[CUDA] Added -f[no-]cuda-short-ptr option

The option enables use of 32-bit pointers for accessing
const/local/shared memory. The feature is disabled by default.

Differential Revision: https://reviews.llvm.org/D46148

llvm-svn: 331938
diff --git a/clang/lib/Basic/Targets/NVPTX.cpp b/clang/lib/Basic/Targets/NVPTX.cpp
index 04293b3..fd4ee16 100644
--- a/clang/lib/Basic/Targets/NVPTX.cpp
+++ b/clang/lib/Basic/Targets/NVPTX.cpp
@@ -68,6 +68,9 @@
 
   if (TargetPointerWidth == 32)
     resetDataLayout("e-p:32:32-i64:64-i128:128-v16:16-v32:32-n16:32:64");
+  else if (Opts.NVPTXUseShortPointers)
+    resetDataLayout(
+        "e-p3:32:32-p4:32:32-p5:32:32-i64:64-i128:128-v16:16-v32:32-n16:32:64");
   else
     resetDataLayout("e-i64:64-i128:128-v16:16-v32:32-n16:32:64");