refactor: remove redundant outputs from kernel procedures

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Changes
 
+- [BREAKING] Removed redundant outputs from kernel procedures: `note::write_assets_to_memory`, `active_note::get_assets`, `input_note::get_assets`, `output_note::get_assets`, `active_note::get_storage`, and `faucet::mint` no longer return values identical to their inputs ([#2523](https://github.com/0xMiden/protocol/issues/2523)).
 - [BREAKING] Renamed `ProvenBatch::new` to `new_unchecked` ([#2687](https://github.com/0xMiden/miden-base/issues/2687)).
 - Added shared `ProcedurePolicy` for AuthMultisig ([#2670](https://github.com/0xMiden/protocol/pull/2670)).
 - [BREAKING] Changed `NoteType` encoding from 2 bits to 1 and makes `NoteType::Private` the default ([#2691](https://github.com/0xMiden/miden-base/issues/2691)).

crates/miden-agglayer/asm/note_scripts/B2AGG.masm

@@ -76,26 +76,26 @@ begin
 
         # Store note storage -> mem[8..14]
         push.B2AGG_NOTE_STORAGE_PTR exec.active_note::get_storage
-        # => [num_storage_items, storage_ptr, pad(16)]
+        # => [num_storage_items, pad(16)]
 
         # Validate the number of storage items
         push.B2AGG_NOTE_NUM_STORAGE_ITEMS assert_eq.err=ERR_B2AGG_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
-        # => [storage_ptr, pad(16)]
+        # => [pad(16)]
 
         # load the 6 B2AGG felts from B2AGG_NOTE_STORAGE_PTR as two words
-        add.4 mem_loadw_le swapw mem_loadw_le.B2AGG_NOTE_STORAGE_PTR
+        push.B2AGG_NOTE_STORAGE_PTR add.4 mem_loadw_le swapw mem_loadw_le.B2AGG_NOTE_STORAGE_PTR
         # => [dest_network, dest_address(5), pad(10)]
 
         # Store note assets -> mem[0..8]
         push.B2AGG_NOTE_ASSETS_PTR exec.active_note::get_assets
-        # => [num_assets, assets_ptr, dest_network, dest_address(5), pad(10)]
+        # => [num_assets, dest_network, dest_address(5), pad(10)]
 
         # Must be exactly 1 asset
         push.B2AGG_NOTE_NUM_ASSETS assert_eq.err=ERR_B2AGG_WRONG_NUMBER_OF_ASSETS
-        # => [assets_ptr, dest_network, dest_address(5), pad(10)]
+        # => [dest_network, dest_address(5), pad(10)]
 
         # Load asset onto the stack from B2AGG_NOTE_ASSETS_PTR
-        exec.asset::load
+        push.B2AGG_NOTE_ASSETS_PTR exec.asset::load
         # => [ASSET_KEY, ASSET_VALUE, dest_network, dest_address(5), pad(10)]
 
         call.bridge_out::bridge_out

crates/miden-agglayer/asm/note_scripts/CLAIM.masm

@@ -85,7 +85,7 @@ begin
     # => [pad(16)]
 
     # Load CLAIM note storage into memory, starting at address 0
-    push.CLAIM_NOTE_STORAGE_PTR exec.active_note::get_storage drop drop
+    push.CLAIM_NOTE_STORAGE_PTR exec.active_note::get_storage drop
     # => [pad(16)]
 
     exec.write_claim_data_into_advice_map_by_key

crates/miden-agglayer/asm/note_scripts/CONFIG_AGG_BRIDGE.masm

@@ -58,10 +58,10 @@ begin
 
     # Load note storage to memory
     push.STORAGE_START_PTR exec.active_note::get_storage
-    # => [num_storage_items, dest_ptr, pad(16)]
+    # => [num_storage_items, pad(16)]
 
     # Validate the number of storage items
-    push.CONFIG_AGG_BRIDGE_NUM_STORAGE_ITEMS assert_eq.err=ERR_CONFIG_AGG_BRIDGE_UNEXPECTED_STORAGE_ITEMS drop
+    push.CONFIG_AGG_BRIDGE_NUM_STORAGE_ITEMS assert_eq.err=ERR_CONFIG_AGG_BRIDGE_UNEXPECTED_STORAGE_ITEMS
     # => [pad(16)]
 
     # Load origin_token_addr(5) and faucet_id from memory

crates/miden-agglayer/asm/note_scripts/UPDATE_GER.masm

@@ -50,10 +50,10 @@ begin
 
     # Load note storage to memory
     push.STORAGE_PTR_GER_LOWER exec.active_note::get_storage
-    # => [num_storage_items, dest_ptr, pad(16)]
+    # => [num_storage_items, pad(16)]
 
