mirrors/Odin
1
0
Fork 0
mirror of https://github.com/odin-lang/Odin.git synced 2026-02-16 16:14:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

shuffle tsc around a little

Browse Source
This commit is contained in:
Colin Davidson
2023-02-22 12:28:24 -08:00
parent 8e5e43f335
commit c6f463b8c9
1 changed files with 13 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
core/time/perf.odin
View File

@@ -41,6 +41,7 @@ _tick_duration_end :: proc "contextless" (d: ^Duration, t: Tick) {
}
when ODIN_ARCH == .amd64 {
@(private)
x86_has_invariant_tsc :: proc "contextless" () -> bool {
eax, _, _, _ := intrinsics.x86_cpuid(0x80_000_000, 0)
@@ -63,27 +64,24 @@ has_invariant_tsc :: proc "contextless" () -> bool {
return false
}
_get_tsc_frequency_fallback :: proc "contextless" () -> u64 {
tsc_begin := intrinsics.read_cycle_counter()
tick_begin := tick_now()
sleep(2 * Second)
tsc_end := intrinsics.read_cycle_counter()
tick_end := tick_now()
time_diff := u128(duration_nanoseconds(tick_diff(tick_begin, tick_end)))
return u64((u128(tsc_end - tsc_begin) * 1_000_000_000) / time_diff)
}
get_tsc_frequency :: proc "contextless" () -> (u64, bool) {
tsc_frequency :: proc "contextless" () -> (u64, bool) {
if !has_invariant_tsc() {
return 0, false
}
hz, ok := _get_tsc_frequency()
if !ok {
hz = _get_tsc_frequency_fallback()
// fallback to approximate TSC
tsc_begin := intrinsics.read_cycle_counter()
tick_begin := tick_now()
sleep(2 * Second)
tsc_end := intrinsics.read_cycle_counter()
tick_end := tick_now()
time_diff := u128(duration_nanoseconds(tick_diff(tick_begin, tick_end)))
hz = u64((u128(tsc_end - tsc_begin) * 1_000_000_000) / time_diff)
}
return hz, true