[mlir] [llvm] [mlir][mesh] Add spmdization pass (PR #80518)

[Chengji Yao via llvm-commits]

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@@ -78,6 +92,35 @@ int64_t collectiveProcessGroupSize(MeshAxesRange &&meshAxes,
   return res;
 }
 
+inline int64_t shardDimension(int64_t dim, int64_t shardCount) {
+  if (ShapedType::isDynamic(dim) || ShapedType::isDynamic(shardCount))
+    return ShapedType::kDynamic;
+
+  assert(dim % shardCount == 0);
+  return ceilDiv(dim, shardCount);
+}
+
+inline int64_t unshardDimension(int64_t dim, int64_t shardCount) {
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yaochengji wrote:

I'm not sure `unshard` is a suitable name or not. Or call it `gatherDimension`?

https://github.com/llvm/llvm-project/pull/80518