Compiler flags

-c

compile to object code (.o)

-S

compile to assembler (.s)

-E

send output of cpp to standard output

-I

add a directory to the include search path (used for finding files named in #include statements.

-l

link against a standard system library (eg -lm links against libm)

-L

add a directory to the standard library search path

-o

Give the output a different name. Most useful for the output of the link step, which by default is a.out.

-O

Specify optimisation level. Usually given as a number from -O0 (no optimisation) to -O3 or -O4. Need to read the compiler manual.

-g

Include symbolic information for debugging purposes.

-p/-pg

Instrument code for profiling.