Most change was done in #ifdef TCC_TARGET_X86_64. So, nothing should be broken by this change.
Summary of current status of x86-64 support:
- produces x86-64 object files and executables.
- the x86-64 code generator is based on x86's.
-- for long long integers, we use 64bit registers instead of tcc's generic implementation.
-- for float or double, we use SSE. SSE registers are not utilized well (we only use xmm0 and xmm1).
-- for long double, we use x87 FPU.
- passes make test.
- passes ./libtcc_test.
- can compile tcc.c. The compiled tcc can compile tcc.c, too. (there should be some bugs since the binary size of tcc2 and tcc3 is differ where tcc tcc.c -o tcc2 and tcc2 tcc.c -o tcc3)
- can compile links browser. It seems working.
- not tested well. I tested this work only on my linux box with few programs.
- calling convention of long-double-integer or struct is not exactly the same as GCC's x86-64 ABI.
- implementation of tcc -run is naive (tcc -run tcctest.c works, but tcc -run tcc.c doesn't work). Relocating 64bit addresses seems to be not as simple as 32bit environments.
- shared object support isn't unimplemented
- no bounds checker support
- some builtin functions such as __divdi3 aren't supported
- Use REL_SECTION_FMT instead of ".rel%s".
- Use PTR_SIZE instead of sizeof(int) for GOT entries.
- Use sizeof(ElfW(Dyn)) instead of magic number 8.
- Use TCC_ELFCLASS instead of ELFCLASS32.
This patch adds a switch --with-libgcc to configure.
When passed it prevents libtcc1.a from being built and links to
/lib/libgcc_s.so.1 instead of PREFIX/lib/tcc/libtcc1.a.
It will work on ARM when using libgcc from GCC >= 4.2.0.
Prior versions don't have the __floatun[sd]i[sdx]f functions.
It won't work on i386 because of two missing symbols emitted when
floats are cast to integers, but users can provide those symbols
(global short constants) in their code if needed.
Daniel
