Concrete
WebsiteLibrariesProducts & ServicesDevelopersSupport
2.10
2.10
  • Welcome
  • Get Started
    • What is Concrete?
    • Installation
    • Quick start
    • Quick overview
    • Terminology
  • Operations
    • Table Lookups basics
    • Non-linear operations
    • Other operations
      • Bit extraction
      • Common tips
      • Extensions
  • Compilation
    • Combining compiled functions
      • With composition
      • With modules
    • Key-related options for faster execution
      • Multi precision
      • Multi parameters
    • Compression
    • Reusing arguments
    • Parameter compatibility with restrictions
    • Common errors
  • Execution / Analysis
    • Simulation
    • Debugging and artifact
    • Performance
    • GPU acceleration
    • Other
      • Statistics
      • Progressbar
      • Formatting and drawing
  • Guides
    • Configure
    • Manage keys
    • Deploy
    • TFHE-rs Interoperability
      • Shared key
      • Serialization
    • Optimization
      • Improve parallelism
        • Dataflow parallelism
        • Tensorizing operations
      • Optimize table lookups
        • Reducing TLU
        • Implementation strategies
        • Round/truncating
        • Approximate mode
        • Bit extraction
      • Optimize cryptographic parameters
        • Error probability
        • Composition
  • Tutorials
    • See all tutorials
    • Part I: Concrete - FHE compiler
    • Part II: The Architecture of Concrete
  • References
    • API
    • Supported operations
  • Explanations
    • Compiler workflow
    • Advanced features
      • Table Lookups advanced
      • Rounding
      • Truncating
      • Floating points
      • Comparisons
      • Min/Max operations
      • Bitwise operations
      • Direct circuits
      • Tagging
    • Cryptography basics
    • Security
    • Frontend fusing
  • Developers
    • Contributing
      • Project layout
      • Compiler backend
        • Adding a new backend
      • Optimizer
      • MLIR FHE dialects
        • FHELinalg dialect
        • FHE dialect
        • TFHE dialect
        • Concrete dialect
        • Tracing dialect
        • Runtime dialect
        • SDFG dialect
      • Call FHE circuits from other languages
      • Benchmarking
      • Examples
      • Making a release
    • Release note
    • Feature request
    • Bug report
Powered by GitBook

Libraries

  • TFHE-rs
  • Concrete
  • Concrete ML
  • fhEVM

Developers

  • Blog
  • Documentation
  • Github
  • FHE resources

Company

  • About
  • Introduction to FHE
  • Media
  • Careers
On this page

Was this helpful?

Export as PDF
  1. Guides
  2. Optimization
  3. Optimize table lookups

Round/truncating

PreviousImplementation strategiesNextApproximate mode

Last updated 1 month ago

Was this helpful?

This guide teaches how to improve the execution time of Concrete circuits by using some special operations that reduce the bit width of the input of the table lookup.

There are two extensions which can reduce the bit width of the table lookup input, and , which can improve performance by sacrificing exactness.

For example the following code:

import numpy as np
from concrete import fhe

inputset = fhe.inputset(fhe.uint10)
for lsbs_to_remove in range(0, 10):
    def f(x):
        return fhe.round_bit_pattern(x, lsbs_to_remove) // 2

    compiler = fhe.Compiler(f, {"x": "encrypted"})
    circuit = compiler.compile(inputset)

    print(f"{lsbs_to_remove=} -> {int(circuit.complexity):>13_} complexity")

prints:

lsbs_to_remove=0 -> 9_134_406_574 complexity
lsbs_to_remove=1 -> 3_209_430_092 complexity
lsbs_to_remove=2 -> 1_536_476_735 complexity
lsbs_to_remove=3 -> 1_588_749_586 complexity
lsbs_to_remove=4 ->   848_133_081 complexity
lsbs_to_remove=5 ->   525_987_801 complexity
lsbs_to_remove=6 ->   358_276_023 complexity
lsbs_to_remove=7 ->   373_311_341 complexity
lsbs_to_remove=8 ->   400_596_351 complexity
lsbs_to_remove=9 ->   438_681_996 complexity
fhe.round_bit_pattern(...)
fhe.truncate_bit_pattern(...)