Changeset 7816 in vbox

Timestamp:

Apr 9, 2008 7:30:56 AM (17 years ago)

Author:

vboxsync

Message:

fixed annoying gcc warnings about dereferencing type-punned pointers

File:

• trunk/include/VBox/stam.h (modified) (1 diff)

trunk/include/VBox/stam.h

@@ -53 +53 @@
  */
 #ifdef __GNUC__
-# define STAM_GET_TS(u64)    \
-    __asm__ __volatile__ ("rdtsc\n\t" : "=a" ( ((uint32_t *)&(u64))[0] ), "=d" ( ((uint32_t *)&(u64))[1]))
+# if defined(RT_ARCH_X86)
+   /* This produces optimal assembler code for x86 but does not work for AMD64 ('A' means 'either rax or rdx') */
+#  define STAM_GET_TS(u64) __asm__ __volatile__ ("rdtsc\n\t" : "=A" (u64));
+# elif defined(RT_ARCH_AMD64)
+#  define STAM_GET_TS(u64) \
+    do { uint64_t low, high; \
+         __asm__ __volatile__ ("rdtsc\n\t" : "=a"(low), "=d"(high)); \
+         (u64) = ((high << 32) | low); \
+    } while (0)
+# endif
 #elif _MSC_VER >= 1400
 # pragma intrinsic(__rdtsc)