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sdk/runtime/vm/flow_graph_compiler.cc
T
Florian Schneider 63a8e5227d VM: More abstract interface for generating stub calls. 
This makes the code in the code generator independent from how stubs
are actually called (i.e. directly embedding the target address, or
indirectly by loading the target address from the code object).

BUG=
R=rmacnak@google.com

Review URL: https://codereview.chromium.org//1270803003 .
2015-08-05 10:18:35 +02:00

1828 lines
64 KiB
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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, 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, 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, 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);
static void NooptModeHandler(bool value) {
if (value) {
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_collect_code = false;
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;
}
}
// --noopt disables optimizer and tunes unoptimized code to run as fast
// as possible.
DEFINE_FLAG_HANDLER(NooptModeHandler,
noopt,
"Run fast unoptimized code only.");
DECLARE_FLAG(bool, lazy_dispatchers);
DECLARE_FLAG(bool, interpret_irregexp);
DECLARE_FLAG(bool, enable_mirrors);
static void PrecompileModeHandler(bool value) {
if (value) {
NooptModeHandler(true);
FLAG_lazy_dispatchers = false;
FLAG_interpret_irregexp = true;
FLAG_enable_mirrors = false;
FLAG_precompile_collect_closures = true;
}
}
DEFINE_FLAG_HANDLER(PrecompileModeHandler,
precompile,
"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)
: 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_(GrowableObjectArray::ZoneHandle(
GrowableObjectArray::New())),
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),
entry_patch_pc_offset_(Code::kInvalidPc),
patch_code_pc_offset_(Code::kInvalidPc),
lazy_deopt_pc_offset_(Code::kInvalidPc),
deopt_id_to_ic_data_(NULL),
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 = isolate()->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;
}
const Array& old_saved_icdata = Array::Handle(zone(),
flow_graph->function().ic_data_array());
const intptr_t saved_len =
old_saved_icdata.IsNull() ? 0 : old_saved_icdata.Length();
for (intptr_t i = 0; i < saved_len; i++) {
ICData& icd = ICData::ZoneHandle(zone());
icd ^= old_saved_icdata.At(i);
(*deopt_id_to_ic_data_)[icd.deopt_id()] = &icd;
}
}
ASSERT(assembler != NULL);
ASSERT(!list_class_.IsNull());
}
void FlowGraphCompiler::InitCompiler() {
pc_descriptors_list_ = new DescriptorList(64);
exception_handlers_list_ = new 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 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();
}
}
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 Function& function =
Function::Handle(instr->env()->code().function());
const Script& s = Script::Handle(function.script());
intptr_t line_nr;
intptr_t column_nr;
s.GetTokenLocation(instr->token_pos(), &line_nr, &column_nr);
const String& line = String::Handle(s.GetLine(line_nr));
assembler()->Comment("Line %" Pd " in '%s':\n %s",
line_nr, 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() {
ISL_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(Isolate::Current());
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();
ISL_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(Isolate::Current());
ISL_Print("Intervals:\n");
for (intptr_t cc = 0; cc < caller_inline_id_.length(); cc++) {
ISL_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());
ISL_Print("% " Pd " start: 0x%" Px " ", i, temp.Value());
temp ^= inlined_code_intervals_.At(i + Code::kInlIntInliningId);
ISL_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 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(Code::kSCallTableEntryLength == 3);
ASSERT(Code::kSCallTableOffsetEntry == 0);
static_calls_target_table_.Add(
Smi::Handle(Smi::New(assembler()->CodeSize())));
ASSERT(Code::kSCallTableFunctionEntry == 1);
static_calls_target_table_.Add(func);
ASSERT(Code::kSCallTableCodeEntry == 2);
static_calls_target_table_.Add(Code::Handle());
}
void FlowGraphCompiler::AddStubCallTarget(const Code& code) {
ASSERT(Code::kSCallTableEntryLength == 3);
ASSERT(Code::kSCallTableOffsetEntry == 0);
static_calls_target_table_.Add(
Smi::Handle(Smi::New(assembler()->CodeSize())));
ASSERT(Code::kSCallTableFunctionEntry == 1);
static_calls_target_table_.Add(Function::Handle());
ASSERT(Code::kSCallTableCodeEntry == 2);
static_calls_target_table_.Add(code);
}
void FlowGraphCompiler::AddDeoptIndexAtCall(intptr_t deopt_id,
intptr_t token_pos) {
ASSERT(is_optimizing());
ASSERT(!intrinsic_mode());
CompilerDeoptInfo* info =
new 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 lowest register number at the
// highest address (i.e., first in the stackmap).
for (intptr_t i = 0; i < kNumberOfCpuRegisters; ++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 lowest to highest register
// number.
for (intptr_t i = 0; i < kNumberOfCpuRegisters; ++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 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);
INC_STAT(isolate(), total_code_size,
ExceptionHandlers::InstanceSize(handlers.num_entries()));
INC_STAT(isolate(), 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_entry_patch_pc_offset(entry_patch_pc_offset_);
code.set_patch_code_pc_offset(patch_code_pc_offset_);
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(Array::MakeArray(static_calls_target_table_));
code.set_static_calls_target_table(targets);
INC_STAT(isolate(), total_code_size, targets.Length() * sizeof(uword));
}
// Returns 'true' if code generation for this function is complete, i.e.,
// no fall-through to regular code is needed.
void 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;
}
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;
}
}
}
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_);
}
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
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