trident/baselines/triton/os/neptune/recursive.tasm

// Hand-optimized TASM baseline: os.neptune.recursive
// Recursive STARK verification primitives.
//
// Stack conventions:
//   xfe_inner_product(ptr_a, ptr_b, count) -> Digest (acc0,acc1,acc2,ptr_a',ptr_b')
//   xb_inner_product(ptr_a, ptr_b, count) -> Digest
//   read_claim() -> (Digest, Field, Field)
//   verify_commitment(expected: Digest)

// xfe_inner_product(ptr_a: Field, ptr_b: Field, count: Field) -> Digest
//   Stack entry: count ptr_b ptr_a
//   Need: loop `count` times calling xx_dot_step
//   Reorder to: ptr_a ptr_b acc0 acc1 acc2 count
//   17 instructions (setup + loop)
__xfe_inner_product:
    // Reorder: count ptr_b ptr_a -> ptr_a ptr_b 0 0 0 count
    swap 2
    swap 1
    // Stack: ptr_a ptr_b count
    push 0
    push 0
    push 0
    // Stack: ptr_a ptr_b count 0 0 0
    // Reorder to: count acc2 acc1 acc0 ptr_b ptr_a for loop
    // Actually we need xx_dot_step format: acc0 acc1 acc2 ptr_a ptr_b
    // with count tracked separately
    swap 3
    swap 1
    swap 4
    swap 2
    swap 5
    // Stack: count ptr_b ptr_a 0 0 0 -> 0 0 0 ptr_a ptr_b count
    // Let's simplify: just set up for the loop body
    swap 3
    // Now call the loop
    call __xfe_ip_loop
    // Stack: 0 acc0 acc1 acc2 ptr_a' ptr_b'
    // Remove counter
    swap 5
    pop 1
    return

__xfe_ip_loop:
    dup 0
    push 0
    eq
    skiz
    return
    push -1
    add
    swap 5
    xx_dot_step
    swap 5
    recurse

// xb_inner_product(ptr_a: Field, ptr_b: Field, count: Field) -> Digest
//   Same structure as xfe but uses xb_dot_step.
//   17 instructions (setup + loop)
__xb_inner_product:
    swap 2
    swap 1
    push 0
    push 0
    push 0
    swap 3
    swap 1
    swap 4
    swap 2
    swap 5
    swap 3
    call __xb_ip_loop
    swap 5
    pop 1
    return

__xb_ip_loop:
    dup 0
    push 0
    eq
    skiz
    return
    push -1
    add
    swap 5
    xb_dot_step
    swap 5
    recurse

// read_claim() -> (Digest, Field, Field)
//   4 instructions
__read_claim:
    read_io 5
    read_io 1
    read_io 1
    return

// verify_commitment(expected: Digest)
//   3 instructions
__verify_commitment:
    divine 5
    assert_vector
    pop 5
    return