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5950 Discussions

Does Intel HLS Compiler combine or split variables?

mnazemi
Beginner
381 Views

Assume I have a component which includes something like the following lines:

bool input_0; bool input_1; bool input_2; bool input_3;   bool wire_0; bool wire_1;   bool output_0;   wire_0 = input_0 & input_1; wire_1 = wire_0 & input_2;   ouput_0 = wire_1 & input_3;

The above code is effectively computing a four-input AND operation which is broken down to three two-input AND operations.

 

If the above code was written in Verilog, it would have been mapped to a single ALUT which takes all four inputs and calculates the output at one shot.

 

I was wondering if the same would happen if I ran the HLS Compiler flow. In other words, If I pass the above code to HLS and later to Quartus, does it allocate registers to wire_0 and wire_1 and compute them separately before generating the final output or will merge these into a four-input AND operation.

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4 Replies
MEIYAN_L_Intel
Employee
164 Views

Hi,

Have you try to compile the code in HLS? The project directory (.prj) will be created after compilation. You can open the design and see the RTL generated.

Thanks

mnazemi
Beginner
164 Views

Obviously, I have done that. But I am not able to find the corresponding Verilog code under components directory.

MEIYAN_L_Intel
Employee
164 Views

Hi,

May I know that do you have insert the "component" keyword in the source code before the top-level C++ function to be synthesized as mentioned in Chapter 3: https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/hls/ug-hls.pdf

If yes, can I have the .cpp code file for further investigation?

Thanks.

MEIYAN_L_Intel
Employee
164 Views

Hi,

May I know any update?

Thanks

Reply