citra/externals/tracy/public/common/TracyQueue.hpp

895 lines
22 KiB
C++
Raw Normal View History

#ifndef __TRACYQUEUE_HPP__
#define __TRACYQUEUE_HPP__
#include <stddef.h>
#include <stdint.h>
namespace tracy
{
enum class QueueType : uint8_t
{
ZoneText,
ZoneName,
Message,
MessageColor,
MessageCallstack,
MessageColorCallstack,
MessageAppInfo,
ZoneBeginAllocSrcLoc,
ZoneBeginAllocSrcLocCallstack,
CallstackSerial,
Callstack,
CallstackAlloc,
CallstackSample,
CallstackSampleContextSwitch,
FrameImage,
ZoneBegin,
ZoneBeginCallstack,
ZoneEnd,
LockWait,
LockObtain,
LockRelease,
LockSharedWait,
LockSharedObtain,
LockSharedRelease,
LockName,
MemAlloc,
MemAllocNamed,
MemFree,
MemFreeNamed,
MemAllocCallstack,
MemAllocCallstackNamed,
MemFreeCallstack,
MemFreeCallstackNamed,
GpuZoneBegin,
GpuZoneBeginCallstack,
GpuZoneBeginAllocSrcLoc,
GpuZoneBeginAllocSrcLocCallstack,
GpuZoneEnd,
GpuZoneBeginSerial,
GpuZoneBeginCallstackSerial,
GpuZoneBeginAllocSrcLocSerial,
GpuZoneBeginAllocSrcLocCallstackSerial,
GpuZoneEndSerial,
PlotDataInt,
PlotDataFloat,
PlotDataDouble,
ContextSwitch,
ThreadWakeup,
GpuTime,
GpuContextName,
CallstackFrameSize,
SymbolInformation,
ExternalNameMetadata,
SymbolCodeMetadata,
SourceCodeMetadata,
FiberEnter,
FiberLeave,
Terminate,
KeepAlive,
ThreadContext,
GpuCalibration,
GpuTimeSync,
Crash,
CrashReport,
ZoneValidation,
ZoneColor,
ZoneValue,
FrameMarkMsg,
FrameMarkMsgStart,
FrameMarkMsgEnd,
FrameVsync,
SourceLocation,
LockAnnounce,
LockTerminate,
LockMark,
MessageLiteral,
MessageLiteralColor,
MessageLiteralCallstack,
MessageLiteralColorCallstack,
GpuNewContext,
CallstackFrame,
SysTimeReport,
SysPowerReport,
TidToPid,
HwSampleCpuCycle,
HwSampleInstructionRetired,
HwSampleCacheReference,
HwSampleCacheMiss,
HwSampleBranchRetired,
HwSampleBranchMiss,
PlotConfig,
ParamSetup,
AckServerQueryNoop,
AckSourceCodeNotAvailable,
AckSymbolCodeNotAvailable,
CpuTopology,
SingleStringData,
SecondStringData,
MemNamePayload,
StringData,
ThreadName,
PlotName,
SourceLocationPayload,
CallstackPayload,
CallstackAllocPayload,
FrameName,
FrameImageData,
ExternalName,
ExternalThreadName,
SymbolCode,
SourceCode,
FiberName,
NUM_TYPES
};
#pragma pack( push, 1 )
struct QueueThreadContext
{
uint32_t thread;
};
struct QueueZoneBeginLean
{
int64_t time;
};
struct QueueZoneBegin : public QueueZoneBeginLean
{
uint64_t srcloc; // ptr
};
struct QueueZoneBeginThread : public QueueZoneBegin
{
uint32_t thread;
};
struct QueueZoneEnd
{
int64_t time;
};
struct QueueZoneEndThread : public QueueZoneEnd
{
uint32_t thread;
};
struct QueueZoneValidation
{
uint32_t id;
};
struct QueueZoneValidationThread : public QueueZoneValidation
{
uint32_t thread;
};
struct QueueZoneColor
{
uint8_t b;
uint8_t g;
uint8_t r;
};
struct QueueZoneColorThread : public QueueZoneColor
