Commit 3404d138 authored by Kevin Modzelewski's avatar Kevin Modzelewski

Handling some more of llvm refcounting

parent b92d42d8
...@@ -23,6 +23,7 @@ ...@@ -23,6 +23,7 @@
#include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h" #include "llvm/IR/Module.h"
#include "llvm/Support/raw_ostream.h" #include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "codegen/codegen.h" #include "codegen/codegen.h"
#include "codegen/gcbuilder.h" #include "codegen/gcbuilder.h"
...@@ -58,6 +59,90 @@ void RefcountTracker::refConsumed(llvm::Value* v, llvm::Instruction* inst) { ...@@ -58,6 +59,90 @@ void RefcountTracker::refConsumed(llvm::Value* v, llvm::Instruction* inst) {
assert(std::find(inst->op_begin(), inst->op_end(), v) != inst->op_end()); assert(std::find(inst->op_begin(), inst->op_end(), v) != inst->op_end());
} }
llvm::Instruction* findIncrefPt(llvm::BasicBlock* BB) {
llvm::Instruction* incref_pt;// = BB->getFirstInsertionPt();
if (llvm::isa<llvm::LandingPadInst>(*BB->begin())) {
// Don't split up the landingpad+extract+cxa_begin_catch
auto it = BB->begin();
++it;
++it;
++it;
incref_pt = &*it;
} else {
incref_pt = BB->getFirstInsertionPt();
}
return incref_pt;
}
void addIncrefs(llvm::Value* v, int num_refs, llvm::Instruction* incref_pt) {
assert(num_refs > 0);
#ifdef Py_REF_DEBUG
auto reftotal_gv = g.cur_module->getOrInsertGlobal("_Py_RefTotal", g.i64);
auto reftotal = new llvm::LoadInst(reftotal_gv, "", incref_pt);
auto new_reftotal = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Add, reftotal,
getConstantInt(num_refs, g.i64), "", incref_pt);
new llvm::StoreInst(new_reftotal, reftotal_gv, incref_pt);
#endif
llvm::ArrayRef<llvm::Value*> idxs({ getConstantInt(0, g.i32), getConstantInt(0, g.i32) });
auto refcount_ptr = llvm::GetElementPtrInst::CreateInBounds(v, idxs, "", incref_pt);
auto refcount = new llvm::LoadInst(refcount_ptr, "", incref_pt);
auto new_refcount = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Add, refcount,
getConstantInt(num_refs, g.i64), "", incref_pt);
new llvm::StoreInst(new_refcount, refcount_ptr, incref_pt);
}
void addDecrefs(llvm::Value* v, int num_refs, llvm::Instruction* decref_pt) {
assert(num_refs > 0);
llvm::IRBuilder<true> builder(decref_pt);
#ifdef Py_REF_DEBUG
auto reftotal_gv = g.cur_module->getOrInsertGlobal("_Py_RefTotal", g.i64);
auto reftotal = new llvm::LoadInst(reftotal_gv, "", decref_pt);
auto new_reftotal = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Sub, reftotal,
getConstantInt(num_refs, g.i64), "", decref_pt);
new llvm::StoreInst(new_reftotal, reftotal_gv, decref_pt);
#endif
llvm::ArrayRef<llvm::Value*> idxs({ getConstantInt(0, g.i32), getConstantInt(0, g.i32) });
auto refcount_ptr = llvm::GetElementPtrInst::CreateInBounds(v, idxs, "", decref_pt);
auto refcount = new llvm::LoadInst(refcount_ptr, "", decref_pt);
auto new_refcount = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Sub, refcount,
getConstantInt(num_refs, g.i64), "", decref_pt);
new llvm::StoreInst(new_refcount, refcount_ptr, decref_pt);
llvm::BasicBlock* cur_block = decref_pt->getParent();
llvm::BasicBlock* dealloc_block = llvm::BasicBlock::Create(g.context, "", decref_pt->getParent()->getParent());
llvm::BasicBlock* continue_block = cur_block->splitBasicBlock(decref_pt);
assert(llvm::isa<llvm::BranchInst>(cur_block->getTerminator()));
cur_block->getTerminator()->eraseFromParent();
builder.SetInsertPoint(cur_block);
auto iszero = builder.CreateICmpEQ(new_refcount, getConstantInt(0, g.i64));
builder.CreateCondBr(iszero, dealloc_block, continue_block);
builder.SetInsertPoint(dealloc_block);
auto cls_ptr = builder.CreateConstInBoundsGEP2_32(v, 0, 1);
auto cls = builder.CreateLoad(cls_ptr);
auto dtor_ptr = builder.CreateConstInBoundsGEP2_32(cls, 0, 4);
#ifndef NDEBUG
llvm::APInt offset(64, 0, true);
assert(llvm::cast<llvm::GetElementPtrInst>(dtor_ptr)->accumulateConstantOffset(*g.tm->getDataLayout(), offset));
assert(offset.getZExtValue() == offsetof(BoxedClass, tp_dealloc));
#endif
auto dtor = builder.CreateLoad(dtor_ptr);
builder.CreateCall(dtor, v);
builder.CreateBr(continue_block);
builder.SetInsertPoint(continue_block);
}
void RefcountTracker::addRefcounts(IRGenState* irstate) { void RefcountTracker::addRefcounts(IRGenState* irstate) {
llvm::Function* f = irstate->getLLVMFunction(); llvm::Function* f = irstate->getLLVMFunction();
RefcountTracker* rt = irstate->getRefcounts(); RefcountTracker* rt = irstate->getRefcounts();
...@@ -160,37 +245,6 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -160,37 +245,6 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
} }
} }
auto addRefcountsToBlock = [](llvm::BasicBlock* BB, llvm::Value* v, int num_refs) {
llvm::Instruction* incref_pt;// = BB->getFirstInsertionPt();
