IR: Change the gep_type_iterator API to avoid always exposing the "current" type.

Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.

Differential Revision: https://reviews.llvm.org/D26594

llvm-svn: 288458

9 files changed, 27 insertions, 32 deletions

diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index f1686a0a615..1df9ee7a94f 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -371,14 +371,14 @@ static bool IsUserOfGlobalSafeForSRA(User *U, GlobalValue *GV) {
   ++GEPI;  // Skip over the pointer index.
 
   // If this is a use of an array allocation, do a bit more checking for sanity.
-  if (ArrayType *AT = dyn_cast<ArrayType>(*GEPI)) {
-    uint64_t NumElements = AT->getNumElements();
+  if (GEPI.isSequential()) {
     ConstantInt *Idx = cast<ConstantInt>(U->getOperand(2));
 
     // Check to make sure that index falls within the array.  If not,
     // something funny is going on, so we won't do the optimization.
     //
-    if (Idx->getZExtValue() >= NumElements)
+    if (GEPI.isBoundedSequential() &&
+        Idx->getZExtValue() >= GEPI.getSequentialNumElements())
       return false;
 
     // We cannot scalar repl this level of the array unless any array
@@ -391,19 +391,13 @@ static bool IsUserOfGlobalSafeForSRA(User *U, GlobalValue *GV) {
     for (++GEPI; // Skip array index.
          GEPI != E;
          ++GEPI) {
-      uint64_t NumElements;
-      if (ArrayType *SubArrayTy = dyn_cast<ArrayType>(*GEPI))
-        NumElements = SubArrayTy->getNumElements();
-      else if (VectorType *SubVectorTy = dyn_cast<VectorType>(*GEPI))
-        NumElements = SubVectorTy->getNumElements();
-      else {
-        assert((*GEPI)->isStructTy() &&
-               "Indexed GEP type is not array, vector, or struct!");
+      if (GEPI.isStruct())
         continue;
-      }
 
       ConstantInt *IdxVal = dyn_cast<ConstantInt>(GEPI.getOperand());
-      if (!IdxVal || IdxVal->getZExtValue() >= NumElements)
+      if (!IdxVal ||
+          (GEPI.isBoundedSequential() &&
+           IdxVal->getZExtValue() >= GEPI.getSequentialNumElements()))
         return false;
     }
   }
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index bacb9ba5d59..c6100027abc 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -517,7 +517,7 @@ static Value *evaluateGEPOffsetExpression(User *GEP, InstCombiner &IC,
       if (CI->isZero()) continue;
 
       // Handle a struct index, which adds its field offset to the pointer.
-      if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+      if (StructType *STy = GTI.getStructTypeOrNull()) {
         Offset += DL.getStructLayout(STy)->getElementOffset(CI->getZExtValue());
       } else {
         uint64_t Size = DL.getTypeAllocSize(GTI.getIndexedType());
@@ -547,7 +547,7 @@ static Value *evaluateGEPOffsetExpression(User *GEP, InstCombiner &IC,
     if (CI->isZero()) continue;
 
     // Handle a struct index, which adds its field offset to the pointer.
-    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+    if (StructType *STy = GTI.getStructTypeOrNull()) {
       Offset += DL.getStructLayout(STy)->getElementOffset(CI->getZExtValue());
     } else {
       uint64_t Size = DL.getTypeAllocSize(GTI.getIndexedType());
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index cdbc8eb4585..90eba686966 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1389,7 +1389,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   for (User::op_iterator I = GEP.op_begin() + 1, E = GEP.op_end(); I != E;
        ++I, ++GTI) {
     // Skip indices into struct types.
-    if (isa<StructType>(*GTI))
+    if (GTI.isStruct())
       continue;
 
     // Index type should have the same width as IntPtr
@@ -1546,7 +1546,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
     bool EndsWithSequential = false;
     for (gep_type_iterator I = gep_type_begin(*Src), E = gep_type_end(*Src);
          I != E; ++I)
-      EndsWithSequential = !(*I)->isStructTy();
+      EndsWithSequential = I.isSequential();
 
     // Can we combine the two pointer arithmetics offsets?
     if (EndsWithSequential) {
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index c74d9111dc5..b19e663cc05 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -52,7 +52,7 @@ static int64_t GetOffsetFromIndex(const GEPOperator *GEP, unsigned Idx,
     if (OpC->isZero()) continue;  // No offset.
 
     // Handle struct indices, which add their field offset to the pointer.
-    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+    if (StructType *STy = GTI.getStructTypeOrNull()) {
       Offset += DL.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
       continue;
     }
diff --git a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
index 81744c08cd3..0a3bf7b4c31 100644
--- a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp
@@ -281,9 +281,10 @@ Instruction *NaryReassociatePass::tryReassociateGEP(GetElementPtrInst *GEP) {
     return nullptr;
 
   gep_type_iterator GTI = gep_type_begin(*GEP);
-  for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I) {
-    if (isa<SequentialType>(*GTI++)) {
-      if (auto *NewGEP = tryReassociateGEPAtIndex(GEP, I - 1, *GTI)) {
+  for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I, ++GTI) {
+    if (GTI.isSequential()) {
+      if (auto *NewGEP = tryReassociateGEPAtIndex(GEP, I - 1,
+                                                  GTI.getIndexedType())) {
         return NewGEP;
       }
     }
diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
index 54ce1d8fb60..66de397676e 100644
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -692,7 +692,7 @@ private:
           break;
 
