Changeset 103649 in vbox for trunk/src/VBox/VMM/include

Timestamp:

Mar 3, 2024 7:11:39 AM (13 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

162009

Message:

VMM/IEM: Delay the RIP update for each instruction if possible to save on potentially two instructions for each executed guest instruction of which one is a memory write, bugref:10373

Location:

trunk/src/VBox/VMM/include

Files:

• IEMInternal.h (modified) (5 diffs)
• IEMN8veRecompiler.h (modified) (4 diffs)

trunk/src/VBox/VMM/include/IEMInternal.h

@@ -84 +84 @@
  || defined(DOXYGEN_RUNNING)
 # define IEM_WITH_THROW_CATCH
+#endif
+
+/** @def IEMNATIVE_WITH_DELAYED_PC_UPDATING
+ * Enables the delayed PC updating optimization (see @bugref{10373}).
+ */
+#if defined(DOXYGEN_RUNNING) || 1
+# define IEMNATIVE_WITH_DELAYED_PC_UPDATING
 #endif
 
@@ -957 +964 @@
     /** Info about a host register shadowing a guest register. */
     kIemTbDbgEntryType_GuestRegShadowing,
+#ifdef IEMNATIVE_WITH_DELAYED_PC_UPDATING
+    /** Info about a delayed RIP update. */
+    kIemTbDbgEntryType_DelayedPcUpdate,
+#endif
     kIemTbDbgEntryType_End
 } IEMTBDBGENTRYTYPE;
@@ -1028 +1039 @@
         uint32_t    idxHstRegPrev : 8;
     } GuestRegShadowing;
+
+#ifdef IEMNATIVE_WITH_DELAYED_PC_UPDATING
+    struct
+    {
+        /* kIemTbDbgEntryType_DelayedPcUpdate. */
+        uint32_t    uType         : 4;
+        /* The instruction offset added to the program counter. */
+        uint32_t    offPc         : 14;
+        /** Number of instructions skipped. */
+        uint32_t    cInstrSkipped : 14;
+    } DelayedPcUpdate;
+#endif
+
 } IEMTBDBGENTRY;
 AssertCompileSize(IEMTBDBGENTRY, sizeof(uint32_t));
@@ -1843 +1867 @@
     STAMCOUNTER             StatNativeLivenessEflOfDelayable;
 
-    uint64_t                au64Padding[3];
+    /** Native recompiler: Number of potential PC updates in total. */
+    STAMCOUNTER             StatNativePcUpdateTotal;
+    /** Native recompiler: Number of PC updates which could be delayed. */
+    STAMCOUNTER             StatNativePcUpdateDelayed;
+
+
+    uint64_t                u64Padding;
     /** @} */
 
@@ -3644 +3674 @@
 FNIEMAIMPLMEDIAPSHUFU128 iemAImpl_vpsrlq_imm_u128, iemAImpl_vpsrlq_imm_u128_fallback;
 FNIEMAIMPLMEDIAPSHUFU256 iemAImpl_vpsrlq_imm_u256, iemAImpl_vpsrlq_imm_u256_fallback;
+FNIEMAIMPLMEDIAPSHUFU128 iemAImpl_vpsrldq_imm_u128, iemAImpl_vpsrldq_imm_u128_fallback;
+FNIEMAIMPLMEDIAPSHUFU256 iemAImpl_vpsrldq_imm_u256, iemAImpl_vpsrldq_imm_u256_fallback;
 
 FNIEMAIMPLMEDIAOPTF3U128     iemAImpl_vpermilps_u128,     iemAImpl_vpermilps_u128_fallback;

trunk/src/VBox/VMM/include/IEMN8veRecompiler.h

@@ -169 +169 @@
 # define IEMNATIVE_REG_FIXED_PCPUMCTX       ARMV8_A64_REG_X27
 # define IEMNATIVE_REG_FIXED_TMP0           ARMV8_A64_REG_X15
+# if defined(IEMNATIVE_WITH_DELAYED_PC_UPDATING) && 0 /* debug the updating with a shadow RIP. */
+#   define IEMNATIVE_REG_FIXED_TMP1         ARMV8_A64_REG_X16
+#   define IEMNATIVE_REG_FIXED_PC_DBG       ARMV8_A64_REG_X26
+#   define IEMNATIVE_REG_FIXED_MASK_ADD     (  RT_BIT_32(IEMNATIVE_REG_FIXED_TMP1) \
+                                             | RT_BIT_32(IEMNATIVE_REG_FIXED_PC_DBG))
+# else
+#   define IEMNATIVE_REG_FIXED_MASK_ADD     0
+# endif
 # define IEMNATIVE_REG_FIXED_MASK           (  RT_BIT_32(ARMV8_A64_REG_SP) \
                                              | RT_BIT_32(ARMV8_A64_REG_LR) \
@@ -175 +183 @@
                                              | RT_BIT_32(IEMNATIVE_REG_FIXED_PCPUMCTX) \
                                              | RT_BIT_32(ARMV8_A64_REG_X18) \
-                                             | RT_BIT_32(IEMNATIVE_REG_FIXED_TMP0) )
+                                             | RT_BIT_32(IEMNATIVE_REG_FIXED_TMP0) \
+                                             | IEMNATIVE_REG_FIXED_MASK_ADD)
 
 #else
@@ -851 +860 @@
     /** Fixed temporary register. */
     kIemNativeWhat_FixedTmp,
+#ifdef IEMNATIVE_WITH_DELAYED_PC_UPDATING
+    /** Shadow RIP for the delayed RIP updating debugging. */
+    kIemNativeWhat_PcShadow,
+#endif
     /** Register reserved by the CPU or OS architecture. */
     kIemNativeWhat_FixedReserved,
@@ -899 +912 @@
 typedef struct IEMNATIVECORESTATE
 {
+#ifdef IEMNATIVE_WITH_DELAYED_PC_UPDATING
+    /** The current instruction offset in bytes from when the guest program counter
+     * was updated last. Used for delaying the write to the guest context program counter
+     * as long as possible. */
+    uint32_t                    offPc;
+    /** Number of instructions where we could skip the updating. */
+    uint32_t                    cInstrPcUpdateSkipped;
+#endif
     /** Allocation bitmap for aHstRegs. */
     uint32_t                    bmHstRegs;