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dart / sdk.git / 3c2d1ddd0c4569a266410e9ef4936c7a876cbf77 / . / runtime / vm / flow_graph_compiler.cc
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// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/globals.h" // Needed here to get TARGET_ARCH_XXX.
#include "vm/flow_graph_compiler.h"
#include "vm/bit_vector.h"
#include "vm/cha.h"
#include "vm/compiler.h"
#include "vm/dart_entry.h"
#include "vm/debugger.h"
#include "vm/deopt_instructions.h"
#include "vm/exceptions.h"
#include "vm/flow_graph_allocator.h"
#include "vm/il_printer.h"
#include "vm/intrinsifier.h"
#include "vm/locations.h"
#include "vm/log.h"
#include "vm/longjump.h"
#include "vm/object_store.h"
#include "vm/parser.h"
#include "vm/raw_object.h"
#include "vm/stack_frame.h"
#include "vm/stub_code.h"
#include "vm/symbols.h"
namespace dart {
DEFINE_FLAG(bool, allow_absolute_addresses, true,
"Allow embedding absolute addresses in generated code.");
DEFINE_FLAG(bool, always_megamorphic_calls, false,
"Instance call always as megamorphic.");
DEFINE_FLAG(bool, enable_simd_inline, true,
"Enable inlining of SIMD related method calls.");
DEFINE_FLAG(int, min_optimization_counter_threshold, 5000,
"The minimum invocation count for a function.");
DEFINE_FLAG(int, optimization_counter_scale, 2000,
"The scale of invocation count, by size of the function.");
DEFINE_FLAG(bool, polymorphic_with_deopt, true,
"Polymorphic calls can be generated so that failure either causes "
"deoptimization or falls through to a megamorphic call");
DEFINE_FLAG(bool, source_lines, false, "Emit source line as assembly comment.");
DEFINE_FLAG(bool, trace_inlining_intervals, false,
"Inlining interval diagnostics");
DEFINE_FLAG(bool, use_megamorphic_stub, true, "Out of line megamorphic lookup");
DECLARE_FLAG(bool, background_compilation);
DECLARE_FLAG(bool, code_comments);
DECLARE_FLAG(bool, deoptimize_alot);
DECLARE_FLAG(int, deoptimize_every);
DECLARE_FLAG(charp, deoptimize_filter);
DECLARE_FLAG(bool, disassemble);
DECLARE_FLAG(bool, disassemble_optimized);
DECLARE_FLAG(bool, emit_edge_counters);
DECLARE_FLAG(bool, fields_may_be_reset);
DECLARE_FLAG(bool, guess_other_cid);
DECLARE_FLAG(bool, ic_range_profiling);
DECLARE_FLAG(bool, intrinsify);
DECLARE_FLAG(bool, load_deferred_eagerly);
DECLARE_FLAG(int, optimization_counter_threshold);
DECLARE_FLAG(bool, propagate_ic_data);
DECLARE_FLAG(int, regexp_optimization_counter_threshold);
DECLARE_FLAG(int, reoptimization_counter_threshold);
DECLARE_FLAG(int, stacktrace_every);
DECLARE_FLAG(charp, stacktrace_filter);
DECLARE_FLAG(bool, support_debugger);
DECLARE_FLAG(bool, use_field_guards);
DECLARE_FLAG(bool, use_cha_deopt);
DECLARE_FLAG(bool, use_osr);
DECLARE_FLAG(bool, warn_on_javascript_compatibility);
DECLARE_FLAG(bool, precompile_collect_closures);
DECLARE_FLAG(bool, print_stop_message);
DECLARE_FLAG(bool, lazy_dispatchers);
DECLARE_FLAG(bool, interpret_irregexp);
DECLARE_FLAG(bool, enable_mirrors);
DECLARE_FLAG(bool, link_natives_lazily);
static void PrecompilationModeHandler(bool value) {
if (value) {
#if defined(TARGET_ARCH_IA32)
FATAL("Precompilation not supported on IA32");
#endif
FLAG_always_megamorphic_calls = true;
FLAG_polymorphic_with_deopt = false;
FLAG_optimization_counter_threshold = -1;
FLAG_use_field_guards = false;
FLAG_use_osr = false;
FLAG_emit_edge_counters = false;
FLAG_support_debugger = false;
FLAG_ic_range_profiling = false;
FLAG_collect_code = false;
FLAG_load_deferred_eagerly = true;
FLAG_deoptimize_alot = false; // Used in some tests.
FLAG_deoptimize_every = 0; // Used in some tests.
FLAG_guess_other_cid = true;
Compiler::set_always_optimize(true);
// Triggers assert if we try to recompile (e.g., because of deferred
// loading, deoptimization, ...). Noopt mode simulates behavior
// of precompiled code, therefore do not allow recompilation.
Compiler::set_allow_recompilation(false);
// TODO(srdjan): Enable CHA deoptimization when eager class finalization is
// implemented, either with precompilation or as a special pass.
FLAG_use_cha_deopt = false;
// Calling the PrintStopMessage stub is not supported in precompiled code
// since it is done at places where no pool pointer is loaded.
FLAG_print_stop_message = false;
FLAG_lazy_dispatchers = false;
FLAG_interpret_irregexp = true;
FLAG_enable_mirrors = false;
FLAG_precompile_collect_closures = true;
FLAG_link_natives_lazily = true;
FLAG_fields_may_be_reset = true;
FLAG_allow_absolute_addresses = false;
// Background compilation relies on two-stage compilation pipeline,
// while precompilation has only one.
FLAG_background_compilation = false;
}
}
DEFINE_FLAG_HANDLER(PrecompilationModeHandler,
precompilation,
"Precompilation mode");
// Assign locations to incoming arguments, i.e., values pushed above spill slots
// with PushArgument. Recursively allocates from outermost to innermost
// environment.
void CompilerDeoptInfo::AllocateIncomingParametersRecursive(
Environment* env,
intptr_t* stack_height) {
if (env == NULL) return;
AllocateIncomingParametersRecursive(env->outer(), stack_height);
for (Environment::ShallowIterator it(env); !it.Done(); it.Advance()) {
if (it.CurrentLocation().IsInvalid() &&
it.CurrentValue()->definition()->IsPushArgument()) {
it.SetCurrentLocation(Location::StackSlot((*stack_height)++));
}
}
}
void CompilerDeoptInfo::EmitMaterializations(Environment* env,
DeoptInfoBuilder* builder) {
for (Environment::DeepIterator it(env); !it.Done(); it.Advance()) {
if (it.CurrentLocation().IsInvalid()) {
MaterializeObjectInstr* mat =
it.CurrentValue()->definition()->AsMaterializeObject();
ASSERT(mat != NULL);
builder->AddMaterialization(mat);
}
}
}
FlowGraphCompiler::FlowGraphCompiler(
Assembler* assembler,
FlowGraph* flow_graph,
const ParsedFunction& parsed_function,
bool is_optimizing,
const GrowableArray<const Function*>& inline_id_to_function,
const GrowableArray<intptr_t>& caller_inline_id)
: thread_(Thread::Current()),
isolate_(Isolate::Current()),
zone_(Thread::Current()->zone()),
assembler_(assembler),
parsed_function_(parsed_function),
flow_graph_(*flow_graph),
block_order_(*flow_graph->CodegenBlockOrder(is_optimizing)),
current_block_(NULL),
exception_handlers_list_(NULL),
pc_descriptors_list_(NULL),
stackmap_table_builder_(NULL),
block_info_(block_order_.length()),
deopt_infos_(),
static_calls_target_table_(),
is_optimizing_(is_optimizing),
may_reoptimize_(false),
intrinsic_mode_(false),
double_class_(Class::ZoneHandle(
isolate_->object_store()->double_class())),
mint_class_(Class::ZoneHandle(
isolate_->object_store()->mint_class())),
float32x4_class_(Class::ZoneHandle(
isolate_->object_store()->float32x4_class())),
float64x2_class_(Class::ZoneHandle(
isolate_->object_store()->float64x2_class())),
int32x4_class_(Class::ZoneHandle(
isolate_->object_store()->int32x4_class())),
list_class_(Class::ZoneHandle(
Library::Handle(Library::CoreLibrary()).
