Immediate Constants - 2024.2 English

Floating-point constants in C are double-precision by default. When using a single-precision FPU, careless coding could result in double-precision software emulation routines being used instead of the native single-precision instructions. To avoid this, explicitly specify (by cast or suffix) that immediate constants in your arithmetic expressions are single-precision values.

For example:

float x = 0.0;
...
x += (float)1.0;                       /* float addition */
x += 1.0F;                             /* alternative to above */
x += 1.0;                              /* warning - uses double addition! */