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There is a newer version: 8.6.0.37351

Using the same value on either side of a binary operator is almost always a mistake. In the case of logical operators, it is either a copy/paste error and therefore a bug, or it is simply wasted code, and should be simplified. In the case of bitwise operators and most binary mathematical operators, having the same value on both sides of an operator yields predictable results, and should be simplified.
This rule ignores *, +, and =. 
Noncompliant Code Example

if ( a == a ) { // always true
  doZ();
}
if ( a != a ) { // always false
  doY();
}
if ( a == b && a == b ) { // if the first one is true, the second one is too
  doX();
}
if ( a == b || a == b ) { // if the first one is true, the second one is too
  doW();
}

int j = 5 / 5; //always 1
int k = 5 - 5; //always 0

Compliant Solution

doZ();

if ( a == b ) {
  doX();
}
if ( a == b ) {
  doW();
}

int j = 1;
int k = 0;

Exceptions

The specific case of testing a floating point value against itself is a valid test for NaN and is therefore ignored.
Similarly, left-shifting 1 onto 1 is common in the construction of bit masks, and is ignored.
float f;
if(f != f) { //test for NaN value
  System.out.println("f is NaN");
}

int i = 1 << 1; // Compliant
int j = a << a; // Noncompliant

See


 CERT, MSC12-C - Detect and remove code that has no effect
 CERT, MSC12-CPP - Detect and remove code that has no effect
 Rule S1656 - Implements a check on =.