Pulled CodeMetrics out of InlineCost.h and made it a bit more general, so it can be reused from PartialSpecializationCost

llvm-svn: 105725

llvm/include/llvm/Analysis/CodeMetrics.h

@@ -0,0 +1,72 @@
+//===- CodeMetrics.h - Measures the weight of a function---------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements various weight measurements for a function, helping
+// the Inliner and PartialSpecialization decide whether to duplicate its
+// contents.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_CODEMETRICS_H
+#define LLVM_ANALYSIS_CODEMETRICS_H
+
+namespace llvm {
+  // CodeMetrics - Calculate size and a few similar metrics for a set of
+  // basic blocks.
+  struct CodeMetrics {
+    /// NeverInline - True if this callee should never be inlined into a
+    /// caller.
+    // bool NeverInline;
+
+    // True if this function contains a call to setjmp or _setjmp
+    bool callsSetJmp;
+
+    // True if this function calls itself
+    bool isRecursive;
+
+    // True if this function contains one or more indirect branches
+    bool containsIndirectBr;
+
+    /// usesDynamicAlloca - True if this function calls alloca (in the C sense).
+    bool usesDynamicAlloca;
+
+    /// NumInsts, NumBlocks - Keep track of how large each function is, which
+    /// is used to estimate the code size cost of inlining it.
+    unsigned NumInsts, NumBlocks;
+
+    /// NumBBInsts - Keeps track of basic block code size estimates.
+    DenseMap<const BasicBlock *, unsigned> NumBBInsts;
+
+    /// NumCalls - Keep track of the number of calls to 'big' functions.
+    unsigned NumCalls;
+
+    /// NumVectorInsts - Keep track of how many instructions produce vector
+    /// values.  The inliner is being more aggressive with inlining vector
+    /// kernels.
+    unsigned NumVectorInsts;
+
+    /// NumRets - Keep track of how many Ret instructions the block contains.
+    unsigned NumRets;
+
+    CodeMetrics() : callsSetJmp(false), isRecursive(false),
+                    containsIndirectBr(false), usesDynamicAlloca(false), 
+                    NumInsts(0), NumBlocks(0), NumCalls(0), NumVectorInsts(0), 
+                    NumRets(0) {}
+
+    /// analyzeBasicBlock - Add information about the specified basic block
+    /// to the current structure.
+    void analyzeBasicBlock(const BasicBlock *BB);
+
+    /// analyzeFunction - Add information about the specified function
+    /// to the current structure.
+    void analyzeFunction(Function *F);
+  };
+}
+
+#endif

llvm/include/llvm/Analysis/InlineCost.h

@@ -19,6 +19,7 @@
 #include <vector>
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/ValueMap.h"
+#include "llvm/Analysis/CodeMetrics.h"
 
 namespace llvm {
 
@@ -29,46 +30,6 @@ namespace llvm {
   template<class PtrType, unsigned SmallSize>
   class SmallPtrSet;
 
-  // CodeMetrics - Calculate size and a few similar metrics for a set of
-  // basic blocks.
-  struct CodeMetrics {
-    /// NeverInline - True if this callee should never be inlined into a
-    /// caller.
-    bool NeverInline;
-
-    /// usesDynamicAlloca - True if this function calls alloca (in the C sense).
-    bool usesDynamicAlloca;
-
-    /// NumInsts, NumBlocks - Keep track of how large each function is, which
-    /// is used to estimate the code size cost of inlining it.
-    unsigned NumInsts, NumBlocks;
-
-    /// NumBBInsts - Keeps track of basic block code size estimates.
-    DenseMap<const BasicBlock *, unsigned> NumBBInsts;
-
-    /// NumCalls - Keep track of the number of calls to 'big' functions.
-    unsigned NumCalls;
-
-    /// NumVectorInsts - Keep track of how many instructions produce vector
-    /// values.  The inliner is being more aggressive with inlining vector
-    /// kernels.
-    unsigned NumVectorInsts;
-
-    /// NumRets - Keep track of how many Ret instructions the block contains.
-    unsigned NumRets;
-
-    CodeMetrics() : NeverInline(false), usesDynamicAlloca(false), NumInsts(0),
-                    NumBlocks(0), NumCalls(0), NumVectorInsts(0), NumRets(0) {}
-
-    /// analyzeBasicBlock - Add information about the specified basic block
-    /// to the current structure.
-    void analyzeBasicBlock(const BasicBlock *BB);
-
-    /// analyzeFunction - Add information about the specified function
-    /// to the current structure.
-    void analyzeFunction(Function *F);
-  };
-
   namespace InlineConstants {
     // Various magic constants used to adjust heuristics.
     const int InstrCost = 5;
@@ -163,6 +124,10 @@ namespace llvm {
       /// analyzeFunction - Add information about the specified function
       /// to the current structure.
       void analyzeFunction(Function *F);
+
+      /// NeverInline - Returns true if the function should never be
+      /// inlined into any caller.
+      bool NeverInline();
     };
 
