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

6 files changed, 55 insertions, 51 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) {
diff --git a/test/Transforms/InstCombine/memset-1.ll b/test/Transforms/InstCombine/memset-1.ll
new file mode 100644
index 0000000000..48b433e137
--- /dev/null
+++ b/test/Transforms/InstCombine/memset-1.ll
@@ -0,0 +1,17 @@
+; Test that the memset library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+
+declare i8* @memset(i8*, i32, i32)
+
+; Check memset(mem1, val, size) -> llvm.memset(mem1, val, size, 1).
+
+define i8* @test_simplify1(i8* %mem, i32 %val, i32 %size) {
+; CHECK: @test_simplify1
+  %ret = call i8* @memset(i8* %mem, i32 %val, i32 %size)
+; CHECK: call void @llvm.memset
+  ret i8* %ret
+; CHECK: ret i8* %mem
+}
diff --git a/test/Transforms/InstCombine/memset-2.ll b/test/Transforms/InstCombine/memset-2.ll
new file mode 100644
index 0000000000..8a9033302d
--- /dev/null
+++ b/test/Transforms/InstCombine/memset-2.ll
@@ -0,0 +1,17 @@
+; Test that the memset library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+
+declare i8 @memset(i8*, i32, i32)
+
+; Check that memset functions with the wrong prototype aren't simplified.
+
+define i8 @test_no_simplify1(i8* %mem, i32 %val, i32 %size) {
+; CHECK: @test_no_simplify1
+  %ret = call i8 @memset(i8* %mem, i32 %val, i32 %size)
+; CHECK: call i8 @memset
+  ret i8 %ret
+; CHECK: ret i8 %ret
+}
diff --git a/test/Transforms/SimplifyLibCalls/memset-64.ll b/test/Transforms/SimplifyLibCalls/memset-64.ll
deleted file mode 100644
index 92412dee71..0000000000
--- a/test/Transforms/SimplifyLibCalls/memset-64.ll
+++ /dev/null
@@ -1,12 +0,0 @@
-; RUN: opt < %s -simplify-libcalls -S | grep "llvm.memset"
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
-target triple = "x86_64-pc-linux-gnu"
-
-define void @a(i8* %x) nounwind {
-entry:
-	%call = call i8* @memset(i8* %x, i32 1, i64 100)		; <i8*> [#uses=0]
-	ret void
-}
-
-declare i8* @memset(i8*, i32, i64)
-
diff --git a/test/Transforms/SimplifyLibCalls/memset.ll b/test/Transforms/SimplifyLibCalls/memset.ll
deleted file mode 100644
index 853215a4d2..0000000000
--- a/test/Transforms/SimplifyLibCalls/memset.ll
+++ /dev/null
@@ -1,12 +0,0 @@
-; RUN: opt < %s -simplify-libcalls -S | grep "llvm.memset"
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
-target triple = "i686-pc-linux-gnu"
-
-define i8* @test(i8* %a, i32 %b, i32 %x) {
-entry:
-	%call = call i8* @memset(i8* %a, i32 %b, i32 %x )
-	ret i8* %call
-}
-
-declare i8* @memset(i8*,i32,i32)
-