Question about m4 in .asm files

[David Sparks]

I notice that, in the .asm files, the arguments to IFDOS() are
sometimes `singly quoted', and sometimes ``doubly quoted''.

For example, mpn/x86_64/mul_1.asm contains:

IFDOS(`	define(`up', ``%rsi'')	') dnl
IFDOS(`	define(`rp', ``%rcx'')	') dnl
IFDOS(`	define(`vl', ``%r9'')	') dnl
IFDOS(`	define(`r9', ``rdi'')	') dnl
IFDOS(`	define(`n',  ``%r8'')	') dnl
IFDOS(`	define(`r8', ``r11'')	') dnl

ASM_START()
	TEXT
	ALIGN(16)
PROLOGUE(mpn_mul_1c)
IFDOS(``push	%rsi		'')
IFDOS(``push	%rdi		'')
IFDOS(``mov	%rdx, %rsi	'')
	push	%rbx
IFSTD(`	mov	%r8, %r10')
IFDOS(`	mov	64(%rsp), %r10')	C 40 + 3*8  (3 push insns)
	jmp	L(common)
EPILOGUE()


It's obvious why the second arguments to define() are doubly
quoted; the goal is replace n -> %r8 and %r8 -> %r11, but not
n -> %r8 -> %r11.

But in the actual code, there's no obvious rhyme or reason to the
double quoting.  Why double-quote "mov %eds,%rsi" but not "mov %r8,%r10"?

Is it just a harmless error that's been propagated by cut & paste, or
is there some rationale I'm not seeing?

Thank you.