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Re: Shrinking the C core
From: |
Alfred M. Szmidt |
Subject: |
Re: Shrinking the C core |
Date: |
Sun, 20 Aug 2023 11:22:46 -0400 |
Please keep the CC intact, not everyone subscribed.
> It should be quite obvious why SBCL is faster than the Emacs
> Lisp VM (or even native). Just look at this call to (car
> "foo"), and compare what happens in Emacs.
>
> * (disassemble 'foo)
> ; disassembly for FOO
> ; Size: 166 bytes. Origin: #x225D873F ; FOO
> ; 3F: 488B042590060020 MOV RAX, [#x20000690]
> ; 47: 488945F8 MOV [RBP-8], RAX
> ; 4B: 48892C2560060020 MOV [#x20000660], RBP
> ; 53: 488B142518000020 MOV RDX, [#x20000018]
> ; 5B: 488D4210 LEA RAX, [RDX+16]
> ; 5F: 483B042520000020 CMP RAX, [#x20000020]
> ; 67: 7770 JA L2
> ; 69: 4889042518000020 MOV [#x20000018], RAX
> ; 71: L0: 488B0570FFFFFF MOV RAX, [RIP-144] ; "foo"
> ; 78: 488902 MOV [RDX], RAX
> ; 7B: 48C7420817010020 MOV QWORD PTR [RDX+8], #x20000117 ; NIL
> ; 83: 80CA07 OR DL, 7
> ; 86: 48312C2560060020 XOR [#x20000660], RBP
> ; 8E: 7402 JEQ L1
> ; 90: CC09 INT3 9 ; pending
interrupt trap
> ; 92: L1: 4C8D4424F0 LEA R8, [RSP-16]
> ; 97: 4883EC30 SUB RSP, 48
> ; 9B: BFAF0B1520 MOV EDI, #x20150BAF ; 'LIST
> ; A0: 488B3551FFFFFF MOV RSI, [RIP-175] ; '(VALUES
> ;
(SIMPLE-ARRAY ..))
> ; A7: 488B0552FFFFFF MOV RAX, [RIP-174] ; '("foo")
> ; AE: 498940F0 MOV [R8-16], RAX
> ; B2: 488B054FFFFFFF MOV RAX, [RIP-177] ; "(CAR
\"foo\")"
> ; B9: 498940E8 MOV [R8-24], RAX
> ; BD: 49C740E017010020 MOV QWORD PTR [R8-32], #x20000117 ; NIL
> ; C5: B90C000000 MOV ECX, 12
> ; CA: 498928 MOV [R8], RBP
> ; CD: 498BE8 MOV RBP, R8
> ; D0: B882B12620 MOV EAX, #x2026B182 ; #<FDEFN
SB-C::%COMPILE-TIME-TYPE-ERROR>
> ; D5: FFD0 CALL RAX
> ; D7: CC10 INT3 16 ; Invalid
argument count trap
> ; D9: L2: 6A10 PUSH 16
> ; DB: FF1425B0080020 CALL [#x200008B0] ;
#x21A00540: LIST-ALLOC-TRAMP
> ; E2: 5A POP RDX
> ; E3: EB8C JMP L0
> NIL
> *
Okay?
I guess that you do not understand the above? Or what? Do you know
and understand what happens in Emacs when a similar call is done? It
is far more than "166 bytes".
>> If we talk about type checking, Elisp uses dynamic typing
>> and compilation cannot do much about it. Native compilation
>> also does not touch C subroutines - the place where
>> typechecks are performed.
>
> SBCL implements a Lisp, Lisp by definition is
> dynamically typed.
Only for the kind of use (code) that we are used to. See this:
https://medium.com/@MartinCracauer/static-type-checking-in-the-programmable-programming-language-lisp-79bb79eb068a
This has literally nothing to do with the difference between static
typing, and dynamic typing. The author, and you, have it completeley
backwards to the point where I need to suggest that you take sometime
to read up on basic Lisp compilers, and then look into very good Lisp
compilers (CMUCL and SBCL come to mind). Since it is already showing
that it is very hard to even explain basic Lisp compiler behaviour
without going to fundamentals.
- Re: Shrinking the C core, (continued)
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/14
- Re: Shrinking the C core, Alfred M. Szmidt, 2023/08/14
- Re: Shrinking the C core, Emanuel Berg, 2023/08/15
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/16
- Re: Shrinking the C core, Emanuel Berg, 2023/08/19
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Emanuel Berg, 2023/08/20
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Alfred M. Szmidt, 2023/08/20
- Re: Shrinking the C core, Emanuel Berg, 2023/08/20
- Re: Shrinking the C core,
Alfred M. Szmidt <=
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Eli Zaretskii, 2023/08/20
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Alfred M. Szmidt, 2023/08/20
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Alfred M. Szmidt, 2023/08/20
- Re: Shrinking the C core, Ihor Radchenko, 2023/08/20
- Re: Shrinking the C core, Alfred M. Szmidt, 2023/08/20
- Re: Shrinking the C core, Eli Zaretskii, 2023/08/20
- Re: Shrinking the C core, Emanuel Berg, 2023/08/27