Index: amdgcn/lib/SOURCES
===================================================================
--- amdgcn/lib/SOURCES
+++ amdgcn/lib/SOURCES
@@ -1,3 +1,4 @@
 synchronization/barrier_impl.ll
 workitem/get_group_id.ll
 workitem/get_local_id.ll
+workitem/get_local_size.ll
Index: amdgcn/lib/workitem/get_local_size.ll
===================================================================
--- /dev/null
+++ amdgcn/lib/workitem/get_local_size.ll
@@ -0,0 +1,35 @@
+declare i8 addrspace(2)* @llvm.amdgcn.dispatch.ptr() #0
+
+define i32 @get_local_size(i32 %dim) #1 {
+  %dispatch_ptr = call noalias nonnull dereferenceable(64) i8 addrspace(2)* @llvm.amdgcn.dispatch.ptr()
+  %dispatch_ptr_i32 = bitcast i8 addrspace(2)* %dispatch_ptr to i32 addrspace(2)*
+  %xy_size_ptr = getelementptr inbounds i32, i32 addrspace(2)* %dispatch_ptr_i32, i64 1
+  %xy_size = load i32, i32 addrspace(2)* %xy_size_ptr, align 4, !invariant.load !0
+  switch i32 %dim, label %default [
+    i32 0, label %x_dim
+    i32 1, label %y_dim
+    i32 2, label %z_dim
+  ]
+
+x_dim:
+  %x_size = and i32 %xy_size, 65535
+  ret i32 %x_size
+
+y_dim:
+  %y_size = lshr i32 %xy_size, 16
+  ret i32 %y_size
+
+z_dim:
+  %z_size_ptr = getelementptr inbounds i32, i32 addrspace(2)* %dispatch_ptr_i32, i64 2
+  %z_size = load i32, i32 addrspace(2)* %z_size_ptr, align 4, !invariant.load !0, !range !1
+  ret i32 %z_size
+
+default:
+  ret i32 1
+}
+
+attributes #0 = { nounwind readnone }
+attributes #1 = { alwaysinline norecurse nounwind readonly }
+
+!0 = !{}
+!1 = !{ i32 0, i32 257 }