Determine callee's hotness and adjust threshold based on that. NFC.

[oota-llvm.git] / lib / Transforms / IPO / Inliner.cpp

diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index 07d3633e941d3884361d335036327bfa9c2b682e..545050171367fa0f9db0cf4e6c01206b994e1e54 100644 (file)
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -228,6 +228,14 @@ static bool InlineCallIfPossible(Pass &P, CallSite CS, InlineFunctionInfo &IFI,
       DEBUG(dbgs() << "    ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: "
                    << *AvailableAlloca << '\n');
       
+      // Move affected dbg.declare calls immediately after the new alloca to
+      // avoid the situation when a dbg.declare preceeds its alloca.
+      if (auto *L = LocalAsMetadata::getIfExists(AI))
+        if (auto *MDV = MetadataAsValue::getIfExists(AI->getContext(), L))
+          for (User *U : MDV->users())
+            if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
+              DDI->moveBefore(AvailableAlloca->getNextNode());
+
       AI->replaceAllUsesWith(AvailableAlloca);
 
       if (Align1 != Align2) {
@@ -280,18 +288,42 @@ unsigned Inliner::getInlineThreshold(CallSite CS) const {
       OptSizeThreshold < Threshold)
     Threshold = OptSizeThreshold;
 
-  // Listen to the inlinehint attribute when it would increase the threshold
-  // and the caller does not need to minimize its size.
   Function *Callee = CS.getCalledFunction();
-  bool InlineHint = Callee && !Callee->isDeclaration() &&
-                    Callee->hasFnAttribute(Attribute::InlineHint);
+  if (!Callee || Callee->isDeclaration())
+    return Threshold;
+
+  // If profile information is available, use that to adjust threshold of hot
+  // and cold functions.
+  // FIXME: The heuristic used below for determining hotness and coldness are
+  // based on preliminary SPEC tuning and may not be optimal. Replace this with
+  // a well-tuned heuristic based on *callsite* hotness and not callee hotness.
+  uint64_t FunctionCount = 0, MaxFunctionCount = 0;
+  bool HasPGOCounts = false;
+  if (Callee->getEntryCount() &&
+      Callee->getParent()->getMaximumFunctionCount()) {
+    HasPGOCounts = true;
+    FunctionCount = Callee->getEntryCount().getValue();
+    MaxFunctionCount =
+        Callee->getParent()->getMaximumFunctionCount().getValue();
+  }
+
+  // Listen to the inlinehint attribute or profile based hotness information
+  // when it would increase the threshold and the caller does not need to
+  // minimize its size.
+  bool InlineHint =
+      Callee->hasFnAttribute(Attribute::InlineHint) ||
+      (HasPGOCounts &&
+       FunctionCount >= (uint64_t)(0.3 * (double)MaxFunctionCount));
   if (InlineHint && HintThreshold > Threshold &&
       !Caller->hasFnAttribute(Attribute::MinSize))
     Threshold = HintThreshold;
 
-  // Listen to the cold attribute when it would decrease the threshold.
-  bool ColdCallee = Callee && !Callee->isDeclaration() &&
-                    Callee->hasFnAttribute(Attribute::Cold);
+  // Listen to the cold attribute or profile based coldness information
+  // when it would decrease the threshold.
+  bool ColdCallee =
+      Callee->hasFnAttribute(Attribute::Cold) ||
+      (HasPGOCounts &&
+       FunctionCount <= (uint64_t)(0.01 * (double)MaxFunctionCount));
   // Command line argument for InlineLimit will override the default
   // ColdThreshold. If we have -inline-threshold but no -inlinecold-threshold,
   // do not use the default cold threshold even if it is smaller.