[WIP] SIMD-170: Reserve lower default CU limits for builtin instructions

src/ballet/pack/fd_compute_budget_program.h

@@ -41,6 +41,9 @@ static const uchar FD_COMPUTE_BUDGET_PROGRAM_ID[FD_TXN_ACCT_ADDR_SZ] = {
    10^(-6) lamports, so 10^(-15) SOL. */
 #define FD_COMPUTE_BUDGET_MICRO_LAMPORTS_PER_LAMPORT     (1000000UL)
 
+/* Corresponds to Agave's MAX_BUILTIN_ALLOCATION_COMPUTE_UNIT_LIMIT, which
+   uses a distinct maximum compute unit limit for builtin instructions. */
+#define FD_MAX_BUILTIN_ALLOCATION_COMPUTE_UNIT_LIMIT     (   3000UL)
 #define FD_COMPUTE_BUDGET_DEFAULT_INSTR_CU_LIMIT         ( 200000UL)
 #define FD_COMPUTE_BUDGET_MAX_CU_LIMIT                   (1400000UL)
 
@@ -149,16 +152,23 @@ fd_compute_budget_program_parse( uchar const * instr_data,
    the per-signature fee) is stored in out_rewards.  The maximum number of
    compute units this transaction can consume is stored in out_compute.  If the
    transaction execution has not completed by this limit, it is terminated and
-   considered failed. */
+   considered failed.
+
+   instr_cnt         - number of non-builtin instructions in the transaction
+   builtin_instr_cnt - number of builtin instructions in the transaction */
 static inline void
 fd_compute_budget_program_finalize( fd_compute_budget_program_state_t const * state,
                                     ulong                                     instr_cnt,
+                                    ulong                                     builtin_instr_cnt,
                                     ulong *                                   out_rewards,
                                     uint *                                    out_compute ) {
   ulong cu_limit = 0UL;
   if( FD_LIKELY( (state->flags & FD_COMPUTE_BUDGET_PROGRAM_FLAG_SET_CU)==0U ) ) {
     /* Use default compute limit */
-    cu_limit = (instr_cnt - state->compute_budget_instr_cnt) * FD_COMPUTE_BUDGET_DEFAULT_INSTR_CU_LIMIT;
+    cu_limit = instr_cnt * FD_COMPUTE_BUDGET_DEFAULT_INSTR_CU_LIMIT;
+
+    /* SIMD-170: Use a different default CU limit for builtin instructions */
+    cu_limit += (builtin_instr_cnt - state->compute_budget_instr_cnt ) * FD_MAX_BUILTIN_ALLOCATION_COMPUTE_UNIT_LIMIT;
   } else cu_limit = state->compute_units;
 
   cu_limit = fd_ulong_min( cu_limit, FD_COMPUTE_BUDGET_MAX_CU_LIMIT );

src/ballet/pack/fd_pack_cost.h

@@ -195,7 +195,7 @@ fd_pack_compute_cost( fd_txn_t const * txn,
 
   ulong fee[1];
   uint compute[1];
-  fd_compute_budget_program_finalize( cbp, txn->instr_cnt, fee, compute );
+  fd_compute_budget_program_finalize( cbp, non_builtin_cnt, txn->instr_cnt - non_builtin_cnt, fee, compute );
 
   non_builtin_cnt = fd_ulong_min( non_builtin_cnt, FD_COMPUTE_BUDGET_MAX_CU_LIMIT/FD_COMPUTE_BUDGET_DEFAULT_INSTR_CU_LIMIT );
 

src/ballet/pack/test_compute_budget_program.c

@@ -21,14 +21,16 @@ test_txn( uchar const * payload,
   fd_compute_budget_program_state_t state;
   fd_compute_budget_program_init( &state );
   uchar const * addresses = payload + txn->acct_addr_off;
+  ulong builtin_instr_cnt = 0UL;
   for( ulong i=0UL; i<txn->instr_cnt; i++ ) {
     if( !memcmp( addresses+FD_TXN_ACCT_ADDR_SZ*txn->instr[ i ].program_id, FD_COMPUTE_BUDGET_PROGRAM_ID, FD_TXN_ACCT_ADDR_SZ ) ) {
+      builtin_instr_cnt += 1UL;
       FD_TEST( fd_compute_budget_program_parse( payload+txn->instr[ i ].data_off, txn->instr[ i ].data_sz, &state ) );
     }
   }
   ulong rewards = 0UL;
   uint  compute = 0U;
-  fd_compute_budget_program_finalize( &state, txn->instr_cnt, &rewards, &compute );
+  fd_compute_budget_program_finalize( &state, txn->instr_cnt - builtin_instr_cnt, builtin_instr_cnt, &rewards, &compute );
   FD_TEST( rewards==expected_fee_lamports );
   FD_TEST( (ulong)compute==expected_max_cu );
 }

src/ballet/pack/test_pack.c

@@ -242,7 +242,7 @@ schedule_validate_microblock( fd_pack_t * pack,
       FD_TEST( fd_compute_budget_program_parse( txnp->payload + ix.data_off, ix.data_sz, &cbp ) );
       ix = txn->instr[1];
       FD_TEST( fd_compute_budget_program_parse( txnp->payload + ix.data_off, ix.data_sz, &cbp ) );
-      fd_compute_budget_program_finalize( &cbp, txn->instr_cnt, &rewards, &compute );
+      fd_compute_budget_program_finalize( &cbp, txn->instr_cnt - 2, 2, &rewards, &compute );
     } /* else it's a vote */
 
     total_rewards += rewards;

src/flamenco/runtime/tests/fd_pack_test.c

@@ -40,6 +40,7 @@ do {
   ulong rewards;
   uint compute_unit_limit;
   fd_compute_budget_program_finalize( cbp,
+                                      0UL,
                                       input->instr_datas_count,
                                       &rewards,
                                       &compute_unit_limit