InstCombine: Use isAllOnesValue() instead of explicit -1.
[oota-llvm.git] / lib / Transforms / IPO / Inliner.cpp
index 2d703980c338b51f2fa87a5d872a3495054d9681..d75d6ca92b3c35fb7793ed5d5ca2488b69ff4b89 100644 (file)
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "inline"
-#include "llvm/Module.h"
-#include "llvm/Instructions.h"
-#include "llvm/IntrinsicInst.h"
+#include "llvm/Transforms/IPO/InlinerPass.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/InlineCost.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Transforms/IPO/InlinerPass.h"
-#include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
 #include "llvm/Support/CallSite.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Statistic.h"
+#include "llvm/Target/TargetLibraryInfo.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/Local.h"
 using namespace llvm;
 
 STATISTIC(NumInlined, "Number of functions inlined");
@@ -36,6 +37,11 @@ STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined");
 STATISTIC(NumDeleted, "Number of functions deleted because all callers found");
 STATISTIC(NumMergedAllocas, "Number of allocas merged together");
 
+// This weirdly named statistic tracks the number of times that, when attempting
+// to inline a function A into B, we analyze the callers of B in order to see
+// if those would be more profitable and blocked inline steps.
+STATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed");
+
 static cl::opt<int>
 InlineLimit("inline-threshold", cl::Hidden, cl::init(225), cl::ZeroOrMore,
         cl::desc("Control the amount of inlining to perform (default = 225)"));
@@ -58,14 +64,48 @@ Inliner::Inliner(char &ID, int Threshold, bool InsertLifetime)
 /// getAnalysisUsage - For this class, we declare that we require and preserve
 /// the call graph.  If the derived class implements this method, it should
 /// always explicitly call the implementation here.
-void Inliner::getAnalysisUsage(AnalysisUsage &Info) const {
-  CallGraphSCCPass::getAnalysisUsage(Info);
+void Inliner::getAnalysisUsage(AnalysisUsage &AU) const {
+  CallGraphSCCPass::getAnalysisUsage(AU);
 }
 
 
 typedef DenseMap<ArrayType*, std::vector<AllocaInst*> >
 InlinedArrayAllocasTy;
 
+/// \brief If the inlined function had a higher stack protection level than the
+/// calling function, then bump up the caller's stack protection level.
+static void AdjustCallerSSPLevel(Function *Caller, Function *Callee) {
+  // If upgrading the SSP attribute, clear out the old SSP Attributes first.
+  // Having multiple SSP attributes doesn't actually hurt, but it adds useless
+  // clutter to the IR.
+  AttrBuilder B;
+  B.addAttribute(Attribute::StackProtect)
+    .addAttribute(Attribute::StackProtectStrong);
+  AttributeSet OldSSPAttr = AttributeSet::get(Caller->getContext(),
+                                              AttributeSet::FunctionIndex,
+                                              B);
+  AttributeSet CallerAttr = Caller->getAttributes(),
+               CalleeAttr = Callee->getAttributes();
+
+  if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex,
+                              Attribute::StackProtectReq)) {
+    Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+    Caller->addFnAttr(Attribute::StackProtectReq);
+  } else if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex,
+                                     Attribute::StackProtectStrong) &&
+             !CallerAttr.hasAttribute(AttributeSet::FunctionIndex,
+                                      Attribute::StackProtectReq)) {
+    Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+    Caller->addFnAttr(Attribute::StackProtectStrong);
+  } else if (CalleeAttr.hasAttribute(AttributeSet::FunctionIndex,
+                                     Attribute::StackProtect) &&
+           !CallerAttr.hasAttribute(AttributeSet::FunctionIndex,
+                                    Attribute::StackProtectReq) &&
+           !CallerAttr.hasAttribute(AttributeSet::FunctionIndex,
+                                    Attribute::StackProtectStrong))
+    Caller->addFnAttr(Attribute::StackProtect);
+}
+
 /// InlineCallIfPossible - If it is possible to inline the specified call site,
 /// do so and update the CallGraph for this operation.
 ///
@@ -76,7 +116,8 @@ InlinedArrayAllocasTy;
 /// any new allocas to the set if not possible.
 static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
                                  InlinedArrayAllocasTy &InlinedArrayAllocas,
-                                 int InlineHistory, bool InsertLifetime) {
+                                 int InlineHistory, bool InsertLifetime,
+                                 const DataLayout *TD) {
   Function *Callee = CS.getCalledFunction();
   Function *Caller = CS.getCaller();
 
@@ -85,13 +126,7 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
   if (!InlineFunction(CS, IFI, InsertLifetime))
     return false;
 
-  // If the inlined function had a higher stack protection level than the
-  // calling function, then bump up the caller's stack protection level.
-  if (Callee->hasFnAttr(Attribute::StackProtectReq))
-    Caller->addFnAttr(Attribute::StackProtectReq);
-  else if (Callee->hasFnAttr(Attribute::StackProtect) &&
-           !Caller->hasFnAttr(Attribute::StackProtectReq))
-    Caller->addFnAttr(Attribute::StackProtect);
+  AdjustCallerSSPLevel(Caller, Callee);
 
