[llvm-commits] CVS: llvm/lib/VMCore/ConstantHandling.cpp
Chris Lattner
lattner at cs.uiuc.edu
Wed Aug 20 11:12:09 PDT 2003
Changes in directory llvm/lib/VMCore:
ConstantHandling.cpp updated: 1.33 -> 1.34
---
Log message:
Implement testcase: Assembler/2003-08-20-ConstantExprGEP-Fold.llx
---
Diffs of the changes:
Index: llvm/lib/VMCore/ConstantHandling.cpp
diff -u llvm/lib/VMCore/ConstantHandling.cpp:1.33 llvm/lib/VMCore/ConstantHandling.cpp:1.34
--- llvm/lib/VMCore/ConstantHandling.cpp:1.33 Wed Aug 13 10:52:25 2003
+++ llvm/lib/VMCore/ConstantHandling.cpp Wed Aug 20 11:11:27 2003
@@ -142,23 +142,27 @@
// FIXME: Implement folding of GEP constant exprs the same as instcombine does
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
- // Implement folding of:
- // void ()** getelementptr (%struct..TorRec* getelementptr
- // ([N x %struct..TorRec]* %llvm.global_dtors, long 0, long 0),
- // long 0, ubyte 1)
- // Into:
- // %struct..TorRec* getelementptr ([N x %struct..TorRec]*
- // %llvm.global_dtors, long 0, long 0, ubyte 1)
+ // Combine Indices - If the source pointer to this getelementptr instruction
+ // is a getelementptr instruction, combine the indices of the two
+ // getelementptr instructions into a single instruction.
//
- if (CE->getOpcode() == Instruction::GetElementPtr)
- if (IdxList[0] == Constant::getNullValue(Type::LongTy)) {
+ if (CE->getOpcode() == Instruction::GetElementPtr) {
+ if (CE->getOperand(CE->getNumOperands()-1)->getType() == Type::LongTy) {
std::vector<Constant*> NewIndices;
NewIndices.reserve(IdxList.size() + CE->getNumOperands());
- for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
+ for (unsigned i = 1, e = CE->getNumOperands()-1; i != e; ++i)
NewIndices.push_back(cast<Constant>(CE->getOperand(i)));
+
+ // Add the last index of the source with the first index of the new GEP.
+ Constant *Combined =
+ ConstantExpr::get(Instruction::Add, IdxList[0],
+ CE->getOperand(CE->getNumOperands()-1));
+
+ NewIndices.push_back(Combined);
NewIndices.insert(NewIndices.end(), IdxList.begin()+1, IdxList.end());
return ConstantExpr::getGetElementPtr(CE->getOperand(0), NewIndices);
}
+ }
// Implement folding of:
// int* getelementptr ([2 x int]* cast ([3 x int]* %X to [2 x int]*),
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