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8231586: enlarge encoding space for OopMapValue offsets 
Backport-of: 4a41f86
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Olga Mikhaltsova authored and Yuri Nesterenko committed Jan 22, 2021
1 parent e0445f1 commit 40e0519
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Showing 6 changed files with 77 additions and 137 deletions.
92 src/hotspot/share/compiler/oopMap.cpp
View file
@@ -48,29 +48,25 @@

// OopMapStream

OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) {
OopMapStream::OopMapStream(OopMap* oop_map) {
_stream = new CompressedReadStream(oop_map->write_stream()->buffer());
_mask = oop_types_mask;
_size = oop_map->omv_count();
_position = 0;
_valid_omv = false;
}

OopMapStream::OopMapStream(const ImmutableOopMap* oop_map, int oop_types_mask) {
OopMapStream::OopMapStream(const ImmutableOopMap* oop_map) {
_stream = new CompressedReadStream(oop_map->data_addr());
_mask = oop_types_mask;
_size = oop_map->count();
_position = 0;
_valid_omv = false;
}

void OopMapStream::find_next() {
while(_position++ < _size) {
if (_position++ < _size) {
_omv.read_from(_stream);
if(((int)_omv.type() & _mask) > 0) {
_valid_omv = true;
return;
}
_valid_omv = true;
return;
}
_valid_omv = false;
}
@@ -140,16 +136,7 @@ void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
debug_only( _locs_used[reg->value()] = x; )

OopMapValue o(reg, x);

if(x == OopMapValue::callee_saved_value) {
// This can never be a stack location, so we don't need to transform it.
assert(optional->is_reg(), "Trying to callee save a stack location");
o.set_content_reg(optional);
} else if(x == OopMapValue::derived_oop_value) {
o.set_content_reg(optional);
}

OopMapValue o(reg, x, optional);
o.write_on(write_stream());
increment_count();
}
@@ -160,11 +147,6 @@ void OopMap::set_oop(VMReg reg) {
}


void OopMap::set_value(VMReg reg) {
// At this time, we don't need value entries in our OopMap.
}


void OopMap::set_narrowoop(VMReg reg) {
set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());
}
@@ -328,7 +310,7 @@ void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
// changed before derived pointer offset has been collected)
OopMapValue omv;
{
OopMapStream oms(map,OopMapValue::derived_oop_value);
OopMapStream oms(map);
if (!oms.is_done()) {
#ifndef TIERED
COMPILER1_PRESENT(ShouldNotReachHere();)
@@ -340,27 +322,28 @@ void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
#endif // !TIERED
do {
omv = oms.current();
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
guarantee(loc != NULL, "missing saved register");
oop *derived_loc = loc;
oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
// Ignore NULL oops and decoded NULL narrow oops which
// equal to CompressedOops::base() when a narrow oop
// implicit null check is used in compiled code.
// The narrow_oop_base could be NULL or be the address
// of the page below heap depending on compressed oops mode.
if (base_loc != NULL && *base_loc != NULL && !CompressedOops::is_base(*base_loc)) {
derived_oop_fn(base_loc, derived_loc);
if (omv.type() == OopMapValue::derived_oop_value) {
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
guarantee(loc != NULL, "missing saved register");
oop *derived_loc = loc;
oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
// Ignore NULL oops and decoded NULL narrow oops which
// equal to CompressedOops::base() when a narrow oop
// implicit null check is used in compiled code.
// The narrow_oop_base could be NULL or be the address
// of the page below heap depending on compressed oops mode.
if (base_loc != NULL && *base_loc != NULL && !CompressedOops::is_base(*base_loc)) {
derived_oop_fn(base_loc, derived_loc);
}
}
oms.next();
} while (!oms.is_done());
}
}

// We want coop and oop oop_types
int mask = OopMapValue::oop_value | OopMapValue::narrowoop_value;
{
for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {
// We want coop and oop oop_types
for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
omv = oms.current();
oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
// It should be an error if no location can be found for a
@@ -436,12 +419,14 @@ void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
assert(map != NULL, "no ptr map found");
DEBUG_ONLY(int nof_callee = 0;)

for (OopMapStream oms(map, OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {
for (OopMapStream oms(map); !oms.is_done(); oms.next()) {
OopMapValue omv = oms.current();
VMReg reg = omv.content_reg();
oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
reg_map->set_location(reg, (address) loc);
DEBUG_ONLY(nof_callee++;)
if (omv.type() == OopMapValue::callee_saved_value) {
VMReg reg = omv.content_reg();
oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
reg_map->set_location(reg, (address) loc);
DEBUG_ONLY(nof_callee++;)
}
}

