Changeset 59527 in vbox for trunk/src/VBox/Runtime/testcase

Timestamp:

Jan 31, 2016 11:54:20 AM (9 years ago)

Author:

vboxsync

Message:

iprt/asm.h: Experimented with alternative serializating instructions (ASMSerializeInstruction), cpuid(0) is very reasonable compared to iret (rdtscp would be preferable).

File:

• trunk/src/VBox/Runtime/testcase/tstRTInlineAsm.cpp (modified) (4 diffs)

trunk/src/VBox/Runtime/testcase/tstRTInlineAsm.cpp

@@ -1596 +1596 @@
     static int64_t  volatile s_i64;
     register unsigned i;
-    const unsigned cRounds = _2M;
+    const unsigned cRounds = _2M;       /* Must be multiple of 8 */
     register uint64_t u64Elapsed;
 
@@ -1616 +1616 @@
         RTThreadYield(); \
         u64Elapsed = RTTimeNanoTS(); \
-        for (i = cRounds; i > 0; i--) \
+        for (i = cRounds / 8; i > 0; i--) \
+        { \
             op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+        } \
         u64Elapsed = RTTimeNanoTS() - u64Elapsed; \
         RTTestValue(g_hTest, str, u64Elapsed / cRounds, RTTESTUNIT_NS_PER_CALL); \
     } while (0)
+#endif
+#if (defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)) && !defined(GCC44_32BIT_PIC)
+# define BENCH_TSC(op, str) \
+    do { \
+        RTThreadYield(); \
+        u64Elapsed = ASMReadTSC(); \
+        for (i = cRounds / 8; i > 0; i--) \
+        { \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+            op; \
+        } \
+        u64Elapsed = ASMReadTSC() - u64Elapsed; \
+        RTTestValue(g_hTest, str, u64Elapsed / cRounds, /*RTTESTUNIT_TICKS_PER_CALL*/ RTTESTUNIT_NONE); \
+    } while (0)
+#else
+# define BENCH_TSC(op, str) BENCH(op, str)
 #endif
 
@@ -1682 +1713 @@
     BENCH(ASMAtomicUoAndU32(&s_u32, 0xffffffff), "ASMAtomicUoAndU32");
     BENCH(ASMAtomicUoOrU32(&s_u32, 0xffffffff),  "ASMAtomicUoOrU32");
+    BENCH_TSC(ASMSerializeInstructionCpuId(),    "ASMSerializeInstructionCpuId");
+    BENCH_TSC(ASMSerializeInstructionIRet(),     "ASMSerializeInstructionIRet");
 
     /* The Darwin gcc does not like this ... */
@@ -1688 +1721 @@
 #endif
 #if !defined(GCC44_32BIT_PIC) && (defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86))
-    BENCH(s_u64 = ASMReadTSC(),                 "ASMReadTSC");
     uint32_t uAux;
     if (   ASMHasCpuId()
         && ASMIsValidExtRange(ASMCpuId_EAX(0x80000000))
         && (ASMCpuId_EDX(0x80000001) & X86_CPUID_EXT_FEATURE_EDX_RDTSCP) )
+    {
+        BENCH_TSC(ASMSerializeInstructionRdTscp(), "ASMSerializeInstructionRdTscp");
         BENCH(s_u64 = ASMReadTscWithAux(&uAux),  "ASMReadTscWithAux");
+    }
+    BENCH(s_u64 = ASMReadTSC(),                 "ASMReadTSC");
     union
     {