summaryrefslogtreecommitdiff
path: root/src/os_timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/os_timer.c')
-rw-r--r--src/os_timer.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/src/os_timer.c b/src/os_timer.c
new file mode 100644
index 000000000..e2a96e8f9
--- /dev/null
+++ b/src/os_timer.c
@@ -0,0 +1,70 @@
+/* $Id$ */
+
+#include "stdafx.h"
+
+#undef RDTSC_AVAILABLE
+
+/* rdtsc for MSC_VER, uses simple inline assembly, or _rdtsc
+ * from external win64.asm because VS2005 does not support inline assembly */
+#if defined(_MSC_VER) && !defined(RDTSC_AVAILABLE)
+# if defined (_M_AMD64)
+extern uint64 _rdtsc(void);
+# else
+uint64 _declspec(naked) _rdtsc(void)
+{
+ _asm {
+ rdtsc
+ ret
+ }
+}
+# endif
+# define RDTSC_AVAILABLE
+#endif
+
+/* rdtsc for OS/2. Hopefully this works, who knows */
+#if defined (__WATCOMC__) && !defined(RDTSC_AVAILABLE)
+unsigned __int64 _rdtsc( void);
+# pragma aux _rdtsc = 0x0F 0x31 value [edx eax] parm nomemory modify exact [edx eax] nomemory;
+# define RDTSC_AVAILABLE
+#endif
+
+/* rdtsc for all other *nix-en (hopefully). Use GCC syntax */
+#if defined(__i386__) || defined(__x86_64__) && !defined(RDTSC_AVAILABLE)
+uint64 _rdtsc(void)
+{
+ uint32 high, low;
+ __asm__ __volatile__ ("rdtsc" : "=a" (low), "=d" (high));
+ return ((uint64)high << 32) | low;
+}
+# define RDTSC_AVAILABLE
+#endif
+
+/* rdtsc for PPC which has this not */
+#if (defined(__POWERPC__) || defined(__powerpc__)) && !defined(RDTSC_AVAILABLE)
+uint64 _rdtsc(void)
+{
+ uint32 high = 0, high2 = 0, low;
+ /* PPC does not have rdtsc, so we cheat by reading the two 32-bit time-counters
+ * it has, 'Move From Time Base (Upper)'. Since these are two reads, in the
+ * very unlikely event that the lower part overflows to the upper part while we
+ * read it; we double-check and reread the registers */
+ asm volatile (
+ "mftbu %0\n"
+ "mftb %1\n"
+ "mftbu %2\n"
+ "cmpw %3,%4\n"
+ "bne- $-16\n"
+ : "=r" (high), "=r" (low), "=r" (high2)
+ : "0" (high), "2" (high2)
+ );
+ return ((uint64)high << 32) | low;
+}
+# define RDTSC_AVAILABLE
+#endif
+
+/* In all other cases we have no support for rdtsc. No major issue,
+ * you just won't be able to profile your code with TIC()/TOC() */
+#if !defined(RDTSC_AVAILABLE)
+#warning "(non-fatal) No support for rdtsc(), you won't be able to profile with TIC/TOC"
+uint64 _rdtsc(void) {return 0;}
+#endif