Sidewalk, Cell, get_direction(), compute_acceleration()

2026-03-19 23:34:22 +01:00
parent 980bb5635e
commit df482ec7aa
2 changed files with 156 additions and 3 deletions
@@ -0,0 +1,94 @@
+/* ==================== GNU C and possibly other UNIX compilers ===================== */
+	#ifndef _WIN32
+
+	#if defined(__GNUC__) || defined(__linux__)
+		#define VOLATILE __volatile__
+		#define ASM __asm__
+	#else
+		/* if we're neither compiling with gcc or under linux, we can hope
+		 * the following lines work, they probably won't */
+		#define ASM asm
+		#define VOLATILE 
+	#endif
+
+	#define myInt64 unsigned long long
+	#define INT32 unsigned int
+
+/* ======================== WIN32 ======================= */
+#else
+
+	#define myInt64 signed __int64
+	#define INT32 unsigned __int32
+
+#endif
+
+/* This is the RDTSC timer.
+ * RDTSC is an instruction on several Intel and compatible CPUs that Reads the
+ * Time Stamp Counter. The Intel manuals contain more information.
+ */
+
+
+#define COUNTER_LO(a) ((a).int32.lo)
+#define COUNTER_HI(a) ((a).int32.hi)
+#define COUNTER_VAL(a) ((a).int64)
+
+#define COUNTER(a) \
+	((unsigned long long)COUNTER_VAL(a))
+
+#define COUNTER_DIFF(a,b) \
+	(COUNTER(a)-COUNTER(b))
+
+/* ==================== GNU C and possibly other UNIX compilers ===================== */
+#ifndef _WIN32
+
+	typedef union
+	{       myInt64 int64;
+		    struct {INT32 lo, hi;} int32;
+	} tsc_counter;
+
+  #define RDTSC(cpu_c) \
+	  ASM VOLATILE ("rdtsc" : "=a" ((cpu_c).int32.lo), "=d"((cpu_c).int32.hi))
+	#define CPUID() \
+		ASM VOLATILE ("cpuid" : : "a" (0) : "bx", "cx", "dx" )
+
+/* ======================== WIN32 ======================= */
+#else
+
+	typedef union
+	{       myInt64 int64;
+			struct {INT32 lo, hi;} int32;
+	} tsc_counter;
+
+	#define RDTSC(cpu_c)   \
+	{       __asm rdtsc    \
+			__asm mov (cpu_c).int32.lo,eax  \
+			__asm mov (cpu_c).int32.hi,edx  \
+	}
+
+	#define CPUID() \
+	{ \
+		__asm mov eax, 0 \
+		__asm cpuid \
+	}
+
+#endif
+
+
+static void init_tsc() {
+	; // no need to initialize anything for x86
+}
+
+static myInt64 start_tsc(void) {
+    tsc_counter start;
+    CPUID();
+    RDTSC(start);
+    return COUNTER_VAL(start);
+}
+
+static myInt64 stop_tsc(myInt64 start) {
+	tsc_counter end;
+	RDTSC(end);
+	CPUID();
+	return COUNTER_VAL(end) - start;
+}
+