Thanks for using Compiler Explorer
Sponsors
Jakt
C++
Ada
Analysis
Android Java
Android Kotlin
Assembly
C
C3
Carbon
C++ (Circle)
CIRCT
Clean
CMake
CMakeScript
COBOL
C++ for OpenCL
MLIR
Cppx
Cppx-Blue
Cppx-Gold
Cpp2-cppfront
Crystal
C#
CUDA C++
D
Dart
Elixir
Erlang
Fortran
F#
Go
Haskell
HLSL
Hook
Hylo
ispc
Java
Julia
Kotlin
LLVM IR
LLVM MIR
Modula-2
Nim
Objective-C
Objective-C++
OCaml
OpenCL C
Pascal
Pony
Python
Racket
Ruby
Rust
Snowball
Scala
Solidity
Spice
Swift
LLVM TableGen
Toit
TypeScript Native
V
Vala
Visual Basic
Zig
Javascript
GIMPLE
c++ source #1
Output
Compile to binary object
Link to binary
Execute the code
Intel asm syntax
Demangle identifiers
Verbose demangling
Filters
Unused labels
Library functions
Directives
Comments
Horizontal whitespace
Debug intrinsics
Compiler
6502-c++ 11.1.0
ARM GCC 10.2.0
ARM GCC 10.3.0
ARM GCC 10.4.0
ARM GCC 10.5.0
ARM GCC 11.1.0
ARM GCC 11.2.0
ARM GCC 11.3.0
ARM GCC 11.4.0
ARM GCC 12.1.0
ARM GCC 12.2.0
ARM GCC 12.3.0
ARM GCC 13.1.0
ARM GCC 13.2.0
ARM GCC 13.2.0 (unknown-eabi)
ARM GCC 4.5.4
ARM GCC 4.6.4
ARM GCC 5.4
ARM GCC 6.3.0
ARM GCC 6.4.0
ARM GCC 7.3.0
ARM GCC 7.5.0
ARM GCC 8.2.0
ARM GCC 8.5.0
ARM GCC 9.3.0
ARM GCC 9.4.0
ARM GCC 9.5.0
ARM GCC trunk
ARM gcc 10.2.1 (none)
ARM gcc 10.3.1 (2021.07 none)
ARM gcc 10.3.1 (2021.10 none)
ARM gcc 11.2.1 (none)
ARM gcc 5.4.1 (none)
ARM gcc 7.2.1 (none)
ARM gcc 8.2 (WinCE)
ARM gcc 8.3.1 (none)
ARM gcc 9.2.1 (none)
ARM msvc v19.0 (WINE)
ARM msvc v19.10 (WINE)
ARM msvc v19.14 (WINE)
ARM64 Morello gcc 10.1 Alpha 2
ARM64 gcc 10.2
ARM64 gcc 10.3
ARM64 gcc 10.4
ARM64 gcc 10.5.0
ARM64 gcc 11.1
ARM64 gcc 11.2
ARM64 gcc 11.3
ARM64 gcc 11.4.0
ARM64 gcc 12.1
ARM64 gcc 12.2.0
ARM64 gcc 12.3.0
ARM64 gcc 13.1.0
ARM64 gcc 13.2.0
ARM64 gcc 5.4
ARM64 gcc 6.3
ARM64 gcc 6.4
ARM64 gcc 7.3
ARM64 gcc 7.5
ARM64 gcc 8.2
ARM64 gcc 8.5
ARM64 gcc 9.3
ARM64 gcc 9.4
ARM64 gcc 9.5
ARM64 gcc trunk
ARM64 msvc v19.14 (WINE)
AVR gcc 10.3.0
AVR gcc 11.1.0
AVR gcc 12.1.0
AVR gcc 12.2.0
AVR gcc 12.3.0
AVR gcc 13.1.0
AVR gcc 13.2.0
AVR gcc 4.5.4
AVR gcc 4.6.4
AVR gcc 5.4.0
AVR gcc 9.2.0
AVR gcc 9.3.0
Arduino Mega (1.8.9)
Arduino Uno (1.8.9)
BPF clang (trunk)
BPF clang 13.0.0
BPF clang 14.0.0
BPF clang 15.0.0
BPF clang 16.0.0
BPF clang 17.0.1
BPF clang 18.1.0
BPF gcc 13.1.0
BPF gcc 13.2.0
BPF gcc trunk
EDG (experimental reflection)
EDG 6.5
EDG 6.5 (GNU mode gcc 13)
EDG 6.6
