Facing Timing Issues with Floating Calculation on STM32F103c6 ( Cortex m3)

Perhaps looking for an integer-based algorithm of your problem ?

Or trying scaled math - using integer, and scaling the number up (before the operation) and down (afterwards) by the number of decimal fractions you require. It comes down to the accuracy you require.

These Methods I tried.

1 Method: Scaling up number before and down after calculation. Yes Accuracy is down and Timing in micro seconds.

2 Method: Partition of float number into mantissa and fraction (Float to Fixed conversion ) than do calculation. Accuracy is good but took too much time near 7-8 microsecond for single float multiplication.

For my requirements any method will be okay, condition-

Accuracy should be good and Float Multiplication time should below 1 microsecond.

Precompute some of the match function in an approximate 2D points with linear interpolation between points.

That's what is done for 8 bit MCUs. Fixed point Q31 recommended when useable.

Change the core to M4 or use a faster core are another option when the expectations are misaligned with the provided implementation.