Re: Why is this code so much slower than the same algorithm in C?

Let's look at what is really going on when these programs run.

First the C program. It translates into the following assembler:
<Reveal this spoiler or all spoilers in this node or all in this thread>
Now the Perl code. It translates into the following ... um...I terrified to apply a term to this because one or more of the local language laywers is going to leap all over what ever term I use to say that it isn't really 'term' because blah, blah, ... more irrelavancies, ... blah!
So, whatever terms suits you, which may include one of the following: <opcodes|bytecode|syntax tree|abstract syntax tree|other>.
(Dodge issue!) This is the output from perl -MO=Concise YourScript.pl:
<Reveal this spoiler>

And within that, there is one line: o <2> modulo[t5] sKP/2 ->p
which is the equivalent of these four assembly instructions from the C version:
```
; Line 8
        mov     eax, DWORD PTR _i$[ebp]
        cdq
        idiv    DWORD PTR _j$[ebp]
        test    edx, edx
[download]
```

Now let's look at the assembler that sits behind that perl modulo instruction:

So the answer to your question is: when you understand why those four instructions in the C version, require those 700+ lines of assembler for the perl version, then you'll understand why the performance difference exists.

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