{
uint32_t thread;
};
struct QueueZoneValue
{
uint64_t value;
};
struct QueueZoneValueThread : public QueueZoneValue
{
uint32_t thread;
};
struct QueueStringTransfer
{
uint64_t ptr;
};
struct QueueFrameMark
{
int64_t time;
uint64_t name; // ptr
};
struct QueueFrameVsync
{
int64_t time;
uint32_t id;
};
struct QueueFrameImage
{
uint32_t frame;
uint16_t w;
uint16_t h;
uint8_t flip;
};
struct QueueFrameImageFat : public QueueFrameImage
{
uint64_t image; // ptr
};
struct QueueSourceLocation
{
uint64_t name;
uint64_t function; // ptr
uint64_t file; // ptr
uint32_t line;
uint8_t b;
uint8_t g;
uint8_t r;
};
struct QueueZoneTextFat
{
uint64_t text; // ptr
uint16_t size;
};
struct QueueZoneTextFatThread : public QueueZoneTextFat
{
uint32_t thread;
};
enum class LockType : uint8_t
{
Lockable,
SharedLockable
};
struct QueueLockAnnounce
{
uint32_t id;
int64_t time;
uint64_t lckloc; // ptr
LockType type;
};
struct QueueFiberEnter
{
int64_t time;
uint64_t fiber; // ptr
uint32_t thread;
};
struct QueueFiberLeave
{
int64_t time;
uint32_t thread;
};
struct QueueLockTerminate
{
uint32_t id;
int64_t time;
};
struct QueueLockWait
{
uint32_t thread;
uint32_t id;
int64_t time;
};
struct QueueLockObtain
{
uint32_t thread;
uint32_t id;
int64_t time;
};
struct QueueLockRelease
{
uint32_t id;
int64_t time;
};
struct QueueLockReleaseShared : public QueueLockRelease
{
uint32_t thread;
};
struct QueueLockMark
{
uint32_t thread;
uint32_t id;
uint64_t srcloc; // ptr
};
struct QueueLockName
{
uint32_t id;
};
struct QueueLockNameFat : public QueueLockName
{
uint64_t name; // ptr
uint16_t size;
};
struct QueuePlotDataBase
{
uint64_t name; // ptr
int64_t time;
};
struct QueuePlotDataInt : public QueuePlotDataBase
{
int64_t val;
};
struct QueuePlotDataFloat : public QueuePlotDataBase
{
float val;
};
struct QueuePlotDataDouble : public QueuePlotDataBase
{
double val;
};
struct QueueMessage
{
int64_t time;
};
struct QueueMessageColor : public QueueMessage
{
uint8_t b;
uint8_t g;
uint8_t r;
};
struct QueueMessageLiteral : public QueueMessage
{
uint64_t text; // ptr
};
struct QueueMessageLiteralThread : public QueueMessageLiteral
{
uint32_t thread;
};
struct QueueMessageColorLiteral : public QueueMessageColor
{
uint64_t text; // ptr
};
struct QueueMessageColorLiteralThread : public QueueMessageColorLiteral
{
uint32_t thread;
};
struct QueueMessageFat : public QueueMessage
{
uint64_t text; // ptr
uint16_t size;
};
struct QueueMessageFatThread : public QueueMessageFat
{
uint32_t thread;
};
struct QueueMessageColorFat : public QueueMessageColor
{
uint64_t text; // ptr
uint16_t size;
};
struct QueueMessageColorFatThread : public QueueMessageColorFat
{
uint32_t thread;
};
// Don't change order, only add new entries at the end, this is also used on trace dumps!
