update test with comments and more checks

Author: frasercrmck

clang/test/CodeGenSYCL/nvptx-short-ptr.cpp

@@ -1,10 +1,27 @@
+// Check that when we see the expected data layouts for NVPTX when we pass the
+// -nvptx-short-ptr option.
+
+// RUN: %clang_cc1 -fsycl-is-device -disable-llvm-passes \
+// RUN:  -triple nvptx-nvidia-cuda -emit-llvm %s -o - \
+// RUN:    | FileCheck %s --check-prefix CHECK32
+
 // RUN: %clang_cc1 -fsycl-is-device -disable-llvm-passes \
 // RUN:  -triple nvptx-nvidia-cuda -emit-llvm -fcuda-short-ptr -mllvm -nvptx-short-ptr %s -o - \
 // RUN:    | FileCheck %s --check-prefix CHECK32
 
+// RUN: %clang_cc1 -fsycl-is-device -disable-llvm-passes \
+// RUN:  -triple nvptx64-nvidia-cuda -emit-llvm %s -o - \
+// RUN:    | FileCheck %s --check-prefix CHECK64-DEFAULT
+
 // RUN: %clang_cc1 -fsycl-is-device -disable-llvm-passes \
 // RUN:  -triple nvptx64-nvidia-cuda -emit-llvm -fcuda-short-ptr -mllvm -nvptx-short-ptr %s -o - \
-// RUN:    | FileCheck %s --check-prefix CHECK64
+// RUN:    | FileCheck %s --check-prefix CHECK64-SHORT
 
+// Targeting a 32-bit NVPTX, check that we see universal 32-bit pointers (the
+// option changes nothing)
 // CHECK32: target datalayout = "e-p:32:32-i64:64-i128:128-v16:16-v32:32-n16:32:64"
-// CHECK64: target datalayout = "e-p3:32:32-p4:32:32-p5:32:32-i64:64-i128:128-v16:16-v32:32-n16:32:64"
+
+// Targeting a 64-bit NVPTX target, check that we see 32-bit pointers for
+// shared (3), const (4), and local (5) address spaces only.
+// CHECK64-DEFAULT: target datalayout = "e-i64:64-i128:128-v16:16-v32:32-n16:32:64"
+// CHECK64-SHORT: target datalayout = "e-p3:32:32-p4:32:32-p5:32:32-i64:64-i128:128-v16:16-v32:32-n16:32:64"