[llvm] [DTLTO][LLVM] Integrated Distributed ThinLTO (DTLTO) (PR #127749)

[Teresa Johnson via llvm-commits]

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@@ -2142,3 +2196,324 @@ std::vector<int> lto::generateModulesOrdering(ArrayRef<BitcodeModule *> R) {
   });
   return ModulesOrdering;
 }
+
+namespace {
+// For this out-of-process backend no codegen is done when invoked for each
+// task. Instead we generate the required information (e.g. the summary index
+// shard, import list, etc..) to allow for the codegen to be performed
+// externally . This backend's `wait` function then invokes an external
+// distributor process to do backend compilations.
+class OutOfProcessThinBackend : public CGThinBackend {
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teresajohnson wrote:

In practice, how much does this share with the original InProcessThinBackend? I am wondering if the approach of having them derive from the same refactored CGThinBackend is useful.

https://github.com/llvm/llvm-project/pull/127749