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* [glibc] AArch64: Fix HP_TIMING_DIFF computation [BZ# 29329]
@ 2023-02-22 17:17 Wilco Dijkstra
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From: Wilco Dijkstra @ 2023-02-22 17:17 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=311a7e0256975275d97077f1af338bc9caf0c837
commit 311a7e0256975275d97077f1af338bc9caf0c837
Author: Jun Tang <juntangc@amazon.com>
Date: Wed Feb 22 16:45:59 2023 +0000
AArch64: Fix HP_TIMING_DIFF computation [BZ# 29329]
Fix the computation to allow for cntfrq_el0 being larger than 1GHz.
Assume cntfrq_el0 is a multiple of 1MHz to increase the maximum
interval (1024 seconds at 1GHz).
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Diff:
---
sysdeps/aarch64/hp-timing.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h
index c8469e3011..b97e878f7b 100644
--- a/sysdeps/aarch64/hp-timing.h
+++ b/sysdeps/aarch64/hp-timing.h
@@ -41,7 +41,7 @@ typedef uint64_t hp_timing_t;
#define HP_TIMING_DIFF(Diff, Start, End) \
({ hp_timing_t freq; \
__asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \
- (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \
+ (Diff) = (((End) - (Start)) * UINT64_C(1000000000 >> 6)) / (freq >> 6); \
})
#endif /* hp-timing.h */
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2023-02-22 17:17 [glibc] AArch64: Fix HP_TIMING_DIFF computation [BZ# 29329] Wilco Dijkstra
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