instcombine: Migrate strcmp and strncmp optimizations

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165915 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 351 insertions, 274 deletions

diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 4cd8742cc3..6df0ee2322 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -135,108 +135,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
 
 namespace {
 //===---------------------------------------===//
-// 'strcmp' Optimizations
-
-struct StrCmpOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    // Verify the "strcmp" function prototype.
-    FunctionType *FT = Callee->getFunctionType();
-    if (FT->getNumParams() != 2 ||
-        !FT->getReturnType()->isIntegerTy(32) ||
-        FT->getParamType(0) != FT->getParamType(1) ||
-        FT->getParamType(0) != B.getInt8PtrTy())
-      return 0;
-
-    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
-    if (Str1P == Str2P)      // strcmp(x,x)  -> 0
-      return ConstantInt::get(CI->getType(), 0);
-
-    StringRef Str1, Str2;
-    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
-    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
-
-    // strcmp(x, y)  -> cnst  (if both x and y are constant strings)
-    if (HasStr1 && HasStr2)
-      return ConstantInt::get(CI->getType(), Str1.compare(Str2));
-
-    if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
-      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
-                                      CI->getType()));
-
-    if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
-      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
-
-    // strcmp(P, "x") -> memcmp(P, "x", 2)
-    uint64_t Len1 = GetStringLength(Str1P);
-    uint64_t Len2 = GetStringLength(Str2P);
-    if (Len1 && Len2) {
-      // These optimizations require DataLayout.
-      if (!TD) return 0;
-
-      return EmitMemCmp(Str1P, Str2P,
-                        ConstantInt::get(TD->getIntPtrType(*Context),
-                        std::min(Len1, Len2)), B, TD, TLI);
-    }
-
-    return 0;
-  }
-};
-
-//===---------------------------------------===//
-// 'strncmp' Optimizations
-
-struct StrNCmpOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    // Verify the "strncmp" function prototype.
-    FunctionType *FT = Callee->getFunctionType();
-    if (FT->getNumParams() != 3 ||
-        !FT->getReturnType()->isIntegerTy(32) ||
-        FT->getParamType(0) != FT->getParamType(1) ||
-        FT->getParamType(0) != B.getInt8PtrTy() ||
-        !FT->getParamType(2)->isIntegerTy())
-      return 0;
-
-    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
-    if (Str1P == Str2P)      // strncmp(x,x,n)  -> 0
-      return ConstantInt::get(CI->getType(), 0);
-
-    // Get the length argument if it is constant.
-    uint64_t Length;
-    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
-      Length = LengthArg->getZExtValue();
-    else
-      return 0;
-
-    if (Length == 0) // strncmp(x,y,0)   -> 0
-      return ConstantInt::get(CI->getType(), 0);
-
-    if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
-      return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD, TLI);
-
-    StringRef Str1, Str2;
-    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
-    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
-
-    // strncmp(x, y)  -> cnst  (if both x and y are constant strings)
-    if (HasStr1 && HasStr2) {
-      StringRef SubStr1 = Str1.substr(0, Length);
-      StringRef SubStr2 = Str2.substr(0, Length);
-      return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
-    }
-
-    if (HasStr1 && Str1.empty())  // strncmp("", x, n) -> -*x
-      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
-                                      CI->getType()));
-
-    if (HasStr2 && Str2.empty())  // strncmp(x, "", n) -> *x
-      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
-
-    return 0;
-  }
-};
-
-
-//===---------------------------------------===//
 // 'strcpy' Optimizations
 
 struct StrCpyOpt : public LibCallOptimization {
@@ -1378,7 +1276,6 @@ namespace {
 
     StringMap<LibCallOptimization*> Optimizations;
     // String and Memory LibCall Optimizations
-    StrCmpOpt StrCmp; StrNCmpOpt StrNCmp;
     StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
     StpCpyOpt StpCpy; StpCpyOpt StpCpyChk;
     StrNCpyOpt StrNCpy;
@@ -1452,8 +1349,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
 /// we know.
 void SimplifyLibCalls::InitOptimizations() {
   // String and Memory LibCall Optimizations
-  Optimizations["strcmp"] = &StrCmp;
-  Optimizations["strncmp"] = &StrNCmp;
   Optimizations["strcpy"] = &StrCpy;
   Optimizations["strncpy"] = &StrNCpy;
   Optimizations["stpcpy"] = &StpCpy;
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 5ce5843b21..bd28ec3527 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -402,6 +402,101 @@ struct StrRChrOpt : public LibCallOptimization {
   }
 };
 
+struct StrCmpOpt : public LibCallOptimization {
+  virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+    // Verify the "strcmp" function prototype.
