Re: [PATCH] wc: make sure input buffer for neon 'wc -l' is aligned

[Pádraig Brady]

On 15/03/2026 04:04, Collin Funk wrote:

* src/wc_neon.c (wc_lines_neon): Use alignas.
---
  src/wc_neon.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/wc_neon.c b/src/wc_neon.c
index 00fa38b6e..571f5051c 100644
--- a/src/wc_neon.c
+++ b/src/wc_neon.c
@@ -35,7 +35,7 @@ wc_lines_neon (int fd)

while (true)

      {
-      unsigned char neon_buf[IO_BUFSIZE];
+      unsigned char alignas (16) neon_buf[IO_BUFSIZE];
        ssize_t bytes_read = read (fd, neon_buf, sizeof neon_buf);
        if (bytes_read <= 0)
          return (struct wc_lines) { bytes_read == 0 ? 0 : errno, lines, bytes 
};

Is this for perf or does the neon code have that alignment requirement?

cheers,
Padraig