From 0ea9950ede4dd5257776b126361c93f28b556eec Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Fri, 21 Jul 2023 08:58:08 +1000 Subject: [PATCH] Document `-Zno-parallel-llvm`. Because it's usefulness wasn't clear to me, and I initially wondered if it could be removed. The text is based on the text in #50972, the PR that added the flag. --- .../unstable-book/src/compiler-flags/no-parallel-llvm.md | 8 ++++++++ 1 file changed, 8 insertions(+) create mode 100644 src/doc/unstable-book/src/compiler-flags/no-parallel-llvm.md diff --git a/src/doc/unstable-book/src/compiler-flags/no-parallel-llvm.md b/src/doc/unstable-book/src/compiler-flags/no-parallel-llvm.md new file mode 100644 index 00000000000..f19ba16b6f7 --- /dev/null +++ b/src/doc/unstable-book/src/compiler-flags/no-parallel-llvm.md @@ -0,0 +1,8 @@ +# `no-parallel-llvm` + +--------------------- + +This flag disables parallelization of codegen and linking, while otherwise preserving +behavior with regard to codegen units and LTO. + +This flag is not useful for regular users, but it can be useful for debugging the backend. Codegen issues commonly only manifest under specific circumstances, e.g. if multiple codegen units are used and ThinLTO is enabled. Serialization of these threaded configurations makes the use of LLVM debugging facilities easier, by avoiding the interleaving of output.