LookupClass(Symbols::List()))),
parallel_move_resolver_(this),
pending_deoptimization_env_(NULL),
lazy_deopt_pc_offset_(Code::kInvalidPc),
deopt_id_to_ic_data_(NULL),
edge_counters_array_(Array::ZoneHandle()),
inlined_code_intervals_(Array::ZoneHandle(Object::empty_array().raw())),
inline_id_to_function_(inline_id_to_function),
caller_inline_id_(caller_inline_id) {
ASSERT(flow_graph->parsed_function().function().raw() ==
parsed_function.function().raw());
if (!is_optimizing) {
const intptr_t len = thread()->deopt_id();
deopt_id_to_ic_data_ = new(zone()) ZoneGrowableArray<const ICData*>(len);
deopt_id_to_ic_data_->SetLength(len);
for (intptr_t i = 0; i < len; i++) {
(*deopt_id_to_ic_data_)[i] = NULL;
}
// TODO(fschneider): Abstract iteration into ICDataArrayIterator.
const Array& old_saved_ic_data = Array::Handle(zone(),
flow_graph->function().ic_data_array());
const intptr_t saved_len =
old_saved_ic_data.IsNull() ? 0 : old_saved_ic_data.Length();
for (intptr_t i = 1; i < saved_len; i++) {
ICData& ic_data = ICData::ZoneHandle(zone());
ic_data ^= old_saved_ic_data.At(i);
(*deopt_id_to_ic_data_)[ic_data.deopt_id()] = &ic_data;
}
}
ASSERT(assembler != NULL);
ASSERT(!list_class_.IsNull());
}
void FlowGraphCompiler::InitCompiler() {
pc_descriptors_list_ = new(zone()) DescriptorList(64);
exception_handlers_list_ = new(zone())ExceptionHandlerList();
block_info_.Clear();
// Conservative detection of leaf routines used to remove the stack check
// on function entry.
bool is_leaf = !parsed_function().function().IsClosureFunction()
&& is_optimizing()
&& !flow_graph().IsCompiledForOsr();
// Initialize block info and search optimized (non-OSR) code for calls
// indicating a non-leaf routine and calls without IC data indicating
// possible reoptimization.
for (int i = 0; i < block_order_.length(); ++i) {
block_info_.Add(new(zone()) BlockInfo());
if (is_optimizing() && !flow_graph().IsCompiledForOsr()) {
BlockEntryInstr* entry = block_order_[i];
for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
Instruction* current = it.Current();
if (current->IsBranch()) {
current = current->AsBranch()->comparison();
}
// In optimized code, ICData is always set in the instructions.
const ICData* ic_data = NULL;
if (current->IsInstanceCall()) {
ic_data = current->AsInstanceCall()->ic_data();
}
if ((ic_data != NULL) && (ic_data->NumberOfUsedChecks() == 0)) {
may_reoptimize_ = true;
}
if (is_leaf &&
!current->IsCheckStackOverflow() &&
!current->IsParallelMove()) {
// Note that we do not care if the code contains instructions that
// can deoptimize.
LocationSummary* locs = current->locs();
if ((locs != NULL) && locs->can_call()) {
is_leaf = false;
}
}
}
}
}
if (is_leaf) {
// Remove the stack overflow check at function entry.
Instruction* first = flow_graph_.graph_entry()->normal_entry()->next();
if (first->IsCheckStackOverflow()) first->RemoveFromGraph();
}
if (!is_optimizing()) {
// Initialize edge counter array.
const intptr_t num_counters = flow_graph_.preorder().length();
const Array& edge_counters =
Array::Handle(Array::New(num_counters, Heap::kOld));
const Smi& zero_smi = Smi::Handle(Smi::New(0));
for (intptr_t i = 0; i < num_counters; ++i) {
edge_counters.SetAt(i, zero_smi);
}
edge_counters_array_ = edge_counters.raw();
}
}
bool FlowGraphCompiler::CanOptimize() {
return FLAG_optimization_counter_threshold >= 0;
}
bool FlowGraphCompiler::CanOptimizeFunction() const {
return CanOptimize() && !parsed_function().function().HasBreakpoint();
}
bool FlowGraphCompiler::CanOSRFunction() const {
return FLAG_use_osr & CanOptimizeFunction() && !is_optimizing();
}
bool FlowGraphCompiler::ForceSlowPathForStackOverflow() const {
if (FLAG_stacktrace_every > 0 || FLAG_deoptimize_every > 0) {
return true;
}
if (FLAG_stacktrace_filter != NULL &&
strstr(parsed_function().function().ToFullyQualifiedCString(),
FLAG_stacktrace_filter) != NULL) {
return true;
}
if (is_optimizing() &&
FLAG_deoptimize_filter != NULL &&
strstr(parsed_function().function().ToFullyQualifiedCString(),
FLAG_deoptimize_filter) != NULL) {
return true;
}
return false;
}
static bool IsEmptyBlock(BlockEntryInstr* block) {
return !block->IsCatchBlockEntry() &&
!block->HasNonRedundantParallelMove() &&
block->next()->IsGoto() &&
!block->next()->AsGoto()->HasNonRedundantParallelMove() &&
!block->IsIndirectEntry();
}
void FlowGraphCompiler::CompactBlock(BlockEntryInstr* block) {
BlockInfo* block_info = block_info_[block->postorder_number()];
// Break out of cycles in the control flow graph.
if (block_info->is_marked()) {
return;
}
block_info->mark();
if (IsEmptyBlock(block)) {
// For empty blocks, record a corresponding nonempty target as their
// jump label.
BlockEntryInstr* target = block->next()->AsGoto()->successor();
CompactBlock(target);
block_info->set_jump_label(GetJumpLabel(target));
}
}
void FlowGraphCompiler::CompactBlocks() {
// This algorithm does not garbage collect blocks in place, but merely
// records forwarding label information. In this way it avoids having to
// change join and target entries.
Label* nonempty_label = NULL;
for (intptr_t i = block_order().length() - 1; i >= 1; --i) {
BlockEntryInstr* block = block_order()[i];
// Unoptimized code must emit all possible deoptimization points.
if (is_optimizing()) {
CompactBlock(block);
}
// For nonempty blocks, record the next nonempty block in the block
// order. Since no code is emitted for empty blocks, control flow is
// eligible to fall through to the next nonempty one.
if (!WasCompacted(block)) {
BlockInfo* block_info = block_info_[block->postorder_number()];
block_info->set_next_nonempty_label(nonempty_label);
nonempty_label = GetJumpLabel(block);
}
}
ASSERT(block_order()[0]->IsGraphEntry());
BlockInfo* block_info = block_info_[block_order()[0]->postorder_number()];
block_info->set_next_nonempty_label(nonempty_label);
}
void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
if (!is_optimizing()) {
if (instr->CanBecomeDeoptimizationTarget() && !instr->IsGoto()) {
// Instructions that can be deoptimization targets need to record kDeopt
// PcDescriptor corresponding to their deopt id. GotoInstr records its
// own so that it can control the placement.
AddCurrentDescriptor(RawPcDescriptors::kDeopt,
instr->deopt_id(),
instr->token_pos());
}
AllocateRegistersLocally(instr);
} else if (instr->MayThrow() &&
(CurrentTryIndex() != CatchClauseNode::kInvalidTryIndex)) {
// Optimized try-block: Sync locals to fixed stack locations.
EmitTrySync(instr, CurrentTryIndex());
}
}
void FlowGraphCompiler::EmitSourceLine(Instruction* instr) {
if ((instr->token_pos() == Scanner::kNoSourcePos) || (instr->env() == NULL)) {
return;
}
const Script& script =
Script::Handle(zone(), instr->env()->function().script());
intptr_t line_nr;
intptr_t column_nr;
script.GetTokenLocation(instr->token_pos(), &line_nr, &column_nr);
const String& line = String::Handle(zone(), script.GetLine(line_nr));
assembler()->Comment("Line %" Pd " in '%s':\n %s",
line_nr,
instr->env()->function().ToFullyQualifiedCString(),
line.ToCString());
}
static void LoopInfoComment(
Assembler* assembler,
const BlockEntryInstr& block,
const ZoneGrowableArray<BlockEntryInstr*>& loop_headers) {
if (Assembler::EmittingComments()) {
for (intptr_t loop_id = 0; loop_id < loop_headers.length(); ++loop_id) {
for (BitVector::Iterator loop_it(loop_headers[loop_id]->loop_info());
!loop_it.Done();
loop_it.Advance()) {
if (loop_it.Current() == block.preorder_number()) {
assembler->Comment(" Loop %" Pd "", loop_id);
}
}
}
}
}
// We collect intervals while generating code.
struct IntervalStruct {
// 'start' and 'end' are pc-offsets.
intptr_t start;
intptr_t inlining_id;
IntervalStruct(intptr_t s, intptr_t id) : start(s), inlining_id(id) {}
void Dump() {
THR_Print("start: 0x%" Px " iid: %" Pd " ", start, inlining_id);
}
};
void FlowGraphCompiler::VisitBlocks() {
CompactBlocks();
const ZoneGrowableArray<BlockEntryInstr*>* loop_headers = NULL;
if (Assembler::EmittingComments()) {
// 'loop_headers' were cleared, recompute.
loop_headers = flow_graph().ComputeLoops();
ASSERT(loop_headers != NULL);
}
// For collecting intervals of inlined code.