// Check that runtime stubs save all callee-saved registers
@@ -452,25 +437,6 @@ void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
#endif // COMPILER2
}

//=============================================================================
// Non-Product code

#ifndef PRODUCT

bool ImmutableOopMap::has_derived_pointer() const {
#if !defined(TIERED) && !INCLUDE_JVMCI
COMPILER1_PRESENT(return false);
#endif // !TIERED
#if COMPILER2_OR_JVMCI
OopMapStream oms(this,OopMapValue::derived_oop_value);
return oms.is_done();
#else
return false;
#endif // COMPILER2_OR_JVMCI
}

#endif //PRODUCT

// Printing code is present in product build for -XX:+PrintAssembly.

static
70 src/hotspot/share/compiler/oopMap.hpp
View file
@@ -53,7 +53,7 @@ class OopMapValue: public StackObj {

public:
// Constants
enum { type_bits = 4,
enum { type_bits = 2,
register_bits = BitsPerShort - type_bits };

enum { type_shift = 0,
@@ -64,19 +64,41 @@ class OopMapValue: public StackObj {
register_mask = right_n_bits(register_bits),
register_mask_in_place = register_mask << register_shift };

enum oop_types { // must fit in type_bits
unused_value =0, // powers of 2, for masking OopMapStream
oop_value = 1,
narrowoop_value = 2,
callee_saved_value = 4,
derived_oop_value= 8 };
enum oop_types {
oop_value,
narrowoop_value,
callee_saved_value,
derived_oop_value,
unused_value = -1 // Only used as a sentinel value
};

// Constructors
OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg, t); set_content_reg(VMRegImpl::Bad()); }
OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg, t); set_content_reg(reg2); }
OopMapValue (CompressedReadStream* stream) { read_from(stream); }
OopMapValue (VMReg reg, oop_types t, VMReg reg2) {
set_reg_type(reg, t);
set_content_reg(reg2);
}

private:
void set_reg_type(VMReg p, oop_types t) {
set_value((p->value() << register_shift) | t);
assert(reg() == p, "sanity check" );
assert(type() == t, "sanity check" );
}

void set_content_reg(VMReg r) {
if (is_callee_saved()) {
// This can never be a stack location, so we don't need to transform it.
assert(r->is_reg(), "Trying to callee save a stack location");
} else if (is_derived_oop()) {
assert (r->is_valid(), "must have a valid VMReg");
} else {
assert (!r->is_valid(), "valid VMReg not allowed");
}
_content_reg = r->value();
}

public:
// Archiving
void write_on(CompressedWriteStream* stream) {
stream->write_int(value());
@@ -94,31 +116,18 @@ class OopMapValue: public StackObj {

// Querying
bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }

void set_oop() { set_value((value() & register_mask_in_place) | oop_value); }
void set_narrowoop() { set_value((value() & register_mask_in_place) | narrowoop_value); }
void set_callee_saved() { set_value((value() & register_mask_in_place) | callee_saved_value); }
void set_derived_oop() { set_value((value() & register_mask_in_place) | derived_oop_value); }

VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }
oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }

static bool legal_vm_reg_name(VMReg p) {
return (p->value() == (p->value() & register_mask));
}

void set_reg_type(VMReg p, oop_types t) {
set_value((p->value() << register_shift) | t);
assert(reg() == p, "sanity check" );
assert(type() == t, "sanity check" );
}


VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
void set_content_reg(VMReg r) { _content_reg = r->value(); }

// Physical location queries
bool is_register_loc() { return reg()->is_reg(); }
@@ -156,6 +165,8 @@ class OopMap: public ResourceObj {
enum DeepCopyToken { _deep_copy_token };
OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy

void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);

public:
OopMap(int frame_size, int arg_count);

