diff src/cpuinfo/SDL_cpuinfo.c @ 745:71ee03909f42

Greatly simplified the SDL CPU info code
author Sam Lantinga <slouken@libsdl.org>
date Mon, 24 Nov 2003 09:16:52 +0000
parents 22dbf364c017
children da36f59485da
line wrap: on
line diff
--- a/src/cpuinfo/SDL_cpuinfo.c	Mon Nov 24 00:21:24 2003 +0000
+++ b/src/cpuinfo/SDL_cpuinfo.c	Mon Nov 24 09:16:52 2003 +0000
@@ -28,16 +28,160 @@
 /* CPU feature detection for SDL */
 
 #include "SDL.h"
-//#include "SDL_cpuinfo.h"
+#include "SDL_cpuinfo.h"
+
+#define CPU_HAS_RDTSC	0x00000001
+#define CPU_HAS_MMX	0x00000002
+#define CPU_HAS_3DNOW	0x00000004
+#define CPU_HAS_SSE	0x00000008
+
+static __inline__ int CPU_haveCPUID()
+{
+	int has_CPUID = 0;
+#if defined(__GNUC__) && defined(i386)
+	__asm__ (
+"push %%ecx\n"
+"        pushfl                      # Get original EFLAGS             \n"
+"        popl    %%eax                                                 \n"
+"        movl    %%eax,%%ecx                                           \n"
+"        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
+"        pushl   %%eax               # Save new EFLAGS value on stack  \n"
+"        popfl                       # Replace current EFLAGS value    \n"
+"        pushfl                      # Get new EFLAGS                  \n"
+"        popl    %%eax               # Store new EFLAGS in EAX         \n"
+"        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
+"        jz      1f                  # Processor=80486                 \n"
+"        movl    $1,%0               # We have CPUID support           \n"
+"1:                                                                    \n"
+"pop %%ecx\n"
+	: "=r" (has_CPUID)
+	:
+	: "%eax", "%ecx"
+	);
+#elif defined(_MSC_VER)
+	__asm__ {
+        pushfd                      ; Get original EFLAGS
+        pop     eax
+        mov     ecx, eax
+        xor     eax, 200000h        ; Flip ID bit in EFLAGS
+        push    eax                 ; Save new EFLAGS value on stack
+        popfd                       ; Replace current EFLAGS value
+        pushfd                      ; Get new EFLAGS
+        pop     eax                 ; Store new EFLAGS in EAX
+        xor     eax, ecx            ; Can not toggle ID bit,
+        jz      done                ; Processor=80486
+        mov     has_CPUID,1         ; We have CPUID support
+done:
+	}
+#endif
+	return has_CPUID;
+}
 
-#define CPU_HAS_MMX	0x00000001
-#define CPU_HAS_3DNOW	0x00000002
-#define CPU_HAS_SSE	0x00000004
+static __inline__ int CPU_getCPUIDFeatures()
+{
+	int features = 0;
+#if defined(__GNUC__) && defined(i386)
+	__asm__ (
+"push %%ebx\n"
+"push %%ecx\n"
+"push %%edx\n"
+"        xorl    %%eax,%%eax         # Set up for CPUID instruction    \n"
+"        cpuid                       # Get and save vendor ID          \n"
+"        cmpl    $1,%%eax            # Make sure 1 is valid input for CPUID\n"
+"        jl      1f                  # We dont have the CPUID instruction\n"
+"        xorl    %%eax,%%eax                                           \n"
+"        incl    %%eax                                                 \n"
+"        cpuid                       # Get family/model/stepping/features\n"
+"        movl    %%edx,%0                                              \n"
+"1:                                                                    \n"
+"pop %%edx\n"
+"pop %%ecx\n"
+"pop %%ebx\n"
+	: "=r" (features)
+	:
+	: "%eax", "%ebx", "%ecx", "%edx"
+	);
+#elif defined(_MSC_VER)
+	__asm__ {
+        xor     eax, eax            ; Set up for CPUID instruction
+        cpuid                       ; Get and save vendor ID
+        cmp     eax, 1              ; Make sure 1 is valid input for CPUID
+        jl      done                ; We dont have the CPUID instruction
+        xor     eax, eax
+        inc     eax
+        cpuid                       ; Get family/model/stepping/features
+        mov     features, edx
+done:
+	}
+#endif
+	return features;
+}
+
+static __inline__ int CPU_haveRDTSC()
+{
+	if ( CPU_haveCPUID() ) {
+		return (CPU_getCPUIDFeatures() & 0x00000010);
+	}
+	return 0;
+}
 
