I tried to create an expression in which I used my words(...) macro twice, one nested in the other. This didn't work but it took me a while to understand why. It appears that the preprocessor doesn't expand the inner use of the smacro. I assume this is intended to avoid recursion, however my use is not recursive.

$ nasm -v
NASM version 2.16rc0 compiled on Sep  6 2022
$ cat test.asm
; %include "lmacros1.mac"

                ; Compute required words/dwords/qwords/paragraphs/pages/KiB of known byte size (rounds up if necessary)
%idefine bytes(b)       (b)
%idefine words(b)       ((b)+1>>1)
%idefine dwords(b)      ((b)+3>>2)
%idefine qwords(b)      ((b)+7>>3)
%idefine paragraphs(b)  ((b)+15>>4)
%idefine paras(b)       ((b)+15>>4)
%idefine pages(b)       ((b)+511>>9)
%idefine kib(b)         ((b)+1023>>10)

                ; Compute required bytes of known word/dword/qword/paragraph/page/KiB size
%idefine frombytes(b)           (b)
%idefine fromwords(w)           ((w)<<1)
%idefine fromdwords(d)          ((d)<<2)
%idefine fromqwords(q)          ((q)<<3)
%idefine fromparagraphs(p)      ((p)<<4)
%idefine fromparas(p)           ((p)<<4)
%idefine frompages(p)           ((p)<<9)
%idefine fromkib(k)             ((k)<<10)

        db fromparas(paras(1))
        db fromwords(words(1))
        db words(fromwords(words(1)))

$ nasm test.asm
test.asm:25: error: expecting `)'
$ nasm test.asm -E | tail -n5
%line 23+1 test.asm
 db ((((1)+15>>4))<<4)
 db ((((1)+1>>1))<<1)
 db ((((words(1))<<1))+1>>1)

$