DataLayout is mandatory, update the API to reflect it with references.

Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740

1 files changed, 20 insertions, 30 deletions

diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index 4a15adfc2e1..1514e78010e 100644
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -103,7 +103,7 @@ static uint64_t getObjectSize(const Value *V, const DataLayout &DL,
                               const TargetLibraryInfo &TLI,
                               bool RoundToAlign = false) {
   uint64_t Size;
-  if (getObjectSize(V, Size, &DL, &TLI, RoundToAlign))
+  if (getObjectSize(V, Size, DL, &TLI, RoundToAlign))
     return Size;
   return AliasAnalysis::UnknownSize;
 }
@@ -221,7 +221,7 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset,
       case Instruction::Or:
         // X|C == X+C if all the bits in C are unset in X.  Otherwise we can't
         // analyze it.
-        if (!MaskedValueIsZero(BOp->getOperand(0), RHSC->getValue(), &DL, 0, AC,
+        if (!MaskedValueIsZero(BOp->getOperand(0), RHSC->getValue(), DL, 0, AC,
                                BOp, DT))
           break;
         // FALL THROUGH.
@@ -292,7 +292,7 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset,
 static const Value *
 DecomposeGEPExpression(const Value *V, int64_t &BaseOffs,
                        SmallVectorImpl<VariableGEPIndex> &VarIndices,
-                       bool &MaxLookupReached, const DataLayout *DL,
+                       bool &MaxLookupReached, const DataLayout &DL,
                        AssumptionCache *AC, DominatorTree *DT) {
   // Limit recursion depth to limit compile time in crazy cases.
   unsigned MaxLookup = MaxLookupSearchDepth;
@@ -341,16 +341,6 @@ DecomposeGEPExpression(const Value *V, int64_t &BaseOffs,
     if (!GEPOp->getOperand(0)->getType()->getPointerElementType()->isSized())
       return V;
 
-    // If we are lacking DataLayout information, we can't compute the offets of
-    // elements computed by GEPs.  However, we can handle bitcast equivalent
-    // GEPs.
-    if (!DL) {
-      if (!GEPOp->hasAllZeroIndices())
-        return V;
-      V = GEPOp->getOperand(0);
-      continue;
-    }
-
     unsigned AS = GEPOp->getPointerAddressSpace();
     // Walk the indices of the GEP, accumulating them into BaseOff/VarIndices.
     gep_type_iterator GTI = gep_type_begin(GEPOp);
@@ -363,30 +353,30 @@ DecomposeGEPExpression(const Value *V, int64_t &BaseOffs,
         unsigned FieldNo = cast<ConstantInt>(Index)->getZExtValue();
         if (FieldNo == 0) continue;
 
-        BaseOffs += DL->getStructLayout(STy)->getElementOffset(FieldNo);
+        BaseOffs += DL.getStructLayout(STy)->getElementOffset(FieldNo);
         continue;
       }
 
       // For an array/pointer, add the element offset, explicitly scaled.
       if (ConstantInt *CIdx = dyn_cast<ConstantInt>(Index)) {
         if (CIdx->isZero()) continue;
-        BaseOffs += DL->getTypeAllocSize(*GTI)*CIdx->getSExtValue();
+        BaseOffs += DL.getTypeAllocSize(*GTI) * CIdx->getSExtValue();
         continue;
       }
 
-      uint64_t Scale = DL->getTypeAllocSize(*GTI);
+      uint64_t Scale = DL.getTypeAllocSize(*GTI);
       ExtensionKind Extension = EK_NotExtended;
 
       // If the integer type is smaller than the pointer size, it is implicitly
       // sign extended to pointer size.
       unsigned Width = Index->getType()->getIntegerBitWidth();
-      if (DL->getPointerSizeInBits(AS) > Width)
+      if (DL.getPointerSizeInBits(AS) > Width)
         Extension = EK_SignExt;
 
       // Use GetLinearExpression to decompose the index into a C1*V+C2 form.
       APInt IndexScale(Width, 0), IndexOffset(Width, 0);
-      Index = GetLinearExpression(Index, IndexScale, IndexOffset, Extension,
-                                  *DL, 0, AC, DT);
+      Index = GetLinearExpression(Index, IndexScale, IndexOffset, Extension, DL,
+                                  0, AC, DT);
 
       // The GEP index scale ("Scale") scales C1*V+C2, yielding (C1*V+C2)*Scale.
       // This gives us an aggregate computation of (C1*Scale)*V + C2*Scale.
@@ -408,7 +398,7 @@ DecomposeGEPExpression(const Value *V, int64_t &BaseOffs,
 