GrowableArray<IntervalStruct> intervals;
intptr_t prev_offset = 0;
intptr_t prev_inlining_id = 0;
intptr_t max_inlining_id = 0;
for (intptr_t i = 0; i < block_order().length(); ++i) {
// Compile the block entry.
BlockEntryInstr* entry = block_order()[i];
assembler()->Comment("B%" Pd "", entry->block_id());
set_current_block(entry);
if (WasCompacted(entry)) {
continue;
}
#if defined(DEBUG)
if (!is_optimizing()) {
FrameStateClear();
}
#endif
LoopInfoComment(assembler(), *entry, *loop_headers);
entry->set_offset(assembler()->CodeSize());
entry->EmitNativeCode(this);
// Compile all successors until an exit, branch, or a block entry.
for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
Instruction* instr = it.Current();
// Compose intervals.
if (instr->has_inlining_id() && is_optimizing()) {
if (prev_inlining_id != instr->inlining_id()) {
intervals.Add(IntervalStruct(prev_offset, prev_inlining_id));
prev_offset = assembler()->CodeSize();
prev_inlining_id = instr->inlining_id();
if (prev_inlining_id > max_inlining_id) {
max_inlining_id = prev_inlining_id;
}
}
}
if (FLAG_code_comments ||
FLAG_disassemble || FLAG_disassemble_optimized) {
if (FLAG_source_lines) {
EmitSourceLine(instr);
}
EmitComment(instr);
}
if (instr->IsParallelMove()) {
parallel_move_resolver_.EmitNativeCode(instr->AsParallelMove());
} else {
EmitInstructionPrologue(instr);
ASSERT(pending_deoptimization_env_ == NULL);
pending_deoptimization_env_ = instr->env();
instr->EmitNativeCode(this);
pending_deoptimization_env_ = NULL;
EmitInstructionEpilogue(instr);
}
#if defined(DEBUG)
if (!is_optimizing()) {
FrameStateUpdateWith(instr);
}
#endif
}
#if defined(DEBUG)
ASSERT(is_optimizing() || FrameStateIsSafeToCall());
#endif
}
if (inline_id_to_function_.length() > max_inlining_id + 1) {
// TODO(srdjan): Some inlined function can disappear,
// truncate 'inline_id_to_function_'.
}
if (is_optimizing()) {
LogBlock lb;
intervals.Add(IntervalStruct(prev_offset, prev_inlining_id));
inlined_code_intervals_ =
Array::New(intervals.length() * Code::kInlIntNumEntries, Heap::kOld);
Smi& start_h = Smi::Handle();
Smi& caller_inline_id = Smi::Handle();
Smi& inline_id = Smi::Handle();
for (intptr_t i = 0; i < intervals.length(); i++) {
if (FLAG_trace_inlining_intervals && is_optimizing()) {
const Function& function =
*inline_id_to_function_.At(intervals[i].inlining_id);
intervals[i].Dump();
THR_Print(" parent iid %" Pd " %s\n",
caller_inline_id_[intervals[i].inlining_id],
function.ToQualifiedCString());
}
const intptr_t id = intervals[i].inlining_id;
start_h = Smi::New(intervals[i].start);
inline_id = Smi::New(id);
caller_inline_id = Smi::New(caller_inline_id_[intervals[i].inlining_id]);
const intptr_t p = i * Code::kInlIntNumEntries;
inlined_code_intervals_.SetAt(p + Code::kInlIntStart, start_h);
inlined_code_intervals_.SetAt(p + Code::kInlIntInliningId, inline_id);
}
}
set_current_block(NULL);
if (FLAG_trace_inlining_intervals && is_optimizing()) {
LogBlock lb;
THR_Print("Intervals:\n");
for (intptr_t cc = 0; cc < caller_inline_id_.length(); cc++) {
THR_Print(" iid: %" Pd " caller iid: %" Pd "\n",
cc, caller_inline_id_[cc]);
}
Smi& temp = Smi::Handle();
for (intptr_t i = 0; i < inlined_code_intervals_.Length();
i += Code::kInlIntNumEntries) {
temp ^= inlined_code_intervals_.At(i + Code::kInlIntStart);
ASSERT(!temp.IsNull());
THR_Print("% " Pd " start: 0x%" Px " ", i, temp.Value());
temp ^= inlined_code_intervals_.At(i + Code::kInlIntInliningId);
THR_Print("iid: %" Pd " ", temp.Value());
}
}
}
void FlowGraphCompiler::Bailout(const char* reason) {
const Function& function = parsed_function_.function();
Report::MessageF(Report::kBailout,
Script::Handle(function.script()),
function.token_pos(),
"FlowGraphCompiler Bailout: %s %s",
String::Handle(function.name()).ToCString(),
reason);
UNREACHABLE();
}
void FlowGraphCompiler::EmitTrySync(Instruction* instr, intptr_t try_index) {
ASSERT(is_optimizing());
Environment* env = instr->env()->Outermost();
CatchBlockEntryInstr* catch_block =
flow_graph().graph_entry()->GetCatchEntry(try_index);
const GrowableArray<Definition*>* idefs = catch_block->initial_definitions();
// Construct a ParallelMove instruction for parameters and locals. Skip the
// special locals exception_var and stacktrace_var since they will be filled
// when an exception is thrown. Constant locations are known to be the same
// at all instructions that may throw, and do not need to be materialized.
// Parameters first.
intptr_t i = 0;
const intptr_t num_non_copied_params = flow_graph().num_non_copied_params();
ParallelMoveInstr* move_instr = new(zone()) ParallelMoveInstr();
for (; i < num_non_copied_params; ++i) {
// Don't sync captured parameters. They are not in the environment.
if (flow_graph().captured_parameters()->Contains(i)) continue;
if ((*idefs)[i]->IsConstant()) continue; // Common constants
Location src = env->LocationAt(i);
intptr_t dest_index = i - num_non_copied_params;
Location dest = Location::StackSlot(dest_index);
move_instr->AddMove(dest, src);
}
// Process locals. Skip exception_var and stacktrace_var.
intptr_t local_base = kFirstLocalSlotFromFp + num_non_copied_params;
intptr_t ex_idx = local_base - catch_block->exception_var().index();
intptr_t st_idx = local_base - catch_block->stacktrace_var().index();
for (; i < flow_graph().variable_count(); ++i) {
// Don't sync captured parameters. They are not in the environment.
if (flow_graph().captured_parameters()->Contains(i)) continue;
if (i == ex_idx || i == st_idx) continue;
if ((*idefs)[i]->IsConstant()) continue;
Location src = env->LocationAt(i);
ASSERT(!src.IsFpuRegister());
ASSERT(!src.IsDoubleStackSlot());
intptr_t dest_index = i - num_non_copied_params;
Location dest = Location::StackSlot(dest_index);
move_instr->AddMove(dest, src);
// Update safepoint bitmap to indicate that the target location
// now contains a pointer.
