[Chapel Merge] Adjust LLVM pass configuration to better match cla

Branch: refs/heads/main
Revision: 23edaa8
Author: mppf
Log Message:

Merge pull request #18324 from mppf/llvm-config-clang

Adjust LLVM pass configuration to better match clang

In looking at some LLVM performance details it occurred to me to compare
how we set up the LLVM optimizations and how clang does it. This PR
updates our code to better match clang. (Where if we discover cases we
should be doing something different we certainly can). So far I have not
noticed any performance impact from this change. However I would expect
that this PR allows for more clang command line options (from --ccflags
arguments) to work correctly.

  • [x] full local testing
  • [x] full local --fast testing
  • [x] perf playground -- no significant performance change

Reviewed by @daviditen - thanks!

Modified Files:
M compiler/llvm/clangUtil.cpp

Compare: https://github.com/chapel-lang/chapel/compare/8741da415940...23edaa889a07