[PTOAS] finalize pipe init nosplit semantics

include/PTO/IR/PTOOps.td

@@ -1187,6 +1187,7 @@ def AicInitializePipeOp : PTO_Op<"aic_initialize_pipe"> {
   let arguments = (ins
       I8Attr:$dir_mask,
       I32Attr:$slot_size,
+      OptionalAttr<BoolAttr>:$nosplit,
       Optional<PtrType>:$gm_slot_buffer,
       I32:$c2v_consumer_buf,
       I32:$v2c_consumer_buf
@@ -1197,7 +1198,9 @@ def AicInitializePipeOp : PTO_Op<"aic_initialize_pipe"> {
 
   let assemblyFormat = [{
     `{` `dir_mask` `=` $dir_mask `,`
-        `slot_size` `=` $slot_size `}`
+        `slot_size` `=` $slot_size
+        (`,` `nosplit` `=` $nosplit^)?
+        `}`
     `(`
       (`gm_slot_buffer` `=` $gm_slot_buffer^ `:` type($gm_slot_buffer) `,`)?
       `c2v_consumer_buf` `=` $c2v_consumer_buf `:` type($c2v_consumer_buf) `,`
@@ -1213,6 +1216,7 @@ def AivInitializePipeOp : PTO_Op<"aiv_initialize_pipe"> {
   let arguments = (ins
       I8Attr:$dir_mask,
       I32Attr:$slot_size,
+      OptionalAttr<BoolAttr>:$nosplit,
       Optional<PtrType>:$gm_slot_buffer,
       I32:$c2v_consumer_buf,
       I32:$v2c_consumer_buf
@@ -1223,7 +1227,9 @@ def AivInitializePipeOp : PTO_Op<"aiv_initialize_pipe"> {
 
   let assemblyFormat = [{
     `{` `dir_mask` `=` $dir_mask `,`
-        `slot_size` `=` $slot_size `}`
+        `slot_size` `=` $slot_size
+        (`,` `nosplit` `=` $nosplit^)?
+        `}`
     `(`
       (`gm_slot_buffer` `=` $gm_slot_buffer^ `:` type($gm_slot_buffer) `,`)?
       `c2v_consumer_buf` `=` $c2v_consumer_buf `:` type($c2v_consumer_buf) `,`

include/PTO/Transforms/Passes.h

@@ -35,6 +35,7 @@ namespace pto {
 
 std::unique_ptr<Pass> createLoweringSyncToPipePass();
 std::unique_ptr<Pass> createPTOLowerFrontendPipeOpsPass();
+std::unique_ptr<Pass> createPTOInferValidatePipeInitPass();
 std::unique_ptr<Pass> createPTOResolveReservedBuffersPass();
 std::unique_ptr<Pass> createPTOWrapFunctionsInSectionsPass();
 std::unique_ptr<Pass> createPTOVerifyTFreePass();

include/PTO/Transforms/Passes.td

@@ -139,15 +139,35 @@ def PTOLowerFrontendPipeOps : Pass<"pto-lower-frontend-pipe-ops", "func::FuncOp"
   ];
 }
 
+def PTOInferValidatePipeInit : Pass<"pto-infer-validate-pipe-init", "ModuleOp"> {
+  let summary = "Infer and validate internal pipe init nosplit configuration";
+  let description = [{
+    Runs after frontend pipe lowering and before memory planning. For each
+    logical pipe, this pass:
+    - validates that downstream `pto.tpush` / `pto.tpop` / `pto.tfree` users
+      do not mix `split = 0` with `split = 1/2`
+    - preserves explicit `nosplit` attrs on internal pipe init ops and rejects
+      conflicts across peer pipe init pairs
+    - infers missing `nosplit` attrs from downstream split usage for backward
+      compatibility with older IR that omitted init-level `nosplit`
+    - propagates the resolved `nosplit` value across peer pipe init pairs so
+      both ends of one logical pipe agree before EmitC lowering
+  }];
+
+  let constructor = "mlir::pto::createPTOInferValidatePipeInitPass()";
+
+  let dependentDialects = [
+    "mlir::pto::PTODialect",
+    "mlir::func::FuncDialect"
+  ];
+}
+
 def PTOResolveReservedBuffers : Pass<"pto-resolve-reserved-buffers", "ModuleOp"> {
   let summary = "Resolve reserved local buffer addresses and peer pipe flag bases";
   let description = [{
     Runs after `pto-plan-memory`. Assumes `pto.reserve_buffer` base addresses
     have already been planned, then:
     - aligns missing `flag_base` attrs for peer internal pipe init ops
-    - infers implicit `nosplit = true` for internal pipe init ops when any
-      downstream `pto.tpush` / `pto.tpop` / `pto.tfree` user on the same
-      logical pipe has `split = 0`
     - rejects internal pipe init ops without explicit `flag_base` when their
       `local_addr` cannot be traced back to `pto.reserve_buffer` /
       `pto.import_reserved_buffer`

lib/PTO/Transforms/CMakeLists.txt

@@ -26,6 +26,7 @@ add_mlir_dialect_library(PTOTransforms
   BufferizableOpInterfaceImpl.cpp
   ConvertToPTOOp.cpp
   PTOLowerFrontendPipeOpsPass.cpp
+  PTOInferValidatePipeInitPass.cpp
   PTOResolveReservedBuffersPass.cpp
   PTOWrapFunctionsInSectionsPass.cpp
   InsertSync/PTOIRTranslator.cpp