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;; 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 "AsmMacros.h"
TEXTAREA
;;-----------------------------------------------------------------------------
;; This helper routine enregisters the appropriate arguments and makes the
;; actual call.
;;
;; INPUT: x0: pointer to CallDescrData struct
;;
;;-----------------------------------------------------------------------------
;;void RhCallDescrWorker(CallDescrData * pCallDescrData);
NESTED_ENTRY RhCallDescrWorker
PROLOG_SAVE_REG_PAIR fp, lr, #-32!
PROLOG_SAVE_REG_PAIR x19, x20, #16
;; Save the value of SP before we start pushing any arguments
mov x20, sp
mov x19, x0 ; save pCallDescrData in x19
ldr w1, [x19, #OFFSETOF__CallDescrData__numStackSlots]
cbz w1, Ldonestack
;; Add frame padding to ensure frame size is a multiple of 16 (a requirement of the OS ABI).
;; We push two registers (above) and numStackSlots arguments (below). If this comes to an odd number
;; of slots we must pad with another. This simplifies to "if the low bit of numStackSlots is set,
;; extend the stack another eight bytes".
ldr x0, [x19, #OFFSETOF__CallDescrData__pSrc]
add x0, x0, x1 lsl #3 ; pSrcEnd=pSrc+8*numStackSlots
ands x2, x1, #1
beq Lstackloop
;; This loop copies numStackSlots words
;; from [pSrcEnd-8,pSrcEnd-16,...] to [sp-8,sp-16,...]
;; Pad and store one stack slot as number of slots are odd
ldr x4, [x0,#-8]!
str x4, [sp,#-16]!
subs x1, x1, #1
beq Ldonestack
Lstackloop
ldp x2, x4, [x0,#-16]!
stp x2, x4, [sp,#-16]!
subs x1, x1, #2
bne Lstackloop
Ldonestack
;; If FP arguments are supplied in registers (x9 != NULL) then initialize all of them from the pointer
;; given in x9.
ldr x9, [x19, #OFFSETOF__CallDescrData__pFloatArgumentRegisters]
cbz x9, LNoFloatingPoint
ldp d0, d1, [x9]
ldp d2, d3, [x9, #16]
ldp d4, d5, [x9, #32]
ldp d6, d7, [x9, #48]
LNoFloatingPoint
;; Copy [pArgumentRegisters, ..., pArgumentRegisters + 64]
;; into x0, ..., x7, x8
ldr x9, [x19, #OFFSETOF__CallDescrData__pArgumentRegisters]
ldp x0, x1, [x9]
ldp x2, x3, [x9, #16]
ldp x4, x5, [x9, #32]
ldp x6, x7, [x9, #48]
ldr x8, [x9, #64]
;; call pTarget
ldr x9, [x19, #OFFSETOF__CallDescrData__pTarget]
blr x9
EXPORT_POINTER_TO_ADDRESS PointerToReturnFromCallDescrThunk
;; Symbol used to identify thunk call to managed function so the special
;; case unwinder can unwind through this function. Sadly we cannot directly
;; export this symbol right now because it confuses DIA unwinder to believe
;; it's the beginning of a new method, therefore we export the address
;; of an auxiliary variable holding the address instead.
ldr w3, [x19, #OFFSETOF__CallDescrData__fpReturnSize]
;; Unlike desktop returnValue is a pointer to a return buffer, not the buffer itself
ldr x19, [x19, #OFFSETOF__CallDescrData__pReturnBuffer]
;; Int return case
cbz w3, LIntReturn
;; Float return case
cmp w3, #4
beq LFloatOrDoubleReturn
;; Double return case
cmp w3, #8
bne LCheckHFAReturn
LFloatOrDoubleReturn
str d0, [x19]
b LReturnDone
LCheckHFAReturn
cmp w3, #16
beq LFloatOrDoubleHFAReturn
cmp w3, #32
beq LFloatOrDoubleHFAReturn
b LNoHFAReturn
LFloatOrDoubleHFAReturn
;;Single/Double HFAReturn return case
stp d0, d1, [x19, #00]
stp d2, d3, [x19, #16]
b LReturnDone
LNoHFAReturn
EMIT_BREAKPOINT ; Unreachable
LIntReturn
;; Save return value(s) into retbuf for int
stp x0, x1, [x19]
LReturnDone
#ifdef _DEBUG
;; Trash the floating point registers to ensure that the HFA return values
;; won't survive by accident
ldp d0, d1, [sp]
ldp d2, d3, [sp, #16]
#endif
;; Restore the value of SP
mov sp, x20
EPILOG_RESTORE_REG_PAIR x19, x20, #16
EPILOG_RESTORE_REG_PAIR fp, lr, #32!
EPILOG_RETURN
NESTED_END RhCallDescrWorker
END
|
