title:Assembler calculate polynomial
keywords:assembler,c,math,polynomial
# Assembler calculate polynomial
Calculating polynomial with asm and C
```asm
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
faddp st1 , st0
fmulp st1 , st0
faddp st1 , st0
pop ebp
ret
```
For calculating polynomial used polish notation
Wiki
In other words a*x*x+b*x+c to reduce operations changed to (a*x+b)*x+c
and then written out operation by priorities [*,+,*,+].
Compiling this with lines
```
fasm poly.asm poly.o
```
```c
#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
```asm
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
fadd b
fmul x
fadd c
pop ebp
ret
```
Now only 5 instructions
# Links
http://en.wikipedia.org/wiki/Polish_notation
