Skip to content

Implement tick() for aarch64 on non-Apple platforms #854

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
mjp41 merged 3 commits into from
Jun 8, 2026
+10 −2
Merged

Implement tick() for aarch64 on non-Apple platforms #854

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
d06fe49
Implement tick() for aarch64 on non-Apple platforms
mjp41 Jun 7, 2026
e3d866a
Fix MSVC build for aarch64 tick()
mjp41 Jun 7, 2026
ea9e613
Merge branch 'main' into arm_tick
mjp41 Jun 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions src/snmalloc/aal/aal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -173,6 +173,7 @@ namespace snmalloc
else
{
#if __has_builtin(__builtin_readcyclecounter) && !defined(__APPLE__) && \
!defined(__aarch64__) && !defined(_M_ARM64) && !defined(_M_ARM64EC) && \
!defined(SNMALLOC_NO_AAL_BUILTINS)
return __builtin_readcyclecounter();
#else
Expand Down
11 changes: 9 additions & 2 deletions src/snmalloc/aal/aal_arm.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
# define SNMALLOC_VA_BITS_64
# ifdef _MSC_VER
# include <arm64_neon.h>
# include <intrin.h>
# endif
#else
# define SNMALLOC_VA_BITS_32
Expand Down Expand Up @@ -32,7 +33,7 @@ namespace snmalloc
* Bitmap of AalFeature flags
*/
static constexpr uint64_t aal_features = IntegerPointers
#if defined(SNMALLOC_VA_BITS_32) || !defined(__APPLE__)
#if defined(SNMALLOC_VA_BITS_32)
| NoCpuCycleCounters
#endif
#if defined(SNMALLOC_COMPILER_SUPPORT_PACA_PACG) && \
Expand Down Expand Up @@ -71,12 +72,18 @@ namespace snmalloc
#endif
}

#if defined(SNMALLOC_VA_BITS_64) && defined(__APPLE__)
#if defined(SNMALLOC_VA_BITS_64)
static inline uint64_t tick() noexcept
{
# ifdef _MSC_VER
// ARM64_SYSREG(op0, op1, CRn, CRm, op2) encoding for CNTVCT_EL0.
return static_cast<uint64_t>(
_ReadStatusReg(ARM64_SYSREG(3, 3, 14, 0, 2)));
# else
uint64_t t;
__asm__ volatile("mrs %0, cntvct_el0" : "=r"(t));
return t;
# endif
}
#endif

Expand Down
Loading