot (when building shared and static libraries).
@DrTimothyAldenDavis: Please, let me know if this is acceptable and I can try to look into that.