instr->locs()->SetStackBit(dest_index);
}
parallel_move_resolver()->EmitNativeCode(move_instr);
}
intptr_t FlowGraphCompiler::StackSize() const {
if (is_optimizing_) {
return flow_graph_.graph_entry()->spill_slot_count();
} else {
return parsed_function_.num_stack_locals() +
parsed_function_.num_copied_params();
}
}
Label* FlowGraphCompiler::GetJumpLabel(
BlockEntryInstr* block_entry) const {
const intptr_t block_index = block_entry->postorder_number();
return block_info_[block_index]->jump_label();
}
bool FlowGraphCompiler::WasCompacted(
BlockEntryInstr* block_entry) const {
const intptr_t block_index = block_entry->postorder_number();
return block_info_[block_index]->WasCompacted();
}
Label* FlowGraphCompiler::NextNonEmptyLabel() const {
const intptr_t current_index = current_block()->postorder_number();
return block_info_[current_index]->next_nonempty_label();
}
bool FlowGraphCompiler::CanFallThroughTo(BlockEntryInstr* block_entry) const {
return NextNonEmptyLabel() == GetJumpLabel(block_entry);
}
BranchLabels FlowGraphCompiler::CreateBranchLabels(BranchInstr* branch) const {
Label* true_label = GetJumpLabel(branch->true_successor());
Label* false_label = GetJumpLabel(branch->false_successor());
Label* fall_through = NextNonEmptyLabel();
BranchLabels result = { true_label, false_label, fall_through };
return result;
}
void FlowGraphCompiler::AddSlowPathCode(SlowPathCode* code) {
slow_path_code_.Add(code);
}
void FlowGraphCompiler::GenerateDeferredCode() {
for (intptr_t i = 0; i < slow_path_code_.length(); i++) {
slow_path_code_[i]->GenerateCode(this);
}
for (intptr_t i = 0; i < deopt_infos_.length(); i++) {
deopt_infos_[i]->GenerateCode(this, i);
}
}
void FlowGraphCompiler::AddExceptionHandler(intptr_t try_index,
intptr_t outer_try_index,
intptr_t pc_offset,
const Array& handler_types,
bool needs_stacktrace) {
exception_handlers_list_->AddHandler(try_index,
outer_try_index,
pc_offset,
handler_types,
needs_stacktrace);
}
void FlowGraphCompiler::SetNeedsStacktrace(intptr_t try_index) {
exception_handlers_list_->SetNeedsStacktrace(try_index);
}
// Uses current pc position and try-index.
void FlowGraphCompiler::AddCurrentDescriptor(RawPcDescriptors::Kind kind,
intptr_t deopt_id,
intptr_t token_pos) {
// When running with optimizations disabled, don't emit deopt-descriptors.
if (!CanOptimize() && (kind == RawPcDescriptors::kDeopt)) return;
pc_descriptors_list()->AddDescriptor(kind,
assembler()->CodeSize(),
deopt_id,
token_pos,
CurrentTryIndex());
}
void FlowGraphCompiler::AddStaticCallTarget(const Function& func) {
ASSERT(func.IsZoneHandle());
static_calls_target_table_.Add(
new(zone()) StaticCallsStruct(assembler()->CodeSize(), &func, NULL));
}
void FlowGraphCompiler::AddStubCallTarget(const Code& code) {
ASSERT(code.IsZoneHandle());
static_calls_target_table_.Add(
new(zone()) StaticCallsStruct(assembler()->CodeSize(), NULL, &code));
}
void FlowGraphCompiler::AddDeoptIndexAtCall(intptr_t deopt_id,
intptr_t token_pos) {
ASSERT(is_optimizing());
ASSERT(!intrinsic_mode());
CompilerDeoptInfo* info =
new(zone()) CompilerDeoptInfo(deopt_id,
ICData::kDeoptAtCall,
0, // No flags.
pending_deoptimization_env_);
info->set_pc_offset(assembler()->CodeSize());
deopt_infos_.Add(info);
}
// This function must be in sync with FlowGraphCompiler::SaveLiveRegisters
// and FlowGraphCompiler::SlowPathEnvironmentFor.
// See StackFrame::VisitObjectPointers for the details of how stack map is
// interpreted.
void FlowGraphCompiler::RecordSafepoint(LocationSummary* locs) {
if (is_optimizing() || locs->live_registers()->HasUntaggedValues()) {
const intptr_t spill_area_size = is_optimizing() ?
flow_graph_.graph_entry()->spill_slot_count() : 0;
RegisterSet* registers = locs->live_registers();
ASSERT(registers != NULL);
const intptr_t kFpuRegisterSpillFactor =
kFpuRegisterSize / kWordSize;
const intptr_t live_registers_size = registers->CpuRegisterCount() +
(registers->FpuRegisterCount() * kFpuRegisterSpillFactor);
BitmapBuilder* bitmap = locs->stack_bitmap();
// An instruction may have two safepoints in deferred code. The
// call to RecordSafepoint has the side-effect of appending the live
// registers to the bitmap. This is why the second call to RecordSafepoint
// with the same instruction (and same location summary) sees a bitmap that
// is larger that StackSize(). It will never be larger than StackSize() +
// live_registers_size.
ASSERT(bitmap->Length() <= (spill_area_size + live_registers_size));
// The first safepoint will grow the bitmap to be the size of
// spill_area_size but the second safepoint will truncate the bitmap and
// append the live registers to it again. The bitmap produced by both calls
// will be the same.
bitmap->SetLength(spill_area_size);
// Mark the bits in the stack map in the same order we push registers in
// slow path code (see FlowGraphCompiler::SaveLiveRegisters).
//
// Slow path code can have registers at the safepoint.
if (!locs->always_calls()) {
RegisterSet* regs = locs->live_registers();
if (regs->FpuRegisterCount() > 0) {
// Denote FPU registers with 0 bits in the stackmap. Based on the
// assumption that there are normally few live FPU registers, this
// encoding is simpler and roughly as compact as storing a separate
// count of FPU registers.
//
// FPU registers have the highest register number at the highest
// address (i.e., first in the stackmap).
for (intptr_t i = kNumberOfFpuRegisters - 1; i >= 0; --i) {
FpuRegister reg = static_cast<FpuRegister>(i);
if (regs->ContainsFpuRegister(reg)) {
for (intptr_t j = 0; j < kFpuRegisterSpillFactor; ++j) {
bitmap->Set(bitmap->Length(), false);
}
}
}
}
// General purpose registers have the highest register number at the
// highest address (i.e., first in the stackmap).
for (intptr_t i = kNumberOfCpuRegisters - 1; i >= 0; --i) {
Register reg = static_cast<Register>(i);
if (locs->live_registers()->ContainsRegister(reg)) {
bitmap->Set(bitmap->Length(), locs->live_registers()->IsTagged(reg));
}
}
}
intptr_t register_bit_count = bitmap->Length() - spill_area_size;
stackmap_table_builder()->AddEntry(assembler()->CodeSize(),
bitmap,
register_bit_count);
}
}
// This function must be kept in sync with:
//
// FlowGraphCompiler::RecordSafepoint
// FlowGraphCompiler::SaveLiveRegisters
// MaterializeObjectInstr::RemapRegisters
//
Environment* FlowGraphCompiler::SlowPathEnvironmentFor(
Instruction* instruction) {
if (instruction->env() == NULL) {
ASSERT(!is_optimizing());
return NULL;
}
Environment* env = instruction->env()->DeepCopy(zone());
// 1. Iterate the registers in the order they will be spilled to compute
// the slots they will be spilled to.
intptr_t next_slot = StackSize() + env->CountArgsPushed();
RegisterSet* regs = instruction->locs()->live_registers();
intptr_t fpu_reg_slots[kNumberOfFpuRegisters];
intptr_t cpu_reg_slots[kNumberOfCpuRegisters];
const intptr_t kFpuRegisterSpillFactor = kFpuRegisterSize / kWordSize;
// FPU registers are spilled first from highest to lowest register number.
for (intptr_t i = kNumberOfFpuRegisters - 1; i >= 0; --i) {
FpuRegister reg = static_cast<FpuRegister>(i);
if (regs->ContainsFpuRegister(reg)) {
// We use the lowest address (thus highest index) to identify a
// multi-word spill slot.
next_slot += kFpuRegisterSpillFactor;
fpu_reg_slots[i] = (next_slot - 1);
} else {
fpu_reg_slots[i] = -1;
}
}
// General purpose registers are spilled from highest to lowest register
// number.
for (intptr_t i = kNumberOfCpuRegisters - 1; i >= 0; --i) {
Register reg = static_cast<Register>(i);
if (regs->ContainsRegister(reg)) {
cpu_reg_slots[i] = next_slot++;
} else {
cpu_reg_slots[i] = -1;
}
}
// 2. Iterate the environment and replace register locations with the
// corresponding spill slot locations.
for (Environment::DeepIterator it(env); !it.Done(); it.Advance()) {
Location loc = it.CurrentLocation();
Value* value = it.CurrentValue();
it.SetCurrentLocation(loc.RemapForSlowPath(
value->definition(), cpu_reg_slots, fpu_reg_slots));
}
return env;
}
Label* FlowGraphCompiler::AddDeoptStub(intptr_t deopt_id,
ICData::DeoptReasonId reason,
uint32_t flags) {
if (intrinsic_mode()) {
return &intrinsic_slow_path_label_;
}
// No deoptimization allowed when 'always_optimize' is set.