+    FunctionType *FT = Callee->getFunctionType();
+    if (FT->getNumParams() != 2 ||
+        !FT->getReturnType()->isIntegerTy(32) ||
+        FT->getParamType(0) != FT->getParamType(1) ||
+        FT->getParamType(0) != B.getInt8PtrTy())
+      return 0;
+
+    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
+    if (Str1P == Str2P)      // strcmp(x,x)  -> 0
+      return ConstantInt::get(CI->getType(), 0);
+
+    StringRef Str1, Str2;
+    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
+
+    // strcmp(x, y)  -> cnst  (if both x and y are constant strings)
+    if (HasStr1 && HasStr2)
+      return ConstantInt::get(CI->getType(), Str1.compare(Str2));
+
+    if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
+      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
+                                      CI->getType()));
+
+    if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
+      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
+
+    // strcmp(P, "x") -> memcmp(P, "x", 2)
+    uint64_t Len1 = GetStringLength(Str1P);
+    uint64_t Len2 = GetStringLength(Str2P);
+    if (Len1 && Len2) {
+      // These optimizations require DataLayout.
+      if (!TD) return 0;
+
+      return EmitMemCmp(Str1P, Str2P,
+                        ConstantInt::get(TD->getIntPtrType(*Context),
+                        std::min(Len1, Len2)), B, TD, TLI);
+    }
+
+    return 0;
+  }
+};
+
+struct StrNCmpOpt : public LibCallOptimization {
+  virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+    // Verify the "strncmp" function prototype.
+    FunctionType *FT = Callee->getFunctionType();
+    if (FT->getNumParams() != 3 ||
+        !FT->getReturnType()->isIntegerTy(32) ||
+        FT->getParamType(0) != FT->getParamType(1) ||
+        FT->getParamType(0) != B.getInt8PtrTy() ||
+        !FT->getParamType(2)->isIntegerTy())
+      return 0;
+
+    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
+    if (Str1P == Str2P)      // strncmp(x,x,n)  -> 0
+      return ConstantInt::get(CI->getType(), 0);
+
+    // Get the length argument if it is constant.
+    uint64_t Length;
+    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
+      Length = LengthArg->getZExtValue();
+    else
+      return 0;
+
+    if (Length == 0) // strncmp(x,y,0)   -> 0
+      return ConstantInt::get(CI->getType(), 0);
+
+    if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
+      return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD, TLI);
+
+    StringRef Str1, Str2;
+    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
+
+    // strncmp(x, y)  -> cnst  (if both x and y are constant strings)
+    if (HasStr1 && HasStr2) {
+      StringRef SubStr1 = Str1.substr(0, Length);
+      StringRef SubStr2 = Str2.substr(0, Length);
+      return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
+    }
+
+    if (HasStr1 && Str1.empty())  // strncmp("", x, n) -> -*x
+      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
+                                      CI->getType()));
+
+    if (HasStr2 && Str2.empty())  // strncmp(x, "", n) -> *x
+      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
+
+    return 0;
+  }
+};
+
 } // End anonymous namespace.
 
 namespace llvm {
@@ -423,6 +518,8 @@ class LibCallSimplifierImpl {
   StrNCatOpt StrNCat;
   StrChrOpt StrChr;
   StrRChrOpt StrRChr;
+  StrCmpOpt StrCmp;
+  StrNCmpOpt StrNCmp;
 
   void initOptimizations();
 public:
@@ -443,6 +540,8 @@ void LibCallSimplifierImpl::initOptimizations() {
   Optimizations["__stpcpy_chk"] = &StrCpyChk;
   Optimizations["__strncpy_chk"] = &StrNCpyChk;
   Optimizations["__stpncpy_chk"] = &StrNCpyChk;
+  Optimizations["strcmp"] = &StrCmp;
+  Optimizations["strncmp"] = &StrNCmp;
 
   // String and memory library call optimizations.
