  double   a     3*{100, 200} = 0 / 1.2
        step 0: 
          block 0: [ 0:49,   0:199] = 0 / 0
          block 1: [50:99,   0:199] = 1 / 1
        step 1: 
          block 0: [ 0:49,   0:199] = 0.1 / 0.1
          block 1: [50:99,   0:199] = 1.1 / 1.1
        step 2: 
          block 0: [ 0:49,   0:199] = 0.2 / 0.2
          block 1: [50:99,   0:199] = 1.2 / 1.2
  float    b     3*{100} = 0 / 1.2
        step 0: 
          block 0: [ 0:49] = 0 / 0
          block 1: [50:99] = 1 / 1
        step 1: 
          block 0: [ 0:49] = 0.1 / 0.1
          block 1: [50:99] = 1.1 / 1.1
        step 2: 
          block 0: [ 0:49] = 0.2 / 0.2
          block 1: [50:99] = 1.2 / 1.2
