Configures the default behavior of front-end compiling.
- When TRUE uses alternative HLS implementation of pipelined loops which enables automatic loop rewind. This accepts values of TRUE or FALSE. The default value is TRUE.
- Specifies the maximum length of function names. If the length of the name is longer than the threshold, the last part of the name is truncated, and digits are added to make the name unique when required. The default is 256.
- Ignores the signedness of floating-point zero so that the compiler can
perform aggressive optimizations on floating-point operations. The default is off.Important: Using this option might change the result of any floating point calculations and result in a mismatch in C/RTL co-simulation. Please ensure your test bench is tolerant of differences and checks for a margin of difference, not exact values.
- Specifies the lower limit used when automatically pipelining loops.
The default is 64, causing Vitis HLS is to
automatically pipeline loops with a tripcount of 64, or greater.
If the option is applied, the innermost loop with a tripcount higher than the threshold is pipelined, or if the tripcount of the innermost loop is less than or equal to the threshold, its parent loop is pipelined. If the innermost loop has no parent loop, the innermost loop is pipelined regardless of its tripcount.Tip: The higher the threshold, the more likely it is that the parent loop is pipelined and the runtime is increased.
-pipeline_style <stp | flp | frp>
- Specifies the default type of pipeline used by Vitis HLS for the PIPELINE pragma or directive, or for loop
pipelining due to the
-pipeline_loopsthreshold specified above. For more information on pipeline styles, refer to Flushing Pipelines.Important: This is a hint not a hard constraint. The tool checks design conditions for enabling pipelining. Some loops might not conform to a particular style and the tool reverts to the default style (stp) if necessary.
- Stall pipeline. Runs only when input data is available otherwise it stalls. This is the default setting, and is the type of pipeline used by Vitis HLS for both loop and function pipelining. Use this when a flushable pipeline is not required. For example, when there are no performance or deadlock issue due to stalls.
- Flushable pipeline architecture: flushes when input data is not available then stalls waiting for new data.
- Free-running, flushable pipeline. Runs even when input data is not available. Use this when you need better timing due to reduced pipeline control signal fanout, or when you need improved performance to avoid deadlocks. However, this pipeline style may consume more power, as the pipeline registers are clocked even if there is no data.
- Enable error messages for misplaced or misused pragmas.
- Specify a TCL script to run prior to starting the
- Ignores the signedness of floating-point zero and enables associative
floating-point operations so that compiler can perform aggressive optimizations on
floating-point operations. The default is OFF.Note: Using this option might change the result of any floating point calculations and result in a mismatch in C/RTL co-simulation. Please ensure your test bench is tolerant of differences and checks for a margin of difference, not exact values.
Pipeline the innermost loop with a tripcount higher than 30, or pipeline the parent loop of the innermost loop when its tripcount is less than or equal 30:
config_compile -pipeline_loops 30
Ignore the signedness of floating-point zero:
Ignore the signedness of floating-point zero and enable the associative floating-point operations: