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Diffstat (limited to 'src/Native/System.Private.TypeLoader.Native/arm64/VTableResolver.asm')
| -rw-r--r-- | src/Native/System.Private.TypeLoader.Native/arm64/VTableResolver.asm | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/Native/System.Private.TypeLoader.Native/arm64/VTableResolver.asm b/src/Native/System.Private.TypeLoader.Native/arm64/VTableResolver.asm new file mode 100644 index 000000000..d22395850 --- /dev/null +++ b/src/Native/System.Private.TypeLoader.Native/arm64/VTableResolver.asm @@ -0,0 +1,155 @@ +;; Licensed to the .NET Foundation under one or more agreements. +;; The .NET Foundation licenses this file to you under the MIT license. +;; See the LICENSE file in the project root for more information. + +#include "kxarm64.h" + + DATAAREA + +g_vtableResolveCallback DCQ 0 ; Address of virtual dispatch resolution callback +g_universalTransition DCQ 0 ; Address of RhpUniversalTransition thunk + +VTableThunkSize EQU 0x20 +;; TODO - do something similar to Redhawk's asmoffsets to compute the value at compile time +EETypeVTableOffset EQU 0x18 +PointerSize EQU 8 + + TEXTAREA + +;; +;; When an EEType is created, its VTable entries are initially filled with calls to the VTableSlot thunks for the appropriate +;; slot numbers. When the thunk is invoked, it checks whether the slot has already been resolved. If yes, then it just calls +;; the universal thunk. Otherwise, it calls the dispatch resolution callback, which will update the VTable slot and then call +;; the universal thunk. +;; + +;; +;; Note: The "__jmpstub__" prefix is used to indicate to debugger +;; that it must step-through this stub when it encounters it while +;; stepping. +;; + + ;; int VTableResolver_Init(IntPtr *__jmpstub__VTableResolverSlot0, + ;; IntPtr vtableResolveCallback, + ;; IntPtr universalTransition, + ;; int *slotCount) + ;; Returns the size of the pre-generated thunks. + ;; + LEAF_ENTRY VTableResolver_Init + adr x9, __jmpstub__VTableSlot00 + str x9, [x0] + ADDROF x10, g_vtableResolveCallback + str x1, [x10] + ADDROF x11, g_universalTransition + str x2, [x11] + mov x12, 100 ; This file defines 100 slot helpers + str x12, [x3] + mov x0, VTableThunkSize ; Each thunk is VTableThunkSize in bytes + ret + LEAF_END VTableResolver_Init + + ;; void* VTableResolver_GetCommonCallingStub() + ;; Returns the address of the common calling stub. + ;; + LEAF_ENTRY VTableResolver_GetCommonCallingStub + adr x0, __jmpstub__VTableResolver_CommonCallingStub + ret + LEAF_END VTableResolver_GetCommonCallingStub + + ;; __jmpstub__VTableResolver_CommonCallingStub(?) + ;; Used when we dynamically need a VTableResolver not pre-generated. + ;; + ;; xip0 contains a pointer to a VTableResolverStruct + ;; struct VTableResolverStruct + ;; { + ;; IntPtr offsetFromStartOfEETypePtr; + ;; IntPtr VTableThunkAddress; + ;; }; + ;; + LEAF_ENTRY __jmpstub__VTableResolver_CommonCallingStub + ;; Load the EEType pointer and add (EETypeVTableOffset + $slot_number * PointerSize) to calculate the VTable slot + ;; address. Compare the pointer stored in the slot to the address of the thunk being executed. If the values are + ;; equal, call the dispatch resolution callback; otherwise, call the function pointer stored in the slot. + + ;; x9 = EEType pointer (x0 is the "this" pointer for the call being made) + ldr x9, [x0] + ;; xip1 = slot offset relative to EEType + ldr xip1, [xip0] + ;; x10 = function pointer stored in the slot + ldr x10, [x9,xip1] + ;; x11 = address of this thunk + ldr x11, [xip0,#PointerSize] + ;; Compare two pointers + cmp x10, x11 + ;; If the method is not resolved yet, resolve it first + beq __jmpstub__JumpToVTableResolver + ;; Otherwise, just call it + br x10 + LEAF_END __jmpstub__VTableResolver_CommonCallingStub + + ;; Calls the dispatch resolution callback with xip1 set to EETypeVTableOffset + ($slot_number * PointerSize) + LEAF_ENTRY __jmpstub__JumpToVTableResolver + ADDROF xip0, g_vtableResolveCallback + ldr xip0, [xip0] + ADDROF x9, g_universalTransition + ldr x9, [x9] + br x9 + LEAF_END __jmpstub__VTableResolver_Init + + MACRO + VTableThunkDecl $name, $slot_number + ;; Force all thunks to be the same size, which allows us to index + ALIGN 16 + LEAF_ENTRY __jmpstub__$name + ;; Load the EEType pointer and add (EETypeVTableOffset + $slot_number * PointerSize) to calculate the VTable slot + ;; address. Compare the pointer stored in the slot to the address of the thunk being executed. If the values are + ;; equal, call the dispatch resolution callback; otherwise, call the function pointer stored in the slot. + + ;; x9 = EEType pointer (x0 is the "this" pointer for the call being made) + ldr x9, [x0] + ;; xip1 = slot offset relative to EEType + mov xip1, EETypeVTableOffset + ($slot_number * PointerSize) + ;; x10 = function pointer stored in the slot + ldr x10, [x9,xip1] + ;; x11 = address of this thunk + adr x11, __jmpstub__$name + ;; Compare two pointers + cmp x10, x11 + ;; If the method is not resolved yet, resolve it first + beq __jmpstub__JumpToVTableResolver + ;; Otherwise, just call it + br x10 + LEAF_END __jmpstub__$name + MEND + + MACRO + VTableThunkDeclTen $slotnumberDecimal + VTableThunkDecl VTableSlot$slotnumberDecimal0,$slotnumberDecimal0 + VTableThunkDecl VTableSlot$slotnumberDecimal1,$slotnumberDecimal1 + VTableThunkDecl VTableSlot$slotnumberDecimal2,$slotnumberDecimal2 + VTableThunkDecl VTableSlot$slotnumberDecimal3,$slotnumberDecimal3 + VTableThunkDecl VTableSlot$slotnumberDecimal4,$slotnumberDecimal4 + VTableThunkDecl VTableSlot$slotnumberDecimal5,$slotnumberDecimal5 + VTableThunkDecl VTableSlot$slotnumberDecimal6,$slotnumberDecimal6 + VTableThunkDecl VTableSlot$slotnumberDecimal7,$slotnumberDecimal7 + VTableThunkDecl VTableSlot$slotnumberDecimal8,$slotnumberDecimal8 + VTableThunkDecl VTableSlot$slotnumberDecimal9,$slotnumberDecimal9 + MEND + + MACRO + VTableThunkDeclHundred $slotnumberPerHundred + VTableThunkDeclTen $slotnumberPerHundred0 + VTableThunkDeclTen $slotnumberPerHundred1 + VTableThunkDeclTen $slotnumberPerHundred2 + VTableThunkDeclTen $slotnumberPerHundred3 + VTableThunkDeclTen $slotnumberPerHundred4 + VTableThunkDeclTen $slotnumberPerHundred5 + VTableThunkDeclTen $slotnumberPerHundred6 + VTableThunkDeclTen $slotnumberPerHundred7 + VTableThunkDeclTen $slotnumberPerHundred8 + VTableThunkDeclTen $slotnumberPerHundred9 + MEND + + VTableThunkDeclHundred "" + + END |