[AMDGPU] Add an experimental buffer fat pointer address space.

Add an experimental buffer fat pointer address space that is currently
unhandled in the backend. This commit reserves address space 7 as a
non-integral pointer repsenting the 160-bit fat pointer (128-bit buffer
descriptor + 32-bit offset) that is heavily used in graphics workloads
using the AMDGPU backend.

Differential Revision: https://reviews.llvm.org/D58957

llvm-svn: 356373

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
index 626c4f35f17..8fcabeba5ed 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
@@ -253,7 +253,8 @@ unsigned GCNTTIImpl::getStoreVectorFactor(unsigned VF, unsigned StoreSize,
 unsigned GCNTTIImpl::getLoadStoreVecRegBitWidth(unsigned AddrSpace) const {
   if (AddrSpace == AMDGPUAS::GLOBAL_ADDRESS ||
       AddrSpace == AMDGPUAS::CONSTANT_ADDRESS ||
-      AddrSpace == AMDGPUAS::CONSTANT_ADDRESS_32BIT) {
+      AddrSpace == AMDGPUAS::CONSTANT_ADDRESS_32BIT ||
+      AddrSpace == AMDGPUAS::BUFFER_FAT_POINTER) {
     return 512;
   }