   Optimizations["strcat"] = &StrCat;
diff --git a/test/Transforms/InstCombine/strcmp-1.ll b/test/Transforms/InstCombine/strcmp-1.ll
new file mode 100644
index 0000000000..0679246e09
--- /dev/null
+++ b/test/Transforms/InstCombine/strcmp-1.ll
@@ -0,0 +1,82 @@
+; Test that the strcmp 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"
+
+@hello = constant [6 x i8] c"hello\00"
+@hell = constant [5 x i8] c"hell\00"
+@bell = constant [5 x i8] c"bell\00"
+@null = constant [1 x i8] zeroinitializer
+
+declare i32 @strcmp(i8*, i8*)
+
+; strcmp("", x) -> -*x
+define i32 @test1(i8* %str2) {
+; CHECK: @test1
+; CHECK: %strcmpload = load i8* %str
+; CHECK: %1 = zext i8 %strcmpload to i32
+; CHECK: %2 = sub i32 0, %1
+; CHECK: ret i32 %2
+
+  %str1 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
+  ret i32 %temp1
+
+}
+
+; strcmp(x, "") -> *x
+define i32 @test2(i8* %str1) {
+; CHECK: @test2
+; CHECK: %strcmpload = load i8* %str
+; CHECK: %1 = zext i8 %strcmpload to i32
+; CHECK: ret i32 %1
+
+  %str2 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
+  ret i32 %temp1
+}
+
+; strcmp(x, y)  -> cnst
+define i32 @test3() {
+; CHECK: @test3
+; CHECK: ret i32 -1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
+  ret i32 %temp1
+}
+
+define i32 @test4() {
+; CHECK: @test4
+; CHECK: ret i32 1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
+  ret i32 %temp1
+}
+
+; strcmp(x, y)   -> memcmp(x, y, <known length>)
+; (This transform is rather difficult to trigger in a useful manner)
+define i32 @test5(i1 %b) {
+; CHECK: @test5
+; CHECK: %memcmp = call i32 @memcmp(i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0), i8* %str2, i32 5)
+; CHECK: ret i32 %memcmp
+
+  %str1 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %temp2 = getelementptr inbounds [5 x i8]* @bell, i32 0, i32 0
+  %str2 = select i1 %b, i8* %temp1, i8* %temp2
+  %temp3 = call i32 @strcmp(i8* %str1, i8* %str2)
+  ret i32 %temp3
+}
+
+; strcmp(x,x)  -> 0
+define i32 @test6(i8* %str) {
+; CHECK: @test6
+; CHECK: ret i32 0
+
+  %temp1 = call i32 @strcmp(i8* %str, i8* %str)
+  ret i32 %temp1
+}
diff --git a/test/Transforms/InstCombine/strcmp-2.ll b/test/Transforms/InstCombine/strcmp-2.ll
new file mode 100644
index 0000000000..20518960f3
--- /dev/null
+++ b/test/Transforms/InstCombine/strcmp-2.ll
@@ -0,0 +1,20 @@
+; Test that the strcmp 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"
+
+@hello = constant [6 x i8] c"hello\00"
+@hell = constant [5 x i8] c"hell\00"
+
+declare i16 @strcmp(i8*, i8*)
+
+define i16 @test_nosimplify() {
+; CHECK: @test_nosimplify
+; CHECK: call i16 @strcmp
+; CHECK: ret i16 %temp1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = call i16 @strcmp(i8* %str1, i8* %str2)
+  ret i16 %temp1
+}
diff --git a/test/Transforms/InstCombine/strncmp-1.ll b/test/Transforms/InstCombine/strncmp-1.ll
new file mode 100644
index 0000000000..48b26d1a5f
--- /dev/null
+++ b/test/Transforms/InstCombine/strncmp-1.ll
@@ -0,0 +1,97 @@
+; Test that the strncmp 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"
+
+@hello = constant [6 x i8] c"hello\00"
+@hell = constant [5 x i8] c"hell\00"
+@bell = constant [5 x i8] c"bell\00"
+@null = constant [1 x i8] zeroinitializer
+
+declare i32 @strncmp(i8*, i8*, i32)
+
+; strncmp("", x, n) -> -*x
