static bool
getFragmentToCompile(Core &core, uint32_t startAddress,
std::vector<InstructionOpcode> &opcode,
std::vector<Operands> &operands,
bool &endOfBlock, uint32_t &nextAddress)
{
uint32_t address = startAddress;
opcode.clear();
operands.clear();
endOfBlock = false;
nextAddress = address;
InstructionOpcode opc;
Operands ops;
InstructionProperties *properties;
do {
if (!getInstruction(core, address, opc, ops)) {
endOfBlock = true;
break;
}
instructionTransform(opc, ops, core, address);
properties = &instructionProperties[opc];
nextAddress = address + properties->size;
if (properties->mayBranch())
endOfBlock = true;
if (!properties->function)
break;
opcode.push_back(opc);
operands.push_back(ops);
address = nextAddress;
} while (!properties->mayBranch());
return !opcode.empty();
}
/// Try and compile a fragment starting at the specified address. Returns
/// true if successful setting \a nextAddress to the first instruction after
/// the fragment. If unsuccessful returns false and sets \a nextAddress to the
/// address after the current function. \a endOfBlock is set to true if the
/// next address is in a new basic block.
bool JITImpl::
compileOneFragment(Core &core, JITCoreInfo &coreInfo, uint32_t startPc,
bool &endOfBlock, uint32_t &pcAfterFragment)
{
assert(initialized);
resetPerFunctionState();
auto infoIt = coreInfo.functionMap.find(startPc);
JITFunctionInfo *info =
(infoIt == coreInfo.functionMap.end()) ? 0 : infoIt->second;
if (info && !info->isStub) {
endOfBlock = true;
return false;
}
std::vector<InstructionOpcode> opcode;
std::vector<Operands> operands;
if (!getFragmentToCompile(core, core.fromRamPc(startPc), opcode, operands,
endOfBlock, pcAfterFragment)) {
pcAfterFragment = core.toRamPc(pcAfterFragment);
return false;
}
std::queue<std::pair<uint32_t,MemoryCheck*> > checks;
placeMemoryChecks(opcode, operands, checks);
LLVMValueRef f;
if (info) {
f = info->value;
info->func = 0;
info->isStub = false;
deleteFunctionBody(f);
} else {
info = new JITFunctionInfo(startPc);
coreInfo.functionMap.insert(std::make_pair(startPc, info));
// Create function to contain the code we are about to add.
info->value = f = LLVMAddFunction(module, "", jitFunctionType);
LLVMSetFunctionCallConv(f, LLVMFastCallConv);
}
threadParam = LLVMGetParam(f, 0);
LLVMValueRef ramBase =
LLVMConstInt(LLVMInt32TypeInContext(context), core.getRamBase(), false);
ramSizeLog2Param =
LLVMConstInt(LLVMInt32TypeInContext(context), core.getRamSizeLog2(), false);
LLVMBasicBlockRef entryBB =
LLVMAppendBasicBlockInContext(context, f, "entry");
LLVMPositionBuilderAtEnd(builder, entryBB);
uint32_t pc = startPc;
bool needsReturn = true;
for (unsigned i = 0, e = opcode.size(); i != e; ++i) {
InstructionOpcode opc = opcode[i];
const Operands &ops = operands[i];
InstructionProperties *properties = &instructionProperties[opc];
uint32_t nextPc = pc + properties->size / 2;
emitMemoryChecks(i, checks);
// Lookup function to call.
LLVMValueRef callee = LLVMGetNamedFunction(module, properties->function);
assert(callee && "Function for instruction not found in module");
LLVMTypeRef calleeType = LLVMGetElementType(LLVMTypeOf(callee));
const unsigned fixedArgs = 4;
const unsigned maxOperands = 6;
unsigned numArgs = properties->getNumExplicitOperands() + fixedArgs;
assert(LLVMCountParamTypes(calleeType) == numArgs);
LLVMTypeRef paramTypes[fixedArgs + maxOperands];
assert(numArgs <= (fixedArgs + maxOperands));
LLVMGetParamTypes(calleeType, paramTypes);
// Build call.
LLVMValueRef args[fixedArgs + maxOperands];
args[0] = threadParam;
args[1] = LLVMConstInt(paramTypes[1], nextPc, false);
args[2] = ramBase;
args[3] = ramSizeLog2Param;
for (unsigned i = fixedArgs; i < numArgs; i++) {
uint32_t value =
properties->getNumExplicitOperands() <= 3 ? ops.ops[i - fixedArgs] :
ops.lops[i - fixedArgs];
args[i] = LLVMConstInt(paramTypes[i], value, false);
}
LLVMValueRef call = emitCallToBeInlined(callee, args, numArgs);
checkReturnValue(call, *properties);
if (properties->mayBranch() && properties->function &&
emitJumpToNextFragment(opc, ops, coreInfo, nextPc, info)) {
needsReturn = false;
}
pc = nextPc;
}
assert(checks.empty() && "Not all checks emitted");
if (needsReturn) {
LLVMValueRef args[] = {
threadParam
};
emitCallToBeInlined(functions.jitUpdateExecutionFrequency, args, 1);
// Build return.
LLVMBuildRet(builder,
LLVMConstInt(LLVMGetReturnType(jitFunctionType),
JIT_RETURN_CONTINUE, 0));
}
// Add incoming phi values.
if (earlyReturnBB) {
LLVMAddIncoming(earlyReturnPhi, &earlyReturnIncomingValues[0],
&earlyReturnIncomingBlocks[0],
earlyReturnIncomingValues.size());
}
if (DEBUG_JIT) {
LLVMDumpValue(f);
LLVMVerifyFunction(f, LLVMAbortProcessAction);
}
// Optimize.
for (LLVMValueRef call : calls) {
LLVMExtraInlineFunction(call);
}
LLVMRunFunctionPassManager(FPM, f);
if (DEBUG_JIT) {
LLVMDumpValue(f);
}
// Compile.
JITInstructionFunction_t compiledFunction =
reinterpret_cast<JITInstructionFunction_t>(
LLVMRecompileAndRelinkFunction(executionEngine, f));
info->isStub = false;
info->func = compiledFunction;
core.setOpcode(startPc, getFunctionThunk(*info), (pc - startPc) * 2);
return true;
}