BTW, here's the state of toolchains, by architecture:
alpha alpha-linux works
arm arm-linux works
arm26 support is gone in gcc4, tree is not well either
cris cris-linux broken [*3][*4], but gets through arch/cris, so
there's some use for it...
frv frv-linux 4.1 mostly works [*2], but "U" constraint
support is still missing in mainline
h8300 h8300-elf broken [*5][*3]
i386 x86_64-linux works
ia64 ia64-linux works
m32r m32r-linux works [*2]
m68k m68k-linux works [*2]
mips mips64-linux works
mips64 mips64-linux works [*1]
parisc hppa-linux works [*4]; gcc-4.1 gives an ICE [*7]
parisc64 hppa64-linux Linus' tree is broken; gcc builds, but doesn't
get far in kernel build; might die later.
powerpc powerpc64-linux works
ppc powerpc64-linux works
s390 s390x-linux works
sh sh-linux works [*4]
sh64 sh64-linux broken [*6]
sparc sparc64-linux works
sparc64 sparc64-linux works
um toolchain of corresponding sub-arch
v850 v850e-linux works [*2][*5]
x86_64 x86_64-linux works
xtensa, m68knommu: have not tried lately
[*1] except that we get bogus flags passed to as(1) if we are building
for 64bit cpu without CONFIG_BUILD_ELF64.
[*2] 64bit bugs in binutils, fixes exist
[*3] ICE during kernel build
[*4] needs a patch to get rid of dependency on target libc headers; fix exists
[*5] 64bit bugs in gcc, fixes exist
[*6] ICE during libgcc build
[*7] 4.0 works, 4.1 gives an ICE when you build on 64bit host with -Os;
trimmed-down reproducer is
void foo(int sig, int *p)
{
if (!((1ULL << ((sig)-1)) & 0x300000edcULL))
*p = 0;
}
