bugprone-integer-division

Finds cases where integer division in a floating point context is likely to cause unintended loss of precision.

No reports are made if divisions are part of the following expressions:

• operands of operators expecting integral or bool types,

• call expressions of integral or bool types, and

• explicit cast expressions to integral or bool types,

as these are interpreted as signs of deliberateness from the programmer.

Examples:

float floatFunc(float);
int intFunc(int);
double d;
int i = 42;

// Warn, floating-point values expected.
d = 32 * 8 / (2 + i);
d = 8 * floatFunc(1 + 7 / 2);
d = i / (1 << 4);

// OK, no integer division.
d = 32 * 8.0 / (2 + i);
d = 8 * floatFunc(1 + 7.0 / 2);
d = (double)i / (1 << 4);

// OK, there are signs of deliberateness.
d = 1 << (i / 2);
d = 9 + intFunc(6 * i / 32);
d = (int)(i / 32) - 8;