@@ -173,19 +184,14 @@ class OopMap: public ResourceObj {
// frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
// slots to hold 4-byte values like ints and floats in the LP64 build.
void set_oop ( VMReg local);
void set_value( VMReg local);
void set_narrowoop(VMReg local);
void set_dead ( VMReg local);
void set_callee_saved( VMReg local, VMReg caller_machine_register );
void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);

int heap_size() const;
void copy_data_to(address addr) const;
OopMap* deep_copy();

bool has_derived_pointer() const PRODUCT_RETURN0;

bool legal_vm_reg_name(VMReg local) {
return OopMapValue::legal_vm_reg_name(local);
}
@@ -269,7 +275,6 @@ class ImmutableOopMap {
public:
ImmutableOopMap(const OopMap* oopmap);

bool has_derived_pointer() const PRODUCT_RETURN0;
int count() const { return _count; }
#ifdef ASSERT
int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
@@ -334,16 +339,15 @@ class ImmutableOopMapSet {
class OopMapStream : public StackObj {
private:
CompressedReadStream* _stream;
int _mask;
int _size;
int _position;
bool _valid_omv;
OopMapValue _omv;
void find_next();

public:
OopMapStream(OopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
OopMapStream(const ImmutableOopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
OopMapStream(OopMap* oop_map);
OopMapStream(const ImmutableOopMap* oop_map);
bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
void next() { find_next(); }
OopMapValue current() { return _omv; }
14 src/hotspot/share/opto/buildOopMap.cpp
View file
@@ -352,7 +352,6 @@ OopMap *OopFlow::build_oop_map( Node *n, int max_reg, PhaseRegAlloc *regalloc, i

} else {
// Other - some reaching non-oop value
omap->set_value( r);
#ifdef ASSERT
if( t->isa_rawptr() && C->cfg()->_raw_oops.member(def) ) {
def->dump();
@@ -377,11 +376,18 @@ OopMap *OopFlow::build_oop_map( Node *n, int max_reg, PhaseRegAlloc *regalloc, i
#endif

#ifdef ASSERT
for( OopMapStream oms1(omap, OopMapValue::derived_oop_value); !oms1.is_done(); oms1.next()) {
for( OopMapStream oms1(omap); !oms1.is_done(); oms1.next()) {
OopMapValue omv1 = oms1.current();
if (omv1.type() != OopMapValue::derived_oop_value) {
continue;
}
bool found = false;
for( OopMapStream oms2(omap,OopMapValue::oop_value); !oms2.is_done(); oms2.next()) {
if( omv1.content_reg() == oms2.current().reg() ) {
for( OopMapStream oms2(omap); !oms2.is_done(); oms2.next()) {
OopMapValue omv2 = oms2.current();
if (omv2.type() != OopMapValue::oop_value) {
continue;
}
if( omv1.content_reg() == omv2.reg() ) {
found = true;
break;
}
31 src/hotspot/share/runtime/interfaceSupport.cpp
View file
@@ -55,12 +55,6 @@ VMEntryWrapper::~VMEntryWrapper() {
if (WalkStackALot) {
InterfaceSupport::walk_stack();
}
#ifdef COMPILER2
// This option is not used by Compiler 1
if (StressDerivedPointers) {
InterfaceSupport::stress_derived_pointers();
}
#endif
if (DeoptimizeALot || DeoptimizeRandom) {
InterfaceSupport::deoptimizeAll();
}
@@ -226,31 +220,6 @@ void InterfaceSupport::deoptimizeAll() {
}


void InterfaceSupport::stress_derived_pointers() {
#ifdef COMPILER2
JavaThread *thread = JavaThread::current();
if (!is_init_completed()) return;
ResourceMark rm(thread);
bool found = false;
for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
CodeBlob* cb = sfs.current()->cb();
if (cb != NULL && cb->oop_maps() ) {
// Find oopmap for current method
const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
assert(map != NULL, "no oopmap found for pc");
found = map->has_derived_pointer();
}
}
if (found) {
// $$$ Not sure what to do here.
/*
Scavenge::invoke(0);
*/
}
#endif
}


void InterfaceSupport::verify_stack() {
JavaThread* thread = JavaThread::current();
ResourceMark rm(thread);
1 src/hotspot/share/runtime/interfaceSupport.inline.hpp
View file
@@ -62,7 +62,6 @@ class InterfaceSupport: AllStatic {

static void zombieAll();
static void deoptimizeAll();
static void stress_derived_pointers();
static void verify_stack();
static void verify_last_frame();
# endif

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