Skip to content

L
libSDL
Commit fb824f9a authored by Sam Lantinga's avatar Sam Lantinga
Browse files
Options

Added cache line size info in SDL_cpuinfo.h 

I also added an implementation to dynamically query it, but didn't expose it since most x86 CPUs have an L1 cache line size of 64 bytes.
parent 1d518f0d
Hide whitespace changes
Inline Side-by-side
Showing with 121 additions and 67 deletions
include/SDL_cpuinfo.h
View file @ fb824f9a
......@@ -39,6 +39,11 @@ extern "C" {
/* *INDENT-ON* */
#endif
/* This is a guess for the cacheline size used for padding, and is correct
* for most x86 processors at this point.
*/
#define SDL_CACHELINE_SIZE 64
/**
* This function returns the number of CPU cores available.
*/
......
src/cpuinfo/SDL_cpuinfo.c
View file @ fb824f9a
......@@ -337,73 +337,125 @@ SDL_GetCPUCount()
static const char *
SDL_GetCPUType()
{
static char SDL_CPUType[48];
static char SDL_CPUType[13];
if (!SDL_CPUType[0]) {
int i = 0;
int a, b, c, d;
if (CPU_haveCPUID()) {
cpuid(0x00000000, a, b, c, d);
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
}
if (!SDL_CPUType[0]) {
SDL_strlcpy(SDL_CPUType, "Unknown", sizeof(SDL_CPUType));
}
}
return SDL_CPUType;
}
static const char *
SDL_GetCPUName()
{
static char SDL_CPUName[48];
if (!SDL_CPUName[0]) {
int i = 0;
int a, b, c, d;
if (CPU_haveCPUID()) {
cpuid(0x80000000, a, b, c, d);
if (a >= 0x80000004) {
cpuid(0x80000002, a, b, c, d);
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
cpuid(0x80000003, a, b, c, d);
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
cpuid(0x80000004, a, b, c, d);
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(a & 0xff); a >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(b & 0xff); b >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(c & 0xff); c >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
SDL_CPUName[i++] = (char)(d & 0xff); d >>= 8;
}
}
if (!SDL_CPUType[0]) {
SDL_strlcpy(SDL_CPUType, "Unknown", sizeof(SDL_CPUType));
if (!SDL_CPUName[0]) {
SDL_strlcpy(SDL_CPUName, "Unknown", sizeof(SDL_CPUName));
}
}
return SDL_CPUType;
return SDL_CPUName;
}
static int
SDL_GetCPUCacheLineSize()
{
const char *cpuType = SDL_GetCPUType();
if (SDL_strcmp(cpuType, "GenuineIntel") == 0) {
int a, b, c, d;
cpuid(0x00000001, a, b, c, d);
return (((b >> 8) & 0xff) * 8);
} else if (SDL_strcmp(cpuType, "AuthenticAMD") == 0) {
int a, b, c, d;
cpuid(0x80000005, a, b, c, d);
return (c & 0xff);
} else {
/* Just make a guess here... */
return SDL_CACHELINE_SIZE;
}
}
static Uint32 SDL_CPUFeatures = 0xFFFFFFFF;
......@@ -521,7 +573,9 @@ int
main()
{
printf("CPU count: %d\n", SDL_GetCPUCount());
printf("CPU name: %s\n", SDL_GetCPUType());
printf("CPU type: %s\n", SDL_GetCPUType());
printf("CPU name: %s\n", SDL_GetCPUName());
printf("CacheLine size: %d\n", SDL_GetCPUCacheLineSize());
printf("RDTSC: %d\n", SDL_HasRDTSC());