EDG 6.6 (GNU mode gcc 13)
FRC 2019
FRC 2020
FRC 2023
KVX ACB 4.1.0 (GCC 7.5.0)
KVX ACB 4.1.0-cd1 (GCC 7.5.0)
KVX ACB 4.10.0 (GCC 10.3.1)
KVX ACB 4.11.1 (GCC 10.3.1)
KVX ACB 4.12.0 (GCC 11.3.0)
KVX ACB 4.2.0 (GCC 7.5.0)
KVX ACB 4.3.0 (GCC 7.5.0)
KVX ACB 4.4.0 (GCC 7.5.0)
KVX ACB 4.6.0 (GCC 9.4.1)
KVX ACB 4.8.0 (GCC 9.4.1)
KVX ACB 4.9.0 (GCC 9.4.1)
M68K gcc 13.1.0
M68K gcc 13.2.0
M68k clang (trunk)
MRISC32 gcc (trunk)
MSP430 gcc 4.5.3
MSP430 gcc 5.3.0
MSP430 gcc 6.2.1
MinGW clang 14.0.3
MinGW clang 14.0.6
MinGW clang 15.0.7
MinGW clang 16.0.0
MinGW clang 16.0.2
MinGW gcc 11.3.0
MinGW gcc 12.1.0
MinGW gcc 12.2.0
MinGW gcc 13.1.0
RISC-V (32-bits) gcc (trunk)
RISC-V (32-bits) gcc 10.2.0
RISC-V (32-bits) gcc 10.3.0
RISC-V (32-bits) gcc 11.2.0
RISC-V (32-bits) gcc 11.3.0
RISC-V (32-bits) gcc 11.4.0
RISC-V (32-bits) gcc 12.1.0
RISC-V (32-bits) gcc 12.2.0
RISC-V (32-bits) gcc 12.3.0
RISC-V (32-bits) gcc 13.1.0
RISC-V (32-bits) gcc 13.2.0
RISC-V (32-bits) gcc 8.2.0
RISC-V (32-bits) gcc 8.5.0
RISC-V (32-bits) gcc 9.4.0
RISC-V (64-bits) gcc (trunk)
RISC-V (64-bits) gcc 10.2.0
RISC-V (64-bits) gcc 10.3.0
RISC-V (64-bits) gcc 11.2.0
RISC-V (64-bits) gcc 11.3.0
RISC-V (64-bits) gcc 11.4.0
RISC-V (64-bits) gcc 12.1.0
RISC-V (64-bits) gcc 12.2.0
RISC-V (64-bits) gcc 12.3.0
RISC-V (64-bits) gcc 13.1.0
RISC-V (64-bits) gcc 13.2.0
RISC-V (64-bits) gcc 8.2.0
RISC-V (64-bits) gcc 8.5.0
RISC-V (64-bits) gcc 9.4.0
RISC-V rv32gc clang (trunk)
RISC-V rv32gc clang 10.0.0
RISC-V rv32gc clang 10.0.1
RISC-V rv32gc clang 11.0.0
RISC-V rv32gc clang 11.0.1
RISC-V rv32gc clang 12.0.0
RISC-V rv32gc clang 12.0.1
RISC-V rv32gc clang 13.0.0
RISC-V rv32gc clang 13.0.1
RISC-V rv32gc clang 14.0.0
RISC-V rv32gc clang 15.0.0
RISC-V rv32gc clang 16.0.0
RISC-V rv32gc clang 17.0.1
RISC-V rv32gc clang 18.1.0
RISC-V rv32gc clang 9.0.0
RISC-V rv32gc clang 9.0.1
RISC-V rv64gc clang (trunk)
RISC-V rv64gc clang 10.0.0
RISC-V rv64gc clang 10.0.1
RISC-V rv64gc clang 11.0.0
RISC-V rv64gc clang 11.0.1
RISC-V rv64gc clang 12.0.0
RISC-V rv64gc clang 12.0.1
RISC-V rv64gc clang 13.0.0
RISC-V rv64gc clang 13.0.1
RISC-V rv64gc clang 14.0.0
RISC-V rv64gc clang 15.0.0
RISC-V rv64gc clang 16.0.0
RISC-V rv64gc clang 17.0.1
RISC-V rv64gc clang 18.1.0
RISC-V rv64gc clang 9.0.0
RISC-V rv64gc clang 9.0.1
Raspbian Buster
Raspbian Stretch
SPARC LEON gcc 12.2.0
SPARC LEON gcc 12.3.0
