From 6af531febe488adb655c7e3de96c7c6bd6536eac Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Thu, 10 Mar 2011 00:21:25 +0000
Subject: Introduce DebugInfoProbe. This is used to monitor how llvm optimizer
 is treating debugging information. It generates output that lools like

8 times line number info lost by Scalar Replacement of Aggregates (SSAUp)
1 times line number info lost by Simplify well-known library calls
12 times variable info lost by Jump Threading



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127381 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/LoopPass.cpp | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

(limited to 'lib/Analysis/LoopPass.cpp')

diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp
index 8e1a7bfef6..10e3f297f9 100644
--- a/lib/Analysis/LoopPass.cpp
+++ b/lib/Analysis/LoopPass.cpp
@@ -14,8 +14,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/LoopPass.h"
+#include "llvm/DebugInfoProbe.h"
 #include "llvm/Assembly/PrintModulePass.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Timer.h"
 using namespace llvm;
 
@@ -51,6 +53,20 @@ public:
 char PrintLoopPass::ID = 0;
 }
 
+//===----------------------------------------------------------------------===//
+// DebugInfoProbe
+
+static DebugInfoProbeInfo *TheDebugProbe;
+static void createDebugInfoProbe() {
+  if (TheDebugProbe) return;
+      
+  // Constructed the first time this is called. This guarantees that the 
+  // object will be constructed, if -enable-debug-info-probe is set, 
+  // before static globals, thus it will be destroyed before them.
+  static ManagedStatic<DebugInfoProbeInfo> DIP;
+  TheDebugProbe = &*DIP;
+}
+
 //===----------------------------------------------------------------------===//
 // LPPassManager
 //
@@ -223,6 +239,7 @@ void LPPassManager::getAnalysisUsage(AnalysisUsage &Info) const {
 bool LPPassManager::runOnFunction(Function &F) {
   LI = &getAnalysis<LoopInfo>();
   bool Changed = false;
+  createDebugInfoProbe();
 
   // Collect inherited analysis from Module level pass manager.
   populateInheritedAnalysis(TPM->activeStack);
@@ -254,19 +271,21 @@ bool LPPassManager::runOnFunction(Function &F) {
     // Run all passes on the current Loop.
     for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {  
       LoopPass *P = getContainedPass(Index);
-
       dumpPassInfo(P, EXECUTION_MSG, ON_LOOP_MSG,
                    CurrentLoop->getHeader()->getName());
       dumpRequiredSet(P);
 
       initializeAnalysisImpl(P);
-
+      if (TheDebugProbe)
+        TheDebugProbe->initialize(P, F);
       {
         PassManagerPrettyStackEntry X(P, *CurrentLoop->getHeader());
         TimeRegion PassTimer(getPassTimer(P));
 
         Changed |= P->runOnLoop(CurrentLoop, *this);
       }
+      if (TheDebugProbe)
+        TheDebugProbe->finalize(P, F);
 
       if (Changed)
         dumpPassInfo(P, MODIFICATION_MSG, ON_LOOP_MSG,
-- 
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