masm directive option prologue:none has no effect

Question

I'm learning how to use masm using MS's official docs, but there's almost nothing written on the option directive (https://learn.microsoft.com/en-us/cpp/assembler/masm/option-masm?view=msvc-170). It was used in the standard library implementation of memcpy where it seems to work properly

my code:

title entry - general purpose testing ground for asm operations
include ksamd64.inc
        subttl  "entry"

    NESTED_ENTRY entry, _TEXT
    option PROLOGUE:NONE, EPILOGUE:NONE
;       error here: "A2220 Missing .ENDPROLOGUE"
        cvtpi2ps xmm0, qword ptr[rcx]
        rsqrtps xmm1, xmm0
        movaps xmmword ptr[rcx], xmm1
    
        cvtpi2ps xmm0, qword ptr[rcx+8]
        rsqrtps xmm1, xmm0
        movups xmmword ptr[rcx+8], xmm1
    .beginepilog
        ret
    NESTED_END entry, _TEXT
end

Answer 1

Indeed poorly documented, but is your code not mixing versions/environments?. I have dug up following info from different corners of the web.

About .ENDPROLOG

Signals the end of the prologue declarations. It is an error to use any of the prologue declarations outside of the region between PROC FRAME and .ENDPROLOG.

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About NESTED_ENTRY

A NESTED_ENTRY must have an associated PROLOG_END (SH-4) and ENTRY_END (SH-4).

About PROLOG_END

This macro must appear following a NESTED_ENTRY (SH-4) or LEAF_ENTRY (SH-4) macro.
It appears after the prolog area and before the matching ENTRY_END (SH-4) macro.

About ENTRY_END

This macro ends the current routine specified by NESTED_ENTRY (SH-4) or LEAF_ENTRY (SH-4).
Syntax ENTRY_END[Name]
Name should be the same name used in the NESTED_ENTRY or LEAF_ENTRY macros.
The ENTRY_END (SH-4) macro currently ignores Name.

---

You didn't use PROLOG_END and you wrote NESTED_END instead of ENTRY_END.

Why do you use the phrase option PROLOGUE:NONE, EPILOGUE:NONE? Perhaps simply remove it...