         // Handle a struct index, which adds its field offset to the pointer.
-        if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+        if (StructType *STy = GTI.getStructTypeOrNull()) {
           unsigned ElementIdx = OpC->getZExtValue();
           const StructLayout *SL = DL.getStructLayout(STy);
           GEPOffset +=
diff --git a/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp b/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
index 62c9f46089a..4d594532c36 100644
--- a/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
+++ b/llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
@@ -722,7 +722,7 @@ bool SeparateConstOffsetFromGEP::canonicalizeArrayIndicesToPointerSize(
   for (User::op_iterator I = GEP->op_begin() + 1, E = GEP->op_end();
        I != E; ++I, ++GTI) {
     // Skip struct member indices which must be i32.
-    if (isa<SequentialType>(*GTI)) {
+    if (GTI.isSequential()) {
       if ((*I)->getType() != IntPtrTy) {
         *I = CastInst::CreateIntegerCast(*I, IntPtrTy, true, "idxprom", GEP);
         Changed = true;
@@ -739,7 +739,7 @@ SeparateConstOffsetFromGEP::accumulateByteOffset(GetElementPtrInst *GEP,
   int64_t AccumulativeByteOffset = 0;
   gep_type_iterator GTI = gep_type_begin(*GEP);
   for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I, ++GTI) {
-    if (isa<SequentialType>(*GTI)) {
+    if (GTI.isSequential()) {
       // Tries to extract a constant offset from this GEP index.
       int64_t ConstantOffset =
           ConstantOffsetExtractor::Find(GEP->getOperand(I), GEP, DT);
@@ -752,7 +752,7 @@ SeparateConstOffsetFromGEP::accumulateByteOffset(GetElementPtrInst *GEP,
             ConstantOffset * DL->getTypeAllocSize(GTI.getIndexedType());
       }
     } else if (LowerGEP) {
-      StructType *StTy = cast<StructType>(*GTI);
+      StructType *StTy = GTI.getStructType();
       uint64_t Field = cast<ConstantInt>(GEP->getOperand(I))->getZExtValue();
       // Skip field 0 as the offset is always 0.
       if (Field != 0) {
@@ -787,7 +787,7 @@ void SeparateConstOffsetFromGEP::lowerToSingleIndexGEPs(
   // Create an ugly GEP for each sequential index. We don't create GEPs for
   // structure indices, as they are accumulated in the constant offset index.
   for (unsigned I = 1, E = Variadic->getNumOperands(); I != E; ++I, ++GTI) {
-    if (isa<SequentialType>(*GTI)) {
+    if (GTI.isSequential()) {
       Value *Idx = Variadic->getOperand(I);
       // Skip zero indices.
       if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx))
@@ -848,7 +848,7 @@ SeparateConstOffsetFromGEP::lowerToArithmetics(GetElementPtrInst *Variadic,
   // don't create arithmetics for structure indices, as they are accumulated
   // in the constant offset index.
   for (unsigned I = 1, E = Variadic->getNumOperands(); I != E; ++I, ++GTI) {
-    if (isa<SequentialType>(*GTI)) {
+    if (GTI.isSequential()) {
       Value *Idx = Variadic->getOperand(I);
       // Skip zero indices.
       if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx))
@@ -928,7 +928,7 @@ bool SeparateConstOffsetFromGEP::splitGEP(GetElementPtrInst *GEP) {
   // handle the constant offset and won't need a new structure index.
   gep_type_iterator GTI = gep_type_begin(*GEP);
   for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I, ++GTI) {
-    if (isa<SequentialType>(*GTI)) {
+    if (GTI.isSequential()) {
       // Splits this GEP index into a variadic part and a constant offset, and
       // uses the variadic part as the new index.
       Value *OldIdx = GEP->getOperand(I);
diff --git a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
index c4d18f1c156..2be3f5c533b 100644
--- a/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
@@ -490,8 +490,8 @@ void StraightLineStrengthReduce::allocateCandidatesAndFindBasisForGEP(
     IndexExprs.push_back(SE->getSCEV(*I));
 
   gep_type_iterator GTI = gep_type_begin(GEP);
-  for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I) {
-    if (!isa<SequentialType>(*GTI++))
+  for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I, ++GTI) {
+    if (GTI.isStruct())
       continue;
 
     const SCEV *OrigIndexExpr = IndexExprs[I - 1];
@@ -501,7 +501,7 @@ void StraightLineStrengthReduce::allocateCandidatesAndFindBasisForGEP(
     // indices except this current one.
     const SCEV *BaseExpr = SE->getGEPExpr(cast<GEPOperator>(GEP), IndexExprs);
     Value *ArrayIdx = GEP->getOperand(I);
-    uint64_t ElementSize = DL->getTypeAllocSize(*GTI);
+    uint64_t ElementSize = DL->getTypeAllocSize(GTI.getIndexedType());
     if (ArrayIdx->getType()->getIntegerBitWidth() <=
         DL->getPointerSizeInBits(GEP->getAddressSpace())) {
       // Skip factoring if ArrayIdx is wider than the pointer size, because
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 323b81ca815..2f4e3e99b3f 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1416,7 +1416,7 @@ static bool canReplaceOperandWithVariable(const Instruction *I,
     if (OpIdx == 0)
       return true;
     gep_type_iterator It = std::next(gep_type_begin(I), OpIdx - 1);
-    return !It->isStructTy();
+    return It.isSequential();
   }
 }