Calculating polynomial with asm and C

``````format ELF
section ".text" executable
public poly
align 4
poly:
a equ dword [ebp+8]
b equ dword [ebp+12]
c equ dword [ebp+16]
x equ dword [ebp+20]
;a*x*x+b*x+c
push ebp
mov ebp , esp
fld c
fld x
fld b
fld x
fld a
fmulp st1 , st0
fmulp st1 , st0
pop ebp
ret
``````

For calculating polynomial used polish notation Wiki In other words axx+bx+c to reduce operations changed to (ax+b)x+c and then written out operation by priorities [,+,*,+]. Compiling this with lines

``````fasm poly.asm poly.o
``````
``````#include <stdio.h>
extern float poly( float , float , float , float );
int main()
{
float res = poly( 1.0 , 2.0 , 3.0 , 3.0 );
printf( "%f\n" , res );
return 0;
}
``````

Compiling this with lines

``````gcc -c main.c -o main.o
``````

Combining

``````gcc main.o poly.o -o main
``````

Update on 06.12.2009 After running dome C code with FPU calculations and -O2 flag

``````format ELF
section ".text" executable

public poly
align 4
poly:
a equ dword [ebp+8]
b equ dword [ebp+12]
c equ dword [ebp+16]
x equ dword [ebp+20]
;a*x*x+b*x+c
push ebp
mov ebp , esp

fld a
fmul x