[RFC 02/14] Remove some 'fastcall' code

[Jose E. Marchesi]

> There are some comments referring to 'fastcall', which apparently is
> some sort of compilation mode for the presumably obsolete Hobbit
> scheme compiler.

I don't think that the Hobbit support has been tested any time in recent
years.  If Frank agrees, I would say it is ok to remove code handling
Hobbit specific stuff.

> This patch removes this code and in the process removes some
> unnecessary global variables, by turning them into let bindings.

The change LGTM.

The only comment I have is that it seems to me the / prefix for symbol
names seems to be used for globals?  I don't think locally let-defined
symbols are to be using that prefix...

> ---
>  sem-frags.scm | 125 ++++++++++++++++++++++----------------------------
>  utils.scm     |  21 ---------
>  2 files changed, 54 insertions(+), 92 deletions(-)
>
> diff --git a/sem-frags.scm b/sem-frags.scm
> index 0fb26f4..0e471a0 100644
> --- a/sem-frags.scm
> +++ b/sem-frags.scm
> @@ -159,12 +159,6 @@
>  
>  ; Hash a statement.
>  
> -; Computed hash value.
> -; Global 'cus /frag-hash-compute! is defined globally so we can use
> -; /fastcall (FIXME: Need /fastcall to work on non-global procs).
> -
> -(define /frag-hash-value-tmp 0)
> -
>  (define (/frag-hash-string str)
>    (let loop ((chars (map char->integer (string->list str))) (result 0))
>      (if (null? chars)
> @@ -172,77 +166,66 @@
>  	(loop (cdr chars) (modulo (+ (* result 7) (car chars)) #xfffffff))))
>  )
>  
> -;; MODE is the name of the mode.
> -
> -(define (/frag-hash-compute! rtx-obj expr parent-expr op-pos tstate appstuff)
> -  (let ((h 0))
> -    (case (rtx-name expr)
> -      ((operand)
> -       (set! h (/frag-hash-string (symbol->string (rtx-operand-name expr)))))
> -      ((local)
> -       (set! h (/frag-hash-string (symbol->string (rtx-local-name expr)))))
> -      ((const)
> -       (set! h (rtx-const-value expr)))
> -      (else
> -       (set! h (rtx-num rtx-obj))))
> -    (set! /frag-hash-value-tmp
> -	  ; Keep number small.
> -	  (modulo (+ (* /frag-hash-value-tmp 3) h op-pos)
> -		  #xfffffff)))
> -
> -  ; #f -> "continue with normal traversing"
> -  #f
> -)
> -
>  (define (/frag-hash-stmt stmt locals size)
> -  (set! /frag-hash-value-tmp 0)
> -  (rtx-traverse-with-locals #f #f stmt /frag-hash-compute! locals #f)
> -  (modulo /frag-hash-value-tmp size)
> +  (let ((/frag-hash-value-tmp 0))
> +    (rtx-traverse-with-locals
> +     #f #f stmt /frag-hash-compute!
> +     (lambda (rtx-obj expr parent-expr op-pos tstate appstuff)
> +       (let ((h 0))
> +	 (case (rtx-name expr)
> +	   ((operand)
> +	    (set! h (/frag-hash-string (symbol->string (rtx-operand-name expr)))))
> +	   ((local)
> +	    (set! h (/frag-hash-string (symbol->string (rtx-local-name expr)))))
> +	   ((const)
> +	    (set! h (rtx-const-value expr)))
> +	   (else
> +	    (set! h (rtx-num rtx-obj))))
> +	 (set! /frag-hash-value-tmp
> +	       ;; Keep number small.
> +	       (modulo (+ (* /frag-hash-value-tmp 3) h op-pos)
> +		       #xfffffff)))
> +
> +       ;; #f -> "continue with normal traversing"
> +       #f
> +       )
> +     locals #f)
> +    (modulo /frag-hash-value-tmp size))