SPARC LEON gcc 13.1.0
SPARC LEON gcc 13.2.0
SPARC gcc 12.2.0
SPARC gcc 12.3.0
SPARC gcc 13.1.0
SPARC gcc 13.2.0
SPARC64 gcc 12.2.0
SPARC64 gcc 12.3.0
SPARC64 gcc 13.1.0
SPARC64 gcc 13.2.0
TI C6x gcc 12.2.0
TI C6x gcc 12.3.0
TI C6x gcc 13.1.0
TI C6x gcc 13.2.0
TI CL430 21.6.1
VAX gcc NetBSDELF 10.4.0
VAX gcc NetBSDELF 10.5.0 (Nov 15 03:50:22 2023)
WebAssembly clang (trunk)
Xtensa ESP32 gcc 11.2.0 (2022r1)
Xtensa ESP32 gcc 12.2.0 (20230208)
Xtensa ESP32 gcc 8.2.0 (2019r2)
Xtensa ESP32 gcc 8.2.0 (2020r1)
Xtensa ESP32 gcc 8.2.0 (2020r2)
Xtensa ESP32 gcc 8.4.0 (2020r3)
Xtensa ESP32 gcc 8.4.0 (2021r1)
Xtensa ESP32 gcc 8.4.0 (2021r2)
Xtensa ESP32-S2 gcc 11.2.0 (2022r1)
Xtensa ESP32-S2 gcc 12.2.0 (20230208)
Xtensa ESP32-S2 gcc 8.2.0 (2019r2)
Xtensa ESP32-S2 gcc 8.2.0 (2020r1)
Xtensa ESP32-S2 gcc 8.2.0 (2020r2)
Xtensa ESP32-S2 gcc 8.4.0 (2020r3)
Xtensa ESP32-S2 gcc 8.4.0 (2021r1)
Xtensa ESP32-S2 gcc 8.4.0 (2021r2)
Xtensa ESP32-S3 gcc 11.2.0 (2022r1)
Xtensa ESP32-S3 gcc 12.2.0 (20230208)
Xtensa ESP32-S3 gcc 8.4.0 (2020r3)
Xtensa ESP32-S3 gcc 8.4.0 (2021r1)
Xtensa ESP32-S3 gcc 8.4.0 (2021r2)
arm64 msvc v19.28 VS16.9
arm64 msvc v19.29 VS16.10
arm64 msvc v19.29 VS16.11
arm64 msvc v19.30
arm64 msvc v19.31
arm64 msvc v19.32
arm64 msvc v19.33
arm64 msvc v19.34
arm64 msvc v19.35
arm64 msvc v19.36
arm64 msvc v19.37
arm64 msvc v19.38
arm64 msvc v19.latest
armv7-a clang (trunk)
armv7-a clang 10.0.0
armv7-a clang 10.0.1
armv7-a clang 11.0.0
armv7-a clang 11.0.1
armv7-a clang 9.0.0
armv7-a clang 9.0.1
armv8-a clang (all architectural features, trunk)
armv8-a clang (trunk)
armv8-a clang 10.0.0
armv8-a clang 10.0.1
armv8-a clang 11.0.0
armv8-a clang 11.0.1
armv8-a clang 12.0.0
armv8-a clang 13.0.0
armv8-a clang 14.0.0
armv8-a clang 15.0.0
armv8-a clang 16.0.0
armv8-a clang 17.0.1
armv8-a clang 18.1.0
armv8-a clang 9.0.0
armv8-a clang 9.0.1
ellcc 0.1.33
ellcc 0.1.34
ellcc 2017-07-16
hexagon-clang 16.0.5
llvm-mos atari2600-3e
llvm-mos atari2600-4k
llvm-mos atari2600-common
llvm-mos atari5200-supercart
llvm-mos atari8-cart-megacart
llvm-mos atari8-cart-std
llvm-mos atari8-cart-xegs
llvm-mos atari8-common
llvm-mos atari8-dos
llvm-mos c128
llvm-mos c64
llvm-mos commodore
llvm-mos cpm65
llvm-mos cx16
llvm-mos dodo
llvm-mos eater
llvm-mos mega65
llvm-mos nes
llvm-mos nes-action53
llvm-mos nes-cnrom
llvm-mos nes-gtrom
llvm-mos nes-mmc1
llvm-mos nes-mmc3
