.POPREG

Generates a WOD_PUSH unwind code entry for the specified register using the current offset in the epilogue.

Syntax

.POPREG register

Parameters

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

Remarks

Important

This directive is experimental and is subject to change. Enable Unwind Version 3 by using the /unwindv3 option in ml64.exe.

.POPREG is only valid in Unwind Version 3. It's the epilogue counterpart to .PUSHREG.

.POPREG 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, .POPREG must appear before the pop instruction that implements the register restore. To ensure agreement, wrap both the unwind directives and the code they're meant to unwind in a macro.

register may 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

In Unwind Version 3, epilogue directives are mandatory for epilogue unwind code generation. The assembler doesn't emit epilogue unwind codes without a .BEGINEPILOG/.ENDEPILOG pair.

Note

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

Example for unwindv3

; ml64 /unwindv3 ex1.asm /link /entry:Example1 /SUBSYSTEM:CONSOLE
_text SEGMENT
Example1 PROC FRAME
   .pushreg rbx
   push rbx
   .pushreg rsi
   push rsi
.endprolog
   ; rest of function ...
   .beginepilog
   .popreg rsi
   pop rsi
   .popreg rbx
   pop rbx
   .endepilog
   ret
Example1 ENDP
_text ENDS
END

See also

x64 Unwind Version 3 (experimental)
Directives Reference
.PUSHREG
.POP2REG
.BEGINEPILOG
MASM BNF Grammar