Re: Why is GForth-ITC fast?

On Apr 30, 10:30 pm, brian....@[EMAIL PROTECTED]
 wrote:
> I have been dis-assembling pieces of GForth and I don't understand why
> it is generally faster than other ITC Forths that are written in
> Assembler like CI-Forth or my old 16 bit HS/Forth.  The Assembler
> primitives seem to be so much smaller from what I can see.  Is the C
> compiler smarter than we are?
>
> Here are some examples
> CIFORTH (Albert van der Horst)
> -------------
>
>
> !
>         POP     EBX      ;ADDR
>         POP     EAX      ;DATA
>         MOV     [EBX],EAX
>         LODSD                 ; NEXT
>         JMP      LONG[EAX]
>
>
> GFORTH-ITC
> ---------------------------------------------
> see !
> Code !
> ( $402B2C )  mov     dword ptr 40F2E0 , ebx  \ $89 $1D $E0 $F2 $40 $0
> ( $402B32 )  mov     edx , dword ptr 4 [esi]  \ $8B $56 $4
> ( $402B35 )  mov     eax , dword ptr [esi]  \ $8B $6
> ( $402B37 )  add     esi , # 8  \ $83 $C6 $8
> ( $402B3A )  mov     dword ptr [eax] , edx  \ $89 $10
> ( $402B3C )  mov     edx , dword ptr [ebx]  \ $8B $13
> ( $402B3E )  add     ebx , # 4  \ $83 $C3 $4
> ( $402B41 )  jmp     dword ptr [edx]  \ $FF $22
> ( $402B43 )  xchg     eax, eax  \ $90
> end-code
>

ISTR that LODSD is slow on more modern CPUs...