llvm-mos nes-nrom
llvm-mos nes-unrom
llvm-mos nes-unrom-512
llvm-mos osi-c1p
llvm-mos pce
llvm-mos pce-cd
llvm-mos pce-common
llvm-mos pet
llvm-mos rp6502
llvm-mos rpc8e
llvm-mos supervision
llvm-mos vic20
loongarch64 gcc 12.2.0
loongarch64 gcc 12.3.0
loongarch64 gcc 13.1.0
loongarch64 gcc 13.2.0
mips clang 13.0.0
mips clang 14.0.0
mips clang 15.0.0
mips clang 16.0.0
mips clang 17.0.1
mips clang 18.1.0
mips gcc 11.2.0
mips gcc 12.1.0
mips gcc 12.2.0
mips gcc 12.3.0
mips gcc 13.1.0
mips gcc 13.2.0
mips gcc 4.9.4
mips gcc 5.4
mips gcc 5.5.0
mips gcc 9.3.0 (codescape)
mips gcc 9.5.0
mips64 (el) gcc 12.1.0
mips64 (el) gcc 12.2.0
mips64 (el) gcc 12.3.0
mips64 (el) gcc 13.1.0
mips64 (el) gcc 13.2.0
mips64 (el) gcc 4.9.4
mips64 (el) gcc 5.4.0
mips64 (el) gcc 5.5.0
mips64 (el) gcc 9.5.0
mips64 clang 13.0.0
mips64 clang 14.0.0
mips64 clang 15.0.0
mips64 clang 16.0.0
mips64 clang 17.0.1
mips64 clang 18.1.0
mips64 gcc 11.2.0
mips64 gcc 12.1.0
mips64 gcc 12.2.0
mips64 gcc 12.3.0
mips64 gcc 13.1.0
mips64 gcc 13.2.0
mips64 gcc 4.9.4
mips64 gcc 5.4.0
mips64 gcc 5.5.0
mips64 gcc 9.5.0
mips64el clang 13.0.0
mips64el clang 14.0.0
mips64el clang 15.0.0
mips64el clang 16.0.0
mips64el clang 17.0.1
mips64el clang 18.1.0
mipsel clang 13.0.0
mipsel clang 14.0.0
mipsel clang 15.0.0
mipsel clang 16.0.0
mipsel clang 17.0.1
mipsel clang 18.1.0
mipsel gcc 12.1.0
mipsel gcc 12.2.0
mipsel gcc 12.3.0
mipsel gcc 13.1.0
mipsel gcc 13.2.0
mipsel gcc 4.9.4
mipsel gcc 5.4.0
mipsel gcc 5.5.0
mipsel gcc 9.5.0
nanoMIPS gcc 6.3.0 (mtk)
power gcc 11.2.0
power gcc 12.1.0
power gcc 12.2.0
power gcc 12.3.0
power gcc 13.1.0
power gcc 13.2.0
power gcc 4.8.5
power64 AT12.0 (gcc8)
power64 AT13.0 (gcc9)
power64 gcc 11.2.0
power64 gcc 12.1.0
power64 gcc 12.2.0
power64 gcc 12.3.0
power64 gcc 13.1.0
power64 gcc 13.2.0
power64 gcc trunk
power64le AT12.0 (gcc8)
power64le AT13.0 (gcc9)
power64le clang (trunk)
power64le gcc 11.2.0
power64le gcc 12.1.0
power64le gcc 12.2.0
power64le gcc 12.3.0
power64le gcc 13.1.0
power64le gcc 13.2.0
power64le gcc 6.3.0
power64le gcc trunk
powerpc64 clang (trunk)
s390x gcc 11.2.0
s390x gcc 12.1.0
s390x gcc 12.2.0
s390x gcc 12.3.0
s390x gcc 13.1.0
s390x gcc 13.2.0
sh gcc 12.2.0
sh gcc 12.3.0
sh gcc 13.1.0
sh gcc 13.2.0
sh gcc 4.9.4
sh gcc 9.5.0
vast (trunk)
x64 msvc v19.0 (WINE)
x64 msvc v19.10 (WINE)
x64 msvc v19.14
x64 msvc v19.14 (WINE)
