FPGA Optimization Guide for Intel® oneAPI Toolkits

Developer Guide

Contents

Floating Point Pragmas

The following table summarizes the floating point pragmas:
Pragma
Description
Example
fp contract(off|fast)
Controls whether the compiler can skip intermediate rounding and conversions mainly between double precision arithmetic operations. 
{
  #pragma clang fp contract(fast)
  float temp1 = 0.0f, temp2 = 0.0f;
  temp1 = accessorA[0] + accessorB[0];
  temp2 = accessorC[0] + accessorD[0];
  accessorRES[0] += temp1 * temp2;
}
fp reassociate(on|off)
Controls the relaxing of the order of floating-point arithmetic operations within the code block that this pragma is applied to. 
{
  #pragma clang fp reassociate(on)
  float temp1 = 0.0f, temp2 = 0.0f;
  temp1 = accessorA[0] + accessorB[0];
  temp2 = accessorC[0] + accessorD[0];
  accessorRES[0] += temp1 * temp2;
}

Product and Performance Information

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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.