Mangle buffer names in MchanDma chunked-1D fallback

When a contiguous DMA transfer exceeds the 17-bit mchan command-size
field, the fallback splits it into `_MAX_1D_TRANSFER_BYTES` chunks and
emits one mchan_transfer_1d(cmd, loc, ext) per chunk.  The opRepr
values were built with `f"((char*){buf.name} + {offset})"`, but
ExecutionBlock._mangleOpRepr only rewrites values that ctxt.is_buffer()
recognises — a formatted string slips through unchanged, so the emitted
C refers to `TILING_CODEGEN_L1_foo_ref` while the declaration is
`DeeployNetwork_TILING_CODEGEN_L1_foo_ref`.

Seen on ResNet8 tiled L1>=200KB L3 for layer3.conv2: the 147456-byte
weight load splits into 131072+16384, and clang fails with "use of
undeclared identifier 'TILING_CODEGEN_L1_node_23_..._weight_ref'".

Fix: call ctxt._mangle() on the buffer names once before the chunking
loop so the emitted strings match the declared variables.  The same
bug is present in the GAP9 MchanDma port — patch both.

This was blocking end-to-end gvsoc runs for any configuration whose
weight tiles exceed 128KB.

Author: runwangdl

Deeploy/Targets/GAP9/DMA/MchanDma.py

@@ -105,14 +105,20 @@ def transfer(self, ctxt: NetworkContext, externalBuffer: VariableBuffer, localBu
             mchanFlags += (1 << 1)  # increment addresses
             mchanFlags += (1 << 3)  # event enable
             template = self._transferTemplates[1]
+            # Explicitly mangle the buffer names: see Siracusa MchanDma for the
+            # same fix — _mangleOpRepr only rewrites plain buffer names, so a
+            # string like "((char*)foo + 0)" would ship without the
+            # DeeployNetwork_ prefix and fail to compile.
+            locName = ctxt._mangle(localBuffer.name)
+            extName = ctxt._mangle(externalBuffer.name)
             chunks: List[CodeSnippet] = []
             offset = 0
             while offset < totalSize:
                 chunkSize = min(self._MAX_1D_TRANSFER_BYTES, totalSize - offset)
                 cmd = (mchanFlags << 17) + chunkSize
                 opRepr: OperatorRepresentation = {
-                    "loc": f"((char*){localBuffer.name} + {offset})",
-                    "ext": f"((char*){externalBuffer.name} + {offset})",
+                    "loc": f"((char*){locName} + {offset})",
+                    "ext": f"((char*){extName} + {offset})",
                     "future": future.name,
                     "cmd": cmd,
                     "size": chunkSize,

Deeploy/Targets/PULPOpen/DMA/MchanDma.py

@@ -91,14 +91,24 @@ def transfer(self, ctxt: NetworkContext, externalBuffer: VariableBuffer, localBu
             mchanFlags += (1 << 1)  # increment addresses
             mchanFlags += (1 << 3)  # event enable
             template = self._transferTemplates[1]
+            # Use the network-prefixed buffer name so the emitted C references
+            # the variable that was actually declared (e.g.
+            # DeeployNetwork_TILING_CODEGEN_L1_foo_ref) rather than the raw
+            # buffer.name.  The mangling normally happens inside
+            # ExecutionBlock._mangleOpRepr, but that pass only rewrites values
+            # that match is_buffer() — a formatted string like
+            # "((char*)foo + 0)" escapes the rewrite and produces undeclared
+            # identifier build errors for any weight/tile >131072 bytes.
+            locName = ctxt._mangle(localBuffer.name)
+            extName = ctxt._mangle(externalBuffer.name)
             chunks: List[CodeSnippet] = []
             offset = 0
             while offset < totalSize:
                 chunkSize = min(self._MAX_1D_TRANSFER_BYTES, totalSize - offset)
                 cmd = (mchanFlags << 17) + chunkSize
                 opRepr: OperatorRepresentation = {
-                    "loc": f"((char*){localBuffer.name} + {offset})",
-                    "ext": f"((char*){externalBuffer.name} + {offset})",
+                    "loc": f"((char*){locName} + {offset})",
+                    "ext": f"((char*){extName} + {offset})",
                     "future": future.name,
                     "cmd": cmd,
                 }