     # Validate the number of storage items
-    push.UPDATE_GER_NOTE_NUM_STORAGE_ITEMS assert_eq.err=ERR_UPDATE_GER_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS drop
+    push.UPDATE_GER_NOTE_NUM_STORAGE_ITEMS assert_eq.err=ERR_UPDATE_GER_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
     # => [pad(16)]
 
     # Load GER_LOWER and GER_UPPER from note storage

crates/miden-protocol/asm/kernels/transaction/api.masm

@@ -741,14 +741,11 @@ end
 #! Mint an asset from the faucet the transaction is being executed against.
 #!
 #! Inputs:  [ASSET_KEY, ASSET_VALUE, pad(8)]
-#! Outputs: [NEW_ASSET_VALUE, pad(12)]
+#! Outputs: [pad(16)]
 #!
 #! Where:
 #! - ASSET_KEY is the vault key of the asset to mint.
-#! - ASSET_VALUE is the value of the asset that was minted.
-#! - NEW_ASSET_VALUE is:
-#!   - For fungible assets: the ASSET_VALUE merged with the existing vault asset value, if any.
-#!   - For non-fungible assets: identical to ASSET_VALUE.
+#! - ASSET_VALUE is the value of the asset to mint.
 #!
 #! Panics if:
 #! - the transaction is not being executed against a faucet.
@@ -773,7 +770,7 @@ pub proc faucet_mint_asset
 
     # mint the asset
     exec.faucet::mint
-    # => [NEW_ASSET_VALUE, pad(12)]
+    # => [pad(16)]
 end
 
 #! Burn an asset from the faucet the transaction is being executed against.

crates/miden-protocol/asm/protocol/active_note.masm

@@ -25,7 +25,7 @@ const ERR_NOTE_INVALID_NUMBER_OF_STORAGE_ITEMS="the specified number of note sto
 #! Writes the assets of the active note into memory starting at the specified address.
 #!
 #! Inputs:  [dest_ptr]
-#! Outputs: [num_assets, dest_ptr]
+#! Outputs: [num_assets]
 #!
 #! Where:
 #! - dest_ptr is the memory address to write the assets.
@@ -54,9 +54,13 @@ pub proc get_assets
     swapdw dropw dropw movup.7 movup.7 movup.7 drop drop drop
     # => [ASSETS_COMMITMENT, num_assets, dest_ptr]
 
+    # save num_assets for the return value
+    dup.4 movdn.6
+    # => [ASSETS_COMMITMENT, num_assets, dest_ptr, num_assets]
+
     # write the assets from the advice map into memory
     exec.note::write_assets_to_memory
-    # => [num_assets, dest_ptr]
+    # => [num_assets]
 end
 
 #! Returns the recipient of the active note.
@@ -97,7 +101,7 @@ end
 #!   Stack: [dest_ptr]
 #!   Advice Map: { NOTE_STORAGE_COMMITMENT: [STORAGE] }
 #! Outputs:
-#!   Stack: [num_storage_items, dest_ptr]
+#!   Stack: [num_storage_items]
 #!
 #! Where:
 #! - dest_ptr is the memory address to write the note storage.
@@ -131,6 +135,10 @@ pub proc get_storage
     # write the inputs to the memory using the provided destination pointer
     exec.write_storage_to_memory
     # => [num_storage_items, dest_ptr]
+
+    # drop dest_ptr as it is identical to the input
+    swap drop
+    # => [num_storage_items]
 end
 
 #! Returns the metadata of the active note.

crates/miden-protocol/asm/protocol/faucet.masm

@@ -63,14 +63,11 @@ end
 #! Mint an asset from the faucet the transaction is being executed against.
 #!
 #! Inputs:  [ASSET_KEY, ASSET_VALUE]
-#! Outputs: [NEW_ASSET_VALUE]
+#! Outputs: []
 #!
 #! Where:
 #! - ASSET_KEY is the vault key of the asset to mint.
 #! - ASSET_VALUE is the value of the asset that was minted.
-#! - NEW_ASSET_VALUE is:
-#!   - For fungible assets: the ASSET_VALUE merged with the existing vault asset value, if any.
-#!   - For non-fungible assets: identical to ASSET_VALUE.
 #!
 #! Panics if:
 #! - the transaction is not being executed against a faucet.
@@ -94,8 +91,8 @@ pub proc mint
     # => [ASSET_VALUE, pad(12)]
 
     # clean the stack
-    swapdw dropw dropw swapw dropw
-    # => [ASSET_VALUE]
+    dropw dropw dropw dropw
+    # => []
 end
 
 #! Burn an asset from the faucet the transaction is being executed against.

