34 lines
1.2 KiB
Diff
34 lines
1.2 KiB
Diff
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From b2781fb5638afae7438b983a912ede126a8c5b85 Mon Sep 17 00:00:00 2001
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From: James Page <james.page@ubuntu.com>
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Date: Fri, 13 Mar 2015 19:46:04 +0000
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Subject: [PATCH] Add support for PPC architecture, provide fallback
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Add high precision cpu cycles support for powerpc and powerpc64.
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Provide a fallback for other architectures and warn during
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compilation.
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Signed-off-by: James Page <james.page@ubuntu.com>
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diff --git a/src/common/Cycles.h b/src/common/Cycles.h
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index 6e47cde..bb47d5c 100644
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--- a/src/common/Cycles.h
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+++ b/src/common/Cycles.h
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@@ -72,8 +72,15 @@ class Cycles {
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uint64_t cntvct;
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asm volatile ("isb; mrs %0, cntvct_el0; isb; " : "=r" (cntvct) :: "memory");
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return cntvct;
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+#elif defined(__powerpc__) || defined (__powerpc64__)
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+ // Based on:
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+ // https://github.com/randombit/botan/blob/net.randombit.botan/src/lib/entropy/hres_timer/hres_timer.cpp
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+ uint32_t lo = 0, hi = 0;
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+ asm volatile("mftbu %0; mftb %1" : "=r" (hi), "=r" (lo));
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+ return (((uint64_t)hi << 32) | lo);
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#else
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-#error No high-precision counter available for your OS/arch
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+#warning No high-precision counter available for your OS/arch
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+ return 0;
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#endif
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}
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