math_brute_force/fma test case does not cover all special test data

[cdai2]

The math_brute_force /fma test cases report errors for ternary special value tests involving float and double data types, introduced in OpenCL-CTS PR #2697.

Root Cause:
The ternary tests (e.g., fma, mad) enumerate the full Cartesian product of special values across their three operands into a single BUFFER_SIZE input buffer. This requires:
specialValuesCount^3 <= BUFFER_SIZE / sizeof(T)

However, the current special values list is a union of values intended for unary and binary tests, which is too large for ternary tests. Specifically:

• Float: 98 special values → 98^3 = 941,192 entries

• Double: 106 special values → 106^3 = 1,191,016 entries

Both cases overflow the buffer, causing test failures.

The proposed fix is to reduce special value list for increase BUFFER_SIZE value.

[cdai2]

The BUFFER_SIZE should be increased from 1024 * 1024 * 2 to 1024 * 1024 * 10 to pass this case.

[cdai2]

Propose: #2780

[cdai2]

@rjodinchr

[rjodinchr]

For sure, we do not want to reduce the special value list.

Increasing BUFFER_SIZE can be done, but I see it more as a workaround than a proper fix, but I'm fine seeing it go in if you want it (maybe more 16MB to keep it as a power of 2).

Can you have a look at #2749 (using the -a option) to see if it would fix this issue?

[bashbaug]

Noting for completeness: this isn't a "buffer overflow" in the sense that the test is writing out-of-bounds and corrupting memory, but the issue does mean that a slightly concerning "Test Error: not all special cases tested" message gets printed to the CTS log and not all special values are tested. At least on my system, the test does pass, even with the "error message":

$ CL_CONFORMANCE_RESULTS_FILENAME=output.json ./test_conformance/math_brute_force/test_bruteforce fma -w
...
fma...
  1:             fma fp32     Test Error: not all special cases tested!
................Wimp pass           0.00 @ {0x0p+0, 0x0p+0, 0x0p+0}
  2:             fma fp64     Test Error: not all special cases tested!
................Wimp pass           0.00 @ {0x0p+0, 0x0p+0, 0x0p+0}
  3:             fma fp16     ................Wimp pass     0.00 @ {0x0p+0, 0x0p+0, 0x0p+0}
fma passed
PASSED 3 of 3 sub-tests.
PASSED test.
Saving results to output.json: success!
...
$ cat output.json
{
        "cmd": "./test_conformance/math_brute_force/test_bruteforce",
        "args": "--wimpy",
        "results": {
                "fma": "pass"
        }
}