Addressing review comments

Also found that -DCHECK_SYCL_ALL is really required for the first run
-DSYCL_TARGET_DEVICES alone is not working.

TODO: need to clarify External/ExtraTests functionality

Author: Pavel V Chupin

SYCL/External/README.md

@@ -5,21 +5,22 @@ sources of tests are expected to be located outside of llvm-test-suite
 repository. Each subdirectory represents external repository for corresponding
 application/test.
 
-# Directory structure
-Every sub-directory (e.g. RSBench) contains the following content:
+# Adding external test
+
+See [RSBench](RSBench) as example, it contains the following:
  * **CMakeLists.txt** - CMake configuration file which is used to obtain
  application binary and data files.
- * **\*.test** - test configuration files, containing command lines, test
-   status lines and verification patterns following
-   [LLVM tests infrastructure](https://llvm.org/docs/TestingGuide.html).
  * **lit.local.cfg** - application specific LIT infrastructure configuration
-   file. In case of RSBench benchmarks it sets LIT test file suffixes to `.test`
+   file. In case of RSBench benchmark it sets LIT test file suffixes to `.test`
    and mark all tests in directory unsupported if corresponding directory is
-   not added to `SYCL_EXTERNAL_TESTS` list.
+   not added to `SYCL_EXTERNAL_TESTS` list. See more at:
+   [LLVM Testing Guide](https://llvm.org/docs/TestingGuide.html#platform-specific-tests)
+ * **\*.test** - test configuration files, containing command lines, test
+   status lines and verification patterns per each platform.
 
 # CMake parameters
 
-All parameters described in [Readme.md](../README.md#cmake-parameters) are
+All parameters described in [README.md](../README.md#cmake-parameters) are
 applicable.
 
 ***SYCL_EXTERNAL_TESTS*** semicolon-separated names of external SYCL
@@ -64,7 +65,7 @@ With compiler tools available in the PATH:
 cmake \
  -DCMAKE_CXX_COMPILER=clang++ \
  -DTEST_SUITE_SUBDIRS=SYCL \
- -DSYCL_TARGET_DEVICES="level_zero:gpu" \
+ -DCHECK_SYCL_ALL="level_zero:gpu" \
  -DSYCL_EXTERNAL_TESTS="RSBench" \
  ..
 

SYCL/README.md

@@ -16,8 +16,9 @@ on testing scope.
 
  - DPC++ compiler. Can be built following these
    [instructions](https://github.com/intel/llvm/blob/sycl/sycl/doc/GetStartedGuide.md#build-dpc-toolchain)
- - LIT tools (llvm-lit, llvm-size). They can be available as part of compiler
-   build or built separately (e.g. with "ninja check").
+   or taken prebuilt from [releases](https://github.com/intel/llvm/releases).
+ - LIT tools (llvm-lit, llvm-size). They are not available at prebuilts above,
+   but can be built in compiler project (e.g. with "ninja check").
  - Target runtime(s) to execute tests on devices other than host. See
    [installation instructions](https://github.com/intel/llvm/blob/sycl/sycl/doc/GetStartedGuide.md#install-low-level-runtime)
 
@@ -39,7 +40,7 @@ With compiler tools available in the PATH:
 cmake \
  -DCMAKE_CXX_COMPILER=clang++ \
  -DTEST_SUITE_SUBDIRS=SYCL \
- -DSYCL_TARGET_DEVICES="host" \
+ -DCHECK_SYCL_ALL="opencl:host" \
  ..
 
 # Build and Run
@@ -74,6 +75,15 @@ collection
 
 ***TEST_SUITE_LIT*** path to llvm-lit tool
 
+***CHECK_SYCL_ALL*** defines selection of multiple SYCL backends with set of
+target devices per each to be tested iteratively. Value is semicolon-separated
+list of configurations. Each configuration includes backend separated
+from comma-separated list of target devices with colon. Example:
+
+```
+-DCHECK_SYCL_ALL="opencl:cpu,host;level_zero:gpu,host;cuda:gpu"
+```
+
 ***SYCL_BE*** SYCL backend to be used for testing. Supported values are:
  - **opencl** - for OpenCL backend;
  - **cuda** - for CUDA backend;
@@ -86,15 +96,6 @@ Default value is cpu,gpu,acc,host. Supported values are:
  - **acc**  - FPGA emulator device available in OpenCL backend only;
  - **host** - SYCL Host device available with all backends.
 
-***CHECK_SYCL_ALL*** defines selection of multiple SYCL backends with set of
-target devices per each to be tested iteratively. Value is semicolon-separated
-list of configurations. Each configuration includes backend separated
-from comma-separated list of target devices with colon. Example:
-
-```
--DCHECK_SYCL_ALL="opencl:cpu,host;level_zero:gpu,host;cuda:gpu"
-```
-
 ***OpenCL_LIBRARY*** path to OpenCL ICD loader library. OpenCL interoperability
 tests require OpenCL ICD loader to be linked with. For such tests OpenCL ICD
 loader library should be installed in the system or available at the full path