On 24-06-2011 17:56, Ian Lance Taylor wrote:
-mcmodel=large.
The large model is not supported. If it was, it would probably be
inefficient.
The large model certainly is supported.
What version of gcc are you using?
You are right. I tried a newer version (gcc 4.5.2, binutils 2.21) and
the large model works.
Now I can make a 64 bit shared object with -mcmodel=large and without
-fpic and it works. But as I suspected, it is not optimal. It uses full
64 bit addresses for almost everything rather than 32 bit relative
addresses. This is inefficient because it makes the code larger and
because 64 bit addressing is poorly supported in the x64 instruction
set. It loads the full absolute address into a 64-bit pointer register
whenever it is reading or writing any register other than eax and when
calling an external function.
I need a memory model between medium and large to allow 32-bit relative
addresses but not 32-bit absolute addresses.
