Add comments to each test

Author: Erich Keane

clang/test/CodeGenSYCL/sub-group-size.cpp

@@ -2,6 +2,9 @@
 // RUN: %clang_cc1 -fsycl-is-device -internal-isystem %S/Inputs -fsycl-default-sub-group-size=primary -sycl-std=2020 -triple spir64-unknown-unknown-sycldevice -disable-llvm-passes -emit-llvm -o - %s | FileCheck %s --check-prefixes=PRIM_DEF,ALL
 // RUN: %clang_cc1 -fsycl-is-device -internal-isystem %S/Inputs -fsycl-default-sub-group-size=10 -sycl-std=2020 -triple spir64-unknown-unknown-sycldevice -disable-llvm-passes -emit-llvm -o - %s | FileCheck %s --check-prefixes=TEN_DEF,ALL
 
+// Ensure that both forms of the new sub_group_size properly emit their metadata
+// on sycl-kernel and sycl-external functions.
+
 #include "Inputs/sycl.hpp"
 using namespace cl::sycl;
 

clang/test/Driver/sycl-sub-group-size.cpp

@@ -1,6 +1,10 @@
+// Ensure that by default the -fsycl-default-sub-group-size doesn't get passed
+// to the cc1 invocation.
 // RUN: %clang -### -fsycl %s 2>&1 | FileCheck %s -check-prefix=CHECK-DEFAULT
 // CHECK-DEFAULT-NOT: "fsycl-default-sub-group-size"
 
+// The next two tests make sure that the -fsycl-default-sub-group-size command
+// line arguments get properly passed unaltered to the cc1 invocation.
 // RUN: %clang -### -fsycl -fsycl-default-sub-group-size=primary %s 2>&1 | FileCheck %s -check-prefix=PRIM
 // PRIM: "-fsycl-default-sub-group-size" "primary"
 

clang/test/SemaSYCL/sub-group-size.cpp

@@ -2,6 +2,12 @@
 // RUN: %clang_cc1 -internal-isystem %S/Inputs -fsycl-is-device -fsycl-default-sub-group-size=primary -sycl-std=2020 -internal-isystem %S/Inputs -fsyntax-only -verify=expected,integer %s
 // RUN: %clang_cc1 -internal-isystem %S/Inputs -fsycl-is-device -fsycl-default-sub-group-size=10 -sycl-std=2020 -internal-isystem %S/Inputs -fsyntax-only -verify=expected,primary %s
 
+// Validate the semantic analysis checks for the interaction betwen the
+// named_sub_group_size and sub_group_size attributes. These are not able to be
+// combined, and require that they only be applied to non-sycl-kernel/
+// non-sycl-device functions if they match the kernel they are being called
+// from.
+
 #include "Inputs/sycl.hpp"
 
 // expected-error@+2 {{'named_sub_group_size' and 'sub_group_size' attributes are not compatible}}