ASSERT(!Compiler::always_optimize());
ASSERT(is_optimizing_);
CompilerDeoptInfoWithStub* stub =
new(zone()) CompilerDeoptInfoWithStub(deopt_id,
reason,
flags,
pending_deoptimization_env_);
deopt_infos_.Add(stub);
return stub->entry_label();
}
void FlowGraphCompiler::FinalizeExceptionHandlers(const Code& code) {
ASSERT(exception_handlers_list_ != NULL);
const ExceptionHandlers& handlers = ExceptionHandlers::Handle(
exception_handlers_list_->FinalizeExceptionHandlers(code.EntryPoint()));
code.set_exception_handlers(handlers);
if (FLAG_compiler_stats) {
Thread* thread = Thread::Current();
INC_STAT(thread, total_code_size,
ExceptionHandlers::InstanceSize(handlers.num_entries()));
INC_STAT(thread, total_code_size, handlers.num_entries() * sizeof(uword));
}
}
void FlowGraphCompiler::FinalizePcDescriptors(const Code& code) {
ASSERT(pc_descriptors_list_ != NULL);
const PcDescriptors& descriptors = PcDescriptors::Handle(
pc_descriptors_list_->FinalizePcDescriptors(code.EntryPoint()));
if (!is_optimizing_) descriptors.Verify(parsed_function_.function());
code.set_pc_descriptors(descriptors);
code.set_lazy_deopt_pc_offset(lazy_deopt_pc_offset_);
}
RawArray* FlowGraphCompiler::CreateDeoptInfo(Assembler* assembler) {
// No deopt information if we 'always_optimize' (no deoptimization allowed).
if (Compiler::always_optimize()) {
return Array::empty_array().raw();
}
// For functions with optional arguments, all incoming arguments are copied
// to spill slots. The deoptimization environment does not track them.
const Function& function = parsed_function().function();
const intptr_t incoming_arg_count =
function.HasOptionalParameters() ? 0 : function.num_fixed_parameters();
DeoptInfoBuilder builder(zone(), incoming_arg_count, assembler);
intptr_t deopt_info_table_size = DeoptTable::SizeFor(deopt_infos_.length());
if (deopt_info_table_size == 0) {
return Object::empty_array().raw();
} else {
const Array& array =
Array::Handle(Array::New(deopt_info_table_size, Heap::kOld));
Smi& offset = Smi::Handle();
TypedData& info = TypedData::Handle();
Smi& reason_and_flags = Smi::Handle();
for (intptr_t i = 0; i < deopt_infos_.length(); i++) {
offset = Smi::New(deopt_infos_[i]->pc_offset());
info = deopt_infos_[i]->CreateDeoptInfo(this, &builder, array);
reason_and_flags = DeoptTable::EncodeReasonAndFlags(
deopt_infos_[i]->reason(),
deopt_infos_[i]->flags());
DeoptTable::SetEntry(array, i, offset, info, reason_and_flags);
}
return array.raw();
}
}
void FlowGraphCompiler::FinalizeStackmaps(const Code& code) {
if (stackmap_table_builder_ == NULL) {
code.set_stackmaps(Object::null_array());
} else {
// Finalize the stack map array and add it to the code object.
code.set_stackmaps(
Array::Handle(stackmap_table_builder_->FinalizeStackmaps(code)));
}
}
void FlowGraphCompiler::FinalizeVarDescriptors(const Code& code) {
if (code.is_optimized()) {
// Optimized code does not need variable descriptors. They are
// only stored in the unoptimized version.
code.set_var_descriptors(Object::empty_var_descriptors());
return;
}
LocalVarDescriptors& var_descs = LocalVarDescriptors::Handle();
if (parsed_function().node_sequence() == NULL) {
// Eager local var descriptors computation for Irregexp function as it is
// complicated to factor out.
// TODO(srdjan): Consider canonicalizing and reusing the local var
// descriptor for IrregexpFunction.
ASSERT(flow_graph().IsIrregexpFunction());
var_descs = LocalVarDescriptors::New(1);
RawLocalVarDescriptors::VarInfo info;
info.set_kind(RawLocalVarDescriptors::kSavedCurrentContext);
info.scope_id = 0;
info.begin_pos = 0;
info.end_pos = 0;
info.set_index(parsed_function().current_context_var()->index());
var_descs.SetVar(0, Symbols::CurrentContextVar(), &info);
}
code.set_var_descriptors(var_descs);
}
void FlowGraphCompiler::FinalizeStaticCallTargetsTable(const Code& code) {
ASSERT(code.static_calls_target_table() == Array::null());
const Array& targets = Array::Handle(zone(), Array::New(
(static_calls_target_table_.length() * Code::kSCallTableEntryLength),
Heap::kOld));
Smi& smi_offset = Smi::Handle(zone());
for (intptr_t i = 0; i < static_calls_target_table_.length(); i++) {
const intptr_t target_ix = Code::kSCallTableEntryLength * i;
smi_offset = Smi::New(static_calls_target_table_[i]->offset);
targets.SetAt(target_ix + Code::kSCallTableOffsetEntry, smi_offset);
if (static_calls_target_table_[i]->function != NULL) {
targets.SetAt(target_ix + Code::kSCallTableFunctionEntry,
*static_calls_target_table_[i]->function);
}
if (static_calls_target_table_[i]->code != NULL) {
targets.SetAt(target_ix + Code::kSCallTableCodeEntry,
*static_calls_target_table_[i]->code);
}
}
code.set_static_calls_target_table(targets);
INC_STAT(Thread::Current(),
total_code_size,
targets.Length() * sizeof(uword));
}
// Returns 'true' if regular code generation should be skipped.
bool FlowGraphCompiler::TryIntrinsify() {
// Intrinsification skips arguments checks, therefore disable if in checked
// mode.
if (FLAG_intrinsify && !isolate()->flags().type_checks()) {
if (parsed_function().function().kind() == RawFunction::kImplicitGetter) {
// An implicit getter must have a specific AST structure.
const SequenceNode& sequence_node = *parsed_function().node_sequence();
ASSERT(sequence_node.length() == 1);
ASSERT(sequence_node.NodeAt(0)->IsReturnNode());
const ReturnNode& return_node = *sequence_node.NodeAt(0)->AsReturnNode();
ASSERT(return_node.value()->IsLoadInstanceFieldNode());
const LoadInstanceFieldNode& load_node =
*return_node.value()->AsLoadInstanceFieldNode();
// Only intrinsify getter if the field cannot contain a mutable double.
// Reading from a mutable double box requires allocating a fresh double.
if (load_node.field().guarded_cid() == kDynamicCid) {
GenerateInlinedGetter(load_node.field().Offset());
return true;
}
return false;
}
if (parsed_function().function().kind() == RawFunction::kImplicitSetter) {
// An implicit setter must have a specific AST structure.
// Sequence node has one store node and one return NULL node.
const SequenceNode& sequence_node = *parsed_function().node_sequence();
ASSERT(sequence_node.length() == 2);
ASSERT(sequence_node.NodeAt(0)->IsStoreInstanceFieldNode());
ASSERT(sequence_node.NodeAt(1)->IsReturnNode());
const StoreInstanceFieldNode& store_node =
*sequence_node.NodeAt(0)->AsStoreInstanceFieldNode();
if (store_node.field().guarded_cid() == kDynamicCid) {
GenerateInlinedSetter(store_node.field().Offset());
return true;
}
}
}
EnterIntrinsicMode();
Intrinsifier::Intrinsify(parsed_function(), this);
ExitIntrinsicMode();
// "Deoptimization" from intrinsic continues here. All deoptimization
// branches from intrinsic code redirect to here where the slow-path
// (normal function body) starts.
// This means that there must not be any side-effects in intrinsic code
// before any deoptimization point.
ASSERT(!intrinsic_slow_path_label_.IsBound());
assembler()->Bind(&intrinsic_slow_path_label_);
return false;
}
void FlowGraphCompiler::GenerateInstanceCall(
intptr_t deopt_id,
intptr_t token_pos,
intptr_t argument_count,
LocationSummary* locs,
const ICData& ic_data) {
if (FLAG_always_megamorphic_calls) {
EmitMegamorphicInstanceCall(ic_data, argument_count,
deopt_id, token_pos, locs);
return;
}
ASSERT(!ic_data.IsNull());
if (is_optimizing() && (ic_data.NumberOfUsedChecks() == 0)) {
// Emit IC call that will count and thus may need reoptimization at
// function entry.
