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| author | Darkvater <darkvater@openttd.org> | 2006-03-26 21:15:09 +0000 |
|---|---|---|
| committer | Darkvater <darkvater@openttd.org> | 2006-03-26 21:15:09 +0000 |
| commit | a91c52e16909976b40951cf2893f2349e9ebf25d (patch) | |
| tree | 07ce18ba583aad9caf062c352c2632ba1ea394c6 /os_timer.c | |
| parent | 4125aa21f8dfc72a60bf70b890b95c2187425112 (diff) | |
| download | openttd-a91c52e16909976b40951cf2893f2349e9ebf25d.tar.xz | |
(svn r4125) - Feature: Add a general TIC() TOC() mechanism using rdtsc or something similar on non-i386 architectures to performance-tune (critical) code. Some systems are probably missing, but those can be added later.
Diffstat (limited to 'os_timer.c')
| -rw-r--r-- | os_timer.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/os_timer.c b/os_timer.c new file mode 100644 index 000000000..89c25d010 --- /dev/null +++ b/os_timer.c @@ -0,0 +1,69 @@ +#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(RDTSC_AVAILABLE)
+uint64 _rdtsc(void)
+{
+ uint32 high, low;
+ uint32 high2 = 0;
+ /* 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 "OS has no support for rdtsc()"
+uint64 _rdtsc(void) {return 0;}
+#endif
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