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| author | Roman Belenov <103195329+r-belenov@users.noreply.github.com> | 2025-03-31 02:59:53 +0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-03-30 16:59:53 -0700 |
| commit | c9d90f15af0c5ed6ad5c5cd3aa988139a2cc34e4 (patch) | |
| tree | 6ae33c7a2aa41c01e11cba9ab82417dcc1e46d57 /llvm/lib/Support/CommandLine.cpp | |
| parent | 5b6386dcbd68d3f7c1ce98dd7acdd4477d5724ad (diff) | |
| download | llvm-c9d90f15af0c5ed6ad5c5cd3aa988139a2cc34e4.zip llvm-c9d90f15af0c5ed6ad5c5cd3aa988139a2cc34e4.tar.gz llvm-c9d90f15af0c5ed6ad5c5cd3aa988139a2cc34e4.tar.bz2 | |
[Exegesis][AArch64] Use more generic cycles counter (#133376)
CPU_CYCLES counter does not work on some Aarch64 CPUs; CYCLES is more
generic and is equivalent to CPU_CYCLES in case the latter is supported.
Longer story - CPU_CYCLES work only on CPU models explicitly recognized
by libpfm4 ( via pfm_arm_detect_*() functions in
https://sourceforge.net/p/perfmon2/libpfm4/ci/master/tree/lib/pfmlib_arm_armv8.c
) and its name is consistent with ARM documentation. However, the
counter is architectural and is supported on all ARMv8 CPUs; libpfm4
recognizes generic PMU on unknown ARMv8 CPUs, but does not provide
CPU_CYCLES event. Instead, CYCLES is provided (an alias to
PERF_COUNT_HW_CPU_CYCLES). Physically, it is the same event with code
0x11. On supported architectures CYCLES also work, so the change should
not introduce regression.
Diffstat (limited to 'llvm/lib/Support/CommandLine.cpp')
0 files changed, 0 insertions, 0 deletions