     // The Function* for a function can be changed (by ArgumentPromotion);

llvm/lib/Analysis/InlineCost.cpp

@@ -162,14 +162,14 @@ void CodeMetrics::analyzeBasicBlock(const BasicBlock *BB) {
       if (Function *F = CS.getCalledFunction()) {
         if (F->isDeclaration() && 
             (F->getName() == "setjmp" || F->getName() == "_setjmp"))
-          NeverInline = true;
+          callsSetJmp = true;
        
         // If this call is to function itself, then the function is recursive.
         // Inlining it into other functions is a bad idea, because this is
         // basically just a form of loop peeling, and our metrics aren't useful
         // for that case.
         if (F == BB->getParent())
-          NeverInline = true;
+          isRecursive = true;
       }
 
       if (!isa<IntrinsicInst>(II) && !callIsSmall(CS.getCalledFunction())) {
@@ -220,7 +220,7 @@ void CodeMetrics::analyzeBasicBlock(const BasicBlock *BB) {
   // jump would jump from the inlined copy of the function into the original
   // function which is extremely undefined behavior.
   if (isa<IndirectBrInst>(BB->getTerminator()))
-    NeverInline = true;
+    containsIndirectBr = true;
 
   // Remember NumInsts for this BB.
   NumBBInsts[BB] = NumInsts - NumInstsBeforeThisBB;
@@ -247,7 +247,7 @@ void InlineCostAnalyzer::FunctionInfo::analyzeFunction(Function *F) {
 
   // Don't bother calculating argument weights if we are never going to inline
   // the function anyway.
-  if (Metrics.NeverInline)
+  if (NeverInline())
     return;
 
   // Check out all of the arguments to the function, figuring out how much
@@ -258,6 +258,14 @@ void InlineCostAnalyzer::FunctionInfo::analyzeFunction(Function *F) {
                                       CountCodeReductionForAlloca(I)));
 }
 
+/// NeverInline - returns true if the function should never be inlined into
+/// any caller
+bool InlineCostAnalyzer::FunctionInfo::NeverInline()
+{
+  return (Metrics.callsSetJmp || Metrics.isRecursive || 
+          Metrics.containsIndirectBr);
+
+}
 // getInlineCost - The heuristic used to determine if we should inline the
 // function call or not.
 //
@@ -315,7 +323,7 @@ InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS,
     CalleeFI->analyzeFunction(Callee);
 
   // If we should never inline this, return a huge cost.
-  if (CalleeFI->Metrics.NeverInline)
+  if (CalleeFI->NeverInline())
     return InlineCost::getNever();
 
   // FIXME: It would be nice to kill off CalleeFI->NeverInline. Then we
@@ -443,10 +451,15 @@ InlineCostAnalyzer::growCachedCostInfo(Function *Caller, Function *Callee) {
   }
   
   // Since CalleeMetrics were already calculated, we know that the CallerMetrics
-  // reference isn't invalidated: both were in the DenseMap.  
-  CallerMetrics.NeverInline |= CalleeMetrics.NeverInline;
+  // reference isn't invalidated: both were in the DenseMap.
   CallerMetrics.usesDynamicAlloca |= CalleeMetrics.usesDynamicAlloca;
 
+  // FIXME: If any of these three are true for the callee, the callee was
+  // not inlined into the caller, so I think they're redundant here.
+  CallerMetrics.callsSetJmp |= CalleeMetrics.callsSetJmp;
+  CallerMetrics.isRecursive |= CalleeMetrics.isRecursive;
+  CallerMetrics.containsIndirectBr |= CalleeMetrics.containsIndirectBr;
+
   CallerMetrics.NumInsts += CalleeMetrics.NumInsts;
   CallerMetrics.NumBlocks += CalleeMetrics.NumBlocks;
   CallerMetrics.NumCalls += CalleeMetrics.NumCalls;

llvm/lib/Transforms/Scalar/LoopUnswitch.cpp

@@ -445,7 +445,7 @@ bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val) {
   // This is a very ad-hoc heuristic.
   if (Metrics.NumInsts > Threshold ||
       Metrics.NumBlocks * 5 > Threshold ||
-      Metrics.NeverInline) {
+      Metrics.containsIndirectBr || Metrics.isRecursive) {
     DEBUG(dbgs() << "NOT unswitching loop %"
           << currentLoop->getHeader()->getName() << ", cost too high: "
           << currentLoop->getBlocks().size() << "\n");