crates/miden-protocol/asm/protocol/input_note.masm

@@ -65,7 +65,7 @@ end
 #! information about the layout of each asset see the description of the `Asset` Rust type.
 #!
 #! Inputs:  [dest_ptr, note_index]
-#! Outputs: [num_assets, dest_ptr, note_index]
+#! Outputs: [num_assets]
 #!
 #! Where:
 #! - dest_ptr is the memory address to write the assets.
@@ -81,9 +81,16 @@ pub proc get_assets
     dup.1 exec.get_assets_info
     # => [ASSETS_COMMITMENT, num_assets, dest_ptr, note_index]
 
+    # save num_assets for the return value and drop note_index
+    dup.4 movdn.7
+    # => [ASSETS_COMMITMENT, num_assets, dest_ptr, note_index, num_assets]
+
+    movup.6 drop
+    # => [ASSETS_COMMITMENT, num_assets, dest_ptr, num_assets]
+
     # write the assets stored in the advice map to the specified memory pointer
     exec.note::write_assets_to_memory
-    # => [num_assets, dest_ptr, note_index]
+    # => [num_assets]
 end
 
 #! Returns the recipient of the input note with the specified index.

crates/miden-protocol/asm/protocol/note.masm

@@ -54,7 +54,7 @@ end
 #!     ASSETS_COMMITMENT: [[ASSETS_DATA]]
 #!   }
 #! Outputs:
-#!   Operand stack: [num_assets, dest_ptr]
+#!   Operand stack: []
 pub proc write_assets_to_memory
     # load the asset data from the advice map to the advice stack
     adv.push_mapval
@@ -75,6 +75,10 @@ pub proc write_assets_to_memory
     exec.mem::pipe_double_words_preimage_to_memory drop
     # OS => [num_assets, dest_ptr]
     # AS => []
+
+    # drop num_assets and dest_ptr as these are identical to the inputs
+    drop drop
+    # OS => []
 end
 
 #! Builds the recipient hash from note storage, script root, and serial number.

crates/miden-protocol/asm/protocol/output_note.masm

@@ -105,7 +105,7 @@ end
 #! information about the layout of each asset see the description of the `Asset` Rust type.
 #!
 #! Inputs:  [dest_ptr, note_index]
-#! Outputs: [num_assets, dest_ptr, note_index]
+#! Outputs: [num_assets]
 #!
 #! Where:
 #! - dest_ptr is the memory address to write the assets.
@@ -121,9 +121,16 @@ pub proc get_assets
     dup.1 exec.get_assets_info
     # => [ASSETS_COMMITMENT, num_assets, dest_ptr, note_index]
 
+    # save num_assets for the return value and drop note_index
+    dup.4 movdn.7
+    # => [ASSETS_COMMITMENT, num_assets, dest_ptr, note_index, num_assets]
+
+    movup.6 drop
+    # => [ASSETS_COMMITMENT, num_assets, dest_ptr, num_assets]
+
     # write the assets stored in the advice map to the specified memory pointer
     exec.note::write_assets_to_memory
-    # => [num_assets, dest_ptr, note_index]
+    # => [num_assets]
 end
 
 #! Adds the asset to the note specified by the index.

crates/miden-standards/asm/standards/faucets/mod.masm

@@ -145,7 +145,6 @@ pub proc mint_and_send
     # this ensures that the asset's faucet ID matches the native account's ID.
     # this is ensured because create_fungible_asset creates the asset with the native account's ID
     exec.faucet::mint
-    dropw
     # => [ASSET_KEY, ASSET_VALUE, note_idx, note_idx]
 
     # Add the asset to the note.
@@ -179,13 +178,13 @@ pub proc burn
 
     # this will fail if not called from a note context.
     push.ASSET_PTR exec.active_note::get_assets
-    # => [num_assets, dest_ptr, pad(16)]
+    # => [num_assets, pad(16)]
 
     # Verify we have exactly one asset
     assert.err=ERR_BASIC_FUNGIBLE_BURN_WRONG_NUMBER_OF_ASSETS
-    # => [dest_ptr, pad(16)]
+    # => [pad(16)]
 
-    exec.asset::load
+    push.ASSET_PTR exec.asset::load
     # => [ASSET_KEY, ASSET_VALUE, pad(16)]
 
     # Burn the asset from the transaction vault

crates/miden-standards/asm/standards/notes/mint.masm

@@ -65,20 +65,20 @@ pub proc main
     # => [pad(16)]
     # Load note storage into memory starting at address 0
     push.0 exec.active_note::get_storage
-    # => [num_storage_items, storage_ptr, pad(16)]
+    # => [num_storage_items, pad(16)]
 
     dup
-    # => [num_storage_items, num_storage_items, storage_ptr, pad(16)]
+    # => [num_storage_items, num_storage_items, pad(16)]
 
     u32assert2.err=ERR_MINT_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
     u32gte.MINT_NOTE_MIN_NUM_STORAGE_ITEMS_PUBLIC
-    # => [is_public_output_note, num_storage_items, storage_ptr, pad(16)]
+    # => [is_public_output_note, num_storage_items, pad(16)]
 
     if.true
         # public output note creation
-        # => [num_storage_items, storage_ptr, pad(16)]
+        # => [num_storage_items, pad(16)]
 
