[llvm-commits] [llvm] r167681 - in /llvm/trunk: include/llvm/Transforms/Utils/SimplifyLibCalls.h lib/Transforms/InstCombine/InstructionCombining.cpp lib/Transforms/Utils/SimplifyLibCalls.cpp

[Meador Inge]

Author: meadori
Date: Sat Nov 10 21:51:43 2012
New Revision: 167681

URL: http://llvm.org/viewvc/llvm-project?rev=167681&view=rev
Log:
Add method for replacing instructions to LibCallSimplifier

In some cases the library call simplifier may need to replace instructions
other than the library call being simplified.  In those cases it may be
necessary for clients of the simplifier to override how the replacements
are actually done.  As such, a new overrideable method for replacing
instructions was added to LibCallSimplifier.

A new subclass of LibCallSimplifier is also defined which overrides
the instruction replacement method.  This is because the instruction
combiner defines its own replacement method which updates the worklist
when instructions are replaced.

Modified:
    llvm/trunk/include/llvm/Transforms/Utils/SimplifyLibCalls.h
    llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
    llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp

Modified: llvm/trunk/include/llvm/Transforms/Utils/SimplifyLibCalls.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/SimplifyLibCalls.h?rev=167681&r1=167680&r2=167681&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/SimplifyLibCalls.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/SimplifyLibCalls.h Sat Nov 10 21:51:43 2012
@@ -19,6 +19,7 @@
   class Value;
   class CallInst;
   class DataLayout;
+  class Instruction;
   class TargetLibraryInfo;
   class LibCallSimplifierImpl;
 
@@ -35,8 +36,16 @@
 
     /// optimizeCall - Take the given call instruction and return a more
     /// optimal value to replace the instruction with or 0 if a more
-    /// optimal form can't be found.
+    /// optimal form can't be found.  Note that the returned value may
+    /// be equal to the instruction being optimized.  In this case all
+    /// other instructions that use the given instruction were modified
+    /// and the given instruction is dead.
     Value *optimizeCall(CallInst *CI);
+
+    /// replaceAllUsesWith - This method is used when the library call
+    /// simplifier needs to replace instructions other than the library
+    /// call being modified.
+    virtual void replaceAllUsesWith(Instruction *I, Value *With) const;
   };
 } // End llvm namespace
 

Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=167681&r1=167680&r2=167681&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Sat Nov 10 21:51:43 2012
@@ -2367,6 +2367,24 @@
   return MadeIRChange;
 }
 
+namespace {
+class InstCombinerLibCallSimplifier : public LibCallSimplifier {
+  InstCombiner *IC;
+public:
+  InstCombinerLibCallSimplifier(const DataLayout *TD,
+                                const TargetLibraryInfo *TLI,
+                                InstCombiner *IC)
+    : LibCallSimplifier(TD, TLI) {
+    this->IC = IC;
+  }
+
+  /// replaceAllUsesWith - override so that instruction replacement
+  /// can be defined in terms of the instruction combiner framework.
+  virtual void replaceAllUsesWith(Instruction *I, Value *With) const {
+    IC->ReplaceInstUsesWith(*I, With);
+  }
+};
+}
 
 bool InstCombiner::runOnFunction(Function &F) {
   TD = getAnalysisIfAvailable<DataLayout>();
@@ -2379,7 +2397,7 @@
                InstCombineIRInserter(Worklist));
   Builder = &TheBuilder;
 
-  LibCallSimplifier TheSimplifier(TD, TLI);
+  InstCombinerLibCallSimplifier TheSimplifier(TD, TLI, this);
   Simplifier = &TheSimplifier;
 
   bool EverMadeChange = false;

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp?rev=167681&r1=167680&r2=167681&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp Sat Nov 10 21:51:43 2012
@@ -34,6 +34,7 @@
   Function *Caller;
   const DataLayout *TD;
   const TargetLibraryInfo *TLI;
+  const LibCallSimplifier *LCS;
   LLVMContext* Context;
 public:
   LibCallOptimization() { }
@@ -48,10 +49,12 @@
     =0;
 
   Value *optimizeCall(CallInst *CI, const DataLayout *TD,
-                      const TargetLibraryInfo *TLI, IRBuilder<> &B) {
+                      const TargetLibraryInfo *TLI,
+                      const LibCallSimplifier *LCS, IRBuilder<> &B) {
     Caller = CI->getParent()->getParent();
     this->TD = TD;
     this->TLI = TLI;
+    this->LCS = LCS;
     if (CI->getCalledFunction())
       Context = &CI->getCalledFunction()->getContext();
 
@@ -840,6 +843,7 @@
 class LibCallSimplifierImpl {
   const DataLayout *TD;
   const TargetLibraryInfo *TLI;
+  const LibCallSimplifier *LCS;
   StringMap<LibCallOptimization*> Optimizations;
 
   // Fortified library call optimizations.
@@ -869,9 +873,11 @@
   void initOptimizations();
   void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
 public:
-  LibCallSimplifierImpl(const DataLayout *TD, const TargetLibraryInfo *TLI) {
+  LibCallSimplifierImpl(const DataLayout *TD, const TargetLibraryInfo *TLI,
+                        const LibCallSimplifier *LCS) {
     this->TD = TD;
     this->TLI = TLI;
+    this->LCS = LCS;
   }
 
   Value *optimizeCall(CallInst *CI);
@@ -918,7 +924,7 @@
   LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
   if (LCO) {
     IRBuilder<> Builder(CI);
-    return LCO->optimizeCall(CI, TD, TLI, Builder);
+    return LCO->optimizeCall(CI, TD, TLI, LCS, Builder);
   }
   return 0;
 }
@@ -930,7 +936,7 @@
 
 LibCallSimplifier::LibCallSimplifier(const DataLayout *TD,
                                      const TargetLibraryInfo *TLI) {
-  Impl = new LibCallSimplifierImpl(TD, TLI);
+  Impl = new LibCallSimplifierImpl(TD, TLI, this);
 }
 
 LibCallSimplifier::~LibCallSimplifier() {
@@ -941,4 +947,9 @@
   return Impl->optimizeCall(CI);
 }
 
+void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) const {
+  I->replaceAllUsesWith(With);
+  I->eraseFromParent();
+}
+
 }