[PATCH] D76916: [Darwin] Respect -fno-unroll-loops during LTO.

[Duncan P. N. Exon Smith via Phabricator via llvm-commits]

dexonsmith added a subscriber: Florian.
dexonsmith added a comment.

@fhahn, please revert, this isn't how we usually pass options in LTO.

If this is something we expect developers to use, it should be specifiable on a per-TU basis.  The way we do this is by specifying it during compilation, attaching string-based function attributes, and checking that attribute at the beginning of the "unroll loop" pass to see whether to skip it for that function.



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Comment at: clang/lib/Driver/ToolChains/Darwin.cpp:546-551
+  // Forward -fno-unroll-loops to the linker in LTO.
+  if (Args.hasArg(options::OPT_fno_unroll_loops)) {
+    CmdArgs.push_back("-mllvm");
+    CmdArgs.push_back(Args.MakeArgString("-lto-no-unroll-loops"));
+  }
+
----------------
I don't understand why we need driver support for this... is this something we expect users to do?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D76916/new/

https://reviews.llvm.org/D76916