Index: MicroBenchmarks/libs/benchmark-1.3.0/src/cycleclock.h =================================================================== --- MicroBenchmarks/libs/benchmark-1.3.0/src/cycleclock.h +++ MicroBenchmarks/libs/benchmark-1.3.0/src/cycleclock.h @@ -164,6 +164,21 @@ uint64_t tsc; asm("stck %0" : "=Q" (tsc) : : "cc"); return tsc; +#elif defined(__riscv) // RISC-V + // Use RDCYCLE (and RDCYCLEH on riscv32) +#if __riscv_xlen == 32 + uint64_t cycles_low, cycles_hi0, cycles_hi1; + asm("rdcycleh %0" : "=r"(cycles_hi0)); + asm("rdcycle %0" : "=r"(cycles_lo)); + asm("rdcycleh %0" : "=r"(cycles_hi1)); + // This matches the PowerPC overflow detection, above + cycles_lo &= -static_cast<int64_t>(cycles_hi0 == cycles_hi1); + return (cycles_hi1 << 32) | cycles_lo; +#else + uint64_t cycles; + asm("rdcycle %0" : "=r"(cycles)); + return cycles; +#endif #else // The soft failover to a generic implementation is automatic only for ARM. // For other platforms the developer is expected to make an attempt to create