src/third_party/v8-3.25/src/hydrogen-instructions.cc
/*
 * This method detects if phi is an induction variable, with phi_operand as
 * its "incremented" value (the other operand would be the "base" value).
 *
 * It cheks is phi_operand has the form "phi + constant".
 * If yes, the constant is the increment that the induction variable gets at
 * every loop iteration.
 * Otherwise it returns 0.
 */
This method detects if phi is an induction variable, with phi_operand as
its "incremented" value (the other operand would be the "base" value).

It cheks is phi_operand has the form "phi + constant".
If yes, the constant is the increment that the induction variable gets at
every loop iteration.
Otherwise it returns 0.
This method detects if phi is an induction variable with phi_operand as its " incremented " value ( the other operand would be the " base " value ) . It cheks is phi_operand has the form " phi + constant " . If yes the constant is the increment that the induction variable gets at every loop iteration . Otherwise it returns 0 .
int32_t InductionVariableData::ComputeIncrement(HPhi* phi,
                                                HValue* phi_operand) {
  if (!phi_operand->representation().IsInteger32()) return 0;
  if (phi_operand->IsAdd()) {
    HAdd* operation = HAdd::cast(phi_operand);
    if (operation->left() == phi &&
        operation->right()->IsInteger32Constant()) {
      return operation->right()->GetInteger32Constant();
    } else if (operation->right() == phi &&
               operation->left()->IsInteger32Constant()) {
      return operation->left()->GetInteger32Constant();
    }
  } else if (phi_operand->IsSub()) {
    HSub* operation = HSub::cast(phi_operand);
    if (operation->left() == phi &&
        operation->right()->IsInteger32Constant()) {
      return -operation->right()->GetInteger32Constant();
    }
  }
  return 0;
}
int32_t InductionVariableData :: ComputeIncrement ( HPhi * phi , HValue * phi_operand ) { if ( ! phi_operand -> representation ( ) . IsInteger32 ( ) ) return 0 ; if ( phi_operand -> IsAdd ( ) ) { HAdd * operation = HAdd :: cast ( phi_operand ) ; if ( operation -> left ( ) == phi && operation -> right ( ) -> IsInteger32Constant ( ) ) { return operation -> right ( ) -> GetInteger32Constant ( ) ; } else if ( operation -> right ( ) == phi && operation -> left ( ) -> IsInteger32Constant ( ) ) { return operation -> left ( ) -> GetInteger32Constant ( ) ; } } else if ( phi_operand -> IsSub ( ) ) { HSub * operation = HSub :: cast ( phi_operand ) ; if ( operation -> left ( ) == phi && operation -> right ( ) -> IsInteger32Constant ( ) ) { return - operation -> right ( ) -> GetInteger32Constant ( ) ; } } return 0 ; }
This method detects if phi is an induction variable, with phi_operand as
 its "incremented" value (the other operand would be the "base" value).
This method detects if phi is an induction variable with phi_operand as its " incremented " value ( the other operand would be the " base " value ) .