Files
nudt-compiler-cpp/src/mir/FrameLowering.cpp

55 lines
1.3 KiB
C++

#include "mir/MIR.h"
#include <stdexcept>
#include <vector>
#include "utils/Log.h"
namespace mir {
namespace {
int AlignTo(int value, int align) {
return ((value + align - 1) / align) * align;
}
} // namespace
void RunFrameLowering(MachineFunction& function) {
int cursor = 0;
for (const auto& slot : function.GetFrameSlots()) {
cursor += slot.size;
}
// Align stack frames to 16 bytes for AArch64
cursor = AlignTo(cursor, 16);
cursor = 0;
for (const auto& slot : function.GetFrameSlots()) {
cursor += slot.size;
function.GetFrameSlot(slot.index).offset = -cursor;
}
function.SetFrameSize(AlignTo(cursor, 16));
auto& blocks = function.GetBlocks();
if (blocks.empty()) return;
// Insert Prologue at the start of the first block
auto& entry_insts = blocks.front().GetInstructions();
entry_insts.insert(entry_insts.begin(), MachineInstr(Opcode::Prologue));
// Insert Epilogue before every Ret in all blocks
for (auto& block : blocks) {
auto& insts = block.GetInstructions();
std::vector<MachineInstr> lowered;
for (const auto& inst : insts) {
if (inst.GetOpcode() == Opcode::Ret) {
lowered.emplace_back(Opcode::Epilogue);
}
lowered.push_back(inst);
}
insts = std::move(lowered);
}
}
} // namespace mir