gcc optimization option flags

[M R Swami Reddy]

Andrew Haley wrote:
> M R Swami Reddy wrote:
>>> They do, and that's right.  Unless you select -O you don't get any
>>> optimizations, no matter what other flags you set.
>> Thank you very much for the clarification.
>> Do I need to set -O1 for case-1 and case-2: "-O followed by disabling
>> all -O1 flags" (ie -O0 equivalently)?
> 
> You won't get exactly the same results as -O0 no matter what you do,
> since a lot of optimizations are just enabled by -O.

Thanks for the clarification.