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Revision df38c1ce660628f05b4686eeaf0b548295ce7967 authored by Mike Kolupaev on 22 April 2019, 15:17:45 UTC, committed by Facebook Github Bot on 22 April 2019, 15:20:35 UTC 
Add BlockBasedTableOptions::index_shortening (#5174)
 
Summary:
Introduce BlockBasedTableOptions::index_shortening to give users control on which key shortening techniques to be used in building index blocks. Before this patch, both separators and successor keys where shortened in indexes. With this patch, the default is set to kShortenSeparators to only shorten the separators. Since each index block has many separators and only one successor (last key), the change should not have negative impact on index block size. However it should prevent many unnecessary block loads where due to approximation introduced by shorted successor, seek would land us to the previous block and then fix it by moving to the next one.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5174

Differential Revision: D14884185

Pulled By: al13n321

fbshipit-source-id: 1b08bc8c03edcf09b6b8c16e9a7eea08ad4dd534
1 parent de76909
Raw File
ppc-opcode.h 
//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
//  Copyright (c) 2017 International Business Machines Corp.
//  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//  This source code is also licensed under the GPLv2 license found in the
//  COPYING file in the root directory of this source tree.

#pragma once

#define __PPC_RA(a) (((a)&0x1f) << 16)
#define __PPC_RB(b) (((b)&0x1f) << 11)
#define __PPC_XA(a) ((((a)&0x1f) << 16) | (((a)&0x20) >> 3))
#define __PPC_XB(b) ((((b)&0x1f) << 11) | (((b)&0x20) >> 4))
#define __PPC_XS(s) ((((s)&0x1f) << 21) | (((s)&0x20) >> 5))
#define __PPC_XT(s) __PPC_XS(s)
#define VSX_XX3(t, a, b) (__PPC_XT(t) | __PPC_XA(a) | __PPC_XB(b))
#define VSX_XX1(s, a, b) (__PPC_XS(s) | __PPC_RA(a) | __PPC_RB(b))

#define PPC_INST_VPMSUMW 0x10000488
#define PPC_INST_VPMSUMD 0x100004c8
#define PPC_INST_MFVSRD 0x7c000066
#define PPC_INST_MTVSRD 0x7c000166

#define VPMSUMW(t, a, b) .long PPC_INST_VPMSUMW | VSX_XX3((t), a, b)
#define VPMSUMD(t, a, b) .long PPC_INST_VPMSUMD | VSX_XX3((t), a, b)
#define MFVRD(a, t) .long PPC_INST_MFVSRD | VSX_XX1((t) + 32, a, 0)
#define MTVRD(t, a) .long PPC_INST_MTVSRD | VSX_XX1((t) + 32, a, 0)
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