-        movdn.9 drop
+        movdn.8
         # => [EMPTY_WORD, EMPTY_WORD, num_storage_items, pad(8)]
 
         mem_loadw_le.8
@@ -104,10 +104,7 @@ pub proc main
     else
         # private output note creation
 
-        eq.MINT_NOTE_NUM_STORAGE_ITEMS_PRIVATE assert.err=ERR_MINT_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS drop
-        # => [storage_ptr, pad(16)]
-
-        drop
+        eq.MINT_NOTE_NUM_STORAGE_ITEMS_PRIVATE assert.err=ERR_MINT_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
         # => [pad(16)]
 
         mem_loadw_le.8

crates/miden-standards/asm/standards/notes/p2id.masm

@@ -44,14 +44,13 @@ const TARGET_ACCOUNT_ID_PREFIX_PTR = STORAGE_PTR + 1
 pub proc main
     # store the note storage to memory starting at address 0
     push.STORAGE_PTR exec.active_note::get_storage
-    # => [num_storage_items, storage_ptr]
+    # => [num_storage_items]
 
     # make sure the number of storage items is 2
     eq.2 assert.err=ERR_P2ID_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
-    # => [storage_ptr]
+    # => []
 
     # read the target account ID from the note storage
-    drop
     mem_load.TARGET_ACCOUNT_ID_PREFIX_PTR
     mem_load.TARGET_ACCOUNT_ID_SUFFIX_PTR
     # => [target_account_id_suffix, target_account_id_prefix]

crates/miden-standards/asm/standards/notes/p2ide.masm

@@ -104,14 +104,14 @@ end
 pub proc main
     # store the note storage to memory starting at address 0
     push.0 exec.active_note::get_storage
-    # => [num_storage_items, storage_ptr]
+    # => [num_storage_items]
 
     # make sure the number of storage items is 4
     eq.4 assert.err=ERR_P2IDE_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
-    # => [storage_ptr]
+    # => []
 
     # read the target account ID, reclaim block height, and timelock_block_height from the note storage
-    mem_loadw_le
+    push.0 mem_loadw_le
     # => [target_account_id_suffix, target_account_id_prefix, reclaim_block_height, timelock_block_height]
 
     movup.3

crates/miden-standards/asm/standards/notes/swap.masm

@@ -62,11 +62,10 @@ pub proc main
 
     # store note storage into memory starting at address 0
     push.0 exec.active_note::get_storage
-    # => [num_storage_items, storage_ptr]
+    # => [num_storage_items]
 
     # check number of storage items
     eq.SWAP_NOTE_NUM_STORAGE_ITEMS assert.err=ERR_SWAP_UNEXPECTED_NUMBER_OF_STORAGE_ITEMS
-    drop
     # => []
 
     padw mem_loadw_le.PAYBACK_RECIPIENT_PTR
@@ -107,14 +106,14 @@ pub proc main
 
     # store the number of note assets to memory starting at address ASSET_PTR
     push.ASSET_PTR exec.active_note::get_assets
-    # => [num_assets, asset_ptr, pad(8)]
+    # => [num_assets, pad(8)]
 
     # make sure the number of assets is 1
     assert.err=ERR_SWAP_WRONG_NUMBER_OF_ASSETS
-    # => [asset_ptr, pad(8)]
+    # => [pad(8)]
 
     # load asset
-    exec.asset::load
+    push.ASSET_PTR exec.asset::load
     # => [ASSET_KEY, ASSET_VALUE, pad(8)]
 
     # add the asset to the account

crates/miden-standards/asm/standards/wallets/basic.masm

@@ -75,10 +75,10 @@ pub proc add_assets_to_account
     # we have allocated ASSET_SIZE * MAX_ASSETS_PER_NOTE number of locals so all assets should fit
     # since the asset memory will be overwritten, we don't have to initialize the locals to zero
     locaddr.0 exec.active_note::get_assets
-    # => [num_of_assets, ptr = 0]
+    # => [num_of_assets]
 
     # compute the pointer at which we should stop iterating
-    mul.ASSET_SIZE dup.1 add
+    mul.ASSET_SIZE locaddr.0 dup movdn.2 add
     # => [end_ptr, ptr]
 
     # pad the stack and move the pointer to the top