c++ - gcc 4.3.3 compiler options enabled by default

Question

I have moved from gcc version 4.0.3 to 4.3.3 and realized that -mfpmath was set to sse by default in gcc 4.3.3. This actually caused errors in my application. In 4.0.3 the -mfpmath was 387.

I want to know how I can get all the default options enabled by gcc for a given version. How can I dump set of all options used by gcc while compiling. This enables me to compare version 4.0.3 vs 4.3.3.

In general it will be great if I can know a comprehensive list of things need to be checked before going for a version change in gcc .(As this has effect on performance and functionality.)

Answer 1

gcc -Q -v

With just a basic tiny c or cpp file as an input file. Should give you a big list of all the options passed to gcc by default, one of those might be causing sse fp math to be enabled.