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;; Copyright 2020 the V8 project authors. All rights reserved.
;; Use of this source code is governed by a BSD-style license that can be
;; found in the LICENSE file.
;; MASM syntax
;; https://docs.microsoft.com/en-us/cpp/assembler/masm/microsoft-macro-assembler-reference?view=vs-2019
public PushAllRegistersAndIterateStack
.code
PushAllRegistersAndIterateStack:
;; Push all callee-saved registers to get them on the stack for conservative
;; stack scanning.
;;
;; We maintain 16-byte alignment at calls. There is an 8-byte return address
;; on the stack and we push 72 bytes which maintains 16-byte stack alignment
;; at the call.
;; Source: https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention
;;
;; rbp is callee-saved. Maintain proper frame pointer for debugging.
push rbp
mov rbp, rsp
push 0CDCDCDh ;; Dummy for alignment.
push rsi
push rdi
push rbx
push r12
push r13
push r14
push r15
;; Pass 1st parameter (rcx) unchanged (Stack*).
;; Pass 2nd parameter (rdx) unchanged (StackVisitor*).
;; Save 3rd parameter (r8; IterateStackCallback)
mov r9, r8
;; Pass 3rd parameter as rsp (stack pointer).
mov r8, rsp
;; Call the callback.
call r9
;; Pop the callee-saved registers.
add rsp, 64
;; Restore rbp as it was used as frame pointer.
pop rbp
ret
end
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