instcombine: Migrate memset optimizations

This patch migrates the memset optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167689 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 27 deletions

diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 40dce657df..0f95e15e97 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -104,28 +104,6 @@ static bool CallHasFloatingPointArgument(const CallInst *CI) {
 //===----------------------------------------------------------------------===//
 
 namespace {
-//===---------------------------------------===//
-// 'memset' Optimizations
-
-struct MemSetOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    // These optimizations require DataLayout.
-    if (!TD) return 0;
-
-    FunctionType *FT = Callee->getFunctionType();
-    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
-        !FT->getParamType(0)->isPointerTy() ||
-        !FT->getParamType(1)->isIntegerTy() ||
-        FT->getParamType(2) != TD->getIntPtrType(*Context))
-      return 0;
-
-    // memset(p, v, n) -> llvm.memset(p, v, n, 1)
-    Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
-    B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
-    return CI->getArgOperand(0);
-  }
-};
-
 //===----------------------------------------------------------------------===//
 // Math Library Optimizations
 //===----------------------------------------------------------------------===//
@@ -794,8 +772,6 @@ namespace {
     TargetLibraryInfo *TLI;
 
     StringMap<LibCallOptimization*> Optimizations;
-    // Memory LibCall Optimizations
-    MemSetOpt MemSet;
     // Math Library Optimizations
     CosOpt Cos; PowOpt Pow; Exp2Opt Exp2;
     UnaryDoubleFPOpt UnaryDoubleFP, UnsafeUnaryDoubleFP;
@@ -861,9 +837,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
 /// Optimizations - Populate the Optimizations map with all the optimizations
 /// we know.
 void SimplifyLibCalls::InitOptimizations() {
-  // Memory LibCall Optimizations
-  AddOpt(LibFunc::memset, &MemSet);
-
   // Math Library Optimizations
   Optimizations["cosf"] = &Cos;
   Optimizations["cos"] = &Cos;
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index b4dc93dead..c3ea63852f 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -997,6 +997,25 @@ struct MemMoveOpt : public LibCallOptimization {
   }
 };
 
+struct MemSetOpt : public LibCallOptimization {
+  virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+    // These optimizations require DataLayout.
+    if (!TD) return 0;
+
+    FunctionType *FT = Callee->getFunctionType();
+    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
+        !FT->getParamType(0)->isPointerTy() ||
+        !FT->getParamType(1)->isIntegerTy() ||
+        FT->getParamType(2) != TD->getIntPtrType(*Context))
+      return 0;
+
+    // memset(p, v, n) -> llvm.memset(p, v, n, 1)
+    Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
+    B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
+    return CI->getArgOperand(0);
+  }
+};
+
 } // End anonymous namespace.
 
 namespace llvm {
@@ -1036,6 +1055,7 @@ class LibCallSimplifierImpl {
   MemCmpOpt MemCmp;
   MemCpyOpt MemCpy;
   MemMoveOpt MemMove;
+  MemSetOpt MemSet;
 
   void initOptimizations();
   void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@@ -1087,6 +1107,7 @@ void LibCallSimplifierImpl::initOptimizations() {
   addOpt(LibFunc::memcmp, &MemCmp);
   addOpt(LibFunc::memcpy, &MemCpy);
   addOpt(LibFunc::memmove, &MemMove);
+  addOpt(LibFunc::memset, &MemSet);
 }
 
 Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {