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try to delete some probably unneeded bitcasts (#1163)
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When we updated to the version of the llvm backend with opaque pointers,
all pointer types become the same type in llvm bitcode. As such, we no
longer need bitcast instructions to cast from one pointer type to
another. These now redundant instructions can be removed.
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@dwightguth
dwightguth authored Nov 25, 2024
1 parent c655b8b commit 5e07327
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Showing 4 changed files with 21 additions and 48 deletions.
6 changes: 2 additions & 4 deletions lib/codegen/CreateStaticTerm.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -83,10 +83,8 @@ llvm::Constant *create_static_term::not_injection_case(

std::vector<llvm::Constant *> idxs
= {llvm::ConstantInt::get(llvm::Type::getInt64Ty(ctx_), 0)};
return llvm::ConstantExpr::getBitCast(
llvm::ConstantExpr::getInBoundsGetElementPtr(
block_type, global_var, idxs),
llvm::PointerType::getUnqual(module_->getContext()));
return llvm::ConstantExpr::getInBoundsGetElementPtr(
block_type, global_var, idxs);
}

std::pair<llvm::Constant *, bool>
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5 changes: 2 additions & 3 deletions lib/codegen/CreateTerm.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -974,15 +974,14 @@ llvm::Value *create_term::not_injection_case(
}

auto *block_ptr = llvm::PointerType::getUnqual(module_->getContext());
auto *bitcast = new llvm::BitCastInst(block, block_ptr, "", current_block_);
if (symbol_decl->attributes().contains(attribute_set::key::Binder)) {
auto *call = llvm::CallInst::Create(
get_or_insert_function(module_, "debruijnize", block_ptr, block_ptr),
bitcast, "withIndices", current_block_);
block, "withIndices", current_block_);
set_debug_loc(call);
return call;
}
return bitcast;
return block;
}

// returns a value and a boolean indicating whether that value could be an
Expand Down
22 changes: 7 additions & 15 deletions lib/codegen/Decision.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -52,10 +52,7 @@ void decision::operator()(decision_node *entry) {
if (fail_pattern_) {
llvm::Value *val = load(std::make_pair(
"_1", getvalue_type({sort_category::Symbol, 0}, module_)));
fail_subject_->addIncoming(
new llvm::BitCastInst(
val, llvm::PointerType::getUnqual(ctx_), "", current_block_),
current_block_);
fail_subject_->addIncoming(val, current_block_);
fail_pattern_->addIncoming(
string_literal("\\bottom{SortGeneratedTopCell{}}()"), current_block_);
fail_sort_->addIncoming(
Expand All @@ -71,8 +68,7 @@ llvm::Value *decision::ptr_term(llvm::Value *val) {
if (val->getType()->isIntegerTy()) {
val = allocate_term(val->getType(), current_block_, "kore_alloc_always_gc");
}
return new llvm::BitCastInst(
val, llvm::PointerType::getUnqual(ctx_), "", current_block_);
return val;
}

