From 1d53e6cb6dbe5d6a3ec03ef436756fd16b65f12a Mon Sep 17 00:00:00 2001 From: Hans Wennborg Date: Mon, 5 Aug 2019 08:14:21 +0000 Subject: [PATCH] Merging r366868: ------------------------------------------------------------------------ r366868 | rogfer01 | 2019-07-24 07:33:46 +0200 (Wed, 24 Jul 2019) | 6 lines [RISCV] Implement benchmark::cycleclock::Now This is a cherrypick of D64237 onto llvm/utils/benchmark and libcxx/utils/google-benchmark. Differential Revision: https://reviews.llvm.org/D65142 ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/libcxx/branches/release_90@367813 91177308-0d34-0410-b5e6-96231b3b80d8 --- utils/google-benchmark/README.LLVM | 6 ++++++ utils/google-benchmark/src/cycleclock.h | 15 +++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/utils/google-benchmark/README.LLVM b/utils/google-benchmark/README.LLVM index e51e2571b..6b81ddf87 100644 --- a/utils/google-benchmark/README.LLVM +++ b/utils/google-benchmark/README.LLVM @@ -4,3 +4,9 @@ LLVM notes This directory contains the Google Benchmark source code with some unnecessary files removed. Note that this directory is under a different license than libc++. + +Changes: +* https://github.com/google/benchmark/commit/4abdfbb802d1b514703223f5f852ce4a507d32d2 + is applied on top of + https://github.com/google/benchmark/commit/4528c76b718acc9b57956f63069c699ae21edcab + to add RISC-V timer support. diff --git a/utils/google-benchmark/src/cycleclock.h b/utils/google-benchmark/src/cycleclock.h index f5e37b011..d5d62c4c7 100644 --- a/utils/google-benchmark/src/cycleclock.h +++ b/utils/google-benchmark/src/cycleclock.h @@ -164,6 +164,21 @@ inline BENCHMARK_ALWAYS_INLINE int64_t Now() { 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(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