Bitblast Transformation: Turning Code into Pure Boolean Logic

Our Code Transformation series continues! After covering Loop Unrolling, Loop Interchange, and Procedure Inline, we’re now looking at a transformation used in formal verification and dependency analysis: Bitblast Transformation.

What is Bitblast Transformation?
Bitblasting converts operations on word-level data types (e.g., 32-bit integers) into equivalent bitwise logic. Instead of treating a variable as a whole, each bit is handled separately, allowing Boolean satisfiability solvers (SAT solvers) to process them more efficiently.

Why use Bitblast?

• Essential for formal verification (e.g., hardware/software verification)
• Enables further compiler optimizations, such as constant propagation and dead code elimination
• Enables deep analysis of bit-level dependencies
• Transforms arithmetic operations into pure Boolean logic

⚠️ While bitblasting allows for precise bitwise analysis, it significantly increases the number of variables, making it computationally expensive for large bitvectors.

Example:
An addition of two 8-bit integers is transformed into individual bit operations using Boolean logic.
Instead of result = x + y; each bit operation is explicitly represented and computed.

Already posted articles:

• Loop Unrolling
• Loop Interchange