Intel® High Level Synthesis Compiler


The Intel® HLS Compiler is a high-level synthesis (HLS) tool that takes in untimed C++ as input and generates production-quality register transfer level (RTL) code that is optimized for Intel® FPGAs. This tool accelerates verification time over RTL by raising the abstraction level for FPGA hardware design. Models developed in C++ are typically verified orders of magnitude faster than RTL.

Intel® HLS Compiler is included in the Intel® Quartus® Prime Design Software installation.

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HLS Compiler Success Story

Horizon Robotics is partnering with Intel to develop embedded AI applications. Learn how Horizon Robotics is using the Intel® Arria® 10 FPGA and Intel® HLS Compiler to do real-time pixel level segmentation for 3D semantic modelling and localization.


The v19.3 release of the Intel® HLS Compiler for Intel® Quartus® Prime Design Software provides various capabilities to enable hardware programmers to use C++ for accelerating their FPGA development process.

  • Uses untimed ANSI C++ as the golden design source
  • Allows you to quickly explore multiple architectures through high-level directives
  • Simplifies tool usage by inferring design intent from high-level constraints
  • Supports verification of RTL by comparison with the original C++ source model
  • Generates reusable intellectual property (IP) for system integration using the Platform Designer (formerly Qsys)
  • Supports inference of streaming, memory mapped, or wire interfaces
  • Performs device-specific timing-driven schedule optimization and technology mapping for Intel® FPGAs
  • Supports a software compiler use model and industry standards including ac_int data types
  • Detailed reporting feature for a birds-eye view: high-level design HTML reports are automatically generated during the simulation stage lets users see bottlenecks in their design
  • Allows users to view and analyze: area utilization, loop structure, memory usage, system data flow, clusters and surrounding logic
  • Supports multiple flows to integrate IP in a system. Integrate HLS code through direct HLD instantiation, through Platform Designer, or onto an Intel® Programmable Acceleration Card (Intel® PAC)

What's New in 19.3

Performance Gains

Extract the highest performance from your design with v19.3 which includes new pragmas and attributes that provide you with even more control over the performance of your Intel® HLS Compiler design. Enhanced reporting features provide further guidance in getting even closer to peak RTL performance of your design. To learn more, check out this video on the new QoR features.

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Documentation and Support

Find technical documentation, videos, and training courses for Intel® HLS Compiler.