Drazen Urch
7bd1550195
* Checkpoint * cpu cycle ffi * Rename * mixnode feature * Bundle libcpucycles
34 lines
800 B
C
34 lines
800 B
C
// version 20230105
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// public domain
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// djb
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// adapted from supercop/cpucycles/mips.c
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// mips32 release 2 instruction rdhwr
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// 7c02103b: read hwr#2 (cycle count) into $2
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// 7c02183b: read hwr#3 (cycle-count multiplier) into $2
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#include "cpucycles_internal.h"
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static unsigned int multiplier = 0;
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static long long multiplier_set(void)
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{
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asm volatile(".long 0x7c02183b; move %0,$2" : "=r"(multiplier) : : "$2");
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return multiplier;
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}
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long long ticks(void)
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{
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unsigned int result;
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asm volatile(".long 0x7c02103b; move %0,$2" : "=r"(result) :: "$2");
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result *= multiplier;
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return (unsigned long long) result;
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}
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long long ticks_setup(void)
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{
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if (!cpucycles_works(multiplier_set)) return cpucycles_SKIP;
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if (!cpucycles_works(ticks)) return cpucycles_SKIP;
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return cpucycles_EXTEND32;
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}
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