[Brought here from LispSucks, since that page already had more clutter than it needed...]
Don't you mean "at assembly"? And isn't an editorial comment to that effect called for? We may have a variety of reactions to the asm below; it doesn't entirely speak for itself.
Negative. This page was abstracted from the original LispSucks page and brought here just to keep the yards of assembly listings out of the main stream of ThreadMode conversation (read, bickering). Therefore, "Lisp sucks, in assembly."
This still isn't clear English, even given your explanation. This amounts to something like "Lisp sucks: assembly examined" or some such?
Not really. It could have been, "Lisp sucks, in Swedish" or "Lisp sucks, in Klingon" but it's in assembly. Eh?
Isn't blazing fast? I guess you aren't talking about CommonLisp then.
I agree that Lisp is faster than most of the popular languages today - JavaLanguage and PythonLanguage. I was really only talking about CeeLanguage and CeePlusPlus, which are still the dominant languages for programming things like servers and large GUI based applications. It's worth pointing out that in both of those cases it has been found useful to embed Lisp in the program.
For my own code, which tends to be highly numeric and nothing like business apps, I usually find Lisp to range around +- 20% of c++ (yes, sometimes it is faster). Sometimes, however I find it is a factor of 2-5 slower on the same code where c++ had a particularly clever optimization I can't get my lisp compiler to make. On the other hand, sometimes my lisp is a factor of 2-5 faster, if I implement an algorithmic improvement which is simply too much trouble in c++. Of course, YourMileageMayVary, but I would expect that raw execution speed is almost never a compelling argument for c++ over CL, for 'normal' applications. I myself touch on some applications (large-scale simulations) where raw execution speed is crucial, but in that case you run on special hardware and expect to jump through many hoops to get that speed, including things like re-implementing in fortran or c++ with compiler-specific extensions etc. Large server apps may have similar constraints, but we are hardly talking about mainstream development now.
ComputerLanguageBenchmarksGame
Without exception, every proprietary Lisp implementation on the market has a native compiler that puts out good machine code and respects optimizing declarations. And some free ones do also.
Some Lisps, like Conan Lisp, do not even contain an interpreter! Every expression processed by Conan Lisp is converted into 80x86 machine code and then executed as such.
And many Lisps are not afraid to get you close to the metal. The disassemble function is a nice example (this is in CMUCL):
* (defun sum (n) (loop for i from 1 to n sum i))
SUM
* (sum 5)
15
PJB: how convenient an example. Rather, try: (sum 5000000000). See also: https://groups.google.com/forum/message/raw?msg=comp.lang.lisp/a36NKUYogvI/KWBtYkb-SXoJ (compare Lisp and C with factorial instead of sum).
* (disassemble #'sum)
Compiling LAMBDA (N):
Compiling Top-Level Form:
48131B90: .ENTRY "LAMBDA (N)"(n) ; (FUNCTION (T) NUMBER)
BA8: POP DWORD PTR [EBP-8]
BAB: LEA ESP, [EBP-32]
BAE: MOV EDI, EDX
BB0: CMP ECX, 4
BB3: JNE L2
BB5: MOV [EBP-12], EDI
BB8: MOV DWORD PTR [EBP-16], 4 ; No-arg-parsing entry point
BBF: MOV DWORD PTR [EBP-20], 0
BC6: JMP L1
BC8: L0: MOV EDX, [EBP-20]
BCB: MOV EDI, [EBP-16]
BCE: CALL #x100001C8
BD3: MOV ESP, EBX
BD5: MOV [EBP-20], EDX
BD8: MOV EDX, [EBP-16]
BDB: MOV EDI, 4
BE0: CALL #x100001C8
BE5: MOV ESP, EBX
BE7: MOV [EBP-16], EDX
BEA: L1: MOV EDX, [EBP-16]
BED: MOV EDI, [EBP-12]
;;; [4] (LOOP FOR I FROM ...)
