TMS320F28069: Possible mistake in compiler optimization guide

Thanks

how much performance increase can be expected from this, than if else of turnery operator. 

Using this __fmax intrinsic instead of equivalent if/else statements is likely to save around 5-10 cycles per instance.  If that occurs in a function that is called many times, or a loop that iterates many times, that can add up to enough cycles to matter.

Thanks and regards,

-George

Thanks.

If i get this function right, this can be used in minimum saturation level check function. 
For ex, 

#define min 10
if(var<min)var=min;

is equals to __fmax(min,var)

Is this correct?

Hello Damith,

I will do some research on this and try to get back to you by Thursday.

Best regards,

Omer Amir

Hello Damith,

I looked into the implementation of fmax and essentially it just compares/returns the greater of the two values passed into it. However, there is some additional checking relating to floating point format (i.e. +0 vs -0 and NaN values).

Best regards,

Omer Amir

Thanks Omar

Sint it bit odd that this one named fmax, but it actually used for finding minimum. 

Hello Damith,

Is this a question or just an observation? I don't know what Sint refers to.

Im sorry. It is.a typo.

It shoud be "isnt it" instead of Sint..

Hello Damith,

I'm sorry, I don't understand your question very well; the functionality is the same, it's still returning the maximum whether it's finding the minimum or maximum. There is no benefit to choosing one over the other, since there are conditionals checking for edge cases anyways.

Best regards,

Omer Amir

Im sorry for the confusion. It doesnt return anything. It just store the minimum value(the constant which we have provided)  in the checking variable.

In other words, eventough this named as max,  We cannot use this to clamp to max. We can only use this to clamp to a minimum value.

Hello Damith,

Can you show an example of what numbers you tested with? If you use the Assembly Step button, are you able to step into the proper function (you can check in the Disassembly view)?

Best regards,

Omer Amir

Hello Amir

I'm sorry but i couldnt understand what did you meant by "return". This intrinsic doesn't return a value like a function. It just copy one to another if the condition is true.  
float __fmax( float x , float y );     MAXF32 y , x     If x>y, copy x to y.

this is equals to

 #define min 10
if(var<min)var=min;

Apologies, could you show test values that you are trying and what the result is for those values? Since this is an intrinsic function, you should still be able to step through it in the Disassembly view.