[libclc] [libclc] Refine __clc_get_sub_group_size with fast full sub-group path (PR #163149)

[Wenju He via cfe-commits]

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@@ -13,14 +13,11 @@
 #include <clc/workitem/clc_get_sub_group_size.h>
 
 _CLC_OVERLOAD _CLC_DEF uint __clc_get_sub_group_size() {
-  if (__clc_get_sub_group_id() != __clc_get_num_sub_groups() - 1) {
-    return __clc_get_max_sub_group_size();
-  }
-  size_t size_x = __clc_get_local_size(0);
-  size_t size_y = __clc_get_local_size(1);
-  size_t size_z = __clc_get_local_size(2);
-  size_t linear_size = size_z * size_y * size_x;
-  size_t uniform_groups = __clc_get_num_sub_groups() - 1;
-  size_t uniform_size = __clc_get_max_sub_group_size() * uniform_groups;
-  return linear_size - uniform_size;
+  size_t linear_size = __clc_get_local_size(0) * __clc_get_local_size(1) *
+                       __clc_get_local_size(2);
+  uint remainder = linear_size % __clc_get_max_sub_group_size();
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wenju-he wrote:

kindly ping

https://github.com/llvm/llvm-project/pull/163149