x64 msvc v19.15
x64 msvc v19.16
x64 msvc v19.20
x64 msvc v19.21
x64 msvc v19.22
x64 msvc v19.23
x64 msvc v19.24
x64 msvc v19.25
x64 msvc v19.26
x64 msvc v19.27
x64 msvc v19.28
x64 msvc v19.28 VS16.9
x64 msvc v19.29 VS16.10
x64 msvc v19.29 VS16.11
x64 msvc v19.30
x64 msvc v19.31
x64 msvc v19.32
x64 msvc v19.33
x64 msvc v19.34
x64 msvc v19.35
x64 msvc v19.36
x64 msvc v19.37
x64 msvc v19.38
x64 msvc v19.latest
x86 djgpp 4.9.4
x86 djgpp 5.5.0
x86 djgpp 6.4.0
x86 djgpp 7.2.0
x86 msvc v19.0 (WINE)
x86 msvc v19.10 (WINE)
x86 msvc v19.14
x86 msvc v19.14 (WINE)
x86 msvc v19.15
x86 msvc v19.16
x86 msvc v19.20
x86 msvc v19.21
x86 msvc v19.22
x86 msvc v19.23
x86 msvc v19.24
x86 msvc v19.25
x86 msvc v19.26
x86 msvc v19.27
x86 msvc v19.28
x86 msvc v19.28 VS16.9
x86 msvc v19.29 VS16.10
x86 msvc v19.29 VS16.11
x86 msvc v19.30
x86 msvc v19.31
x86 msvc v19.32
x86 msvc v19.33
x86 msvc v19.34
x86 msvc v19.35
x86 msvc v19.36
x86 msvc v19.37
x86 msvc v19.38
x86 msvc v19.latest
x86 nvc++ 22.11
x86 nvc++ 22.7
x86 nvc++ 22.9
x86 nvc++ 23.1
x86 nvc++ 23.11
x86 nvc++ 23.3
x86 nvc++ 23.5
x86 nvc++ 23.7
x86 nvc++ 23.9
x86 nvc++ 24.1
x86 nvc++ 24.3
x86-64 Zapcc 190308
x86-64 clang (amd-stg-open)
x86-64 clang (assertions trunk)
x86-64 clang (clangir)
x86-64 clang (experimental -Wlifetime)
x86-64 clang (experimental P1061)
x86-64 clang (experimental P1144)
x86-64 clang (experimental P1221)
x86-64 clang (experimental P2996)
x86-64 clang (experimental metaprogramming - P2632)
x86-64 clang (experimental pattern matching)
x86-64 clang (old concepts branch)
x86-64 clang (reflection)
x86-64 clang (resugar)
x86-64 clang (thephd.dev)
x86-64 clang (trunk)
x86-64 clang (variadic friends - P2893)
x86-64 clang (widberg)
x86-64 clang 10.0.0
x86-64 clang 10.0.0 (assertions)
x86-64 clang 10.0.1
x86-64 clang 11.0.0
x86-64 clang 11.0.0 (assertions)
x86-64 clang 11.0.1
x86-64 clang 12.0.0
x86-64 clang 12.0.0 (assertions)
x86-64 clang 12.0.1
x86-64 clang 13.0.0
x86-64 clang 13.0.0 (assertions)
x86-64 clang 13.0.1
x86-64 clang 14.0.0
x86-64 clang 14.0.0 (assertions)
x86-64 clang 15.0.0
x86-64 clang 15.0.0 (assertions)
x86-64 clang 16.0.0
x86-64 clang 16.0.0 (assertions)
x86-64 clang 17.0.1
x86-64 clang 17.0.1 (assertions)
x86-64 clang 18.1.0
x86-64 clang 18.1.0 (assertions)
x86-64 clang 2.6.0 (assertions)
x86-64 clang 2.7.0 (assertions)
x86-64 clang 2.8.0 (assertions)
