new builtins: @workItemId, @workGroupId, @workGroupSize

* @workItemId returns the index of the work item in a work group for a
  dimension.
* @workGroupId returns the index of the work group in the kernel dispatch for a
  dimension.
* @workGroupSize returns the size of the work group for a dimension.

These builtins are mainly useful for GPU backends. They are currently only
implemented for the AMDGCN LLVM backend.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/arch/wasm/CodeGen.zig b/src/arch/wasm/CodeGen.zig
index 199ddada65..fc5d13e5a4 100644
--- a/src/arch/wasm/CodeGen.zig
+++ b/src/arch/wasm/CodeGen.zig
@@ -1997,6 +1997,11 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
         .reduce_optimized,
         .float_to_int_optimized,
         => return func.fail("TODO implement optimized float mode", .{}),
+
+        .work_item_id,
+        .work_group_size,
+        .work_group_id,
+        => unreachable,
     };
 }