Revert a part of r223583, for now. It seems causing different emission between stage2...

[oota-llvm.git] / lib / Analysis / InstructionSimplify.cpp

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 85ebf694e695d8661322a8b1b56b2ea2ec66ae9e..5c536aa79c480c657aefd31481aa65ef1aecddf9 100644 (file)
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1443,12 +1443,52 @@ Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
                             RecursionLimit);
 }
 
+static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
+                                         ICmpInst *UnsignedICmp, bool IsAnd) {
+  Value *X, *Y;
+
+  ICmpInst::Predicate EqPred;
+  if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) &&
+      ICmpInst::isEquality(EqPred))
+    return nullptr;
+
+  ICmpInst::Predicate UnsignedPred;
+  if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) &&
+      ICmpInst::isUnsigned(UnsignedPred))
+    ;
+  else if (match(UnsignedICmp,
+                 m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) &&
+           ICmpInst::isUnsigned(UnsignedPred))
+    UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred);
+  else
+    return nullptr;
+
+  // X < Y && Y != 0  -->  X < Y
+  // X < Y || Y != 0  -->  Y != 0
+  if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE)
+    return IsAnd ? UnsignedICmp : ZeroICmp;
+
+  // X >= Y || Y != 0  -->  true
+  // X >= Y || Y == 0  -->  X >= Y
+  if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) {
+    if (EqPred == ICmpInst::ICMP_NE)
+      return getTrue(UnsignedICmp->getType());
+    return UnsignedICmp;
+  }
+
+  return nullptr;
+}
+
 // Simplify (and (icmp ...) (icmp ...)) to true when we can tell that the range
 // of possible values cannot be satisfied.
 static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
   ICmpInst::Predicate Pred0, Pred1;
   ConstantInt *CI1, *CI2;
   Value *V;
+
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
+    return X;
+
   if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
                          m_ConstantInt(CI2))))
    return nullptr;
@@ -1602,6 +1642,10 @@ static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
   ICmpInst::Predicate Pred0, Pred1;
   ConstantInt *CI1, *CI2;
   Value *V;
+
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+    return X;
+
   if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
                          m_ConstantInt(CI2))))
    return nullptr;
@@ -2026,12 +2070,23 @@ static Constant *computePointerICmp(const DataLayout *DL,
     };
 
     // Is the set of underlying objects all things which must be disjoint from
-    // noalias calls.
+    // noalias calls. For allocas, we consider only static ones (dynamic
+    // allocas might be transformed into calls to malloc not simultaneously
+    // live with the compared-to allocation). For globals, we exclude symbols
+    // that might be resolve lazily to symbols in another dynamically-loaded
+    // library (and, thus, could be malloc'ed by the implementation).
     auto IsAllocDisjoint = [](SmallVectorImpl<Value *> &Objects) {
       return std::all_of(Objects.begin(), Objects.end(),
                          [](Value *V){
-                           if (isa<AllocaInst>(V) || isa<GlobalValue>(V))
-                             return true;
+                           if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
+                             return AI->getParent() && AI->getParent()->getParent() &&
+                                    AI->isStaticAlloca();
+                           if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
+                             return (GV->hasLocalLinkage() ||
+                                     GV->hasHiddenVisibility() ||
+                                     GV->hasProtectedVisibility() ||
+                                     GV->hasUnnamedAddr()) &&
+                                    !GV->isThreadLocal();
                            if (const Argument *A = dyn_cast<Argument>(V))
                              return A->hasByValAttr();
                            return false;