From 186f8d90df976349481ccf8c8e24c37c6ec5ffb4 Mon Sep 17 00:00:00 2001
From: Meador Inge <meadori@codesourcery.com>
Date: Sat, 13 Oct 2012 16:45:37 +0000
Subject: instcombine: Migrate strchr and strrchr optimizations

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165875 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/SimplifyLibCalls.cpp | 91 ------------------------------
 1 file changed, 91 deletions(-)

(limited to 'lib/Transforms/Scalar/SimplifyLibCalls.cpp')

diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 22a01fc968..4cd8742cc3 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -134,94 +134,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
 //===----------------------------------------------------------------------===//
 
 namespace {
-//===---------------------------------------===//
-// 'strchr' Optimizations
-
-struct StrChrOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    // Verify the "strchr" function prototype.
-    FunctionType *FT = Callee->getFunctionType();
-    if (FT->getNumParams() != 2 ||
-        FT->getReturnType() != B.getInt8PtrTy() ||
-        FT->getParamType(0) != FT->getReturnType() ||
-        !FT->getParamType(1)->isIntegerTy(32))
-      return 0;
-
-    Value *SrcStr = CI->getArgOperand(0);
-
-    // If the second operand is non-constant, see if we can compute the length
-    // of the input string and turn this into memchr.
-    ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
-    if (CharC == 0) {
-      // These optimizations require DataLayout.
-      if (!TD) return 0;
-
-      uint64_t Len = GetStringLength(SrcStr);
-      if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32))// memchr needs i32.
-        return 0;
-
-      return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
-                        ConstantInt::get(TD->getIntPtrType(*Context), Len),
-                        B, TD, TLI);
-    }
-
-    // Otherwise, the character is a constant, see if the first argument is
-    // a string literal.  If so, we can constant fold.
-    StringRef Str;
-    if (!getConstantStringInfo(SrcStr, Str))
-      return 0;
-
-    // Compute the offset, make sure to handle the case when we're searching for
-    // zero (a weird way to spell strlen).
-    size_t I = CharC->getSExtValue() == 0 ?
-        Str.size() : Str.find(CharC->getSExtValue());
-    if (I == StringRef::npos) // Didn't find the char.  strchr returns null.
-      return Constant::getNullValue(CI->getType());
-
-    // strchr(s+n,c)  -> gep(s+n+i,c)
-    return B.CreateGEP(SrcStr, B.getInt64(I), "strchr");
-  }
-};
-
-//===---------------------------------------===//
-// 'strrchr' Optimizations
-
-struct StrRChrOpt : public LibCallOptimization {
-  virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
-    // Verify the "strrchr" function prototype.
-    FunctionType *FT = Callee->getFunctionType();
-    if (FT->getNumParams() != 2 ||
-        FT->getReturnType() != B.getInt8PtrTy() ||
-        FT->getParamType(0) != FT->getReturnType() ||
-        !FT->getParamType(1)->isIntegerTy(32))
-      return 0;
-
-    Value *SrcStr = CI->getArgOperand(0);
-    ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
-
-    // Cannot fold anything if we're not looking for a constant.
-    if (!CharC)
-      return 0;
-
-    StringRef Str;
-    if (!getConstantStringInfo(SrcStr, Str)) {
-      // strrchr(s, 0) -> strchr(s, 0)
-      if (TD && CharC->isZero())
-        return EmitStrChr(SrcStr, '\0', B, TD, TLI);
-      return 0;
-    }
-
-    // Compute the offset.
-    size_t I = CharC->getSExtValue() == 0 ?
-        Str.size() : Str.rfind(CharC->getSExtValue());
-    if (I == StringRef::npos) // Didn't find the char. Return null.
-      return Constant::getNullValue(CI->getType());
-
-    // strrchr(s+n,c) -> gep(s+n+i,c)
-    return B.CreateGEP(SrcStr, B.getInt64(I), "strrchr");
-  }
-};
-
 //===---------------------------------------===//
 // 'strcmp' Optimizations
 
@@ -1466,7 +1378,6 @@ namespace {
 
     StringMap<LibCallOptimization*> Optimizations;
     // String and Memory LibCall Optimizations
-    StrChrOpt StrChr; StrRChrOpt StrRChr;
     StrCmpOpt StrCmp; StrNCmpOpt StrNCmp;
     StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
     StpCpyOpt StpCpy; StpCpyOpt StpCpyChk;
@@ -1541,8 +1452,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
 /// we know.
 void SimplifyLibCalls::InitOptimizations() {
   // String and Memory LibCall Optimizations
-  Optimizations["strchr"] = &StrChr;
-  Optimizations["strrchr"] = &StrRChr;
   Optimizations["strcmp"] = &StrCmp;
   Optimizations["strncmp"] = &StrNCmp;
   Optimizations["strcpy"] = &StrCpy;
-- 
cgit v1.2.3