[AMDGPU] Fix dwordx3/southern-islands failures.

This commit fixes the dwordx3/southern-islands failures that were found
in bugzilla https://bugs.llvm.org/show_bug.cgi?id=40129, by not
generating the dwordx3 variants of load/store instructions that were
added to the ISA after southern islands.

Differential Revision: https://reviews.llvm.org/D56434

llvm-svn: 350838

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
index 51be81a7a81..43c83efe47b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
@@ -822,6 +822,11 @@ public:
     return getGeneration() != AMDGPUSubtarget::SOUTHERN_ISLANDS;
   }
 
+  // \returns true if the subtarget supports DWORDX3 load/store instructions.
+  bool hasDwordx3LoadStores() const {
+    return CIInsts;
+  }
+
   bool hasSMovFedHazard() const {
     return getGeneration() >= AMDGPUSubtarget::GFX9;
   }