[llvm-branch-commits] [llvm] 14eea6b - [LegacyPM] Update InversedLastUser on the fly. NFC.

[Jay Foad via llvm-branch-commits]

Author: Jay Foad
Date: 2021-01-22T09:48:54Z
New Revision: 14eea6b0ecddfe7d1c68754a8bfb7c21cde82df8

URL: https://github.com/llvm/llvm-project/commit/14eea6b0ecddfe7d1c68754a8bfb7c21cde82df8
DIFF: https://github.com/llvm/llvm-project/commit/14eea6b0ecddfe7d1c68754a8bfb7c21cde82df8.diff

LOG: [LegacyPM] Update InversedLastUser on the fly. NFC.

This speeds up setLastUser enough to give a 5% to 10% speed up on
trivial invocations of opt and llc, as measured by:

perf stat -r 100 opt -S -o /dev/null -O3 /dev/null
perf stat -r 100 llc -march=amdgcn /dev/null -filetype null

Don't dump last use information unless -debug-pass=Details to avoid
printing lots of spam that will break some existing lit tests. Before
this patch, dumping last use information was broken anyway, because it
used InversedLastUser before it had been populated.

Differential Revision: https://reviews.llvm.org/D92309

Added: 
    

Modified: 
    llvm/include/llvm/IR/LegacyPassManagers.h
    llvm/lib/IR/LegacyPassManager.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/LegacyPassManagers.h b/llvm/include/llvm/IR/LegacyPassManagers.h
index 498e736a0100..f4fae184e428 100644
--- a/llvm/include/llvm/IR/LegacyPassManagers.h
+++ b/llvm/include/llvm/IR/LegacyPassManagers.h
@@ -230,11 +230,11 @@ class PMTopLevelManager {
 
   // Map to keep track of last user of the analysis pass.
   // LastUser->second is the last user of Lastuser->first.
+  // This is kept in sync with InversedLastUser.
   DenseMap<Pass *, Pass *> LastUser;
 
   // Map to keep track of passes that are last used by a pass.
-  // This inverse map is initialized at PM->run() based on
-  // LastUser map.
+  // This is kept in sync with LastUser.
   DenseMap<Pass *, SmallPtrSet<Pass *, 8> > InversedLastUser;
 
   /// Immutable passes are managed by top level manager.

diff  --git a/llvm/lib/IR/LegacyPassManager.cpp b/llvm/lib/IR/LegacyPassManager.cpp
index 5575bc469a87..4547c3a01239 100644
--- a/llvm/lib/IR/LegacyPassManager.cpp
+++ b/llvm/lib/IR/LegacyPassManager.cpp
@@ -568,7 +568,12 @@ PMTopLevelManager::setLastUser(ArrayRef<Pass*> AnalysisPasses, Pass *P) {
     PDepth = P->getResolver()->getPMDataManager().getDepth();
 
   for (Pass *AP : AnalysisPasses) {
-    LastUser[AP] = P;
+    // Record P as the new last user of AP.
+    auto &LastUserOfAP = LastUser[AP];
+    if (LastUserOfAP)
+      InversedLastUser[LastUserOfAP].erase(AP);
+    LastUserOfAP = P;
+    InversedLastUser[P].insert(AP);
 
     if (P == AP)
       continue;
@@ -598,13 +603,13 @@ PMTopLevelManager::setLastUser(ArrayRef<Pass*> AnalysisPasses, Pass *P) {
     if (P->getResolver())
       setLastUser(LastPMUses, P->getResolver()->getPMDataManager().getAsPass());
 
-
     // If AP is the last user of other passes then make P last user of
     // such passes.
-    for (auto &LU : LastUser) {
-      if (LU.second == AP)
-        LU.second = P;
-    }
+    auto &LastUsedByAP = InversedLastUser[AP];
+    for (Pass *L : LastUsedByAP)
+      LastUser[L] = P;
+    InversedLastUser[P].insert(LastUsedByAP.begin(), LastUsedByAP.end());
+    LastUsedByAP.clear();
   }
 }
 
@@ -850,11 +855,6 @@ void PMTopLevelManager::initializeAllAnalysisInfo() {
   // Initailize other pass managers
   for (PMDataManager *IPM : IndirectPassManagers)
     IPM->initializeAnalysisInfo();
-
-  for (auto LU : LastUser) {
-    SmallPtrSet<Pass *, 8> &L = InversedLastUser[LU.second];
-    L.insert(LU.first);
-  }
 }
 
 /// Destructor
@@ -1151,6 +1151,8 @@ Pass *PMDataManager::findAnalysisPass(AnalysisID AID, bool SearchParent) {
 
 // Print list of passes that are last used by P.
 void PMDataManager::dumpLastUses(Pass *P, unsigned Offset) const{
+  if (PassDebugging < Details)
+    return;
 
   SmallVector<Pass *, 12> LUses;