MLBEDSW-2269: Fix the buffer overlap issue for multi subgraphes

Signed-off-by: Charles Xu <charles.xu@arm.com>
Change-Id: Ia7127148d00280bf9c3759dd6dcbe500a4cfcc78

2 files changed, 14 insertions, 8 deletions

diff --git a/ethosu/vela/greedy_allocation.py b/ethosu/vela/greedy_allocation.py
index d6896a59..8393434d 100644
--- a/ethosu/vela/greedy_allocation.py
+++ b/ethosu/vela/greedy_allocation.py
@@ -46,8 +46,8 @@ class GreedyAllocator:
 
             current_offset = start_addr + lr.size
 
+        best_offset = new_lr.set_address(best_offset)
         self.memory_required = max(self.memory_required, best_offset + size)
-        new_lr.set_address(best_offset)
         self.current_allocs.append((best_offset, new_lr))
         self.current_allocs = list(sorted(self.current_allocs))
 
@@ -77,7 +77,7 @@ class GreedyAllocator:
             for m in lrs:
                 if n != m and n.overlaps_ranges(m):
                     overlap, tens_n, tens_m = n.overlaps_address(m)
-                    if overlap:
+                    if overlap and not (tens_n.equivalence_id == tens_m.equivalence_id and tens_n.address == tens_m.address):
                         print("Solution failed, overlapping buffer!")
                         print(tens_n.address, tens_n.address + n.size, n.name)
                         print(tens_m.address, tens_m.address + m.size, m.name)
diff --git a/ethosu/vela/live_range.py b/ethosu/vela/live_range.py
index 23ab67d9..2a35a119 100644
--- a/ethosu/vela/live_range.py
+++ b/ethosu/vela/live_range.py
@@ -86,12 +86,18 @@ class LiveRange:
         # Set address of all unaddressed tensors in LiveRange
         for tens in self.tensors:
             if tens.address == 0:
-                tens.address = address
-                # Also need to set the address to the tensor's cpu/npu clones
-                if tens.cpu_tensor is not None:
-                    tens.cpu_tensor.address = address
-                if tens.npu_tensor is not None:
-                    tens.npu_tensor.address = address
+                addr = address
+            else:
+                # Limit to single tensor for the lr if the tensor address already assigned
+                assert len(self.tensors) == 1
+                addr = tens.address
+            tens.address = addr
+            # Also need to set the address to the tensor's cpu/npu clones
+            if tens.cpu_tensor is not None:
+                tens.cpu_tensor.address = addr
+            if tens.npu_tensor is not None:
+                tens.npu_tensor.address = addr
+        return addr
 
     def get_alignment(self):
         # Get max alignment of LiveRange's tensors