Implement hint from get_felt_bitlength (Garaga)

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 #### Upcoming Changes
 
+* Implement hint on `get_felt_bitlength` [#993](https://github.com/lambdaclass/cairo-rs/pull/993)
+
+  `BuiltinHintProcessor` now supports the following hint:
+  ```python
+  x = ids.x
+  ids.bit_length = x.bit_length()
+  ```
+  Used by the [`Garaga` library function `get_felt_bitlength`](https://github.com/keep-starknet-strange/garaga/blob/249f8a372126b3a839f9c1e1080ea8c6f9374c0c/src/utils.cairo#L54)
+
 * Add missing hint on cairo_secp lib [#1008](https://github.com/lambdaclass/cairo-rs/pull/1008):
 
     `BuiltinHintProcessor` now supports the following hint:

cairo_programs/garaga.cairo

@@ -0,0 +1,344 @@
+%builtins range_check bitwise
+
+from starkware.cairo.common.uint256 import (
+    Uint256,
+    uint256_reverse_endian,
+    uint256_unsigned_div_rem,
+    uint256_mul,
+    uint256_add,
+    uint256_pow2,
+)
+
+from starkware.cairo.common.cairo_builtins import BitwiseBuiltin
+from starkware.cairo.common.registers import get_label_location
+from starkware.cairo.common.math import unsigned_div_rem as felt_divmod, split_felt
+from starkware.cairo.common.math_cmp import is_le
+from starkware.cairo.common.alloc import alloc
+from starkware.cairo.common.pow import pow
+
+// y MUST be a power of 2
+func bitwise_divmod{range_check_ptr, bitwise_ptr: BitwiseBuiltin*}(x: felt, y: felt) -> (
+    q: felt, r: felt
+) {
+    assert bitwise_ptr.x = x;
+    assert bitwise_ptr.y = y - 1;
+    let x_and_y = bitwise_ptr.x_and_y;
+
+    let bitwise_ptr = bitwise_ptr + BitwiseBuiltin.SIZE;
+    return (q=(x - x_and_y) / y, r=x_and_y);
+}
+func felt_divmod_no_input_check{range_check_ptr}(value, div) -> (q: felt, r: felt) {
+    // let r = [range_check_ptr];
+    // let q = [range_check_ptr + 1];
+    // let range_check_ptr = range_check_ptr + 2;
+    alloc_locals;
+    local r;
+    local q;
+    %{
+        from starkware.cairo.common.math_utils import assert_integer
+        assert_integer(ids.div)
+        assert 0 < ids.div <= PRIME // range_check_builtin.bound, \
+            f'div={hex(ids.div)} is out of the valid range.'
+        ids.q, ids.r = divmod(ids.value, ids.div)
+    %}
+
+    assert [range_check_ptr] = div - 1 - r;
+    let range_check_ptr = range_check_ptr + 1;
+    // assert_le(r, div - 1);
+
+    assert value = q * div + r;
+    return (q, r);
+}
+
+func get_felt_bitlength{range_check_ptr, bitwise_ptr: BitwiseBuiltin*}(x: felt) -> felt {
+    alloc_locals;
+    local bit_length;
+    %{
+        x = ids.x
+        ids.bit_length = x.bit_length()
+    %}
+
+    // Next two lines Not necessary : will fail if pow2(bit_length) is too big, unknown cell.
+    // let le = is_le(bit_length, 252);
+    // assert le = 1;
+    assert bitwise_ptr[0].x = x;
+    let n = pow2(bit_length);
+    assert bitwise_ptr[0].y = n - 1;
+    tempvar word = bitwise_ptr[0].x_and_y;
+    assert word = x;
+
+    assert bitwise_ptr[1].x = x;
+
+    let n = pow2(bit_length - 1);
+
+    assert bitwise_ptr[1].y = n - 1;
+    tempvar word = bitwise_ptr[1].x_and_y;
+    assert word = x - n;
+
+    let bitwise_ptr = bitwise_ptr + 2 * BitwiseBuiltin.SIZE;
+    return bit_length;
+}
+
+func pow2(i) -> felt {
+    let (data_address) = get_label_location(data);
+    return [data_address + i];
+
+    data:
+    dw 0x1;
+    dw 0x2;
+    dw 0x4;
+    dw 0x8;
+    dw 0x10;
+    dw 0x20;
+    dw 0x40;
+    dw 0x80;
+    dw 0x100;
+    dw 0x200;
+    dw 0x400;
+    dw 0x800;
+    dw 0x1000;
+    dw 0x2000;
+    dw 0x4000;
+    dw 0x8000;
+    dw 0x10000;
+    dw 0x20000;
+    dw 0x40000;
+    dw 0x80000;
+    dw 0x100000;
+    dw 0x200000;
+    dw 0x400000;
+    dw 0x800000;
+    dw 0x1000000;
+    dw 0x2000000;
+    dw 0x4000000;
+    dw 0x8000000;
+    dw 0x10000000;
+    dw 0x20000000;
+    dw 0x40000000;
+    dw 0x80000000;
+    dw 0x100000000;
+    dw 0x200000000;
+    dw 0x400000000;
+    dw 0x800000000;
+    dw 0x1000000000;
+    dw 0x2000000000;
+    dw 0x4000000000;
+    dw 0x8000000000;
+    dw 0x10000000000;
+    dw 0x20000000000;
+    dw 0x40000000000;
+    dw 0x80000000000;
+    dw 0x100000000000;
+    dw 0x200000000000;
+    dw 0x400000000000;
+    dw 0x800000000000;
+    dw 0x1000000000000;
+    dw 0x2000000000000;
