gcc optimization option flags

[Andrew Haley]

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.

Andrew.