ASSERT(!is_optimizing()
|| may_reoptimize()
|| flow_graph().IsCompiledForOsr());
switch (ic_data.NumArgsTested()) {
case 1:
EmitOptimizedInstanceCall(
*StubCode::OneArgOptimizedCheckInlineCache_entry(), ic_data,
argument_count, deopt_id, token_pos, locs);
return;
case 2:
EmitOptimizedInstanceCall(
*StubCode::TwoArgsOptimizedCheckInlineCache_entry(), ic_data,
argument_count, deopt_id, token_pos, locs);
return;
default:
UNIMPLEMENTED();
}
return;
}
if (is_optimizing() &&
// Do not make the instance call megamorphic if the callee needs to decode
// the calling code sequence to lookup the ic data and verify if a JS
// warning has already been issued or not.
(!FLAG_warn_on_javascript_compatibility ||
!ic_data.MayCheckForJSWarning())) {
EmitMegamorphicInstanceCall(ic_data, argument_count,
deopt_id, token_pos, locs);
return;
}
switch (ic_data.NumArgsTested()) {
case 1:
EmitInstanceCall(
*StubCode::OneArgCheckInlineCache_entry(), ic_data, argument_count,
deopt_id, token_pos, locs);
break;
case 2:
EmitInstanceCall(
*StubCode::TwoArgsCheckInlineCache_entry(), ic_data, argument_count,
deopt_id, token_pos, locs);
break;
default:
UNIMPLEMENTED();
}
}
void FlowGraphCompiler::GenerateStaticCall(intptr_t deopt_id,
intptr_t token_pos,
const Function& function,
intptr_t argument_count,
const Array& argument_names,
LocationSummary* locs,
const ICData& ic_data) {
const Array& arguments_descriptor = Array::ZoneHandle(
ic_data.IsNull() ? ArgumentsDescriptor::New(argument_count,
argument_names)
: ic_data.arguments_descriptor());
// Proper reporting of Javascript incompatibilities requires icdata and
// may therefore prevent the optimization of some static calls.
if (is_optimizing() &&
!(FLAG_warn_on_javascript_compatibility &&
(MethodRecognizer::RecognizeKind(function) ==
MethodRecognizer::kObjectIdentical))) {
EmitOptimizedStaticCall(function, arguments_descriptor,
argument_count, deopt_id, token_pos, locs);
} else {
ICData& call_ic_data = ICData::ZoneHandle(ic_data.raw());
if (call_ic_data.IsNull()) {
const intptr_t kNumArgsChecked = 0;
call_ic_data = GetOrAddStaticCallICData(deopt_id,
function,
arguments_descriptor,
kNumArgsChecked)->raw();
}
EmitUnoptimizedStaticCall(argument_count, deopt_id, token_pos, locs,
call_ic_data);
}
}
void FlowGraphCompiler::GenerateNumberTypeCheck(Register kClassIdReg,
const AbstractType& type,
Label* is_instance_lbl,
Label* is_not_instance_lbl) {
assembler()->Comment("NumberTypeCheck");
GrowableArray<intptr_t> args;
if (type.IsNumberType()) {
args.Add(kDoubleCid);
args.Add(kMintCid);
args.Add(kBigintCid);
} else if (type.IsIntType()) {
args.Add(kMintCid);
args.Add(kBigintCid);
} else if (type.IsDoubleType()) {
args.Add(kDoubleCid);
}
CheckClassIds(kClassIdReg, args, is_instance_lbl, is_not_instance_lbl);
}
void FlowGraphCompiler::GenerateStringTypeCheck(Register kClassIdReg,
Label* is_instance_lbl,
Label* is_not_instance_lbl) {
assembler()->Comment("StringTypeCheck");
GrowableArray<intptr_t> args;
args.Add(kOneByteStringCid);
args.Add(kTwoByteStringCid);
args.Add(kExternalOneByteStringCid);
args.Add(kExternalTwoByteStringCid);
CheckClassIds(kClassIdReg, args, is_instance_lbl, is_not_instance_lbl);
}
void FlowGraphCompiler::GenerateListTypeCheck(Register kClassIdReg,
Label* is_instance_lbl) {
assembler()->Comment("ListTypeCheck");
Label unknown;
GrowableArray<intptr_t> args;
args.Add(kArrayCid);
args.Add(kGrowableObjectArrayCid);
args.Add(kImmutableArrayCid);
CheckClassIds(kClassIdReg, args, is_instance_lbl, &unknown);
assembler()->Bind(&unknown);
}
void FlowGraphCompiler::EmitComment(Instruction* instr) {
char buffer[256];
BufferFormatter f(buffer, sizeof(buffer));
instr->PrintTo(&f);
assembler()->Comment("%s", buffer);
}
bool FlowGraphCompiler::NeedsEdgeCounter(TargetEntryInstr* block) {
// Only emit an edge counter if there is not goto at the end of the block,
// except for the entry block.
return (FLAG_emit_edge_counters
&& (!block->last_instruction()->IsGoto()
|| (block == flow_graph().graph_entry()->normal_entry())));
}
// Allocate a register that is not explicitly blocked.
static Register AllocateFreeRegister(bool* blocked_registers) {
for (intptr_t regno = 0; regno < kNumberOfCpuRegisters; regno++) {
if (!blocked_registers[regno]) {
blocked_registers[regno] = true;
return static_cast<Register>(regno);
}
}
UNREACHABLE();
return kNoRegister;
}
static uword RegMaskBit(Register reg) {
return ((reg) != kNoRegister) ? (1 << (reg)) : 0;
}
// Mask of globally reserved registers. Some other registers are only reserved
// in particular code (e.g., ARGS_DESC_REG in intrinsics).
static const uword kReservedCpuRegisters = RegMaskBit(SPREG)
| RegMaskBit(FPREG)
| RegMaskBit(TMP)
| RegMaskBit(TMP2)
| RegMaskBit(PP)
| RegMaskBit(THR);
void FlowGraphCompiler::AllocateRegistersLocally(Instruction* instr) {
ASSERT(!is_optimizing());
instr->InitializeLocationSummary(zone(),
false); // Not optimizing.
LocationSummary* locs = instr->locs();
bool blocked_registers[kNumberOfCpuRegisters];
// Mark all available registers free.
for (intptr_t i = 0; i < kNumberOfCpuRegisters; i++) {
blocked_registers[i] = false;
}
// Block all registers globally reserved by the assembler, etc.
for (intptr_t i = 0; i < kNumberOfCpuRegisters; i++) {
if ((kReservedCpuRegisters & (1 << i)) != 0) {
blocked_registers[i] = true;
}
}
// Mark all fixed input, temp and output registers as used.
for (intptr_t i = 0; i < locs->input_count(); i++) {
Location loc = locs->in(i);
if (loc.IsRegister()) {
// Check that a register is not specified twice in the summary.
ASSERT(!blocked_registers[loc.reg()]);
blocked_registers[loc.reg()] = true;
}
}
for (intptr_t i = 0; i < locs->temp_count(); i++) {
Location loc = locs->temp(i);
if (loc.IsRegister()) {
// Check that a register is not specified twice in the summary.
