Update extensions.md (#874)

Co-authored-by: MexicanAce <[email protected]>

docs/zk-stack/components/compiler/specification/instructions/extensions.md

@@ -30,7 +30,7 @@ For some simulations below we assume that there exist a hidden global pseudo-var
 | to_l1(is_first, in0, in1                                                    | if_first (bool)    | 0xFFFF                 | in0 (u256)                                            | in1 (u256)                  | 0xFFFF to prevent optimizing out by Yul   | 0                            | 0                            | \_                                                                                                                       | call                                        | @llvm.syncvm.tol1(i256 %in0, i256 %in1, i256 %is_first)                                                                   | Send messages to L1                                                                                |
 | code_source                                                                 | 0                  | 0xFFFE                 | -                                                     | 0                           | 0xFFFF to prevent optimizing out by Yul   | 0                            | 0                            | address                                                                                                                  | staticcall                                  | @llvm.syncvm.context(i256 %param) ; param == 2 (see SyncVM.h)                                                             | Largely to be able to catch “delegatecalls” in system contracts (by comparing this == code_source) |
 | precompile(in0, ergs_to_burn, out0)                                         | in0 (u256)         | 0xFFFD                 | -                                                     | ergs_to_burn (u32)          | 0xFFFF to prevent optimizing out by Yul   | 0                            | 0                            | out0                                                                                                                     | staticcall                                  | @llvm.syncvm.precompile(i256 %in0, i256 %ergs)                                                                            | way to trigger call to precompile in VM                                                            |
-| meta                                                                        | 0                  | 0xFFFC                 | -                                                     | 0                           | 0xFFFF to prevent optimizing out by Yul   | 0                            | 0                            | [u256 tight packing](https://github.com/matter-labs/era-zkevm_opcode_defs/src/definitions/abi/meta.rs)                   | staticcall                                  | @llvm.syncvm.context(i256 %param) ; param == 3 (see SyncVM.h)                                                             | way to trigger call to meta information about some small pieces of the state in VM                 |
+| meta                                                                        | 0                  | 0xFFFC                 | -                                                     | 0                           | 0xFFFF to prevent optimizing out by Yul   | 0                            | 0                            | [u256 tight packing](https://github.com/matter-labs/era-zkevm_opcode_defs/blob/v1.4.1/src/definitions/abi/meta.rs)       | staticcall                                  | @llvm.syncvm.context(i256 %param) ; param == 3 (see SyncVM.h)                                                             | way to trigger call to meta information about some small pieces of the state in VM                 |
 | mimic_call(to, abi_data, implicit r5 = who to mimic)                        | who_to_call        | 0xFFFB                 | 0                                                     | abi_data                    | who_to_mimic                              | 0                            | 0                            | WILL mess up the registers and WILL use r1-r4 for our standard ABI convention and r5 for the extra who_to_mimic argument | any in the code; mimic call in the bytecode | Runtime*{i256, i1} \_\_mimiccall(i256, i256, i256, *{i256, i1})                                                           |                                                                                                    |
 | system_mimic_call(to, abi_data, implicit r3, r4, r5 = who to mimic)         | who_to_call        | 0xFFFA                 | 0                                                     | abi_data                    | who_to_mimic                              | value_to_put_into_r3         | value_to_put_into_r4         | WILL mess up the registers and WILL use r1-r4 for our standard ABI convention and r5 for the extra who_to_mimic argument | any in the code; mimic call in the bytecode | Runtime _{i256, i1} \_\_mimiccall(i256, i256, i256,_{i256, i1})                                                           |                                                                                                    |
 | mimic_call_byref(to, ACTIVE_PTR, implicit r5 = who to mimic)                | who_to_call        | 0xFFF9                 | 0                                                     | 0                           | who_to_mimic                              | 0                            | 0                            | WILL mess up the registers and WILL use r1-r4 for our standard ABI convention and r5 for the extra who_to_mimic argument | any in the code; mimic call in the bytecode | Runtime *{i256, i1} \_\_mimiccall(*i8 addrspace(3), i256, i256, \*{i256, i1})                                             | Same as one above, but takes ABI data from ACTIVE_PTR                                              |