JIT: Fold const RVA access (via const index)

src/coreclr/inc/corinfo.h

@@ -3212,6 +3212,7 @@ class ICorDynamicInfo : public ICorStaticInfo
                     CORINFO_FIELD_HANDLE    field,
                     uint8_t                *buffer,
                     int                     bufferSize,
+                    int                     valueOffset = 0,
                     bool                    ignoreMovableObjects = true
                     ) = 0;
 

src/coreclr/inc/icorjitinfoimpl_generated.h

@@ -625,6 +625,7 @@ bool getReadonlyStaticFieldValue(
           CORINFO_FIELD_HANDLE field,
           uint8_t* buffer,
           int bufferSize,
+          int valueOffset,
           bool ignoreMovableObjects) override;
 
 CORINFO_CLASS_HANDLE getStaticFieldCurrentClass(

src/coreclr/inc/jiteeversionguid.h

@@ -43,11 +43,11 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* da097b39-7f43-458a-990a-0b65406d5ff3 */
-    0xda097b39,
-    0x7f43,
-    0x458a,
-    {0x99, 0xa, 0xb, 0x65, 0x40, 0x6d, 0x5f, 0xf3}
+constexpr GUID JITEEVersionIdentifier = { /* 0330a175-dd05-4760-840f-a1a4c47284d3 */
+    0x330a175,
+    0xdd05,
+    0x4760,
+    {0x84, 0xf, 0xa1, 0xa4, 0xc4, 0x72, 0x84, 0xd3}
   };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp

@@ -1488,10 +1488,11 @@ bool WrapICorJitInfo::getReadonlyStaticFieldValue(
           CORINFO_FIELD_HANDLE field,
           uint8_t* buffer,
           int bufferSize,
+          int valueOffset,
           bool ignoreMovableObjects)
 {
     API_ENTER(getReadonlyStaticFieldValue);
-    bool temp = wrapHnd->getReadonlyStaticFieldValue(field, buffer, bufferSize, ignoreMovableObjects);
+    bool temp = wrapHnd->getReadonlyStaticFieldValue(field, buffer, bufferSize, valueOffset, ignoreMovableObjects);
     API_LEAVE(getReadonlyStaticFieldValue);
     return temp;
 }

src/coreclr/jit/assertionprop.cpp

@@ -3335,7 +3335,8 @@ GenTree* Compiler::optConstantAssertionProp(AssertionDsc*        curAssertion,
         return nullptr;
     }
 
-    GenTree* newTree = tree;
+    GenTree* newTree       = tree;
+    bool     propagateType = false;
 
     // Update 'newTree' with the new value from our table
     // Typically newTree == tree and we are updating the node in place
@@ -3364,9 +3365,16 @@ GenTree* Compiler::optConstantAssertionProp(AssertionDsc*        curAssertion,
         case O2K_CONST_INT:
 
             // Don't propagate handles if we need to report relocs.
-            if (opts.compReloc && curAssertion->op2.HasIconFlag())
+            if (opts.compReloc && curAssertion->op2.HasIconFlag() && curAssertion->op2.u1.iconVal != 0)
             {
-                return nullptr;
+                if (curAssertion->op2.GetIconFlag() == GTF_ICON_STATIC_HDL)
+                {
+                    propagateType = true;
+                }
+                else
+                {
+                    return nullptr;
+                }
             }
 
             // We assume that we do not try to do assertion prop on mismatched
@@ -3394,6 +3402,11 @@ GenTree* Compiler::optConstantAssertionProp(AssertionDsc*        curAssertion,
                         // Conservatively don't allow propagation of ICON TYP_REF into BYREF
                         return nullptr;
                     }
+                    propagateType = true;
+                }
+
+                if (propagateType)
+                {
                     newTree->ChangeType(tree->TypeGet());
                 }
             }

src/coreclr/jit/codegencommon.cpp

@@ -1107,7 +1107,11 @@ bool CodeGen::genCreateAddrMode(
     if (op2->IsIntCnsFitsInI32() && (op2->gtType != TYP_REF) && FitsIn<INT32>(cns + op2->AsIntConCommon()->IconValue()))
     {
         // We should not be building address modes out of non-foldable constants
-        assert(op2->AsIntConCommon()->ImmedValCanBeFolded(compiler, addr->OperGet()));
+        if (!op2->AsIntConCommon()->ImmedValCanBeFolded(compiler, addr->OperGet()))
+        {
+            assert(compiler->opts.compReloc);
+            return false;
+        }
 
