Re: Baby X is bor nagain

On 25/06/2024 21:28, DFS wrote:

On 6/25/2024 3:39 PM, bart wrote:

On 25/06/2024 17:52, DFS wrote:

On 6/25/2024 7:18 AM, bart wrote:

On 25/06/2024 09:19, David Brown wrote:
>

At no point in all this does anyone care in the slightest about the speed of your little toys or of the cute little tcc.  tcc might be ideal for the half-dozen people in the world who think C scripts are a good idea, and it had its place in a time when "live Linux" systems were booted from floppies, but that's about it.

>
Yet, projects like mine, and like tcc, show what is possible: just how fast should it take to turn lower level code into machine code.

>
>
Can you use tcc to generate assembly from a .c source file?
>
similar to:
>
$ gcc -S sourcefile.c

>
>
I don't think that's an option with tcc.

 It's not listed in the tcc help anyway.
  

gcc works by generating intermediate assembly anyway, and the -S option exposes it.
>
Generally it depends on compiler. Mine has it for example.

 Cool.
 If you don't mind, what assembly code does your compiler generate for this C code:

I've shown the main code below. I normally use alternate registers names, I've changed it to use Intel; it looks about right.
This is for Win64 ABI running on x64.
Although I'm not sure how helpful this will be. Most of the runtime in your program will be spent inside library functions.
----------------------------------------
`main::
     `main.argc = -8
     `main.argv = -16
     `R.main.N = edi
     `R.main.nums = rbx
     `R.main.datafile = rsi
     `R.main.i.3 = r12d
     `main.$env = -24
     `main.$info = -152
     push    rdi
     push    rbx
     push    rsi
     push    r12
     push    rbp
     mov     rbp, rsp
     sub     rsp, 192
;...   (some code which sets up argc/argv via __getmainargs() ...
     mov     edi, 0
     mov     rcx, 8
     call    `malloc*
     mov     rbx, rax
     mov     rax, [rbp+`main.argv]
     lea     rax, [rax+8]
     mov     rax, [rax]
     mov     rcx, rax
     mov     rdx, L6
     call    `fopen*
     mov     rsi, rax
     jmp     L7
L9:
     lea     eax, [rdi+1]
     movsx   rax, eax
     shl     rax, 2
     mov     rcx, rbx
     mov     rdx, rax
     call    `realloc*
     mov     rbx, rax
L7:
     mov     eax, edi
     inc     edi
     movsx   rax, eax
     lea     r10, [rbx+rax*4]
     mov     rcx, rsi
     mov     rdx, L10
     mov     r8, r10
     call    `fscanf*
     cmp     eax, 1
     jz      L9
L8:
     mov     rcx, rsi
     call    `fclose*
     dec     edi
     mov     r12d, 0
     jmp     L13
L14:
     mov     eax, r12d
     movsx   rax, eax
     lea     r10, [rbx+rax*4]
     mov     r10d, [r10]
     lea     eax, [r12+1]
     mov     rcx, L15
     mov     edx, eax
     mov     r8d, r10d
     call    `printf*
L11:
     inc     r12d
L13:
     cmp     r12d, edi
     jl      L14
L12:
     mov     rcx, rbx
     call    `free*
     mov     rcx, L16
     call    `printf*
;------------------------
     xor     ecx, ecx
     call    `exit*
     add     rsp, 192
     pop     rbp
     pop     r12
     pop     rsi
     pop     rbx
     pop     rdi
     ret