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Observer
Observer
4,528 Views
Registered: ‎11-26-2014

C code not synthesizable by functions

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Hello All,

 

I have a c program that contains several subfunctions that the main function calls. When I use Vivado HLS to synthesize the main function it works fine, and it also works when I tell the compiler to synthesize a particular subfunction.  This works for most subfunctions, however when I try to synthesize some of the sub-functions I get this error:

 

CRITICAL WARNING: [SYNCHK 200-61] ../benchmarks/chstone/adpcm/adpcm.c:585: unsupported memory access on variable 'x' which is (or contains) an array with unknown size at compile time.
INFO: [SYNCHK 200-10] 1 error(s), 0 warning(s).
CRITICAL WARNING: [HLS 200-70] Synthesizability check failed.

 

This only happens for two of the sub-functions. I think that the inputs of the subfuctions are not supported by vivado hls and therefore it causes the error, Is there a way to modify the code to be able to synthezise these functions?

 

The not synthesizable functions are:

filtez

upzero

 

the c source file is attached

 

Best Regards,

Raul

 

 

 

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Teacher
Teacher
7,283 Views
Registered: ‎03-31-2012
I think if you change the pointers to arrays with sizes, it should work:

int filtez (int bpl[6], int dlt[6]);

etc.
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Teacher
Teacher
7,284 Views
Registered: ‎03-31-2012
I think if you change the pointers to arrays with sizes, it should work:

int filtez (int bpl[6], int dlt[6]);

etc.
- Please mark the Answer as "Accept as solution" if information provided is helpful.
Give Kudos to a post which you think is helpful and reply oriented.

View solution in original post

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Xilinx Employee
Xilinx Employee
1,713 Views
Registered: ‎05-06-2008

Hello Joseraul,

 

I also found an AR (https://www.xilinx.com/support/answers/59829.html) and another forum post (https://forums.xilinx.com/t5/Vivado-High-Level-Synthesis-HLS/C-code-not-synthesizable-by-functions/td-p/732796) about the error messages.

 

I am not sure if you already read them, but I wanted to make you aware of them.

 

Thanks,
Chris

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