BF0: CALL #x10000460
BF5: MOV ESP, EBX
BF7: CMP EDX, #x2800000B ; NIL
BFD: JEQ L0
BFF: MOV EDX, [EBP-20]
C02: MOV ECX, [EBP-8]
C05: MOV EAX, [EBP-4]
C08: ADD ECX, 2
C0B: MOV ESP, EBP
C0D: MOV EBP, EAX
C0F: JMP ECX
C11: NOP
C12: NOP
C13: NOP
C14: NOP
C15: NOP
C16: NOP
C17: NOP
C18: L2: BREAK 10 ; Error trap
C1A: BYTE #x02
C1B: BYTE #x19 ; INVALID-ARGUMENT-COUNT-ERROR
C1C: BYTE #x4D ; ECX
Note that disassemble is a standard feature. Here's how it works in CLISP, a bytecode-interpreting implementation:
[1]> (defun sum (n) (loop for i from 1 to n sum i))
SUM
[2]> (disassemble #'sum)
Disassembly of function SUM
(CONST 0) = 0
(CONST 1) = 1
1 required arguments
0 optional arguments
No rest parameter
No keyword parameters
0 (CONST&PUSH 0) ; 0
1 (CONST&PUSH 1) ; 1
2 (JMP L12)
4 L4
4 (LOAD&PUSH 1)
5 (LOAD&PUSH 1)
6 (CALLSR&STORE 2 54 1) ; +
10 (LOAD&INC&STORE 0)
12 L12
12 (LOAD&PUSH 0)
13 (LOAD&PUSH 4)
14 (CALLSR&JMPIFNOT 1 49 L4) ; >
18 (LOAD 1)
19 (SKIP&RET 4)
#<COMPILED-CLOSURE SUM>
CommonLisp ain't for QuicheEaters!
By the way, if anyone's looking at the disassembled x86 machine code for the SUM function above and thinking "yeccch, that's ten times worse than it would be in C", here's what you get if you throw in some type declarations (like you need all the time in C) and tell the compiler to prefer speed over safety (like you get all the time in C).
48081060: .ENTRY SUM(n) ; (FUNCTION (FIXNUM) FIXNUM)
78: POP DWORD PTR [EBP-8]
7B: LEA ESP, [EBP-32]
7E: MOV EAX, 4 ; No-arg-parsing entry point
83: XOR ECX, ECX
85: JMP L1
87: L0: ADD ECX, EAX
89: ADD EAX, 4
8C: L1: CMP EAX, EDX
8E: JLE L0
90: MOV EDX, ECX
92: MOV ECX, [EBP-8]
95: MOV EAX, [EBP-4]
98: ADD ECX, 2
9B: MOV ESP, EBP
9D: MOV EBP, EAX
9F: JMP ECX
A1: NOP
A2: NOP
A3: NOP
A4: NOP
;;; [7] (LOOP FOR I FIXNUM ...)
A5: NOP
A6: NOP
A7: NOP
Of course, a really smart compiler could produce
480C65D0: .ENTRY SUM(n) ; (FUNCTION (FIXNUM)
(SIGNED-BYTE 29))
5E8: POP DWORD PTR [EBP-8]
5EB: LEA ESP, [EBP-32]
5EE: LEA EAX, [EDX+4] ; No-arg-parsing entry point
5F1: SAR EDX, 2
5F4: IMUL EDX, EAX
5F7: SAR EDX, 1
5F9: AND EDX, 4294967292
5FF: MOV ECX, [EBP-8]
602: MOV EAX, [EBP-4]
605: ADD ECX, 2
608: MOV ESP, EBP
60A: MOV EBP, EAX
60C: JMP ECX
60E: NOP
60F: NOP
instead ...
I saw the title and initially envisioned something that looked like this :-)
(EAX (JMP (SAR EPX NOP) ESP LEA) MOV (ADD EBP)) JLE EBP)