         /* We're adding a constant */
 

src/coreclr/jit/valuenum.cpp

@@ -2113,7 +2113,7 @@ ValueNum ValueNumStore::VNForFunc(var_types typ, VNFunc func, ValueNum arg0VN)
                         {
                             uint8_t buffer[TARGET_POINTER_SIZE] = {0};
                             if (m_pComp->info.compCompHnd->getReadonlyStaticFieldValue(field, buffer,
-                                                                                       TARGET_POINTER_SIZE, false))
+                                                                                       TARGET_POINTER_SIZE, 0, false))
                             {
                                 // In case of 64bit jit emitting 32bit codegen this handle will be 64bit
                                 // value holding 32bit handle with upper half zeroed (hence, "= NULL").
@@ -8494,6 +8494,65 @@ void Compiler::fgValueNumberSsaVarDef(GenTreeLclVarCommon* lcl)
     }
 }
 
+//----------------------------------------------------------------------------------
+// fgGetFieldSeqAndAddress: Try to obtain a constant address with a FieldSeq from the
+//    given tree. It can be either INT_CNS or e.g. ADD(INT_CNS, ADD(INT_CNS, INT_CNS))
+//    tree where only one of the constants is expected to have a field sequence.
+//
+// Arguments:
+//    tree     - tree node to inspect
+//    pAddress - [Out] resulting address with all offsets combined
+//    pFseq    - [Out] field sequence
+//
+// Return Value:
+//    true if the pattern was recognized and a new VN is assigned
+//
+static bool fgGetFieldSeqAndAddress(GenTree* tree, ssize_t* pAddress, FieldSeq** pFseq)
+{
+    if (tree->IsCnsIntOrI())
+    {
+        ssize_t   val  = tree->AsIntCon()->IconValue();
+        FieldSeq* fseq = tree->AsIntCon()->gtFieldSeq;
+        if (fseq != nullptr)
+        {
+            *pFseq    = fseq;
+            *pAddress = val;
+            return true;
+        }
+        return false;
+    }
+
+    ssize_t val = 0;
+    while (tree->OperIs(GT_ADD))
+    {
+        GenTree* op1 = tree->gtGetOp1();
+        GenTree* op2 = tree->gtGetOp2();
+        if (op1->IsCnsIntOrI() && (op1->AsIntCon()->gtFieldSeq == nullptr))
+        {
+            val += op1->AsIntCon()->IconValue();
+            tree = op2;
+        }
+        else if (op2->IsCnsIntOrI() && (op2->AsIntCon()->gtFieldSeq == nullptr))
+        {
+            val += op2->AsIntCon()->IconValue();
+            tree = op1;
+        }
+        else
+        {
+            // Unsupported tree
+            return false;
+        }
+    }
+
+    if (tree->IsCnsIntOrI() && (tree->AsIntCon()->gtFieldSeq != nullptr))
+    {
+        *pFseq    = tree->AsIntCon()->gtFieldSeq;
+        *pAddress = tree->AsIntCon()->IconValue() + val;
+        return true;
+    }
+    return false;
+}
+
 //----------------------------------------------------------------------------------
 // fgValueNumberConstLoad: Try to detect const_immutable_array[cns_index] tree
 //    and apply a constant VN representing given element at cns_index in that array.
@@ -8506,9 +8565,104 @@ void Compiler::fgValueNumberSsaVarDef(GenTreeLclVarCommon* lcl)
 //
 bool Compiler::fgValueNumberConstLoad(GenTreeIndir* tree)
 {
+    if (!tree->gtVNPair.BothEqual())
+    {
+        return false;
+    }
+
+    // First, let's check if we can detect RVA[const_index] pattern to fold, e.g.:
+    //
+    //   static ReadOnlySpan<sbyte> RVA => new sbyte[] { -100, 100 }