enum class GpuContextType : uint8_t
{
Invalid,
OpenGl,
Vulkan,
OpenCL,
Direct3D12,
Direct3D11
};
enum GpuContextFlags : uint8_t
{
GpuContextCalibration = 1 << 0
};
struct QueueGpuNewContext
{
int64_t cpuTime;
int64_t gpuTime;
uint32_t thread;
float period;
uint8_t context;
GpuContextFlags flags;
GpuContextType type;
};
struct QueueGpuZoneBeginLean
{
int64_t cpuTime;
uint32_t thread;
uint16_t queryId;
uint8_t context;
};
struct QueueGpuZoneBegin : public QueueGpuZoneBeginLean
{
uint64_t srcloc;
};
struct QueueGpuZoneEnd
{
int64_t cpuTime;
uint32_t thread;
uint16_t queryId;
uint8_t context;
};
struct QueueGpuTime
{
int64_t gpuTime;
uint16_t queryId;
uint8_t context;
};
struct QueueGpuCalibration
{
int64_t gpuTime;
int64_t cpuTime;
int64_t cpuDelta;
uint8_t context;
};
struct QueueGpuTimeSync
{
int64_t gpuTime;
int64_t cpuTime;
uint8_t context;
};
struct QueueGpuContextName
{
uint8_t context;
};
struct QueueGpuContextNameFat : public QueueGpuContextName
{
uint64_t ptr;
uint16_t size;
};
struct QueueMemNamePayload
{
uint64_t name;
};
struct QueueMemAlloc
{
int64_t time;
uint32_t thread;
uint64_t ptr;
char size[6];
};
struct QueueMemFree
{
int64_t time;
uint32_t thread;
uint64_t ptr;
};
struct QueueCallstackFat
{
uint64_t ptr;
};
struct QueueCallstackFatThread : public QueueCallstackFat
{
uint32_t thread;
};
struct QueueCallstackAllocFat
{
uint64_t ptr;
uint64_t nativePtr;
};
struct QueueCallstackAllocFatThread : public QueueCallstackAllocFat
{
uint32_t thread;
};
struct QueueCallstackSample
{
int64_t time;
uint32_t thread;
};
struct QueueCallstackSampleFat : public QueueCallstackSample
{
uint64_t ptr;
};
struct QueueCallstackFrameSize
{
uint64_t ptr;
uint8_t size;
};
struct QueueCallstackFrameSizeFat : public QueueCallstackFrameSize
{
uint64_t data;
uint64_t imageName;
};
struct QueueCallstackFrame
{
uint32_t line;
uint64_t symAddr;
uint32_t symLen;
};
struct QueueSymbolInformation
{
uint32_t line;
uint64_t symAddr;
};
struct QueueSymbolInformationFat : public QueueSymbolInformation
{
uint64_t fileString;
uint8_t needFree;
};
struct QueueCrashReport
{
int64_t time;
uint64_t text; // ptr
};
struct QueueCrashReportThread
{
uint32_t thread;
};
struct QueueSysTime
{
int64_t time;
float sysTime;
};
struct QueueSysPower
{
int64_t time;
uint64_t delta;
uint64_t name; // ptr
};
struct QueueContextSwitch
{
int64_t time;
uint32_t oldThread;
uint32_t newThread;
uint8_t cpu;
uint8_t reason;
uint8_t state;
};
struct QueueThreadWakeup
{
int64_t time;
uint32_t thread;
};
struct QueueTidToPid
{
uint64_t tid;
uint64_t pid;
};
struct QueueHwSample
{
uint64_t ip;
int64_t time;
};
enum class PlotFormatType : uint8_t
{
Number,
Memory,
Percentage
};
struct QueuePlotConfig
{
uint64_t name; // ptr
uint8_t type;
uint8_t step;
uint8_t fill;
uint32_t color;
};
struct QueueParamSetup
{
uint32_t idx;
uint64_t name; // ptr
uint8_t isBool;
int32_t val;
};
struct QueueSourceCodeNotAvailable
{
uint32_t id;
};
struct QueueCpuTopology
{
uint32_t package;
uint32_t core;
uint32_t thread;
};
struct QueueExternalNameMetadata
{
uint64_t thread;
uint64_t name;
uint64_t threadName;
};
struct QueueSymbolCodeMetadata
{
uint64_t symbol;
uint64_t ptr;
uint32_t size;
};
struct QueueSourceCodeMetadata
{
uint64_t ptr;
uint32_t size;
uint32_t id;
};
struct QueueHeader
{
union
{
QueueType type;
uint8_t idx;
};
};
struct QueueItem
{
QueueHeader hdr;
union
{
