Re: [PATCH v2] machine descriptor: New compact syntax for insn and insn_split in Machine Descriptions.

[Mikael Morin <morin-mikael@orange.fr>]

Le 08/06/2023 à 11:58, Tamar Christina via Gcc-patches a écrit :
> Hi,
> 
> New version of the patch, I've omitted the explanation again 😊
> 
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
> 
> Any feedback?
> 
Hello,

this is not my area of expertise, but I saw the following:

> +  /* [ns..ns + len) should be a string with the id of the rtx to match
> +     i.e. if rtx is the relevant match_operand or match_scratch then
> +     [ns..ns + len) should equal itoa (XINT (rtx, 0)), and if set_attr then
> +     [ns..ns + len) should equal XSTR (rtx, 0).  */
> +  conlist (const char *ns, unsigned int len, bool numeric)
> +  {
> +    /* Trim leading whitespaces.  */
> +    while (ISSPACE (*ns))
> +      {
> +	ns++;
> +	len--;
> +      }
> +
> +    /* Trim trailing whitespace.  */
> +    for (int i = len - 1; i >= 0; i++, len--)
> +      if (!ISSPACE (*ns))
> +	break;
> +
This for loop makes little sense to me.  Shouldn't the iteration step be 
i-- rather than i++ and the pointer dereference *(ns + i) rather than *ns?