>  )
>  
>  ; Compute the speed/size costs of a statement.
>  
> -; Compute speed/size costs.
> -; Global 'cus /frag-cost-compute! is defined globally so we can use
> -; /fastcall (FIXME: Need /fastcall to work on non-global procs).
> -
> -(define /frag-speed-cost-tmp 0)
> -(define /frag-size-cost-tmp 0)
> -
> -;; MODE is the name of the mode.
> -
> -(define (/frag-cost-compute! rtx-obj expr parent-expr op-pos tstate appstuff)
> -  ; FIXME: wip
> -  (let ((speed 0)
> -	(size 0))
> -    (case (rtx-class rtx-obj)
> -      ((ARG)
> -       #f) ; these don't contribute to costs (at least for now)
> -      ((SET)
> -       ; FIXME: speed/size = 0?
> -       (set! speed 1)
> -       (set! size 1))
> -      ((UNARY BINARY TRINARY COMPARE)
> -       (set! speed 1)
> -       (set! size 1))
> -      ((IF)
> -       (set! speed 2)
> -       (set! size 2))
> -      (else
> -       (set! speed 4)
> -       (set! size 4)))
> -    (set! /frag-speed-cost-tmp (+ /frag-speed-cost-tmp speed))
> -    (set! /frag-size-cost-tmp (+ /frag-size-cost-tmp size)))
> -
> -  ; #f -> "continue with normal traversing"
> -  #f
> -)
> -
>  (define (/frag-stmt-cost stmt locals)
> -  (set! /frag-speed-cost-tmp 0)
> -  (set! /frag-size-cost-tmp 0)
> -  (rtx-traverse-with-locals #f #f stmt /frag-cost-compute! locals #f)
> -  (cons /frag-speed-cost-tmp /frag-size-cost-tmp)
> +  (let ((/frag-speed-cost-tmp 0)
> +	(/frag-size-cost-tmp 0))
> +    (rtx-traverse-with-locals
> +     #f #f stmt
> +     (lambda (rtx-obj expr parent-expr op-pos tstate appstuff)
> +       ;; FIXME: wip
> +       (let ((speed 0)
> +	     (size 0))
> +	 (case (rtx-class rtx-obj)
> +	   ((ARG)
> +	    #f) ; these don't contribute to costs (at least for now)
> +	   ((SET)
> +	    ;; FIXME: speed/size = 0?
> +	    (set! speed 1)
> +	    (set! size 1))
> +	   ((UNARY BINARY TRINARY COMPARE)
> +	    (set! speed 1)
> +	    (set! size 1))
> +	   ((IF)
> +	    (set! speed 2)
> +	    (set! size 2))
> +	   (else
> +	    (set! speed 4)
> +	    (set! size 4)))
> +	 (set! /frag-speed-cost-tmp (+ /frag-speed-cost-tmp speed))
> +	 (set! /frag-size-cost-tmp (+ /frag-size-cost-tmp size)))
> +       ;; #f -> "continue with normal traversing"
> +       #f)
> +     locals #f)
> +    (cons /frag-speed-cost-tmp /frag-size-cost-tmp))
>  )
>  
>  ; Add STMT to statement table DATA.
> diff --git a/utils.scm b/utils.scm
> index 8204838..330880b 100644
> --- a/utils.scm
> +++ b/utils.scm
> @@ -13,27 +13,6 @@
>  
>  (define nil '())
>  
> -; Hobbit support code; for when not using hobbit.
> -; FIXME: eliminate this stuff ASAP.
> -
> -(defmacro /fastcall-make (proc) proc)
> -
> -(defmacro fastcall4 (proc arg1 arg2 arg3 arg4)
> -  (list proc arg1 arg2 arg3 arg4)
> -)
> -
> -(defmacro fastcall5 (proc arg1 arg2 arg3 arg4 arg5)
> -  (list proc arg1 arg2 arg3 arg4 arg5)
> -)
> -
> -(defmacro fastcall6 (proc arg1 arg2 arg3 arg4 arg5 arg6)
> -  (list proc arg1 arg2 arg3 arg4 arg5 arg6)
> -)
> -
> -(defmacro fastcall7 (proc arg1 arg2 arg3 arg4 arg5 arg6 arg7)
> -  (list proc arg1 arg2 arg3 arg4 arg5 arg6 arg7)
> -)
> -
>  ; Value doesn't matter too much here, just ensure it's portable.
>  (define *UNSPECIFIED* (if #f 1))