ASSERT(!blocked_registers[loc.reg()]);
blocked_registers[loc.reg()] = true;
}
}
if (locs->out(0).IsRegister()) {
// Fixed output registers are allowed to overlap with
// temps and inputs.
blocked_registers[locs->out(0).reg()] = true;
}
// Block all non-free registers.
for (intptr_t i = 0; i < kFirstFreeCpuRegister; i++) {
blocked_registers[i] = true;
}
for (intptr_t i = kLastFreeCpuRegister + 1; i < kNumberOfCpuRegisters; i++) {
blocked_registers[i] = true;
}
// Allocate all unallocated input locations.
const bool should_pop = !instr->IsPushArgument() && !instr->IsPushTemp();
for (intptr_t i = locs->input_count() - 1; i >= 0; i--) {
Location loc = locs->in(i);
Register reg = kNoRegister;
if (loc.IsRegister()) {
reg = loc.reg();
} else if (loc.IsUnallocated() || loc.IsConstant()) {
ASSERT(loc.IsConstant() ||
((loc.policy() == Location::kRequiresRegister) ||
(loc.policy() == Location::kWritableRegister) ||
(loc.policy() == Location::kAny)));
reg = AllocateFreeRegister(blocked_registers);
locs->set_in(i, Location::RegisterLocation(reg));
}
ASSERT(reg != kNoRegister);
// Inputs are consumed from the simulated frame. In case of a call argument
// we leave it until the call instruction.
if (should_pop) {
assembler()->PopRegister(reg);
}
}
// Allocate all unallocated temp locations.
for (intptr_t i = 0; i < locs->temp_count(); i++) {
Location loc = locs->temp(i);
if (loc.IsUnallocated()) {
ASSERT(loc.policy() == Location::kRequiresRegister);
loc = Location::RegisterLocation(
AllocateFreeRegister(blocked_registers));
locs->set_temp(i, loc);
}
}
Location result_location = locs->out(0);
if (result_location.IsUnallocated()) {
switch (result_location.policy()) {
case Location::kAny:
case Location::kPrefersRegister:
case Location::kRequiresRegister:
case Location::kWritableRegister:
result_location = Location::RegisterLocation(
AllocateFreeRegister(blocked_registers));
break;
case Location::kSameAsFirstInput:
result_location = locs->in(0);
break;
case Location::kRequiresFpuRegister:
UNREACHABLE();
break;
}
locs->set_out(0, result_location);
}
}
ParallelMoveResolver::ParallelMoveResolver(FlowGraphCompiler* compiler)
: compiler_(compiler), moves_(32) {}
void ParallelMoveResolver::EmitNativeCode(ParallelMoveInstr* parallel_move) {
ASSERT(moves_.is_empty());
// Build up a worklist of moves.
BuildInitialMoveList(parallel_move);
for (int i = 0; i < moves_.length(); ++i) {
const MoveOperands& move = *moves_[i];
// Skip constants to perform them last. They don't block other moves
// and skipping such moves with register destinations keeps those
// registers free for the whole algorithm.
if (!move.IsEliminated() && !move.src().IsConstant()) PerformMove(i);
}
// Perform the moves with constant sources.
for (int i = 0; i < moves_.length(); ++i) {
const MoveOperands& move = *moves_[i];
if (!move.IsEliminated()) {
ASSERT(move.src().IsConstant());
EmitMove(i);
}
}
moves_.Clear();
}
void ParallelMoveResolver::BuildInitialMoveList(
ParallelMoveInstr* parallel_move) {
// Perform a linear sweep of the moves to add them to the initial list of
// moves to perform, ignoring any move that is redundant (the source is
// the same as the destination, the destination is ignored and
// unallocated, or the move was already eliminated).
for (int i = 0; i < parallel_move->NumMoves(); i++) {
MoveOperands* move = parallel_move->MoveOperandsAt(i);
if (!move->IsRedundant()) moves_.Add(move);
}
}
void ParallelMoveResolver::PerformMove(int index) {
// Each call to this function performs a move and deletes it from the move
// graph. We first recursively perform any move blocking this one. We
// mark a move as "pending" on entry to PerformMove in order to detect
// cycles in the move graph. We use operand swaps to resolve cycles,
// which means that a call to PerformMove could change any source operand
// in the move graph.
ASSERT(!moves_[index]->IsPending());
ASSERT(!moves_[index]->IsRedundant());
// Clear this move's destination to indicate a pending move. The actual
// destination is saved in a stack-allocated local. Recursion may allow
// multiple moves to be pending.
ASSERT(!moves_[index]->src().IsInvalid());
Location destination = moves_[index]->MarkPending();
// Perform a depth-first traversal of the move graph to resolve
// dependencies. Any unperformed, unpending move with a source the same
// as this one's destination blocks this one so recursively perform all
// such moves.
for (int i = 0; i < moves_.length(); ++i) {
const MoveOperands& other_move = *moves_[i];
if (other_move.Blocks(destination) && !other_move.IsPending()) {
// Though PerformMove can change any source operand in the move graph,
// this call cannot create a blocking move via a swap (this loop does
// not miss any). Assume there is a non-blocking move with source A
// and this move is blocked on source B and there is a swap of A and
// B. Then A and B must be involved in the same cycle (or they would
// not be swapped). Since this move's destination is B and there is
// only a single incoming edge to an operand, this move must also be
// involved in the same cycle. In that case, the blocking move will
// be created but will be "pending" when we return from PerformMove.
PerformMove(i);
}
}
// We are about to resolve this move and don't need it marked as
// pending, so restore its destination.
moves_[index]->ClearPending(destination);
// This move's source may have changed due to swaps to resolve cycles and
// so it may now be the last move in the cycle. If so remove it.
if (moves_[index]->src().Equals(destination)) {
moves_[index]->Eliminate();
return;
}
// The move may be blocked on a (at most one) pending move, in which case
// we have a cycle. Search for such a blocking move and perform a swap to
// resolve it.
for (int i = 0; i < moves_.length(); ++i) {
const MoveOperands& other_move = *moves_[i];
if (other_move.Blocks(destination)) {
ASSERT(other_move.IsPending());
EmitSwap(index);
return;
}
}
// This move is not blocked.
EmitMove(index);
}
bool ParallelMoveResolver::IsScratchLocation(Location loc) {
for (int i = 0; i < moves_.length(); ++i) {
if (moves_[i]->Blocks(loc)) {
return false;
}
}
for (int i = 0; i < moves_.length(); ++i) {
if (moves_[i]->dest().Equals(loc)) {
return true;
}
}
return false;
}
intptr_t ParallelMoveResolver::AllocateScratchRegister(
Location::Kind kind,
uword blocked_mask,
intptr_t first_free_register,
intptr_t last_free_register,
bool* spilled) {
COMPILE_ASSERT(static_cast<intptr_t>(sizeof(blocked_mask)) * kBitsPerByte >=
kNumberOfFpuRegisters);
COMPILE_ASSERT(static_cast<intptr_t>(sizeof(blocked_mask)) * kBitsPerByte >=
kNumberOfCpuRegisters);
intptr_t scratch = -1;
for (intptr_t reg = first_free_register; reg <= last_free_register; reg++) {
if ((((1 << reg) & blocked_mask) == 0) &&
IsScratchLocation(Location::MachineRegisterLocation(kind, reg))) {
scratch = reg;
break;
}
}
if (scratch == -1) {
*spilled = true;
for (intptr_t reg = first_free_register; reg <= last_free_register; reg++) {
if (((1 << reg) & blocked_mask) == 0) {
scratch = reg;
break;
}
}
} else {
*spilled = false;
}
return scratch;
}
ParallelMoveResolver::ScratchFpuRegisterScope::ScratchFpuRegisterScope(
ParallelMoveResolver* resolver, FpuRegister blocked)
: resolver_(resolver),
reg_(kNoFpuRegister),
spilled_(false) {
COMPILE_ASSERT(FpuTMP != kNoFpuRegister);
uword blocked_mask = ((blocked != kNoFpuRegister) ? 1 << blocked : 0)
| 1 << FpuTMP;
reg_ = static_cast<FpuRegister>(
resolver_->AllocateScratchRegister(Location::kFpuRegister,
blocked_mask,
0,
kNumberOfFpuRegisters - 1,
&spilled_));
if (spilled_) {
resolver->SpillFpuScratch(reg_);
}
}
ParallelMoveResolver::ScratchFpuRegisterScope::~ScratchFpuRegisterScope() {
if (spilled_) {
resolver_->RestoreFpuScratch(reg_);
}
}
ParallelMoveResolver::ScratchRegisterScope::ScratchRegisterScope(
ParallelMoveResolver* resolver, Register blocked)
: resolver_(resolver),
reg_(kNoRegister),
spilled_(false) {
uword blocked_mask = RegMaskBit(blocked) | kReservedCpuRegisters;
if (resolver->compiler_->intrinsic_mode()) {
// Block additional registers that must be preserved for intrinsics.
blocked_mask |= RegMaskBit(ARGS_DESC_REG);
}
reg_ = static_cast<Register>(
resolver_->AllocateScratchRegister(Location::kRegister,
blocked_mask,
kFirstFreeCpuRegister,
kLastFreeCpuRegister,
&spilled_));
if (spilled_) {
resolver->SpillScratch(reg_);
}
}
ParallelMoveResolver::ScratchRegisterScope::~ScratchRegisterScope() {
if (spilled_) {
resolver_->RestoreScratch(reg_);
}
}
static int HighestCountFirst(const CidTarget* a, const CidTarget* b) {
// Negative if 'a' should sort before 'b'.
return b->count - a->count;
}
// Returns 'sorted' array in decreasing count order.