QueueThreadContext threadCtx;
QueueZoneBegin zoneBegin;
QueueZoneBeginLean zoneBeginLean;
QueueZoneBeginThread zoneBeginThread;
QueueZoneEnd zoneEnd;
QueueZoneEndThread zoneEndThread;
QueueZoneValidation zoneValidation;
QueueZoneValidationThread zoneValidationThread;
QueueZoneColor zoneColor;
QueueZoneColorThread zoneColorThread;
QueueZoneValue zoneValue;
QueueZoneValueThread zoneValueThread;
QueueStringTransfer stringTransfer;
QueueFrameMark frameMark;
QueueFrameVsync frameVsync;
QueueFrameImage frameImage;
QueueFrameImageFat frameImageFat;
QueueSourceLocation srcloc;
QueueZoneTextFat zoneTextFat;
QueueZoneTextFatThread zoneTextFatThread;
QueueLockAnnounce lockAnnounce;
QueueLockTerminate lockTerminate;
QueueLockWait lockWait;
QueueLockObtain lockObtain;
QueueLockRelease lockRelease;
QueueLockReleaseShared lockReleaseShared;
QueueLockMark lockMark;
QueueLockName lockName;
QueueLockNameFat lockNameFat;
QueuePlotDataInt plotDataInt;
QueuePlotDataFloat plotDataFloat;
QueuePlotDataDouble plotDataDouble;
QueueMessage message;
QueueMessageColor messageColor;
QueueMessageLiteral messageLiteral;
QueueMessageLiteralThread messageLiteralThread;
QueueMessageColorLiteral messageColorLiteral;
QueueMessageColorLiteralThread messageColorLiteralThread;
QueueMessageFat messageFat;
QueueMessageFatThread messageFatThread;
QueueMessageColorFat messageColorFat;
QueueMessageColorFatThread messageColorFatThread;
QueueGpuNewContext gpuNewContext;
QueueGpuZoneBegin gpuZoneBegin;
QueueGpuZoneBeginLean gpuZoneBeginLean;
QueueGpuZoneEnd gpuZoneEnd;
QueueGpuTime gpuTime;
QueueGpuCalibration gpuCalibration;
QueueGpuTimeSync gpuTimeSync;
QueueGpuContextName gpuContextName;
QueueGpuContextNameFat gpuContextNameFat;
QueueMemAlloc memAlloc;
QueueMemFree memFree;
QueueMemNamePayload memName;
QueueCallstackFat callstackFat;
QueueCallstackFatThread callstackFatThread;
QueueCallstackAllocFat callstackAllocFat;
QueueCallstackAllocFatThread callstackAllocFatThread;
QueueCallstackSample callstackSample;
QueueCallstackSampleFat callstackSampleFat;
QueueCallstackFrameSize callstackFrameSize;
QueueCallstackFrameSizeFat callstackFrameSizeFat;
QueueCallstackFrame callstackFrame;
QueueSymbolInformation symbolInformation;
QueueSymbolInformationFat symbolInformationFat;
QueueCrashReport crashReport;
QueueCrashReportThread crashReportThread;
QueueSysTime sysTime;
QueueSysPower sysPower;
QueueContextSwitch contextSwitch;
QueueThreadWakeup threadWakeup;
QueueTidToPid tidToPid;
QueueHwSample hwSample;
QueuePlotConfig plotConfig;
QueueParamSetup paramSetup;
QueueCpuTopology cpuTopology;
QueueExternalNameMetadata externalNameMetadata;
QueueSymbolCodeMetadata symbolCodeMetadata;
QueueSourceCodeMetadata sourceCodeMetadata;
QueueSourceCodeNotAvailable sourceCodeNotAvailable;
QueueFiberEnter fiberEnter;
QueueFiberLeave fiberLeave;
};
};
#pragma pack( pop )
enum { QueueItemSize = sizeof( QueueItem ) };
static constexpr size_t QueueDataSize[] = {
sizeof( QueueHeader ), // zone text
sizeof( QueueHeader ), // zone name
sizeof( QueueHeader ) + sizeof( QueueMessage ),
sizeof( QueueHeader ) + sizeof( QueueMessageColor ),
sizeof( QueueHeader ) + sizeof( QueueMessage ), // callstack
sizeof( QueueHeader ) + sizeof( QueueMessageColor ), // callstack
sizeof( QueueHeader ) + sizeof( QueueMessage ), // app info
sizeof( QueueHeader ) + sizeof( QueueZoneBeginLean ), // allocated source location
