On Mon, Aug 12, 2019 at 12:32:57PM -0700, Nathan Chancellor wrote: > Clang errors out when building this macro: > > lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a > inline asm context requiring an l-value: remove the cast or build with > -fheinous-gnu-extensions > umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); > ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > lib/mpi/longlong.h:652:20: note: expanded from macro 'umul_ppmm' > : "=l" ((USItype)(w0)), \ > ~~~~~~~~~~^~~ > lib/mpi/generic_mpih-mul1.c:37:3: error: invalid output constraint '=h' > in asm > umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); > ^ > lib/mpi/longlong.h:653:7: note: expanded from macro 'umul_ppmm' > "=h" ((USItype)(w1)) \ > ^ > 2 errors generated. > > The C version that is used for GCC 4.4 and up works well with clang; > however, it is not currently being used because Clang masks itself > as GCC 4.2.1 for compatibility reasons. As Nick points out, we require > GCC 4.6 and newer in the kernel so we can eliminate all of the > versioning checks and just use the C version of umul_ppmm for all > supported compilers. > > Link: https://github.com/ClangBuiltLinux/linux/issues/605 > Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > > This supersedes the following two patches: > > https://lore.kernel.org/lkml/20190812033120.43013-4-natechancellor@xxxxxxxxx/ > > https://lore.kernel.org/lkml/20190812033120.43013-5-natechancellor@xxxxxxxxx/ > > I labelled this as a v2 so those don't get applied. > > lib/mpi/longlong.h | 36 +----------------------------------- > 1 file changed, 1 insertion(+), 35 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