+define i32 @test1(i8* %str2) {
+; CHECK: @test1
+; CHECK: %strcmpload = load i8* %str
+; CHECK: %1 = zext i8 %strcmpload to i32
+; CHECK: %2 = sub i32 0, %1
+; CHECK: ret i32 %2
+
+  %str1 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 10)
+  ret i32 %temp1
+}
+
+; strncmp(x, "", n) -> *x
+define i32 @test2(i8* %str1) {
+; CHECK: @test2
+; CHECK: %strcmpload = load i8* %str1
+; CHECK: %1 = zext i8 %strcmpload to i32
+; CHECK: ret i32 %1
+
+  %str2 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 10)
+  ret i32 %temp1
+}
+
+; strncmp(x, y, n)  -> cnst
+define i32 @test3() {
+; CHECK: @test3
+; CHECK: ret i32 -1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 10)
+  ret i32 %temp1
+}
+
+define i32 @test4() {
+; CHECK: @test4
+; CHECK: ret i32 1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [1 x i8]* @null, i32 0, i32 0
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 10)
+  ret i32 %temp1
+}
+
+define i32 @test5() {
+; CHECK: @test5
+; CHECK: ret i32 0
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 4)
+  ret i32 %temp1
+}
+
+; strncmp(x,y,1) -> memcmp(x,y,1)
+; TODO: Once the memcmp simplifier gets moved into the instcombine pass
+; the following memcmp will be folded into two loads and a subtract.
+define i32 @test6(i8* %str1, i8* %str2) {
+; CHECK: @test6
+; CHECK: call i32 @memcmp
+; CHECK: ret i32 %memcmp
+
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 1)
+  ret i32 %temp1
+}
+
+; strncmp(x,y,0)   -> 0
+define i32 @test7(i8* %str1, i8* %str2) {
+; CHECK: @test7
+; CHECK: ret i32 0
+
+  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 0)
+  ret i32 %temp1
+}
+
+; strncmp(x,x,n)  -> 0
+define i32 @test8(i8* %str, i32 %n) {
+; CHECK: @test8
+; CHECK: ret i32 0
+
+  %temp1 = call i32 @strncmp(i8* %str, i8* %str, i32 %n)
+  ret i32 %temp1
+}
diff --git a/test/Transforms/InstCombine/strncmp-2.ll b/test/Transforms/InstCombine/strncmp-2.ll
new file mode 100644
index 0000000000..3fc43a6fd4
--- /dev/null
+++ b/test/Transforms/InstCombine/strncmp-2.ll
@@ -0,0 +1,20 @@
+; Test that the strncmp 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"
+
+@hello = constant [6 x i8] c"hello\00"
+@hell = constant [5 x i8] c"hell\00"
+
+declare i16 @strncmp(i8*, i8*, i32)
+
+define i16 @test_nosimplify() {
+; CHECK: @test_nosimplify
+; CHECK: call i16 @strncmp
+; CHECK: ret i16 %temp1
+
+  %str1 = getelementptr inbounds [5 x i8]* @hell, i32 0, i32 0
+  %str2 = getelementptr inbounds [6 x i8]* @hello, i32 0, i32 0
+  %temp1 = call i16 @strncmp(i8* %str1, i8* %str2, i32 10)
+  ret i16 %temp1
+}
diff --git a/test/Transforms/InstCombine/weak-symbols.ll b/test/Transforms/InstCombine/weak-symbols.ll
new file mode 100644
index 0000000000..0039b5962f
--- /dev/null
+++ b/test/Transforms/InstCombine/weak-symbols.ll
@@ -0,0 +1,33 @@
+; PR4738 - Test that the library call simplifier doesn't assume anything about
+; weak symbols.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+@real_init = weak_odr constant [2 x i8] c"y\00"
+@fake_init = weak constant [2 x i8] c"y\00"
+@.str = private constant [2 x i8] c"y\00"
+
+define i32 @foo() nounwind {
+; CHECK: define i32 @foo
+; CHECK: call i32 @strcmp
+; CHECK: ret i32 %temp1
+
+entry:
+  %str1 = getelementptr inbounds [2 x i8]* @fake_init, i64 0, i64 0