+    dw 0x4000000000000;
+    dw 0x8000000000000;
+    dw 0x10000000000000;
+    dw 0x20000000000000;
+    dw 0x40000000000000;
+    dw 0x80000000000000;
+    dw 0x100000000000000;
+    dw 0x200000000000000;
+    dw 0x400000000000000;
+    dw 0x800000000000000;
+    dw 0x1000000000000000;
+    dw 0x2000000000000000;
+    dw 0x4000000000000000;
+    dw 0x8000000000000000;
+    dw 0x10000000000000000;
+    dw 0x20000000000000000;
+    dw 0x40000000000000000;
+    dw 0x80000000000000000;
+    dw 0x100000000000000000;
+    dw 0x200000000000000000;
+    dw 0x400000000000000000;
+    dw 0x800000000000000000;
+    dw 0x1000000000000000000;
+    dw 0x2000000000000000000;
+    dw 0x4000000000000000000;
+    dw 0x8000000000000000000;
+    dw 0x10000000000000000000;
+    dw 0x20000000000000000000;
+    dw 0x40000000000000000000;
+    dw 0x80000000000000000000;
+    dw 0x100000000000000000000;
+    dw 0x200000000000000000000;
+    dw 0x400000000000000000000;
+    dw 0x800000000000000000000;
+    dw 0x1000000000000000000000;
+    dw 0x2000000000000000000000;
+    dw 0x4000000000000000000000;
+    dw 0x8000000000000000000000;
+    dw 0x10000000000000000000000;
+    dw 0x20000000000000000000000;
+    dw 0x40000000000000000000000;
+    dw 0x80000000000000000000000;
+    dw 0x100000000000000000000000;
+    dw 0x200000000000000000000000;
+    dw 0x400000000000000000000000;
+    dw 0x800000000000000000000000;
+    dw 0x1000000000000000000000000;
+    dw 0x2000000000000000000000000;
+    dw 0x4000000000000000000000000;
+    dw 0x8000000000000000000000000;
+    dw 0x10000000000000000000000000;
+    dw 0x20000000000000000000000000;
+    dw 0x40000000000000000000000000;
+    dw 0x80000000000000000000000000;
+    dw 0x100000000000000000000000000;
+    dw 0x200000000000000000000000000;
+    dw 0x400000000000000000000000000;
+    dw 0x800000000000000000000000000;
+    dw 0x1000000000000000000000000000;
+    dw 0x2000000000000000000000000000;
+    dw 0x4000000000000000000000000000;
+    dw 0x8000000000000000000000000000;
+    dw 0x10000000000000000000000000000;
+    dw 0x20000000000000000000000000000;
+    dw 0x40000000000000000000000000000;
+    dw 0x80000000000000000000000000000;
+    dw 0x100000000000000000000000000000;
+    dw 0x200000000000000000000000000000;
+    dw 0x400000000000000000000000000000;
+    dw 0x800000000000000000000000000000;
+    dw 0x1000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000000000000000;
+    dw 0x800000000000000000000000000000000000000000000000000000000000;
+    dw 0x1000000000000000000000000000000000000000000000000000000000000;
+    dw 0x2000000000000000000000000000000000000000000000000000000000000;
+    dw 0x4000000000000000000000000000000000000000000000000000000000000;
+    dw 0x8000000000000000000000000000000000000000000000000000000000000;
+    dw 0x10000000000000000000000000000000000000000000000000000000000000;
+    dw 0x20000000000000000000000000000000000000000000000000000000000000;
+    dw 0x40000000000000000000000000000000000000000000000000000000000000;
+    dw 0x80000000000000000000000000000000000000000000000000000000000000;
+    dw 0x100000000000000000000000000000000000000000000000000000000000000;
+    dw 0x200000000000000000000000000000000000000000000000000000000000000;
+    dw 0x400000000000000000000000000000000000000000000000000000000000000;
+}
+
+func main{range_check_ptr: felt, bitwise_ptr: BitwiseBuiltin*}() {
+    let x = get_felt_bitlength(42);
+    assert x = 6;
+    return ();
+}

src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs

@@ -80,6 +80,8 @@ use felt::Felt252;
 #[cfg(feature = "skip_next_instruction_hint")]
 use crate::hint_processor::builtin_hint_processor::skip_next_instruction::skip_next_instruction;
 
+use super::garaga::get_felt_bitlenght;
+
 pub struct HintProcessorData {
     pub code: String,
     pub ap_tracking: ApTracking,
@@ -367,6 +369,9 @@ impl HintProcessor for BuiltinHintProcessor {
                 &hint_data.ids_data,
                 &hint_data.ap_tracking,
             ),
+            hint_code::GET_FELT_BIT_LENGTH => {
+                get_felt_bitlenght(vm, &hint_data.ids_data, &hint_data.ap_tracking)
+            }
             hint_code::DIV_MOD_N_PACKED_DIVMOD_EXTERNAL_N => div_mod_n_packed_external_n(
                 vm,
                 exec_scopes,