sizeof( QueueHeader ) + sizeof( QueueZoneBeginLean ), // allocated source location, callstack
sizeof( QueueHeader ), // callstack memory
sizeof( QueueHeader ), // callstack
sizeof( QueueHeader ), // callstack alloc
sizeof( QueueHeader ) + sizeof( QueueCallstackSample ),
sizeof( QueueHeader ) + sizeof( QueueCallstackSample ), // context switch
sizeof( QueueHeader ) + sizeof( QueueFrameImage ),
sizeof( QueueHeader ) + sizeof( QueueZoneBegin ),
sizeof( QueueHeader ) + sizeof( QueueZoneBegin ), // callstack
sizeof( QueueHeader ) + sizeof( QueueZoneEnd ),
sizeof( QueueHeader ) + sizeof( QueueLockWait ),
sizeof( QueueHeader ) + sizeof( QueueLockObtain ),
sizeof( QueueHeader ) + sizeof( QueueLockRelease ),
sizeof( QueueHeader ) + sizeof( QueueLockWait ), // shared
sizeof( QueueHeader ) + sizeof( QueueLockObtain ), // shared
sizeof( QueueHeader ) + sizeof( QueueLockReleaseShared ),
sizeof( QueueHeader ) + sizeof( QueueLockName ),
sizeof( QueueHeader ) + sizeof( QueueMemAlloc ),
sizeof( QueueHeader ) + sizeof( QueueMemAlloc ), // named
sizeof( QueueHeader ) + sizeof( QueueMemFree ),
sizeof( QueueHeader ) + sizeof( QueueMemFree ), // named
sizeof( QueueHeader ) + sizeof( QueueMemAlloc ), // callstack
sizeof( QueueHeader ) + sizeof( QueueMemAlloc ), // callstack, named
sizeof( QueueHeader ) + sizeof( QueueMemFree ), // callstack
sizeof( QueueHeader ) + sizeof( QueueMemFree ), // callstack, named
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBegin ),
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBegin ), // callstack
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBeginLean ),// allocated source location
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBeginLean ),// allocated source location, callstack
sizeof( QueueHeader ) + sizeof( QueueGpuZoneEnd ),
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBegin ), // serial
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBegin ), // serial, callstack
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBeginLean ),// serial, allocated source location
sizeof( QueueHeader ) + sizeof( QueueGpuZoneBeginLean ),// serial, allocated source location, callstack
sizeof( QueueHeader ) + sizeof( QueueGpuZoneEnd ), // serial
sizeof( QueueHeader ) + sizeof( QueuePlotDataInt ),
sizeof( QueueHeader ) + sizeof( QueuePlotDataFloat ),
sizeof( QueueHeader ) + sizeof( QueuePlotDataDouble ),
sizeof( QueueHeader ) + sizeof( QueueContextSwitch ),
sizeof( QueueHeader ) + sizeof( QueueThreadWakeup ),
sizeof( QueueHeader ) + sizeof( QueueGpuTime ),
sizeof( QueueHeader ) + sizeof( QueueGpuContextName ),
sizeof( QueueHeader ) + sizeof( QueueCallstackFrameSize ),
sizeof( QueueHeader ) + sizeof( QueueSymbolInformation ),
sizeof( QueueHeader ), // ExternalNameMetadata - not for wire transfer
sizeof( QueueHeader ), // SymbolCodeMetadata - not for wire transfer
sizeof( QueueHeader ), // SourceCodeMetadata - not for wire transfer
sizeof( QueueHeader ) + sizeof( QueueFiberEnter ),
sizeof( QueueHeader ) + sizeof( QueueFiberLeave ),
// above items must be first
sizeof( QueueHeader ), // terminate
sizeof( QueueHeader ), // keep alive
sizeof( QueueHeader ) + sizeof( QueueThreadContext ),
sizeof( QueueHeader ) + sizeof( QueueGpuCalibration ),
sizeof( QueueHeader ) + sizeof( QueueGpuTimeSync ),
sizeof( QueueHeader ), // crash
sizeof( QueueHeader ) + sizeof( QueueCrashReport ),