x86-64 clang 2.9.0 (assertions)
x86-64 clang 3.0.0
x86-64 clang 3.0.0 (assertions)
x86-64 clang 3.1
x86-64 clang 3.1 (assertions)
x86-64 clang 3.2
x86-64 clang 3.2 (assertions)
x86-64 clang 3.3
x86-64 clang 3.3 (assertions)
x86-64 clang 3.4 (assertions)
x86-64 clang 3.4.1
x86-64 clang 3.5
x86-64 clang 3.5 (assertions)
x86-64 clang 3.5.1
x86-64 clang 3.5.2
x86-64 clang 3.6
x86-64 clang 3.6 (assertions)
x86-64 clang 3.7
x86-64 clang 3.7 (assertions)
x86-64 clang 3.7.1
x86-64 clang 3.8
x86-64 clang 3.8 (assertions)
x86-64 clang 3.8.1
x86-64 clang 3.9.0
x86-64 clang 3.9.0 (assertions)
x86-64 clang 3.9.1
x86-64 clang 4.0.0
x86-64 clang 4.0.0 (assertions)
x86-64 clang 4.0.1
x86-64 clang 5.0.0
x86-64 clang 5.0.0 (assertions)
x86-64 clang 5.0.1
x86-64 clang 5.0.2
x86-64 clang 6.0.0
x86-64 clang 6.0.0 (assertions)
x86-64 clang 6.0.1
x86-64 clang 7.0.0
x86-64 clang 7.0.0 (assertions)
x86-64 clang 7.0.1
x86-64 clang 7.1.0
x86-64 clang 8.0.0
x86-64 clang 8.0.0 (assertions)
x86-64 clang 8.0.1
x86-64 clang 9.0.0
x86-64 clang 9.0.0 (assertions)
x86-64 clang 9.0.1
x86-64 clang rocm-4.5.2
x86-64 clang rocm-5.0.2
x86-64 clang rocm-5.1.3
x86-64 clang rocm-5.2.3
x86-64 clang rocm-5.3.3
x86-64 clang rocm-5.7.0
x86-64 gcc (contract labels)
x86-64 gcc (contracts natural syntax)
x86-64 gcc (contracts)
x86-64 gcc (coroutines)
x86-64 gcc (modules)
x86-64 gcc (trunk)
x86-64 gcc 10.1
x86-64 gcc 10.2
x86-64 gcc 10.3
x86-64 gcc 10.4
x86-64 gcc 10.5
x86-64 gcc 11.1
x86-64 gcc 11.2
x86-64 gcc 11.3
x86-64 gcc 11.4
x86-64 gcc 12.1
x86-64 gcc 12.2
x86-64 gcc 12.3
x86-64 gcc 13.1
x86-64 gcc 13.2
x86-64 gcc 4.1.2
x86-64 gcc 4.4.7
x86-64 gcc 4.5.3
x86-64 gcc 4.6.4
x86-64 gcc 4.7.1
x86-64 gcc 4.7.2
x86-64 gcc 4.7.3
x86-64 gcc 4.7.4
x86-64 gcc 4.8.1
x86-64 gcc 4.8.2
x86-64 gcc 4.8.3
x86-64 gcc 4.8.4
x86-64 gcc 4.8.5
x86-64 gcc 4.9.0
x86-64 gcc 4.9.1
x86-64 gcc 4.9.2
x86-64 gcc 4.9.3
x86-64 gcc 4.9.4
x86-64 gcc 5.1
x86-64 gcc 5.2
x86-64 gcc 5.3
x86-64 gcc 5.4
x86-64 gcc 5.5
x86-64 gcc 6.1
x86-64 gcc 6.2
x86-64 gcc 6.3
x86-64 gcc 6.4
x86-64 gcc 7.1
x86-64 gcc 7.2
x86-64 gcc 7.3
x86-64 gcc 7.4
x86-64 gcc 7.5
x86-64 gcc 8.1
x86-64 gcc 8.2
x86-64 gcc 8.3
x86-64 gcc 8.4
x86-64 gcc 8.5
x86-64 gcc 9.1
x86-64 gcc 9.2
x86-64 gcc 9.3
x86-64 gcc 9.4
x86-64 gcc 9.5
x86-64 icc 13.0.1
x86-64 icc 16.0.3
x86-64 icc 17.0.0
x86-64 icc 18.0.0
x86-64 icc 19.0.0
