Intel High Level Synthesis Compiler Pro Edition: Version 19.4 Release Notes
Version Information
| Updated for: |
|---|
| Intel® Quartus® Prime Design Suite 19.4 |
1. Intel High Level Synthesis Compiler Pro Edition Version 19.4 Release Notes
The Intel® High Level Synthesis Compiler Pro Edition Release Notes provide late-breaking information about the Intel® High Level Synthesis Compiler Pro Edition Version 19.4.
For the most recent Standard Edition release notes, see the Intel® High Level Synthesis Compiler Standard Edition Release Notes .
About the Intel® HLS Compiler Documentation Library
| Title and Description | ||
|---|---|---|
|
Release
Notes
Provide late-breaking information about the Intel® HLS Compiler. |
Link | Link |
|
Getting Started
Guide
Get up and running with the Intel® HLS Compiler by learning how to initialize your compiler environment and reviewing the various design examples and tutorials provided with the Intel® HLS Compiler. |
Link | Link |
|
User Guide
Provides instructions on synthesizing, verifying, and simulating intellectual property (IP) that you design for Intel FPGA products. Go through the entire development flow of your component from creating your component and testbench up to integrating your component IP into a larger system with the Intel Quartus Prime software. |
Link | Link |
|
Reference
Manual
Provides reference information about the features supported by the Intel HLS Compiler. Find details on Intel® HLS Compiler command options, header files, pragmas, attributes, macros, declarations, arguments, and template libraries. |
Link | Link |
|
Best Practices
Guide
Provides techniques and practices that you can apply to improve the FPGA area utilization and performance of your HLS component. Typically, you apply these best practices after you verify the functional correctness of your component. |
Link | Link |
|
Quick
Reference
Provides a brief summary of Intel HLS Compiler declarations and attributes on a single two-sided page. |
Link | Link |
1.1. New Features and Enhancements
- Added the ihc::launch_always_run System of Tasks API to launch a task function at component power-on or reset and continuously execute the function.
- Added the --daz command option to disable subnormal support in double-precision floating-point computations
- Added the --rounding command option to control the rounding scheme used for double-precision adders, multipliers, and dividers.
Changes in Software Support
- The Intel® High Level Synthesis Compiler documentation library has been split into separate libraries for Pro Edition and Standard Edition. For details, see About the Intel HLS Compiler Documentation Library.
1.2. Intel High Level Synthesis Compiler Pro Edition Prerequisites
For detailed instructions about installing Intel® Quartus® Prime software, including system requirements, prerequisites, and licensing requirements, see Intel® FPGA Software Installation and Licensing .
The Intel® HLS Compiler requires the following software in addition to Intel® Quartus® Prime:
C++ Compiler
-
You must install these libraries manually. See Installing the Intel® HLS Compiler on Linux Systems for instructions.
- Microsoft Visual Studio 2017 Professional
- Microsoft Visual Studio 2017 Community
Mentor Graphics* ModelSim* Software
- ModelSim* - Intel® FPGA Edition
- ModelSim* - Intel® FPGA Starter Edition
On RedHat Linux systems, ModelSim* software requires the Red Hat development tools packages. Additionally, any 32-bit versions of ModelSim* software (including those provided with Intel® Quartus® Prime) require additional 32-bit libraries. The commands to install these requirements are provided in Installing the Intel® HLS Compiler on Linux Systems.
On SUSE Linux systems, you must use your own licensed version of Mentor Graphics* ModelSim* software.
For information about all the ModelSim* software versions that the Intel® software supports, refer to the EDA Interface Information section in the Software and Device Support Release Notes for your edition of Intel® Quartus® Prime
1.3. Known Issues and Workarounds
This section provides information about known issues that affect the Intel® HLS Compiler Pro Edition Version 19.4.
| Description | Workaround |
|---|---|
|
(Windows only) Compiling a design in a directory with a long path name can result in compile failures. |
Compile the design in a directory with a short path name. |
| (Windows only) A long path for your Intel® Quartus® Prime installation directory can prevent you from successfully compiling and running the Intel® HLS Compiler tutorials and example designs. | Move the tutorials and examples to a short path name before trying to run them. |
| When you use the -c command option to have separate compilation and linking stages in your workflow, and if you do not specify the -march option in the linking stage (or specify a different -march option value), your linking stage might fail with or without error messages. | Ensure that you use the same -march option value for both the compilation with the -c command option stage and the linking stage. |
| Applying the hls_merge memory attribute to an array declared within an unrolled or partially unrolled loop creates an unexpectedly wide memory. | Avoid using the hls_merge memory attribute in unrolled
loops. If you need to merge memories in an unrolled loop, explicitly declare an array of struct type. |
| Slave memories cannot be implemented as MLABs. They can be implemented only as M20K blocks. | N/A |
| In the Function Memory Viewer high-level design report, some function-scoped memories might appear as "optimized away". | None. When a file contains functions that are components and functions that are not components, all function-scoped variables are listed in the Function Memory List pane, but only variables from components have information about them to show in the Function Memory View pane. |
|
When developing a library, if you have a
#define defining a value that
you use later in a #pragma, the
fpga_crossgen command fails. For example, the following code cannot be
compiled by the fpga_crossgen
command:
#define unroll_factor 5
int foo(int array_size) {
int tmp[100];
int sum =0;
//pragma unroll unroll_factor
#pragma ivdep array(tmp) safelen(unroll_factor)
for (int i=0;i<array_size;i++) {
sum+=tmp[i];
}
return sum;
}
|
Use __pragma instead of #pragma. For example, the following
compiles successfully with the fpga_crossgen
command:
#define unroll_factor 5
int foo(int array_size) {
int tmp[100];
int sum =0;
//pragma unroll unroll_factor
__pragma ivdep array(tmp) safelen(unroll_factor)
for (int i=0;i<array_size;i++) {
sum+=tmp[i];
}
return sum;
}
|
| Some high-level design reports fail in Microsoft* Internet Explorer*. | Use one of the following browsers
to view the reports:
|
| Libraries that target OpenCL* and are written in HLS might cause OpenCL* kernels that include the library to have a more conservative incremental compilation. | N/A |
| Libraries that target OpenCL* and are written in HLS cannot use streams. | N/A |
| Libraries written in HLS or OpenCL* are not supported on Microsoft* Windows* operating systems. | N/A |
Library functions that use the following HLS
features cannot be emulated:
|
N/A |
|
Using a struct of a single ac_int data type in steaming interface that uses
packets (ihc::usesPackets<true>) does not work. For example, the following code snippet does
not
work:
// class definition
class DataType {
ac_int<155, false> data;
...
}
// stream definition
typedef ihc::stream_in<DataType,
ihc::usesPackets<true>,
ihc::usesEmpty<true>
> DataStreamIn;
|
To use this combination in your
design, obey the following restrictions:
|
(Windows only)
When you run the init_hls.bat script, you might
receive the following warning
message:WARNING: Detected Microsoft Visual C++ 2017 installation. The i++ compiler is not tested with this version. |
You can safely ignore this warning. |
1.4. Software Issues Resolved
1.5. Intel High Level Synthesis Compiler Pro Edition Release Notes Archives
1.6. Document Revision History for Intel HLS Compiler Pro Edition Version 19.4 Release Notes
| Document Version | Intel® Quartus® Prime Version | Changes |
|---|---|---|
| 2020.01.31 | 19.4 |
|
| 2019.12.16 | 19.4 |
|