A few other macros seem to suffer from the same issue.  What I've done was:
cat gcc/config/i386/*intrin.h | sed -e ':x /\\$/ { N; s/\\\n//g ; bx }' \
| grep '^[[:blank:]]*#[[:blank:]]*define[[:blank:]].*(' | sed 's/[ 	]\+/ /g' \
> /tmp/macros
and then looking for regexps:
)[a-zA-Z]
) [a-zA-Z]
[a-zA-Z][-+*/%]
[a-zA-Z] [-+*/%]
[-+*/%][a-zA-Z]
[-+*/%] [a-zA-Z]
in the resulting file.

2020-04-29  Jakub Jelinek  <jakub@redhat.com>

	PR target/94832
	* config/i386/avx512bwintrin.h (_mm512_alignr_epi8,
	_mm512_mask_alignr_epi8, _mm512_maskz_alignr_epi8): Wrap macro operands
	used in casts into parens.
	* config/i386/avx512fintrin.h (_mm512_cvt_roundps_ph, _mm512_cvtps_ph,
	_mm512_mask_cvt_roundps_ph, _mm512_mask_cvtps_ph,
	_mm512_maskz_cvt_roundps_ph, _mm512_maskz_cvtps_ph,
	_mm512_mask_cmp_epi64_mask, _mm512_mask_cmp_epi32_mask,
	_mm512_mask_cmp_epu64_mask, _mm512_mask_cmp_epu32_mask,
	_mm512_mask_cmp_round_pd_mask, _mm512_mask_cmp_round_ps_mask,
	_mm512_mask_cmp_pd_mask, _mm512_mask_cmp_ps_mask): Likewise.
	* config/i386/avx512vlbwintrin.h (_mm256_mask_alignr_epi8,
	_mm256_maskz_alignr_epi8, _mm_mask_alignr_epi8, _mm_maskz_alignr_epi8,
	_mm256_mask_cmp_epu8_mask): Likewise.
	* config/i386/avx512vlintrin.h (_mm_mask_cvtps_ph, _mm_maskz_cvtps_ph,
	_mm256_mask_cvtps_ph, _mm256_maskz_cvtps_ph): Likewise.
	* config/i386/f16cintrin.h (_mm_cvtps_ph, _mm256_cvtps_ph): Likewise.
	* config/i386/shaintrin.h (_mm_sha1rnds4_epu32): Likewise.