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.POP2REG

Generates a two-register pop unwind code entry for the specified register pair using the current offset in the epilogue.

Syntax

.POP2REG register1, register2

Parameters

register1
The first register to pop. Must be a general-purpose 64-bit register.

register2
The second register to pop. Must be a general-purpose 64-bit register.

register1 and register2 may each be one of:
RAX, RCX, RDX, RBX, RDI, RSI, RBP, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31.

Remarks

Important

This directive is experimental and is subject to change. Enable Unwind Version 3 with ml64.exe /unwindv3.

  • .POP2REG is only valid in Unwind Version 3. It's the epilogue counterpart to .PUSH2REG.
  • .POP2REG is only allowed within an epilogue region, between .BEGINEPILOG and .ENDEPILOG.
  • These directives generate unwind metadata (.xdata and .pdata sections) but don't produce executable code.
  • In Unwind Version 3, .POP2REG must appear before the instruction that actually implements the action to be unwound.
  • In Unwind Version 3, epilogue directives are mandatory for epilogue unwind code generation. No epilogue unwind codes are emitted without a .BEGINEPILOG/.ENDEPILOG pair.
  • To ensure agreement, wrap both the unwind directives and the code they're meant to unwind in a macro.

If register1 and register2 are consecutive and in increasing order, MASM emits a WOD_PUSH_CONSECUTIVE_2 unwind code. Otherwise, MASM emits a WOD_PUSH2 unwind code.

Note

In Unwind Version 1, the directive appears after the corresponding instruction. In Unwind Version 3, the directive appears before the instruction.

Example

; ml64 /unwindv3 ex1.asm /link /entry:Example1 /SUBSYSTEM:CONSOLE
_text SEGMENT
Example1 PROC FRAME
   .push2reg rbx, rsi
   push2 rbx, rsi
   .push2reg r10, r11
   push2 r10, r11
.endprolog
   ; rest of function ...
   .beginepilog
   .pop2reg r10, r11
   pop2 r10, r11
   .pop2reg rbx, rsi
   pop2 rbx, rsi
   .endepilog
   ret
Example1 ENDP
_text ENDS
END

See also

x64 Unwind Version 3 (experimental)
Directives Reference
.PUSH2REG
.POPREG
.BEGINEPILOG
MASM BNF Grammar

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