if (llvm::isa<llvm::LandingPadInst>(*BB->begin())) {
// Don't split up the landingpad+extract+cxa_begin_catch
auto it = BB->begin();
++it;
++it;
++it;
incref_pt = &*it;
} else {
incref_pt = BB->getFirstInsertionPt();
}
#ifdef Py_REF_DEBUG
auto reftotal_gv = g.cur_module->getOrInsertGlobal("_Py_RefTotal", g.i64);
auto reftotal = new llvm::LoadInst(reftotal_gv, "", incref_pt);
auto new_reftotal = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Add, reftotal,
getConstantInt(num_refs, g.i64), "", incref_pt);
new llvm::StoreInst(new_reftotal, reftotal_gv, "", incref_pt);
#endif
llvm::ArrayRef<llvm::Value*> idxs({ getConstantInt(0, g.i32), getConstantInt(0, g.i32) });
auto refcount_ptr = llvm::GetElementPtrInst::CreateInBounds(v, idxs, "", incref_pt);
auto refcount = new llvm::LoadInst(refcount_ptr, "", incref_pt);
auto new_refcount = llvm::BinaryOperator::Create(
llvm::BinaryOperator::BinaryOps::Add, refcount,
getConstantInt(num_refs, g.i64), "", incref_pt);
new llvm::StoreInst(new_refcount, refcount_ptr, "", incref_pt);
};
while (!block_queue.empty()) { while (!block_queue.empty()) {
llvm::BasicBlock& BB = *block_queue.front(); llvm::BasicBlock& BB = *block_queue.front();
block_queue.pop_front(); block_queue.pop_front();
...@@ -241,13 +295,16 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -241,13 +295,16 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
this_refs = it->second; this_refs = it->second;
} }
if (this_refs > min_refs) { if (this_refs > min_refs) {
addRefcountsToBlock(SBB, v, this_refs - min_refs); addIncrefs(v, this_refs - min_refs, findIncrefPt(SBB));
//llvm::outs() << *incref_pt << '\n'; //llvm::outs() << *incref_pt << '\n';
//llvm::outs() << "Need to incref " << *v << " at beginning of " << SBB->getName() << "\n"; //llvm::outs() << "Need to incref " << *v << " at beginning of " << SBB->getName() << "\n";
} }
} }
state.refs[v] = min_refs; if (min_refs)
state.refs[v] = min_refs;
else
assert(state.refs.count(v) == 0);
} else { } else {
assert(0 && "finish implementing"); assert(0 && "finish implementing");
} }
...@@ -287,7 +344,7 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -287,7 +344,7 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
if (num_times_as_op[op] > num_consumed) { if (num_times_as_op[op] > num_consumed) {
if (rt->vars[op].reftype == RefType::BORROWED) { if (rt->vars[op].reftype == RefType::BORROWED) {
} else { } else {
assert(0 && "handle this case"); assert(state.refs.count(op) && "handle this case (last reference of an owned var)");
} }
} }
...@@ -297,14 +354,21 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -297,14 +354,21 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
} }
// Handle variables that were defined in this BB: // Handle variables that were defined in this BB:
for (auto it = state.refs.begin(), end = state.refs.end(); it != end; ) { for (auto&& p : rt->vars) {
llvm::Instruction* inst = llvm::dyn_cast<llvm::Instruction>(it->first); llvm::Instruction* inst = llvm::dyn_cast<llvm::Instruction>(p.first);
if (inst && inst->getParent() == &BB) { if (inst && inst->getParent() == &BB) {
assert(it->second == 1 && rt->vars[it->first].reftype == RefType::OWNED); int starting_refs = (p.second.reftype == RefType::OWNED ? 1 : 0);
state.refs.erase(it); if (state.refs[inst] != starting_refs) {
++it; llvm::Instruction* insertion_pt = inst->getNextNode();
} else { assert(insertion_pt);
++it; if (state.refs[inst] < starting_refs) {
assert(p.second.reftype == RefType::OWNED);
addDecrefs(inst, starting_refs - state.refs[inst], insertion_pt);
} else {
addIncrefs(inst, state.refs[inst] - starting_refs, insertion_pt);
}
}
state.refs.erase(inst);
} }
} }
...@@ -313,7 +377,7 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -313,7 +377,7 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
llvm::outs() << *p.first << " " << p.second << '\n'; llvm::outs() << *p.first << " " << p.second << '\n';
assert(llvm::isa<llvm::GlobalVariable>(p.first)); assert(llvm::isa<llvm::GlobalVariable>(p.first));
assert(rt->vars[p.first].reftype == RefType::BORROWED); assert(rt->vars[p.first].reftype == RefType::BORROWED);
addRefcountsToBlock(&BB, p.first, p.second); addIncrefs(p.first, p.second, findIncrefPt(&BB));
} }
state.refs.clear(); state.refs.clear();
} }
...@@ -342,7 +406,8 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) { ...@@ -342,7 +406,8 @@ void RefcountTracker::addRefcounts(IRGenState* irstate) {
fprintf(stderr, "After refcounts:\n"); fprintf(stderr, "After refcounts:\n");
fprintf(stderr, "\033[35m"); fprintf(stderr, "\033[35m");
dumpPrettyIR(f); f->dump();
//dumpPrettyIR(f);
fprintf(stderr, "\033[0m"); fprintf(stderr, "\033[0m");
} }
......
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