On Mon, Sep 21, 2026 at 5:12 PM Matt Turner <[email protected]> wrote: > > Several blocks of longlong.h do not build with clang, because clang > rejects casts on asm output operands. This affects libgcrypt, which > imports longlong.h, and wide-int.cc in GCC itself.
Again NO. Go talk with libgcrypt to pick up the GMP version of longlong.h. > > 1. Remove the Z8000 block, as Richard suggested. Unchanged from v2. > > 2. Update the header comment, which still says the file is part of > the GNU C Library. glibc removed its copy of longlong.h in 2.43. > > 3. Wrap each output cast in a macro, as Jakub suggested: > > : "=r" __ll_check_output (USItype, sh), > > 4. Let wide-int.cc include longlong.h under clang again, so a GCC > built by clang without bootstrapping uses umul_ppmm. > > With GCC, patch 3 expands to the same casts as before. With clang, the > i386 block, the x86_64 and sparc64 blocks for W_TYPE_SIZE 64, and the > arm blocks as C now build. The arm blocks still fail as C++, because > the arm umul_ppmm declares a register variable, which C++17 does not > allow; that is a separate problem. > > Tested by building x86_64-pc-linux-gnu with clang 22 as the host > compiler (--disable-bootstrap). wi::mul_internal now uses mulq, the > selftests pass and the target libraries build. > > Changes in v3: > - Replace the sizeof check with __ll_check_output, which keeps the cast > for GCC and drops it for clang (Jakub). GCC's cast check rejects > any conversion that is not a no-op, while the size check accepted > outputs of a different type with the same size. > - Drop v2 patches 3 and 4 (__ll_out and the libquadmath register > change). They are no longer needed since GCC keeps the cast. > - New patch 2: say longlong.h is part of GCC, not the GNU C Library, > and update the stale comment on attribute_hidden. > - New patch 4: include longlong.h in wide-int.cc with clang. > - Link to v2: > https://inbox.sourceware.org/gcc-patches/[email protected]/ > > Changes in v2: > - Keep the output size check instead of dropping it (patch 2). > - Remove the Z8000 block instead of editing it (patch 1). > - New, optional: patches 3 and 4. > - v1 patch 2/2 (sdiv_qrnnd parentheses) is already committed. > - Link to v1: > https://inbox.sourceware.org/gcc-patches/[email protected]/ > > --- > Matt Turner (4): > include: Remove Z8000 support from longlong.h > include: Say longlong.h is part of GCC, not the GNU C Library > include: Wrap the casts on asm output operands in longlong.h in a macro > wide-int.cc: Include longlong.h when built with clang [PR61146] > > gcc/wide-int.cc | 3 +- > include/longlong.h | 241 > ++++++++++++++++++++++++----------------------------- > 2 files changed, 110 insertions(+), 134 deletions(-) > --- > base-commit: e47eccbe6d118023e4fe83bde14075729c40e030 > change-id: 20260921-longlong-fixes-v2-d8f7bb2376cc > > Best regards, > -- > Matt Turner <[email protected]> >