+    //
+    //   sbyte GetVal() => RVA[1]; // fold to '100'
+    //
+    ssize_t   address  = 0;
+    FieldSeq* fieldSeq = nullptr;
+    if (fgGetFieldSeqAndAddress(tree->gtGetOp1(), &address, &fieldSeq) &&
+        (fieldSeq->GetKind() == FieldSeq::FieldKind::SimpleStaticKnownAddress))
+    {
+        CORINFO_FIELD_HANDLE fieldHandle = fieldSeq->GetFieldHandle();
+
+        ssize_t   byteOffset     = address - fieldSeq->GetOffset();
+        int       size           = (int)genTypeSize(tree->TypeGet());
+        const int maxElementSize = sizeof(int64_t);
+        if ((fieldHandle != nullptr) && (size > 0) && (size <= maxElementSize) && ((size_t)byteOffset < INT_MAX))
+        {
+            uint8_t buffer[maxElementSize] = {0};
+            if (info.compCompHnd->getReadonlyStaticFieldValue(fieldHandle, (uint8_t*)&buffer, size, (int)byteOffset))
+            {
+                // For now we only support these primitives, we can extend this list to FP, SIMD and structs in future.
+                switch (tree->TypeGet())
+                {
+#define READ_VALUE(typ)                                                                                                \
+    typ val = 0;                                                                                                       \
+    memcpy(&val, buffer, sizeof(typ));
+
+                    case TYP_BOOL:
+                    case TYP_UBYTE:
+                    {
+                        READ_VALUE(uint8_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_BYTE:
+                    {
+                        READ_VALUE(int8_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_SHORT:
+                    {
+                        READ_VALUE(int16_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_USHORT:
+                    {
+                        READ_VALUE(uint16_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_INT:
+                    {
+                        READ_VALUE(int32_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_UINT:
+                    {
+                        READ_VALUE(uint32_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForIntCon(val));
+                        return true;
+                    }
+                    case TYP_LONG:
+                    {
+                        READ_VALUE(int64_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForLongCon(val));
+                        return true;
+                    }
+                    case TYP_ULONG:
+                    {
+                        READ_VALUE(uint64_t);
+                        tree->gtVNPair.SetBoth(vnStore->VNForLongCon(val));
+                        return true;
+                    }
+                    default:
+                        break;
+                }
+            }
+        }
+    }
+
+    // Throughput check, the logic below is only for USHORT (char)
+    if (!tree->TypeIs(TYP_USHORT))
+    {
+        return false;
+    }
+
     ValueNum  addrVN = tree->gtGetOp1()->gtVNPair.GetLiberal();
     VNFuncApp funcApp;
-    if (!tree->TypeIs(TYP_USHORT) || !tree->gtVNPair.BothEqual() || !vnStore->GetVNFunc(addrVN, &funcApp))
+    if (!vnStore->GetVNFunc(addrVN, &funcApp))
     {
         return false;
     }

src/coreclr/tools/Common/JitInterface/CorInfoImpl_generated.cs

@@ -2244,12 +2244,12 @@ private static uint _getClassDomainID(IntPtr thisHandle, IntPtr* ppException, CO
         }
 