printf("MMX: %d\n", SDL_HasMMX());
printf("MMXExt: %d\n", SDL_HasMMXExt());
......
src/timer/SDL_timer.c
View file @ fb824f9a
......@@ -24,6 +24,7 @@
#include "SDL_timer.h"
#include "SDL_timer_c.h"
#include "SDL_atomic.h"
#include "SDL_cpuinfo.h"
#include "SDL_thread.h"
/* #define DEBUG_TIMERS */
......@@ -46,9 +47,6 @@ typedef struct _SDL_TimerMap
struct _SDL_TimerMap *next;
} SDL_TimerMap;
/* A reasonable guess */
#define CACHELINE_SIZE 128
/* The timers are kept in a sorted list */
typedef struct {
/* Data used by the main thread */
......@@ -58,7 +56,7 @@ typedef struct {
SDL_mutex *timermap_lock;
/* Padding to separate cache lines between threads */
char pad[CACHELINE_SIZE];
char cache_pad[SDL_CACHELINE_SIZE];
/* Data used to communicate with the timer thread */
SDL_SpinLock lock;
......
test/testatomic.c
View file @ fb824f9a
......@@ -243,9 +243,6 @@ void RunEpicTest()
#define NUM_WRITERS 4
#define EVENTS_PER_WRITER 1000000
/* A decent guess for the size of a cache line on this architecture */
#define CACHELINE 64
/* The number of entries must be a power of 2 */
#define MAX_ENTRIES 256
#define WRAP_MASK (MAX_ENTRIES-1)
......@@ -260,22 +257,22 @@ typedef struct
{
SDL_EventQueueEntry entries[MAX_ENTRIES];
char cache_pad1[CACHELINE-((sizeof(SDL_EventQueueEntry)*MAX_ENTRIES)%CACHELINE)];
char cache_pad1[SDL_CACHELINE_SIZE-((sizeof(SDL_EventQueueEntry)*MAX_ENTRIES)%SDL_CACHELINE_SIZE)];
SDL_atomic_t enqueue_pos;
char cache_pad2[CACHELINE-sizeof(SDL_atomic_t)];
char cache_pad2[SDL_CACHELINE_SIZE-sizeof(SDL_atomic_t)];
SDL_atomic_t dequeue_pos;
char cache_pad3[CACHELINE-sizeof(SDL_atomic_t)];
char cache_pad3[SDL_CACHELINE_SIZE-sizeof(SDL_atomic_t)];
#ifdef TEST_SPINLOCK_FIFO
SDL_SpinLock lock;
SDL_atomic_t rwcount;
SDL_atomic_t watcher;
char cache_pad4[CACHELINE-sizeof(SDL_SpinLock)-2*sizeof(SDL_atomic_t)];
char cache_pad4[SDL_CACHELINE_SIZE-sizeof(SDL_SpinLock)-2*sizeof(SDL_atomic_t)];
#endif
volatile SDL_bool active;
......@@ -470,10 +467,10 @@ typedef struct
{
SDL_EventQueue *queue;
int index;
char padding1[CACHELINE-(sizeof(SDL_EventQueue*)+sizeof(int))%CACHELINE];
char padding1[SDL_CACHELINE_SIZE-(sizeof(SDL_EventQueue*)+sizeof(int))%SDL_CACHELINE_SIZE];
int waits;
SDL_bool lock_free;
char padding2[CACHELINE-sizeof(int)-sizeof(SDL_bool)];
char padding2[SDL_CACHELINE_SIZE-sizeof(int)-sizeof(SDL_bool)];
} WriterData;
typedef struct
......@@ -482,7 +479,7 @@ typedef struct
int counters[NUM_WRITERS];
int waits;
SDL_bool lock_free;
char padding[CACHELINE-(sizeof(SDL_EventQueue*)+sizeof(int)*NUM_WRITERS+sizeof(int)+sizeof(SDL_bool))%CACHELINE];
char padding[SDL_CACHELINE_SIZE-(sizeof(SDL_EventQueue*)+sizeof(int)*NUM_WRITERS+sizeof(int)+sizeof(SDL_bool))%SDL_CACHELINE_SIZE];
} ReaderData;
static int FIFO_Writer(void* _data)
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment