Код:

int8_t Test8(int8_t x)
{
    x += 20;
    x *= 12;
    x -= 3;
    x /= 5;
    x = x % 178;

    return x;
}

int16_t Test16(int16_t x)
{
    x += 102;
    x *= 14;
    x -= 32;
    x /= 52;
    x = x % 17820;

    return x;
}

int32_t Test32(int32_t x)
{
    x += 10232;
    x *= 412;
    x -= 3286;
    x /= 3;
    x = x % 1782543424;

    return x;
}


float Test_f(float x)
{
    x += 102.543f;
    x *= 412.54f;
    x -= 32.432f;
    x /= 3.432f;

    return x;
}


double Test_d(double x)
{
    x += 102.543d;
    x *= 412.54d;
    x -= 32.432d;
    x /= 3.432d;

    return x;
}

Код:

Function Test8(byval X As Byte) As Byte
    X = X + 20
    X = X * 12
    X = X - 3
    X = x / 5
    X = X Mod 178

    Test8 = X
End Function

Function Test16(byval X As Integer) As Integer
    X = X + 102
    X = X * 14
    X = x - 32
    X = x / 52
    X = X Mod 17820

    Test16 = X
End Function

Function Test32(byval X As Long) As Long
    X = X + 10232
    X = X * 412
    X = x - 3286
    X = X / 3
    X = X Mod 1782543424

    Test32 = X
End Function


Function Test_s(byval X As Single) As Single
    X = X + 102.543
    X = X * 412.54
    X = x - 32.432
    X = x / 3.432

    Test_s = X
End Function


Function Test_d(byval X As Double) As Double
    X = X + 102.543
    X = X * 412.54
    X = X - 32.432
    X = X / 3.432

    Test_d = X
End Function

Код:

STM32F103C8T6 - GCC 5.4, O2 + LTO. 

1 byte = 34333
2 byte = 33757
4 byte = 38022
float  = 193096
double = 1567736
Размер прошивки - 5304 байт.


STM32F407VGT6 - GCC 5.4, O2 + LTO. 

1 byte = 17050
2 byte = 17980
4 byte = 18024
float  = 26022
double = 812320
Размер прошивки - 4872 байт.

STM32H750VBT6 - GCC 5.4, O2.

1 byte = 26018
2 byte = 28020
4 byte = 30028
float  = 26024
double = 30010
Размер прошивки - 5588 байт.

STM32F030F4P6 - GCC 5.4, O2 + LTO.

1 byte = 122301
2 byte = 185132
4 byte = 246360
float  = 1474306
double = 3404609
Размер прошивки - 12324 байт.


ATmega328 - Bascom 2.0.8.1.

1 byte = 467566
2 byte = 1019516
4 byte = 2632705
Single = 2221984
Double = 5944625
Размер прошивки - 5188 байт.


ATmega328 - GCC 3.3.0, O2.

1 byte = 556851
2 byte = 729659
4 byte = 1935740
Float = 7015553
Double = 7015559
Размер прошивки - 5418 байт.