   // Look at all of the allocas that we inlined through this call site.  If we
   // have already inlined other allocas through other calls into this function,
@@ -155,6 +190,14 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
     bool MergedAwayAlloca = false;
     for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) {
       AllocaInst *AvailableAlloca = AllocasForType[i];
+
+      unsigned Align1 = AI->getAlignment(),
+               Align2 = AvailableAlloca->getAlignment();
+      // If we don't have data layout information, and only one alloca is using
+      // the target default, then we can't safely merge them because we can't
+      // pick the greater alignment.
+      if (!TD && (!Align1 || !Align2) && Align1 != Align2)
+        continue;
       
       // The available alloca has to be in the right function, not in some other
       // function in this SCC.
@@ -172,6 +215,20 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
                    << *AvailableAlloca << '\n');
       
       AI->replaceAllUsesWith(AvailableAlloca);
+
+      if (Align1 != Align2) {
+        if (!Align1 || !Align2) {
+          assert(TD && "DataLayout required to compare default alignments");
+          unsigned TypeAlign = TD->getABITypeAlignment(AI->getAllocatedType());
+
+          Align1 = Align1 ? Align1 : TypeAlign;
+          Align2 = Align2 ? Align2 : TypeAlign;
+        }
+
+        if (Align1 > Align2)
+          AvailableAlloca->setAlignment(AI->getAlignment());
+      }
+
       AI->eraseFromParent();
       MergedAwayAlloca = true;
       ++NumMergedAllocas;
@@ -196,19 +253,28 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI,
 }
 
 unsigned Inliner::getInlineThreshold(CallSite CS) const {
-  int thres = InlineThreshold;
+  int thres = InlineThreshold; // -inline-threshold or else selected by
+                               // overall opt level
 
-  // Listen to optsize when -inline-limit is not given.
+  // If -inline-threshold is not given, listen to the optsize attribute when it
+  // would decrease the threshold.
   Function *Caller = CS.getCaller();
-  if (Caller && !Caller->isDeclaration() &&
-      Caller->hasFnAttr(Attribute::OptimizeForSize) &&
-      InlineLimit.getNumOccurrences() == 0)
+  bool OptSize = Caller && !Caller->isDeclaration() &&
+    Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                         Attribute::OptimizeForSize);
+  if (!(InlineLimit.getNumOccurrences() > 0) && OptSize &&
+      OptSizeThreshold < thres)
     thres = OptSizeThreshold;
 
-  // Listen to inlinehint when it would increase the threshold.
+  // 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();
-  if (HintThreshold > thres && Callee && !Callee->isDeclaration() &&
-      Callee->hasFnAttr(Attribute::InlineHint))
+  bool InlineHint = Callee && !Callee->isDeclaration() &&
+    Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                         Attribute::InlineHint);
+  if (InlineHint && HintThreshold > thres
+      && !Caller->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                               Attribute::MinSize))
     thres = HintThreshold;
 
   return thres;
@@ -277,6 +343,7 @@ bool Inliner::shouldInline(CallSite CS) {
       }
 
       InlineCost IC2 = getInlineCost(CS2);
+      ++NumCallerCallersAnalyzed;
       if (!IC2) {
         callerWillBeRemoved = false;
         continue;
@@ -329,7 +396,8 @@ static bool InlineHistoryIncludes(Function *F, int InlineHistoryID,
 
 bool Inliner::runOnSCC(CallGraphSCC &SCC) {
   CallGraph &CG = getAnalysis<CallGraph>();
-  const TargetData *TD = getAnalysisIfAvailable<TargetData>();
+  const DataLayout *TD = getAnalysisIfAvailable<DataLayout>();
+  const TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
 
   SmallPtrSet<Function*, 8> SCCFunctions;
   DEBUG(dbgs() << "Inliner visiting SCC:");
@@ -408,7 +476,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
       // just delete the call instead of trying to inline it, regardless of
       // size.  This happens because IPSCCP propagates the result out of the
       // call and then we're left with the dead call.
-      if (isInstructionTriviallyDead(CS.getInstruction())) {
+      if (isInstructionTriviallyDead(CS.getInstruction(), TLI)) {
         DEBUG(dbgs() << "    -> Deleting dead call: "
                      << *CS.getInstruction() << "\n");
         // Update the call graph by deleting the edge from Callee to Caller.
@@ -437,7 +505,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) {
 
         // Attempt to inline the function.
         if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas,
-                                  InlineHistoryID, InsertLifetime))
+                                  InlineHistoryID, InsertLifetime, TD))
           continue;
         ++NumInlined;
         
@@ -521,7 +589,9 @@ bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) {
     // Handle the case when this function is called and we only want to care
     // about always-inline functions. This is a bit of a hack to share code
     // between here and the InlineAlways pass.
-    if (AlwaysInlineOnly && !F->hasFnAttr(Attribute::AlwaysInline))
+    if (AlwaysInlineOnly &&
+        !F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                         Attribute::AlwaysInline))
       continue;
 
     // If the only remaining users of the function are dead constants, remove
@@ -552,7 +622,7 @@ bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) {
   // Note that it doesn't matter that we are iterating over a non-stable order
   // here to do this, it doesn't matter which order the functions are deleted
   // in.
-  std::sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
+  array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
   FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(),
                                       FunctionsToRemove.end()),
                           FunctionsToRemove.end());