[ThinLTO] Add optional import message and statistics
Summary:
Add a statistic to count the number of imported functions. Also, add a
new -print-imports option to emit a trace of imported functions, that
works even for an NDEBUG build.
Note that emitOptimizationRemark does not work for the above printing as
it expects a Function object and DebugLoc, neither of which we have
with summary-based importing.
This is part 2 of D18487, the first part was committed separately as
r264536.
Reviewers: joker.eph
Subscribers: llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D18487
llvm-svn: 264537
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 896ac5d..a99739c 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -14,6 +14,7 @@
#include "llvm/Transforms/IPO/FunctionImport.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/DiagnosticPrinter.h"
@@ -31,6 +32,8 @@
using namespace llvm;
+STATISTIC(NumImported, "Number of functions imported");
+
/// Limit on instruction count of imported functions.
static cl::opt<unsigned> ImportInstrLimit(
"import-instr-limit", cl::init(100), cl::Hidden, cl::value_desc("N"),
@@ -43,6 +46,9 @@
"`import-instr-limit` threshold by this factor "
"before processing newly imported functions"));
+static cl::opt<bool> PrintImports("print-imports", cl::init(false), cl::Hidden,
+ cl::desc("Print imported functions"));
+
// Load lazily a module from \p FileName in \p Context.
static std::unique_ptr<Module> loadFile(const std::string &FileName,
LLVMContext &Context) {
@@ -348,6 +354,12 @@
if (renameModuleForThinLTO(*SrcModule, Index, &GlobalsToImport))
return true;
+ if (PrintImports) {
+ for (const auto *GV : GlobalsToImport)
+ dbgs() << DestModule.getSourceFileName() << ": Import " << GV->getName()
+ << " from " << SrcModule->getSourceFileName() << "\n";
+ }
+
if (TheLinker.linkInModule(std::move(SrcModule), Linker::Flags::None,
&GlobalsToImport))
report_fatal_error("Function Import: link error");
@@ -355,6 +367,8 @@
ImportedCount += GlobalsToImport.size();
}
+ NumImported += ImportedCount;
+
DEBUG(dbgs() << "Imported " << ImportedCount << " functions for Module "
<< DestModule.getModuleIdentifier() << "\n");
return ImportedCount;