       // Make sure that we have a scale that makes sense for this target's
       // pointer size.
-      if (unsigned ShiftBits = 64 - DL->getPointerSizeInBits(AS)) {
+      if (unsigned ShiftBits = 64 - DL.getPointerSizeInBits(AS)) {
         Scale <<= ShiftBits;
         Scale = (int64_t)Scale >> ShiftBits;
       }
@@ -610,7 +600,7 @@ BasicAliasAnalysis::pointsToConstantMemory(const Location &Loc, bool OrLocal) {
   SmallVector<const Value *, 16> Worklist;
   Worklist.push_back(Loc.Ptr);
   do {
-    const Value *V = GetUnderlyingObject(Worklist.pop_back_val(), DL);
+    const Value *V = GetUnderlyingObject(Worklist.pop_back_val(), *DL);
     if (!Visited.insert(V).second) {
       Visited.clear();
       return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
@@ -828,7 +818,7 @@ BasicAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
   assert(notDifferentParent(CS.getInstruction(), Loc.Ptr) &&
          "AliasAnalysis query involving multiple functions!");
 
-  const Value *Object = GetUnderlyingObject(Loc.Ptr, DL);
+  const Value *Object = GetUnderlyingObject(Loc.Ptr, *DL);
 
   // If this is a tail call and Loc.Ptr points to a stack location, we know that
   // the tail call cannot access or modify the local stack.
@@ -1045,10 +1035,10 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
         SmallVector<VariableGEPIndex, 4> GEP2VariableIndices;
         const Value *GEP2BasePtr =
             DecomposeGEPExpression(GEP2, GEP2BaseOffset, GEP2VariableIndices,
-                                   GEP2MaxLookupReached, DL, AC2, DT);
+                                   GEP2MaxLookupReached, *DL, AC2, DT);
         const Value *GEP1BasePtr =
             DecomposeGEPExpression(GEP1, GEP1BaseOffset, GEP1VariableIndices,
-                                   GEP1MaxLookupReached, DL, AC1, DT);
+                                   GEP1MaxLookupReached, *DL, AC1, DT);
         // DecomposeGEPExpression and GetUnderlyingObject should return the
         // same result except when DecomposeGEPExpression has no DataLayout.
         if (GEP1BasePtr != UnderlyingV1 || GEP2BasePtr != UnderlyingV2) {
@@ -1077,14 +1067,14 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
     // about the relation of the resulting pointer.
     const Value *GEP1BasePtr =
         DecomposeGEPExpression(GEP1, GEP1BaseOffset, GEP1VariableIndices,
-                               GEP1MaxLookupReached, DL, AC1, DT);
+                               GEP1MaxLookupReached, *DL, AC1, DT);
 
     int64_t GEP2BaseOffset;
     bool GEP2MaxLookupReached;
     SmallVector<VariableGEPIndex, 4> GEP2VariableIndices;
     const Value *GEP2BasePtr =
         DecomposeGEPExpression(GEP2, GEP2BaseOffset, GEP2VariableIndices,
-                               GEP2MaxLookupReached, DL, AC2, DT);
+                               GEP2MaxLookupReached, *DL, AC2, DT);
 
     // DecomposeGEPExpression and GetUnderlyingObject should return the
     // same result except when DecomposeGEPExpression has no DataLayout.
@@ -1134,7 +1124,7 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
 
     const Value *GEP1BasePtr =
         DecomposeGEPExpression(GEP1, GEP1BaseOffset, GEP1VariableIndices,
-                               GEP1MaxLookupReached, DL, AC1, DT);
+                               GEP1MaxLookupReached, *DL, AC1, DT);
 
     // DecomposeGEPExpression and GetUnderlyingObject should return the
     // same result except when DecomposeGEPExpression has no DataLayout.
@@ -1203,7 +1193,7 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
         const Value *V = GEP1VariableIndices[i].V;
 
         bool SignKnownZero, SignKnownOne;
-        ComputeSignBit(const_cast<Value *>(V), SignKnownZero, SignKnownOne, DL,
+        ComputeSignBit(const_cast<Value *>(V), SignKnownZero, SignKnownOne, *DL,
                        0, AC1, nullptr, DT);
 
         // Zero-extension widens the variable, and so forces the sign
@@ -1412,8 +1402,8 @@ BasicAliasAnalysis::aliasCheck(const Value *V1, uint64_t V1Size,
     return NoAlias;  // Scalars cannot alias each other
 
   // Figure out what objects these things are pointing to if we can.
-  const Value *O1 = GetUnderlyingObject(V1, DL, MaxLookupSearchDepth);
-  const Value *O2 = GetUnderlyingObject(V2, DL, MaxLookupSearchDepth);
+  const Value *O1 = GetUnderlyingObject(V1, *DL, MaxLookupSearchDepth);
+  const Value *O2 = GetUnderlyingObject(V2, *DL, MaxLookupSearchDepth);
 
   // Null values in the default address space don't point to any object, so they
   // don't alias any other pointer.