+  %str2 = getelementptr inbounds [2 x i8]* @.str, i64 0, i64 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2) nounwind readonly
+  ret i32 %temp1
+}
+
+define i32 @bar() nounwind {
+; CHECK: define i32 @bar
+; CHECK: ret i32 0
+
+entry:
+  %str1 = getelementptr inbounds [2 x i8]* @real_init, i64 0, i64 0
+  %str2 = getelementptr inbounds [2 x i8]* @.str, i64 0, i64 0
+  %temp1 = call i32 @strcmp(i8* %str1, i8* %str2) nounwind readonly
+  ret i32 %temp1
+}
+
+declare i32 @strcmp(i8*, i8*) nounwind readonly
diff --git a/test/Transforms/SimplifyLibCalls/StrCmp.ll b/test/Transforms/SimplifyLibCalls/StrCmp.ll
deleted file mode 100644
index 60854d76c9..0000000000
--- a/test/Transforms/SimplifyLibCalls/StrCmp.ll
+++ /dev/null
@@ -1,65 +0,0 @@
-; Test that the StrCmpOptimizer works correctly
-; RUN: opt < %s -simplify-libcalls -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"
-
-@hello = constant [6 x i8] c"hello\00"		; <[6 x i8]*> [#uses=1]
-@hell = constant [5 x i8] c"hell\00"		; <[5 x i8]*> [#uses=1]
-@bell = constant [5 x i8] c"bell\00"		; <[5 x i8]*> [#uses=1]
-@null = constant [1 x i8] zeroinitializer		; <[1 x i8]*> [#uses=1]
-
-declare i32 @strcmp(i8*, i8*)
-
-; strcmp("", x) -> -*x
-define i32 @test1(i8* %str) {
-  %temp1 = call i32 @strcmp(i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0), i8* %str)
-  ret i32 %temp1
-  ; CHECK: @test1
-  ; CHECK: %strcmpload = load i8* %str
-  ; CHECK: %1 = zext i8 %strcmpload to i32
-  ; CHECK: %temp1 = sub i32 0, %1
-  ; CHECK: ret i32 %temp1
-}
-
-; strcmp(x, "") -> *x
-define i32 @test2(i8* %str) {
-  %temp1 = call i32 @strcmp(i8* %str, i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0))
-  ret i32 %temp1
-  ; CHECK: @test2
-  ; CHECK: %strcmpload = load i8* %str
-  ; CHECK: %temp1 = zext i8 %strcmpload to i32
-  ; CHECK: ret i32 %temp1
-}
-
-; strcmp(x, y)  -> cnst
-define i32 @test3() {
-  %temp1 = call i32 @strcmp(i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0))
-  ret i32 %temp1
-  ; CHECK: @test3
-  ; CHECK: ret i32 -1
-}
-define i32 @test4() {
-  %temp1 = call i32 @strcmp(i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0))
-  ret i32 %temp1
-  ; CHECK: @test4
-  ; CHECK: ret i32 1
-}
-
-; strcmp(x, y)   -> memcmp(x, y, <known length>)
-; (This transform is rather difficult to trigger in a useful manner)
-define i32 @test5(i1 %b) {
-  %sel = select i1 %b, i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([5 x i8]* @bell, i32 0, i32 0)
-  %temp1 = call i32 @strcmp(i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0), i8* %sel)
-  ret i32 %temp1
-  ; CHECK: @test5
-  ; CHECK: %memcmp = call i32 @memcmp(i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0), i8* %sel, i32 5)
-  ; CHECK: ret i32 %memcmp
-}
-
-; strcmp(x,x)  -> 0
-define i32 @test6(i8* %str) {
-  %temp1 = call i32 @strcmp(i8* %str, i8* %str)
-  ret i32 %temp1
-  ; CHECK: @test6
-  ; CHECK: ret i32 0
-}
diff --git a/test/Transforms/SimplifyLibCalls/StrNCmp.ll b/test/Transforms/SimplifyLibCalls/StrNCmp.ll
deleted file mode 100644
index 0b2a501a3c..0000000000
--- a/test/Transforms/SimplifyLibCalls/StrNCmp.ll
+++ /dev/null
@@ -1,78 +0,0 @@
-; Test that the StrCmpOptimizer works correctly
-; RUN: opt < %s -simplify-libcalls -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"