sizeof( QueueHeader ) + sizeof( QueueZoneValidation ),
sizeof( QueueHeader ) + sizeof( QueueZoneColor ),
sizeof( QueueHeader ) + sizeof( QueueZoneValue ),
sizeof( QueueHeader ) + sizeof( QueueFrameMark ), // continuous frames
sizeof( QueueHeader ) + sizeof( QueueFrameMark ), // start
sizeof( QueueHeader ) + sizeof( QueueFrameMark ), // end
sizeof( QueueHeader ) + sizeof( QueueFrameVsync ),
sizeof( QueueHeader ) + sizeof( QueueSourceLocation ),
sizeof( QueueHeader ) + sizeof( QueueLockAnnounce ),
sizeof( QueueHeader ) + sizeof( QueueLockTerminate ),
sizeof( QueueHeader ) + sizeof( QueueLockMark ),
sizeof( QueueHeader ) + sizeof( QueueMessageLiteral ),
sizeof( QueueHeader ) + sizeof( QueueMessageColorLiteral ),
sizeof( QueueHeader ) + sizeof( QueueMessageLiteral ), // callstack
sizeof( QueueHeader ) + sizeof( QueueMessageColorLiteral ), // callstack
sizeof( QueueHeader ) + sizeof( QueueGpuNewContext ),
sizeof( QueueHeader ) + sizeof( QueueCallstackFrame ),
sizeof( QueueHeader ) + sizeof( QueueSysTime ),
sizeof( QueueHeader ) + sizeof( QueueSysPower ),
sizeof( QueueHeader ) + sizeof( QueueTidToPid ),
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // cpu cycle
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // instruction retired
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // cache reference
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // cache miss
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // branch retired
sizeof( QueueHeader ) + sizeof( QueueHwSample ), // branch miss
sizeof( QueueHeader ) + sizeof( QueuePlotConfig ),
sizeof( QueueHeader ) + sizeof( QueueParamSetup ),
sizeof( QueueHeader ), // server query acknowledgement
sizeof( QueueHeader ) + sizeof( QueueSourceCodeNotAvailable ),
sizeof( QueueHeader ), // symbol code not available
sizeof( QueueHeader ) + sizeof( QueueCpuTopology ),
sizeof( QueueHeader ), // single string data
sizeof( QueueHeader ), // second string data
sizeof( QueueHeader ) + sizeof( QueueMemNamePayload ),
// keep all QueueStringTransfer below
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // string data
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // thread name
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // plot name
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // allocated source location payload
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // callstack payload
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // callstack alloc payload
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // frame name
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // frame image data
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // external name
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // external thread name
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // symbol code
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // source code
sizeof( QueueHeader ) + sizeof( QueueStringTransfer ), // fiber name
};
static_assert( QueueItemSize == 32, "Queue item size not 32 bytes" );
static_assert( sizeof( QueueDataSize ) / sizeof( size_t ) == (uint8_t)QueueType::NUM_TYPES, "QueueDataSize mismatch" );
static_assert( sizeof( void* ) <= sizeof( uint64_t ), "Pointer size > 8 bytes" );
static_assert( sizeof( void* ) == sizeof( uintptr_t ), "Pointer size != uintptr_t" );
}
#endif