-/* These functions come from SciTech's PM library */
-extern int CPU_haveMMX();
-extern int CPU_have3DNow();
-extern int CPU_haveSSE();
+static __inline__ int CPU_haveMMX()
+{
+	if ( CPU_haveCPUID() ) {
+		return (CPU_getCPUIDFeatures() & 0x00800000);
+	}
+	return 0;
+}
+
+static __inline__ int CPU_have3DNow()
+{
+	int has_3DNow = 0;
+#if defined(__GNUC__) && defined(i386)
+	__asm__ (
+"push %%ebx\n"
+"push %%ecx\n"
+"push %%edx\n"
+"        movl    $0x80000000,%%eax   # Query for extended functions    \n"
+"        cpuid                       # Get extended function limit     \n"
+"        cmpl    $0x80000001,%%eax                                     \n"
+"        jbe     1f                  # Nope, we dont have function 800000001h\n"
+"        movl    $0x80000001,%%eax   # Setup extended function 800000001h\n"
+"        cpuid                       # and get the information         \n"
+"        testl   $0x80000000,%%edx   # Bit 31 is set if 3DNow! present \n"
+"        jz      1f                  # Nope, we dont have 3DNow support\n"
+"        movl    $1,%0               # Yep, we have 3DNow! support!    \n"
+"1:                                                                    \n"
+"pop %%edx\n"
+"pop %%ecx\n"
+"pop %%ebx\n"
+	: "=r" (has_3DNow)
+	:
+	: "%eax", "%ebx", "%ecx", "%edx"
+	);
+#elif defined(_MSC_VER)
+	__asm__ {
+        mov     eax,80000000h       ; Query for extended functions
+        cpuid                       ; Get extended function limit
+        cmp     eax,80000001h
+        jbe     done                ; Nope, we dont have function 800000001h
+        mov     eax,80000001h       ; Setup extended function 800000001h
+        cpuid                       ; and get the information
+        test    edx,80000000h       ; Bit 31 is set if 3DNow! present
+        jz      done                ; Nope, we dont have 3DNow support
+        mov     has_3DNow,1         ; Yep, we have 3DNow! support!
+done:
+	}
+#endif
+	return has_3DNow;
+}
+
+static __inline__ int CPU_haveSSE()
+{
+	if ( CPU_haveCPUID() ) {
+		return (CPU_getCPUIDFeatures() & 0x02000000);
+	}
+	return 0;
+}
 
 static Uint32 SDL_CPUFeatures = 0xFFFFFFFF;
 
@@ -45,6 +189,9 @@
 {
 	if ( SDL_CPUFeatures == 0xFFFFFFFF ) {
 		SDL_CPUFeatures = 0;
+		if ( CPU_haveRDTSC() ) {
+			SDL_CPUFeatures |= CPU_HAS_RDTSC;
+		}
 		if ( CPU_haveMMX() ) {
 			SDL_CPUFeatures |= CPU_HAS_MMX;
 		}
@@ -58,6 +205,14 @@
 	return SDL_CPUFeatures;
 }
 
+SDL_bool SDL_HasRDTSC()
+{
+	if ( SDL_GetCPUFeatures() & CPU_HAS_RDTSC ) {
+		return SDL_TRUE;
+	}
+	return SDL_FALSE;
+}
+
 SDL_bool SDL_HasMMX()
 {
 	if ( SDL_GetCPUFeatures() & CPU_HAS_MMX ) {
@@ -91,6 +246,7 @@
 	printf("MMX: %d\n", SDL_HasMMX());
 	printf("3DNow: %d\n", SDL_Has3DNow());
 	printf("SSE: %d\n", SDL_HasSSE());
+	return 0;
 }
 
 #endif /* TEST_MAIN */