[llvm] [LTO] Introduce getSourceModules (NFC) (PR #105955)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata updated https://github.com/llvm/llvm-project/pull/105955

>From 5ed04b7769024d4581dfccf010af2fdb3761609f Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 24 Aug 2024 11:35:20 -0700
Subject: [PATCH 1/2] [LTO] Introduce getSourceModules (NFC)

This patch introduces getSourceModules to compute the list of source
modules in the ascending alphabetical order.  The new function is
intended to hide implementation details of ImportMapTy while
simplifying FunctionImporter::importFunctions a little bit.
---
 .../llvm/Transforms/IPO/FunctionImport.h       |  4 ++++
 llvm/lib/Transforms/IPO/FunctionImport.cpp     | 18 ++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/llvm/include/llvm/Transforms/IPO/FunctionImport.h b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
index 93d831c26938bb..b5b969220df85b 100644
--- a/llvm/include/llvm/Transforms/IPO/FunctionImport.h
+++ b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
@@ -139,6 +139,10 @@ class FunctionImporter {
         maybeAddDeclaration(FromModule, GUID);
     }
 
+    // Return the list of source modules sorted in the ascending alphabetical
+    // order.
+    SmallVector<StringRef, 0> getSourceModules() const;
+
     const ImportMapTyImpl &getImportMap() const { return ImportMap; }
 
   private:
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 74a71cbf101b5d..cc70d5ceb81bfc 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -352,6 +352,16 @@ void FunctionImporter::ImportMapTy::maybeAddDeclaration(
   ImportMap[FromModule].try_emplace(GUID, GlobalValueSummary::Declaration);
 }
 
+SmallVector<StringRef, 0>
+FunctionImporter::ImportMapTy::getSourceModules() const {
+  SetVector<StringRef> ModuleSet;
+  for (const auto &[SrcMod, GUID] : ImportMap)
+    ModuleSet.insert(SrcMod);
+  SmallVector<StringRef, 0> Modules = ModuleSet.takeVector();
+  llvm::sort(Modules);
+  return Modules;
+}
+
 /// Import globals referenced by a function or other globals that are being
 /// imported, if importing such global is possible.
 class GlobalsImporter final {
@@ -1770,11 +1780,6 @@ Expected<bool> FunctionImporter::importFunctions(
   unsigned ImportedCount = 0, ImportedGVCount = 0;
 
   IRMover Mover(DestModule);
-  // Do the actual import of functions now, one Module at a time
-  std::set<StringRef> ModuleNameOrderedList;
-  for (const auto &FunctionsToImportPerModule : ImportList.getImportMap()) {
-    ModuleNameOrderedList.insert(FunctionsToImportPerModule.first);
-  }
 
   auto getImportType = [&](const FunctionsToImportTy &GUIDToImportType,
                            GlobalValue::GUID GUID)
@@ -1785,7 +1790,8 @@ Expected<bool> FunctionImporter::importFunctions(
     return Iter->second;
   };
 
-  for (const auto &Name : ModuleNameOrderedList) {
+  // Do the actual import of functions now, one Module at a time
+  for (const auto &Name : ImportList.getSourceModules()) {
     // Get the module for the import
     const auto &FunctionsToImportPerModule =
         ImportList.getImportMap().find(Name);

>From f454406bfb2c5fa2cc77ce4c7b9d535a6fbaba34 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Mon, 26 Aug 2024 09:12:29 -0700
Subject: [PATCH 2/2] Use SmallVector instead of SetVector.

---
 llvm/lib/Transforms/IPO/FunctionImport.cpp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index cc70d5ceb81bfc..dd01d143b066b9 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -354,10 +354,7 @@ void FunctionImporter::ImportMapTy::maybeAddDeclaration(
 
 SmallVector<StringRef, 0>
 FunctionImporter::ImportMapTy::getSourceModules() const {
-  SetVector<StringRef> ModuleSet;
-  for (const auto &[SrcMod, GUID] : ImportMap)
-    ModuleSet.insert(SrcMod);
-  SmallVector<StringRef, 0> Modules = ModuleSet.takeVector();
+  SmallVector<StringRef, 0> Modules(make_first_range(ImportMap));
   llvm::sort(Modules);
   return Modules;
 }