bool decision_node::begin_node(decision *d, std::string const &name) {
Expand Down Expand Up @@ -236,14 +232,13 @@ void switch_node::codegen(decision *d) {
int offset = 0;
llvm::StructType *block_type = get_block_type(
d->module_, d->definition_, switch_case.get_constructor());
auto *cast = new llvm::BitCastInst(val, ptr_ty, "", d->current_block_);
kore_symbol_declaration *symbol_decl
= d->definition_->get_symbol_declarations().at(
switch_case.get_constructor()->get_name());
llvm::Instruction *renamed = nullptr;
for (auto const &binding : switch_case.get_bindings()) {
llvm::Value *child_ptr = llvm::GetElementPtrInst::CreateInBounds(
block_type, cast,
block_type, val,
{llvm::ConstantInt::get(llvm::Type::getInt64Ty(d->ctx_), 0),
llvm::ConstantInt::get(
llvm::Type::getInt32Ty(d->ctx_),
Expand Down Expand Up @@ -894,7 +889,7 @@ void abort_when_stuck(
}
new llvm::StoreInst(child_value, child_ptr, current_block);
}
ptr = new llvm::BitCastInst(block, block_ptr, "", current_block);
ptr = block;
}
auto *func = get_or_insert_function(
module, "finish_rewriting", llvm::Type::getVoidTy(ctx), block_ptr,
Expand Down Expand Up @@ -971,10 +966,8 @@ static void store_ptrs_for_gc(
{zero, llvm::ConstantInt::get(
llvm::Type::getInt64Ty(module->getContext()), i)},
"", collect);
auto *casted = new llvm::BitCastInst(
ptr, llvm::PointerType::getUnqual(module->getContext()), "", collect);
new llvm::StoreInst(roots[i], casted, collect);
root_ptrs.emplace_back(casted, ptr_types[i]);
new llvm::StoreInst(roots[i], ptr, collect);
root_ptrs.emplace_back(ptr, ptr_types[i]);
}
}

