[PATCH] D94643: [llvm-link] Improve link time for bitcode archives [NFC]

[Sergey Dmitriev via Phabricator via llvm-commits]

sdmitriev created this revision.
sdmitriev added reviewers: tra, jdoerfert, RaviNarayanaswamy.
sdmitriev requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Linking large bitcode archives currently takes a lot of time with llvm-link,
this patch adds couple improvements which reduce link time for archives

- Use one Linker instance for archive instead of recreating it for each member
- Lazy load archive members


https://reviews.llvm.org/D94643

Files:
  llvm/tools/llvm-link/llvm-link.cpp


Index: llvm/tools/llvm-link/llvm-link.cpp
===================================================================
--- llvm/tools/llvm-link/llvm-link.cpp
+++ llvm/tools/llvm-link/llvm-link.cpp
@@ -146,6 +146,7 @@
                                           std::unique_ptr<MemoryBuffer> Buffer,
                                           LLVMContext &Context) {
   std::unique_ptr<Module> Result(new Module("ArchiveModule", Context));
+  Linker L(*Result);
   StringRef ArchiveName = Buffer->getBufferIdentifier();
   if (Verbose)
     errs() << "Reading library archive file '" << ArchiveName
@@ -186,7 +187,12 @@
       return nullptr;
     }
 
-    std::unique_ptr<Module> M = parseIR(MemBuf.get(), ParseErr, Context);
+    std::unique_ptr<Module> M;
+    if (DisableLazyLoad)
+      M = parseIR(MemBuf.get(), ParseErr, Context);
+    else
+      M = getLazyIRModule(MemoryBuffer::getMemBuffer(MemBuf.get(), false),
+                          ParseErr, Context);
 
     if (!M.get()) {
       errs() << Argv0 << ": ";
@@ -197,7 +203,7 @@
     }
     if (Verbose)
       errs() << "Linking member '" << ChildName << "' of archive library.\n";
-    if (Linker::linkModules(*Result, std::move(M)))
+    if (L.linkInModule(std::move(M)))
       return nullptr;
   } // end for each child
   ExitOnErr(std::move(Err));


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