Re: [Chicken-hackers] [PATCH] Do not assume all fixnum literals will be fixnums at runtime [was: Re: [PATCH][5] types.db entries for the overflow-aware ops]

[Evan Hanson]

Hi folks,

Good discussion, thank you Peter and Lemon for considering this.

> diff --git a/lfa2.scm b/lfa2.scm
> index 0fd4612..4c7ff84 100644
> --- a/lfa2.scm
> +++ b/lfa2.scm
> @@ -173,17 +173,14 @@
>        ;; a simplified variant of the one in scrutinizer.scm
>        (cond ((string? lit) 'string)
>           ((symbol? lit) 'symbol)
> +         ;; Do not assume fixnum width matches target platform's!
> +         ((or (big-fixnum? lit)
> +              (bignum? lit))
> +          'integer)
>           ((fixnum? lit) 'fixnum)
> -         ((bignum? lit) 'bignum)
>           ((flonum? lit) 'float)
>           ((ratnum? lit) 'ratnum)
>           ((cplxnum? lit) 'cplxnum)

You use `bignum?' for the non-fixnum part of the width check here in
lfa2.scm, but `small-bignum?' in scrutinizer.scm -- why is that? (This
is in the chicken-5 patch.)

> diff --git a/scrutinizer.scm b/scrutinizer.scm
> index cf7c6ad..2d63f19 100644
> --- a/scrutinizer.scm
> +++ b/scrutinizer.scm
> @@ -196,16 +196,15 @@
>      (define (constant-result lit)
>        (cond ((string? lit) 'string)
>           ((symbol? lit) 'symbol)
> +         ;; Do not assume fixnum width matches target platform's!
> +         ((or (big-fixnum? lit)
> +              (small-bignum? lit))
> +          'integer)
>           ((fixnum? lit) 'fixnum)
> -         ((flonum? lit) 'float)      ; Why not "flonum", for consistency?
>           ((bignum? lit) 'bignum)
> +         ((flonum? lit) 'float)      ; Why not "flonum", for consistency?
>           ((ratnum? lit) 'ratnum)
>           ((cplxnum? lit) 'cplxnum)

Cheers,

Evan

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