On 10/8/26 3:31 PM, Matt Turner wrote:
On Mon, Sep 21, 2026 at 8:12 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. 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]>Any further comments or can someone push this for me?
Richi, Jakub, Andrea, any further concerns here? Jeff
