On Mon, 26 Apr 2021 00:36:31 -0700 Josh Triplett <j...@joshtriplett.org> wrote: > Package: musl > Version: 1.2.2-1 > Severity: normal > X-Debbugs-Cc: j...@joshtriplett.org > > aarch64 gcc appears to default to -moutline-atomics, which causes gcc to > emit references to function symbols for atomic operations rather than > inlining the corresponding instruction sequences. > > However, musl doesn't appear to provide the corresponding function > symbols. This results in errors like these (from compiling libgit2): > > attrcache.c:(.text.git_attr_cache__get+0x144): undefined reference to > `__aarch64_swp8_acq_rel' > attrcache.c:(.text.git_attr_cache__get+0x158): undefined reference to > `__aarch64_ldadd4_acq_rel' > attrcache.c:(.text.git_attr_cache__get+0x168): undefined reference to > `__aarch64_swp8_acq_rel' > attrcache.c:(.text.git_attr_cache__get+0x180): undefined reference to > `__aarch64_swp8_acq_rel' > attrcache.c:(.text.git_attr_cache__get+0x224): undefined reference to > `__aarch64_cas8_acq_rel' > attrcache.c:(.text.git_attr_cache__get+0x248): undefined reference to > `__aarch64_swp8_acq_rel' > > Would it make sense for the aarch64 musl-gcc wrapper to pass > -mno-outline-atomics, which resolves this problem and makes gcc no > longer emit references to those symbols?
Following up on this: given the performance wins associated with -moutline-atomics, it may also make sense for musl to provide those symbols, or for the aarch64 musl-gcc to ensure that an appropriate libgcc with those symbols is linked in.
