At different levels of GCC, the value of the same optimization option will be different.
How to determine the parameter values of relevant optimization options under different optimization levels?
As shown in the figure:
for example:-fexcess-precision=[fast|standard]
Parameter values include fast and standard,
At what level is 'fast' used?
At what level is 'standard' used?
I don't understand what you mean. If you want the parameters at -O1, -O2, -O3 etc you just call it multiple times?
gcc -Q --help=param -O1 gives you the values at -O1, gcc -Q --help=param -O2 at -O2 etc.
There's no simple command that gives you a table of all the values, you have to make it yourself.