-
-@hello = constant [6 x i8] c"hello\00"		; <[6 x i8]*> [#uses=1]
-@hell = constant [5 x i8] c"hell\00"		; <[5 x i8]*> [#uses=1]
-@bell = constant [5 x i8] c"bell\00"		; <[5 x i8]*> [#uses=1]
-@null = constant [1 x i8] zeroinitializer		; <[1 x i8]*> [#uses=1]
-
-declare i32 @strncmp(i8*, i8*, i32)
-
-; strcmp("", x) -> -*x
-define i32 @test1(i8* %str) {
-  %temp1 = call i32 @strncmp(i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0), i8* %str, i32 10)
-  ret i32 %temp1
-  ; CHECK: @test1
-  ; CHECK: %strcmpload = load i8* %str
-  ; CHECK: %1 = zext i8 %strcmpload to i32
-  ; CHECK: %temp1 = sub i32 0, %1
-  ; CHECK: ret i32 %temp1
-}
-
-; strcmp(x, "") -> *x
-define i32 @test2(i8* %str) {
-  %temp1 = call i32 @strncmp(i8* %str, i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0), i32 10)
-  ret i32 %temp1
-  ; CHECK: @test2
-  ; CHECK: %strcmpload = load i8* %str
-  ; CHECK: %temp1 = zext i8 %strcmpload to i32
-  ; CHECK: ret i32 %temp1
-}
-
-; strncmp(x, y, n)  -> cnst
-define i32 @test3() {
-  %temp1 = call i32 @strncmp(i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0), i32 10)
-  ret i32 %temp1
-  ; CHECK: @test3
-  ; CHECK: ret i32 -1
-}
-define i32 @test4() {
-  %temp1 = call i32 @strncmp(i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([1 x i8]* @null, i32 0, i32 0), i32 10)
-  ret i32 %temp1
-  ; CHECK: @test4
-  ; CHECK: ret i32 1
-}
-define i32 @test5() {
-  %temp1 = call i32 @strncmp(i8* getelementptr inbounds ([5 x i8]* @hell, i32 0, i32 0), i8* getelementptr inbounds ([6 x i8]* @hello, i32 0, i32 0), i32 4)
-  ret i32 %temp1
-  ; CHECK: @test5
-  ; CHECK: ret i32 0
-}
-
-; strncmp(x,y,1) -> memcmp(x,y,1)
-define i32 @test6(i8* %str1, i8* %str2) {
-  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 1)
-  ret i32 %temp1
-  ; CHECK: @test6
-  ; CHECK: load i8*
-  ; CHECK: load i8*
-  ; CHECK: sub i32
-}
-
-; strncmp(x,y,0)   -> 0
-define i32 @test7(i8* %str1, i8* %str2) {
-  %temp1 = call i32 @strncmp(i8* %str1, i8* %str2, i32 0)
-  ret i32 %temp1
-  ; CHECK: @test7
-  ; CHECK: ret i32 0
-}
-
-; strncmp(x,x,n)  -> 0
-define i32 @test8(i8* %str, i32 %n) {
-  %temp1 = call i32 @strncmp(i8* %str, i8* %str, i32 %n)
-  ret i32 %temp1
-  ; CHECK: @test8
-  ; CHECK: ret i32 0
-}
diff --git a/test/Transforms/SimplifyLibCalls/weak-symbols.ll b/test/Transforms/SimplifyLibCalls/weak-symbols.ll
deleted file mode 100644
index 5875b211f7..0000000000
--- a/test/Transforms/SimplifyLibCalls/weak-symbols.ll
+++ /dev/null
@@ -1,26 +0,0 @@
-; RUN: opt < %s -simplify-libcalls -S | FileCheck %s
-; PR4738
-
-; SimplifyLibcalls shouldn't assume anything about weak symbols.
-
-@real_init = weak_odr constant [2 x i8] c"y\00"
-@fake_init = weak constant [2 x i8] c"y\00"
-@.str = private constant [2 x i8] c"y\00"
-
-; CHECK: define i32 @foo
-; CHECK: call i32 @strcmp
-define i32 @foo() nounwind {
-entry:
-  %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @fake_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly
-  ret i32 %t0
-}
-
-; CHECK: define i32 @bar
-; CHECK: ret i32 0
-define i32 @bar() nounwind {
-entry:
-  %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @real_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly
-  ret i32 %t0
-}
-
-declare i32 @strcmp(i8*, i8*) nounwind readonly