Expand Down Expand Up @@ -1113,8 +1106,7 @@ std::pair<std::vector<llvm::Value *>, llvm::BasicBlock *> step_function_header(
{arr,
llvm::ConstantInt::get(
llvm::Type::getInt8Ty(module->getContext()), nroots),
llvm::ConstantExpr::getBitCast(layout, ptr_ty),
llvm::ConstantInt::getFalse(module->getContext())},
layout, llvm::ConstantInt::getFalse(module->getContext())},
"", collect);
set_debug_loc(call);
std::vector<llvm::Value *> phis;
Expand Down
36 changes: 10 additions & 26 deletions lib/codegen/EmitConfigParser.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -326,24 +326,19 @@ static llvm::Value *get_arg_value(
case sort_category::Bool:
case sort_category::MInt: {
auto *val_ty = getvalue_type(cat, mod);
auto *cast = new llvm::BitCastInst(arg, ptr_ty, "", case_block);
auto *load = new llvm::LoadInst(val_ty, cast, "", case_block);
auto *load = new llvm::LoadInst(val_ty, arg, "", case_block);
arg = load;
break;
}
case sort_category::Map:
case sort_category::RangeMap:
case sort_category::List:
case sort_category::Set:
arg = new llvm::BitCastInst(arg, ptr_ty, "", case_block);
break;
case sort_category::Int:
case sort_category::Float:
case sort_category::StringBuffer:
case sort_category::Symbol:
case sort_category::Variable:
arg = new llvm::BitCastInst(arg, getvalue_type(cat, mod), "", case_block);
break;
case sort_category::Variable: break;
case sort_category::MapIter:
case sort_category::SetIter:
case sort_category::Uncomputed: abort();
Expand Down Expand Up @@ -386,19 +381,15 @@ static std::pair<llvm::Value *, llvm::BasicBlock *> get_eval(
case sort_category::Map:
case sort_category::RangeMap:
case sort_category::List:
case sort_category::Set:
retval = new llvm::BitCastInst(
result, ptr_ty, "", creator.get_current_block());
break;
case sort_category::Set: retval = result; break;
case sort_category::Bool:
case sort_category::MInt: {
auto *malloc = create_malloc(
creator.get_current_block(),
llvm::ConstantExpr::getSizeOf(result->getType()),
get_or_insert_function(mod, "malloc", ptr_ty, ptr_ty));
new llvm::StoreInst(result, malloc, creator.get_current_block());
retval = new llvm::BitCastInst(
malloc, ptr_ty, "", creator.get_current_block());
retval = malloc;
break;
}
case sort_category::MapIter:
Expand Down Expand Up @@ -554,8 +545,7 @@ static void emit_get_token(kore_definition *definition, llvm::Module *module) {
case_block, llvm::ConstantExpr::getSizeOf(compare->getType()),
get_or_insert_function(module, "malloc", ptr_ty, ptr_ty));
new llvm::StoreInst(compare, malloc, case_block);
auto *result = new llvm::BitCastInst(malloc, ptr_ty, "", case_block);
phi->addIncoming(result, case_block);
phi->addIncoming(malloc, case_block);
llvm::BranchInst::Create(merge_block, case_block);
break;
}
Expand All @@ -568,8 +558,7 @@ static void emit_get_token(kore_definition *definition, llvm::Module *module) {
module, "init_float", llvm::Type::getVoidTy(ctx), ptr_ty, ptr_ty);
llvm::CallInst::Create(
init_float, {term, func->arg_begin() + 2}, "", case_block);
auto *cast = new llvm::BitCastInst(term, ptr_ty, "", case_block);
phi->addIncoming(cast, case_block);
phi->addIncoming(term, case_block);
llvm::BranchInst::Create(merge_block, case_block);
break;
}
Expand Down Expand Up @@ -611,9 +600,8 @@ static void emit_get_token(kore_definition *definition, llvm::Module *module) {
*case_block, llvm::CmpInst::ICMP_EQ, call, zero32);
auto *abort_block = llvm::BasicBlock::Create(ctx, "invalid_int", func);
add_abort(abort_block, module);
auto *cast = new llvm::BitCastInst(term, ptr_ty, "", case_block);
llvm::BranchInst::Create(merge_block, abort_block, icmp, case_block);
phi->addIncoming(cast, case_block);
phi->addIncoming(term, case_block);
break;
}
case sort_category::Variable:
Expand Down Expand Up @@ -661,9 +649,8 @@ static void emit_get_token(kore_definition *definition, llvm::Module *module) {
llvm::CallInst::Create(
memcpy, {str_ptr, func->arg_begin() + 2, func->arg_begin() + 1}, "",
current_block);
auto *cast = new llvm::BitCastInst(block, ptr_ty, "", current_block);
llvm::BranchInst::Create(merge_block, current_block);
phi->addIncoming(cast, current_block);
phi->addIncoming(block, current_block);
llvm::ReturnInst::Create(ctx, phi, merge_block);
merge_block->insertInto(func);
}
Expand Down Expand Up @@ -777,16 +764,14 @@ static void get_store(
llvm::Value *arguments_array = func->arg_begin() + 1;
int idx = 0;
auto *block_type = get_block_type(module, definition, symbol);
auto *cast = new llvm::BitCastInst(
func->arg_begin(), llvm::PointerType::getUnqual(ctx), "", case_block);
for (auto const &sort : symbol->get_arguments()) {
value_type cat = dynamic_cast<kore_composite_sort *>(sort.get())
->get_category(definition);
llvm::Value *arg
= get_arg_value(arguments_array, idx, case_block, cat, module);
llvm::Type *arg_ty = get_arg_type(cat, module);
llvm::Value *child_ptr = llvm::GetElementPtrInst::CreateInBounds(
block_type, cast,
block_type, func->arg_begin(),
{zero, llvm::ConstantInt::get(
llvm::Type::getInt32Ty(ctx),
get_block_offset(definition, symbol, idx++))},
Expand Down Expand Up @@ -896,7 +881,6 @@ static void get_visitor(
llvm::Function *func = case_block->getParent();
int idx = 0;
auto *block_type = get_block_type(module, definition, symbol);
auto *cast = new llvm::BitCastInst(func->arg_begin(), ptr_ty, "", case_block);
unsigned i = 0;

auto *state_ptr = func->arg_end() - 1;
Expand All @@ -905,7 +889,7 @@ static void get_visitor(
auto *composite_sort = dynamic_cast<kore_composite_sort *>(sort.get());
value_type cat = composite_sort->get_category(definition);
llvm::Value *child_ptr = llvm::GetElementPtrInst::CreateInBounds(
block_type, cast,
block_type, func->arg_begin(),
{zero, llvm::ConstantInt::get(
llvm::Type::getInt32Ty(ctx),
get_block_offset(definition, symbol, idx++))},
Expand Down

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