Gcc compilation for different targets

Question

I was just trying to understand something about cross compilers which made me ask this question. gcc is a cross-compiler.
By default what it the target architecture for gcc compilation if none is specified is the native target on which I am compiling the source. Correct ?

If the above is correct then how does it manage to generate the code for several different architectures even when it is explicitly specified ?
Shouldn't it have to know all the ISA's ? How is this managed ? Do they have all the information for all the existing ISA's ?

Basile Starynkevitch · Accepted Answer · 2013-12-29T15:24:26.013

4

A given (particular) gcc is built for a particular given target. Use gcc -v to find out which.

Often, cross-compilers are installed as different commands, e.g. avr-gcc on Debian for the Atmel AVR processor (with specific options ...)

On some architectures and systems (typically x86 & Linux) you may compile for a different variant. See this. In particular you may want to use -mtune=native or -march=haswell or -m32 ...

If you build gcc yourself from its source tarball, you'll give it at configure time specific configure options (e.g. --program-suffix=-avr and --target=avr for the avr-gcc etc....)

edited Dec 29 '13 at 15:24

answered Dec 29 '13 at 15:06

Basile Starynkevitch

223,805
18
296
547

You mean this comes from `installing` different kinds of `gcc`s ? – user3144089 Dec 29 '13 at 15:08
Yes, as I am explaining in my revised answer. – Basile Starynkevitch Dec 29 '13 at 15:13
Thank you very much. And the link is nice. I will refer to the gnu docs from now on an understand. – user3144089 Dec 29 '13 at 15:16

Gcc compilation for different targets

1 Answers1