Implement getelementptr instruction as well as the load and store forms
that incorporate gep
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1036 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/Interpreter/Execution.cpp b/lib/ExecutionEngine/Interpreter/Execution.cpp
index 60bd77b..52d7e86 100644
--- a/lib/ExecutionEngine/Interpreter/Execution.cpp
+++ b/lib/ExecutionEngine/Interpreter/Execution.cpp
@@ -568,10 +568,45 @@
free((void*)Value.ULongVal); // Free memory
}
+
+// getElementOffset - The workhorse for getelementptr, load and store. This
+// function returns the offset that arguments ArgOff+1 -> NumArgs specify for
+// the pointer type specified by argument Arg.
+//
+static uint64_t getElementOffset(Instruction *I, unsigned ArgOff) {
+ assert(isa<PointerType>(I->getOperand(ArgOff)->getType()) &&
+ "Cannot getElementOffset of a nonpointer type!");
+
+ uint64_t Total = 0;
+ const Type *Ty =
+ cast<PointerType>(I->getOperand(ArgOff++)->getType())->getValueType();
+
+ while (ArgOff < I->getNumOperands()) {
+ const StructType *STy = cast<StructType>(Ty);
+ const StructLayout *SLO = TD.getStructLayout(STy);
+
+ // Indicies must be ubyte constants...
+ const ConstPoolUInt *CPU = cast<ConstPoolUInt>(I->getOperand(ArgOff++));
+ assert(CPU->getType() == Type::UByteTy);
+ Total += SLO->MemberOffsets[CPU->getValue()];
+ }
+
+ return Total;
+}
+
+static void executeGEPInst(GetElementPtrInst *I, ExecutionContext &SF) {
+ uint64_t SrcPtr = getOperandValue(I->getPtrOperand(), SF).ULongVal;
+
+ GenericValue Result;
+ Result.ULongVal = SrcPtr + getElementOffset(I, 0);
+ SetValue(I, Result, SF);
+}
+
static void executeLoadInst(LoadInst *I, ExecutionContext &SF) {
- assert(I->getNumOperands() == 1 && "NI!");
- GenericValue *Ptr =
- (GenericValue*)getOperandValue(I->getPtrOperand(), SF).ULongVal;
+ uint64_t SrcPtr = getOperandValue(I->getPtrOperand(), SF).ULongVal;
+ SrcPtr += getElementOffset(I, 0); // Handle any structure indices
+
+ GenericValue *Ptr = (GenericValue*)SrcPtr;
GenericValue Result;
switch (I->getType()->getPrimitiveID()) {
@@ -595,10 +630,11 @@
}
static void executeStoreInst(StoreInst *I, ExecutionContext &SF) {
- GenericValue *Ptr =
- (GenericValue *)getOperandValue(I->getPtrOperand(), SF).ULongVal;
+ uint64_t SrcPtr = getOperandValue(I->getPtrOperand(), SF).ULongVal;
+ SrcPtr += getElementOffset(I, 1); // Handle any structure indices
+
+ GenericValue *Ptr = (GenericValue *)SrcPtr;
GenericValue Val = getOperandValue(I->getOperand(0), SF);
- assert(I->getNumOperands() == 2 && "NI!");
switch (I->getOperand(0)->getType()->getPrimitiveID()) {
case Type::BoolTyID:
@@ -850,6 +886,8 @@
case Instruction::Free: executeFreeInst (cast<FreeInst> (I), SF); break;
case Instruction::Load: executeLoadInst (cast<LoadInst> (I), SF); break;
case Instruction::Store: executeStoreInst (cast<StoreInst>(I), SF); break;
+ case Instruction::GetElementPtr:
+ executeGEPInst(cast<GetElementPtrInst>(I), SF); break;
// Miscellaneous Instructions
case Instruction::Call: executeCallInst (cast<CallInst> (I), SF); break;