-O4 do anything different than -O3

Accelerated Computing HPC Compilers Legacy PGI Compilers
1

Dear PGI:

Does -O4 do anything different than -O3? The release notes says -O4 does more algebraic transformations and register scheduling (I am paraphrasing). Is this true?

Thanks,
Tony

2

Hi Tony,

Yes, that is true.

Hongyon