QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 1 | // Copyright 2017 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef QUICHE_QUIC_PLATFORM_API_QUIC_PREFETCH_H_ |
| 6 | #define QUICHE_QUIC_PLATFORM_API_QUIC_PREFETCH_H_ |
| 7 | |
| 8 | #include "net/quic/platform/impl/quic_prefetch_impl.h" |
| 9 | |
| 10 | namespace quic { |
| 11 | |
| 12 | // Move data into the cache before it is read, or "prefetch" it. |
| 13 | // |
| 14 | // The value of `addr` is the address of the memory to prefetch. If |
| 15 | // the target and compiler support it, data prefetch instructions are |
| 16 | // generated. If the prefetch is done some time before the memory is |
| 17 | // read, it may be in the cache by the time the read occurs. |
| 18 | // |
| 19 | // The function names specify the temporal locality heuristic applied, |
| 20 | // using the names of Intel prefetch instructions: |
| 21 | // |
| 22 | // T0 - high degree of temporal locality; data should be left in as |
| 23 | // many levels of the cache possible |
| 24 | // T1 - moderate degree of temporal locality |
| 25 | // T2 - low degree of temporal locality |
| 26 | // Nta - no temporal locality, data need not be left in the cache |
| 27 | // after the read |
| 28 | // |
| 29 | // Incorrect or gratuitous use of these functions can degrade |
| 30 | // performance, so use them only when representative benchmarks show |
| 31 | // an improvement. |
| 32 | |
| 33 | inline void QuicPrefetchT0(const void* addr) { |
| 34 | return QuicPrefetchT0Impl(addr); |
| 35 | } |
| 36 | |
| 37 | } // namespace quic |
| 38 | |
| 39 | #endif // QUICHE_QUIC_PLATFORM_API_QUIC_PREFETCH_H_ |