// The expected number of elements to sort is less than 10.
void FlowGraphCompiler::SortICDataByCount(const ICData& ic_data,
GrowableArray<CidTarget>* sorted,
bool drop_smi) {
ASSERT(ic_data.NumArgsTested() == 1);
const intptr_t len = ic_data.NumberOfChecks();
sorted->Clear();
for (int i = 0; i < len; i++) {
intptr_t receiver_cid = ic_data.GetReceiverClassIdAt(i);
if (drop_smi && (receiver_cid == kSmiCid)) continue;
sorted->Add(CidTarget(receiver_cid,
&Function::ZoneHandle(ic_data.GetTargetAt(i)),
ic_data.GetCountAt(i)));
}
sorted->Sort(HighestCountFirst);
}
const ICData* FlowGraphCompiler::GetOrAddInstanceCallICData(
intptr_t deopt_id,
const String& target_name,
const Array& arguments_descriptor,
intptr_t num_args_tested) {
if ((deopt_id_to_ic_data_ != NULL) &&
((*deopt_id_to_ic_data_)[deopt_id] != NULL)) {
const ICData* res = (*deopt_id_to_ic_data_)[deopt_id];
ASSERT(res->deopt_id() == deopt_id);
ASSERT(res->target_name() == target_name.raw());
ASSERT(res->NumArgsTested() == num_args_tested);
return res;
}
const ICData& ic_data = ICData::ZoneHandle(zone(), ICData::New(
parsed_function().function(), target_name,
arguments_descriptor, deopt_id, num_args_tested));
if (deopt_id_to_ic_data_ != NULL) {
(*deopt_id_to_ic_data_)[deopt_id] = &ic_data;
}
return &ic_data;
}
const ICData* FlowGraphCompiler::GetOrAddStaticCallICData(
intptr_t deopt_id,
const Function& target,
const Array& arguments_descriptor,
intptr_t num_args_tested) {
if ((deopt_id_to_ic_data_ != NULL) &&
((*deopt_id_to_ic_data_)[deopt_id] != NULL)) {
const ICData* res = (*deopt_id_to_ic_data_)[deopt_id];
ASSERT(res->deopt_id() == deopt_id);
ASSERT(res->target_name() == target.name());
ASSERT(res->NumArgsTested() == num_args_tested);
return res;
}
const ICData& ic_data = ICData::ZoneHandle(zone(), ICData::New(
parsed_function().function(), String::Handle(zone(), target.name()),
arguments_descriptor, deopt_id, num_args_tested));
ic_data.AddTarget(target);
if (deopt_id_to_ic_data_ != NULL) {
(*deopt_id_to_ic_data_)[deopt_id] = &ic_data;
}
return &ic_data;
}
intptr_t FlowGraphCompiler::GetOptimizationThreshold() const {
intptr_t threshold;
if (is_optimizing()) {
threshold = FLAG_reoptimization_counter_threshold;
} else if (parsed_function_.function().IsIrregexpFunction()) {
threshold = FLAG_regexp_optimization_counter_threshold;
} else {
const intptr_t basic_blocks = flow_graph().preorder().length();
ASSERT(basic_blocks > 0);
threshold = FLAG_optimization_counter_scale * basic_blocks +
FLAG_min_optimization_counter_threshold;
if (threshold > FLAG_optimization_counter_threshold) {
threshold = FLAG_optimization_counter_threshold;
}
}
return threshold;
}
const Class& FlowGraphCompiler::BoxClassFor(Representation rep) {
switch (rep) {
case kUnboxedDouble:
return double_class();
case kUnboxedFloat32x4:
return float32x4_class();
case kUnboxedFloat64x2:
return float64x2_class();
case kUnboxedInt32x4:
return int32x4_class();
case kUnboxedMint:
return mint_class();
default:
UNREACHABLE();
return Class::ZoneHandle();
}
}
RawArray* FlowGraphCompiler::InliningIdToFunction() const {
if (inline_id_to_function_.length() == 0) {
return Object::empty_array().raw();
}
const Array& res = Array::Handle(
Array::New(inline_id_to_function_.length(), Heap::kOld));
for (intptr_t i = 0; i < inline_id_to_function_.length(); i++) {
res.SetAt(i, *inline_id_to_function_[i]);
}
return res.raw();
}
RawArray* FlowGraphCompiler::CallerInliningIdMap() const {
if (caller_inline_id_.length() == 0) {
return Object::empty_array().raw();
}
const Array& res = Array::Handle(
Array::New(caller_inline_id_.length(), Heap::kOld));
Smi& smi = Smi::Handle();
for (intptr_t i = 0; i < caller_inline_id_.length(); i++) {
smi = Smi::New(caller_inline_id_[i]);
res.SetAt(i, smi);
}
return res.raw();
}
void FlowGraphCompiler::EmitPolymorphicInstanceCall(
const ICData& ic_data,
intptr_t argument_count,
const Array& argument_names,
intptr_t deopt_id,
intptr_t token_pos,
LocationSummary* locs) {
if (FLAG_polymorphic_with_deopt) {
Label* deopt = AddDeoptStub(deopt_id,
ICData::kDeoptPolymorphicInstanceCallTestFail);
Label ok;
EmitTestAndCall(ic_data, argument_count, argument_names,
deopt, // No cid match.
&ok, // Found cid.
deopt_id, token_pos, locs);
assembler()->Bind(&ok);
} else {
// Instead of deoptimizing, do a megamorphic call when no matching
// cid found.
Label megamorphic, ok;
EmitTestAndCall(ic_data, argument_count, argument_names,
&megamorphic, // No cid match.
&ok, // Found cid.
deopt_id, token_pos, locs);
// Fall through if last test is match.
assembler()->Jump(&ok);
assembler()->Bind(&megamorphic);
EmitMegamorphicInstanceCall(ic_data, argument_count, deopt_id,
token_pos, locs);
assembler()->Bind(&ok);
}
}
#if defined(DEBUG)
void FlowGraphCompiler::FrameStateUpdateWith(Instruction* instr) {
ASSERT(!is_optimizing());
switch (instr->tag()) {
case Instruction::kPushArgument:
case Instruction::kPushTemp:
// Do nothing.
break;
case Instruction::kDropTemps:
FrameStatePop(instr->locs()->input_count() +
instr->AsDropTemps()->num_temps());
break;
default:
FrameStatePop(instr->locs()->input_count());
break;
}
ASSERT(!instr->locs()->can_call() || FrameStateIsSafeToCall());
FrameStatePop(instr->ArgumentCount());
Definition* defn = instr->AsDefinition();
if ((defn != NULL) && defn->HasTemp()) {
FrameStatePush(defn);
}
}
void FlowGraphCompiler::FrameStatePush(Definition* defn) {
Representation rep = defn->representation();
if ((rep == kUnboxedDouble) ||
(rep == kUnboxedFloat64x2) ||
(rep == kUnboxedFloat32x4)) {
// LoadField instruction lies about its representation in the unoptimized
// code because Definition::representation() can't depend on the type of
// compilation but MakeLocationSummary and EmitNativeCode can.
ASSERT(defn->IsLoadField() && defn->AsLoadField()->IsUnboxedLoad());
ASSERT(defn->locs()->out(0).IsRegister());
rep = kTagged;
}
ASSERT(!is_optimizing());
ASSERT((rep == kTagged) || (rep == kUntagged));
ASSERT(rep != kUntagged || flow_graph_.IsIrregexpFunction());
frame_state_.Add(rep);
}
void FlowGraphCompiler::FrameStatePop(intptr_t count) {
ASSERT(!is_optimizing());
frame_state_.TruncateTo(Utils::Maximum(static_cast<intptr_t>(0),
frame_state_.length() - count));
}
bool FlowGraphCompiler::FrameStateIsSafeToCall() {
ASSERT(!is_optimizing());
for (intptr_t i = 0; i < frame_state_.length(); i++) {
if (frame_state_[i] != kTagged) {
return false;
}
}
return true;
}
void FlowGraphCompiler::FrameStateClear() {
ASSERT(!is_optimizing());
frame_state_.TruncateTo(0);
}
#endif
} // namespace dart