ID 683176
Date 9/24/2018
Public

2.4.2. Area Analysis of System

The area analysis of system report shows an area breakdown of your OpenCL system that is the closest approximation to the hardware that is implemented in the FPGA.

OpenCL kernel example that includes four loops:

 1  // ND-Range kernel with unrolled loops
2  __attribute((reqd_work_group_size(1024,1,1)))
3  kernel void t (global int * out, int N) {
4    int i = get_global_id(0);
5    int j = 1;
6    for (int k = 0; k < 4; k++) {
7      #pragma unroll
8      for (int n = 0; n < 4; n++) {
9        j += out[k+n];
10      }
11    }
12    out[i] = j;
13
14    int m = 0;
15    #pragma unroll 1
16    for (int k = 0; k < N; k++) {
17      m += out[k/3];
18    }
19    #pragma unroll
20    for (int k = 0; k < 6; k++) {
21      m += out[k];
22    }
23    #pragma unroll 2
24    for (int k = 0; k < 6; k++) {
25      m += out[k];
26    }
27    out[2] = m;
28  }
Figure 25. System View of an Example Area Report

In the system view, the kernel is divided into logic blocks. To view the area usage information for the code lines associated with a block, simply expand the report entry for that block. In this example, area information for the code line out[i] = j (line 12) is available under Block1. The estimated area usage for line 12 in the system view is the same as the estimation in the source view.