         [UnmanagedCallersOnly]
-        private static byte _getReadonlyStaticFieldValue(IntPtr thisHandle, IntPtr* ppException, CORINFO_FIELD_STRUCT_* field, byte* buffer, int bufferSize, byte ignoreMovableObjects)
+        private static byte _getReadonlyStaticFieldValue(IntPtr thisHandle, IntPtr* ppException, CORINFO_FIELD_STRUCT_* field, byte* buffer, int bufferSize, int valueOffset, byte ignoreMovableObjects)
         {
             var _this = GetThis(thisHandle);
             try
             {
-                return _this.getReadonlyStaticFieldValue(field, buffer, bufferSize, ignoreMovableObjects != 0) ? (byte)1 : (byte)0;
+                return _this.getReadonlyStaticFieldValue(field, buffer, bufferSize, valueOffset, ignoreMovableObjects != 0) ? (byte)1 : (byte)0;
             }
             catch (Exception ex)
             {
@@ -2838,7 +2838,7 @@ private static IntPtr GetUnmanagedCallbacks()
             callbacks[148] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_CLASS_STRUCT_*, byte>)&_isRIDClassDomainID;
             callbacks[149] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_CLASS_STRUCT_*, void**, uint>)&_getClassDomainID;
             callbacks[150] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_FIELD_STRUCT_*, void**, void*>)&_getFieldAddress;
-            callbacks[151] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_FIELD_STRUCT_*, byte*, int, byte, byte>)&_getReadonlyStaticFieldValue;
+            callbacks[151] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_FIELD_STRUCT_*, byte*, int, int, byte, byte>)&_getReadonlyStaticFieldValue;
             callbacks[152] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_FIELD_STRUCT_*, byte*, CORINFO_CLASS_STRUCT_*>)&_getStaticFieldCurrentClass;
             callbacks[153] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_SIG_INFO*, void**, IntPtr>)&_getVarArgsHandle;
             callbacks[154] = (delegate* unmanaged<IntPtr, IntPtr*, CORINFO_SIG_INFO*, byte>)&_canGetVarArgsHandle;

src/coreclr/tools/Common/JitInterface/ThunkGenerator/ThunkInput.txt

@@ -308,7 +308,7 @@ FUNCTIONS
     bool isRIDClassDomainID(CORINFO_CLASS_HANDLE cls);
     unsigned getClassDomainID (CORINFO_CLASS_HANDLE    cls, void                  **ppIndirection);
     void* getFieldAddress(CORINFO_FIELD_HANDLE    field, VOIDSTARSTAR ppIndirection);
-    bool getReadonlyStaticFieldValue(CORINFO_FIELD_HANDLE field, uint8_t *buffer, int bufferSize, bool ignoreMovableObjects);
+    bool getReadonlyStaticFieldValue(CORINFO_FIELD_HANDLE field, uint8_t *buffer, int bufferSize, int valueOffset, bool ignoreMovableObjects);
     CORINFO_CLASS_HANDLE getStaticFieldCurrentClass(CORINFO_FIELD_HANDLE    field,  BoolStar pIsSpeculative);
     CORINFO_VARARGS_HANDLE getVarArgsHandle(CORINFO_SIG_INFO       *pSig, void                  **ppIndirection);
     bool canGetVarArgsHandle(CORINFO_SIG_INFO       *pSig);

src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs

@@ -2998,8 +2998,28 @@ private int getExactClasses(CORINFO_CLASS_STRUCT_* baseType, int maxExactClasses
             return 0;
         }
 
-        private bool getReadonlyStaticFieldValue(CORINFO_FIELD_STRUCT_* fieldHandle, byte* buffer, int bufferSize, bool ignoreMovableObjects)
+        private bool getReadonlyStaticFieldValue(CORINFO_FIELD_STRUCT_* fieldHandle, byte* buffer, int bufferSize, int valueOffset, bool ignoreMovableObjects)
         {
+            Debug.Assert(fieldHandle != null);
+            Debug.Assert(buffer != null);
+            Debug.Assert(bufferSize > 0);
+            Debug.Assert(valueOffset >= 0);
+
+            FieldDesc field = HandleToObject(fieldHandle);
+            Debug.Assert(field.IsStatic);
+
+            if (!_compilation.NodeFactory.CompilationModuleGroup.VersionsWithType(field.OwningType))
+                return false;
+
+            if (!field.IsThreadStatic && field.IsInitOnly && field.HasRva && field is EcmaField ecmaField)
+            {
+                ReadOnlySpan<byte> rvaData = ecmaField.GetFieldRvaData();
+                if (rvaData.Length >= bufferSize && valueOffset <= rvaData.Length - bufferSize)
+                {
+                    rvaData.Slice(valueOffset, bufferSize).CopyTo(new Span<byte>(buffer, bufferSize));
+                    return true;
+                }
+            }
             return false;
         }