[NFC] Replace several manual GEP loops with gep_type_iterator.

Reviewers: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16335

llvm-svn: 258262

2 files changed, 13 insertions, 31 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index bf4121346fa..e36f99fbfa6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -56,6 +56,7 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -492,13 +493,11 @@ bool FastISel::selectGetElementPtr(const User *I) {
   uint64_t TotalOffs = 0;
   // FIXME: What's a good SWAG number for MaxOffs?
   uint64_t MaxOffs = 2048;
-  Type *Ty = I->getOperand(0)->getType();
   MVT VT = TLI.getPointerTy(DL);
-  for (GetElementPtrInst::const_op_iterator OI = I->op_begin() + 1,
-                                            E = I->op_end();
-       OI != E; ++OI) {
-    const Value *Idx = *OI;
-    if (auto *StTy = dyn_cast<StructType>(Ty)) {
+  for (gep_type_iterator GTI = gep_type_begin(I), E = gep_type_end(I);
+       GTI != E; ++GTI) {
+    const Value *Idx = GTI.getOperand();
+    if (auto *StTy = dyn_cast<StructType>(*GTI)) {
       uint64_t Field = cast<ConstantInt>(Idx)->getZExtValue();
       if (Field) {
         // N = N + Offset
@@ -511,15 +510,8 @@ bool FastISel::selectGetElementPtr(const User *I) {
           TotalOffs = 0;
         }
       }
-      Ty = StTy->getElementType(Field);
     } else {
-      if (Ty->isPointerTy()) {
-        // The only pointer type is for the very first index,
-        // therefore the next type is the source element type.
-        Ty = cast<GEPOperator>(I)->getSourceElementType();
-      } else {
-        Ty = cast<SequentialType>(Ty)->getElementType();
-      }
+      Type *Ty = GTI.getIndexedType();
 
       // If this is a constant subscript, handle it quickly.
       if (const auto *CI = dyn_cast<ConstantInt>(Idx)) {
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index ac740047140..3b8d3094b3a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -42,6 +42,7 @@
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"
@@ -2982,8 +2983,7 @@ void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
   Value *Op0 = I.getOperand(0);
   // Note that the pointer operand may be a vector of pointers. Take the scalar
   // element which holds a pointer.
-  Type *Ty = Op0->getType()->getScalarType();
-  unsigned AS = Ty->getPointerAddressSpace();
+  unsigned AS = Op0->getType()->getScalarType()->getPointerAddressSpace();
   SDValue N = getValue(Op0);
   SDLoc dl = getCurSDLoc();
 
@@ -2997,10 +2997,10 @@ void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
     SmallVector<SDValue, 16> Ops(VectorWidth, N);
     N = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
   }
-  for (GetElementPtrInst::const_op_iterator OI = I.op_begin()+1, E = I.op_end();
-       OI != E; ++OI) {
-    const Value *Idx = *OI;
-    if (StructType *StTy = dyn_cast<StructType>(Ty)) {
+  for (gep_type_iterator GTI = gep_type_begin(&I), E = gep_type_end(&I);
+       GTI != E; ++GTI) {
+    const Value *Idx = GTI.getOperand();
+    if (StructType *StTy = dyn_cast<StructType>(*GTI)) {
       unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue();
       if (Field) {
         // N = N + Offset
@@ -3015,21 +3015,11 @@ void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
         N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N,
                         DAG.getConstant(Offset, dl, N.getValueType()), &Flags);
       }
-
-      Ty = StTy->getElementType(Field);
     } else {
-      if (Ty->isPointerTy()) {
-        // The only pointer type is for the very first index,
-        // therefore the next type is the source element type.
-        Ty = cast<GEPOperator>(&I)->getSourceElementType();
-      } else {
-        Ty = cast<SequentialType>(Ty)->getElementType();
-      }
-
       MVT PtrTy =
           DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout(), AS);
       unsigned PtrSize = PtrTy.getSizeInBits();
-      APInt ElementSize(PtrSize, DL->getTypeAllocSize(Ty));
+      APInt ElementSize(PtrSize, DL->getTypeAllocSize(GTI.getIndexedType()));
 
       // If this is a scalar constant or a splat vector of constants,
       // handle it quickly.