Selecting one of the following will take you directly to that section:
Turns on aggressive optimization. The optimizations at this level are distinguished from -O2 by their aggressiveness, generally seeking highest-quality generated code even if it requires extensive compile time. They may include optimizations that are generally beneficial but may hurt performance.
Turn on extensive optimizations. This is the default. The optimizations at this level are generally conservative, in the sense that they are virtually always beneficial and avoid changes which affect such things as floating point accuracy. In addition to the level 1 optimizations, do inner loop unrolling, if-conversion, two passes of instruction scheduling, global register allocation, dead store elimination, instruction scheduling across basic blocks, and partial redundancy elimination.
Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
Turn off all optimizations.
Enable OpenACC directives.
Target AMD HAWAII GPUs.
Relaxed precision for Target device.
Disable MI scheduler (use alternative scheduler).
Disable register pressure control in the scheduler.
Select C89 standard with GNU extensions.