mirror of
https://github.com/ProvableHQ/leo.git
synced 2024-11-23 23:23:50 +03:00
27 lines
1.2 KiB
Markdown
27 lines
1.2 KiB
Markdown
# FAQs
|
|
|
|
#### For some given code, changing the value in a constant variable changes the number of constraints in the generated circuit. Is this behavior correct?
|
|
|
|
**Yes**, take the integers as an example. In Leo, integers are represented as its binary decomposition,
|
|
with each bit occupying one field element (that takes on 0 or 1). Then, for an expression such as `a == 4u32`, the operation to evaluate equality
|
|
would comprise a linear pass of bitwise `AND` operations, comparing every bit in the **variable** value with each bit in the **constant** value.
|
|
|
|
As the constant value is already known to the compiler during circuit synthesis, the compiler is already able to complete part of the equality evaluation,
|
|
by assuming that any bit in the constant value that is `0` will clearly evaluate to `0`. As such, depending on the value of the constant integer in your code,
|
|
the total number of constraints in the generate circuit can vary.
|
|
|
|
To illustrate this, here are two examples to show the difference:
|
|
```
|
|
const = 00000001
|
|
variable = abcdefgh
|
|
---------------------------------
|
|
output = 0000000h (1 constraint)
|
|
```
|
|
|
|
```
|
|
const = 01110001
|
|
variable = abcdefgh
|
|
---------------------------------
|
|
output = 0bcd000h (4 constraints)
|
|
```
|