[llvm-commits] CVS: llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp

[Chris Lattner]

Changes in directory llvm-poolalloc/lib/PoolAllocate:

PointerCompress.cpp updated: 1.8 -> 1.9
---
Log message:

Implement the simple and common 3-operand form of getelementptr: gep P, 0, uint


---
Diffs of the changes:  (+28 -1)

 PointerCompress.cpp |   29 ++++++++++++++++++++++++++++-
 1 files changed, 28 insertions(+), 1 deletion(-)


Index: llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp
diff -u llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.8 llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.9
--- llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.8	Sun Feb 13 09:57:23 2005
+++ llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp	Sun Feb 13 14:36:10 2005
@@ -248,13 +248,14 @@
   
     const PointerCompress::PoolInfoMap &PoolInfo;
 
+    const TargetData &TD;
     const DSGraph &DSG;
 
     PointerCompress &PtrComp;
   public:
     InstructionRewriter(const PointerCompress::PoolInfoMap &poolInfo,
                         const DSGraph &dsg, PointerCompress &ptrcomp)
-      : PoolInfo(poolInfo), DSG(dsg), PtrComp(ptrcomp) {
+      : PoolInfo(poolInfo), TD(dsg.getTargetData()), DSG(dsg), PtrComp(ptrcomp){
     }
 
     ~InstructionRewriter();
@@ -318,6 +319,7 @@
     void visitCastInst(CastInst &CI);
     void visitPHINode(PHINode &PN);
     void visitSetCondInst(SetCondInst &SCI);
+    void visitGetElementPtrInst(GetElementPtrInst &GEPI);
     void visitLoadInst(LoadInst &LI);
     void visitStoreInst(StoreInst &SI);
 
@@ -406,6 +408,31 @@
   SCI.eraseFromParent();
 }
 
+void InstructionRewriter::visitGetElementPtrInst(GetElementPtrInst &GEPI) {
+  const CompressedPoolInfo *PI = getPoolInfo(&GEPI);
+  if (PI == 0) return;
+
+  // For now, we only support very very simple getelementptr instructions, with
+  // two indices, where the first is zero.
+  assert(GEPI.getNumOperands() == 3 && isa<Constant>(GEPI.getOperand(1)) &&
+         cast<Constant>(GEPI.getOperand(1))->isNullValue());
+  const Type *IdxTy = 
+    cast<PointerType>(GEPI.getOperand(0)->getType())->getElementType();
+  assert(isa<StructType>(IdxTy) && "Can only handle structs right now!");
+
+  Value *Val = getTransformedValue(GEPI.getOperand(0));
+
+  unsigned Field = (unsigned)cast<ConstantUInt>(GEPI.getOperand(2))->getValue();
+  if (Field) {
+    const StructType *NTy = cast<StructType>(PI->getNewType());
+    uint64_t FieldOffs = TD.getStructLayout(NTy)->MemberOffsets[Field];
+    Constant *FieldOffsCst = ConstantUInt::get(UINTTYPE, FieldOffs);
+    Val = BinaryOperator::createAdd(Val, FieldOffsCst, GEPI.getName(), &GEPI);
+  }
+
+  setTransformedValue(GEPI, Val);
+}
+
 void InstructionRewriter::visitLoadInst(LoadInst &LI) {
   if (isa<ConstantPointerNull>(LI.getOperand(0))) return; // load null ??