26 lines
663 B
C
26 lines
663 B
C
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#include <stdio.h>
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uint64_t getcycles();
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static void do_something()
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{
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for (int i = 0; i < 1000; ++i) {
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__asm__("NOP");
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}
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}
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int main(void)
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{
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// Instruction cache misses are relatively expensive, so for more
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// consistent benchmarks that depend less on the relative speed of
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// the QSPI flash, you might want to fill the instruction cache first.
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// Note that it can hold 16 KiB of instructions on the HiFive1.
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do_something();
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getcycles();
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uint64_t oldcount = getcycles();
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do_something();
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uint64_t newcount = getcycles();
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printf("That took %d cycles.\n", (unsigned int)(newcount-oldcount));
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return 0;
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}
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