[AMDGPU][MC] New syntax for ds_swizzle_b32 offset

See Bug 28601: https://bugs.llvm.org//show_bug.cgi?id=28601

Reviewers: artem.tamazov, vpykhtin

Differential Revision: https://reviews.llvm.org/D33542

llvm-svn: 304309
diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDGPUAsmUtils.cpp b/llvm/lib/Target/AMDGPU/Utils/AMDGPUAsmUtils.cpp
index b6868de..03b11ae 100644
--- a/llvm/lib/Target/AMDGPU/Utils/AMDGPUAsmUtils.cpp
+++ b/llvm/lib/Target/AMDGPU/Utils/AMDGPUAsmUtils.cpp
@@ -65,5 +65,18 @@
 };
 
 } // namespace Hwreg
+
+namespace Swizzle {
+
+// This must be in sync with llvm::AMDGPU::Swizzle::Id enum members, see SIDefines.h.
+const char* const IdSymbolic[] = {
+  "QUAD_PERM",
+  "BITMASK_PERM",
+  "SWAP",
+  "REVERSE",
+  "BROADCAST",
+};
+
+} // namespace Swizzle
 } // namespace AMDGPU
 } // namespace llvm