x86-64 icc 19.0.1
x86-64 icc 2021.1.2
x86-64 icc 2021.10.0
x86-64 icc 2021.2.0
x86-64 icc 2021.3.0
x86-64 icc 2021.4.0
x86-64 icc 2021.5.0
x86-64 icc 2021.6.0
x86-64 icc 2021.7.0
x86-64 icc 2021.7.1
x86-64 icc 2021.8.0
x86-64 icc 2021.9.0
x86-64 icx (latest)
x86-64 icx 2021.1.2
x86-64 icx 2021.2.0
x86-64 icx 2021.3.0
x86-64 icx 2021.4.0
x86-64 icx 2022.0.0
x86-64 icx 2022.1.0
x86-64 icx 2022.2.0
x86-64 icx 2022.2.1
x86-64 icx 2023.0.0
x86-64 icx 2023.1.0
x86-64 icx 2023.2.1
x86-64 icx 2024.0.0
zig c++ 0.10.0
zig c++ 0.11.0
zig c++ 0.6.0
zig c++ 0.7.0
zig c++ 0.7.1
zig c++ 0.8.0
zig c++ 0.9.0
zig c++ trunk
Options
Source code
// Type your code here, or load an example. #include <fstream> #include <iostream> #include <unordered_map> #include "string.h" #ifndef ROBIN_HOOD_H_INCLUDED #define ROBIN_HOOD_H_INCLUDED // see https://semver.org/ #define ROBIN_HOOD_VERSION_MAJOR 3 // for incompatible API changes #define ROBIN_HOOD_VERSION_MINOR 11 // for adding functionality in a backwards-compatible manner #define ROBIN_HOOD_VERSION_PATCH 5 // for backwards-compatible bug fixes #include <algorithm> #include <cstdlib> #include <cstring> #include <functional> #include <limits> #include <memory> // only to support hash of smart pointers #include <stdexcept> #include <string> #include <type_traits> #include <utility> #if __cplusplus >= 201703L # include <string_view> #endif // #define ROBIN_HOOD_LOG_ENABLED #ifdef ROBIN_HOOD_LOG_ENABLED # include <iostream> # define ROBIN_HOOD_LOG(...) \ std::cout << __FUNCTION__ << "@" << __LINE__ << ": " << __VA_ARGS__ << std::endl; #else # define ROBIN_HOOD_LOG(x) #endif // #define ROBIN_HOOD_TRACE_ENABLED #ifdef ROBIN_HOOD_TRACE_ENABLED # include <iostream> # define ROBIN_HOOD_TRACE(...) \ std::cout << __FUNCTION__ << "@" << __LINE__ << ": " << __VA_ARGS__ << std::endl; #else # define ROBIN_HOOD_TRACE(x) #endif // #define ROBIN_HOOD_COUNT_ENABLED #ifdef ROBIN_HOOD_COUNT_ENABLED # include <iostream> # define ROBIN_HOOD_COUNT(x) ++counts().x; namespace robin_hood { struct Counts { uint64_t shiftUp{}; uint64_t shiftDown{}; }; inline std::ostream& operator<<(std::ostream& os, Counts const& c) { return os << c.shiftUp << " shiftUp" << std::endl << c.shiftDown << " shiftDown" << std::endl; } static Counts& counts() { static Counts counts{}; return counts; } } // namespace robin_hood #else # define ROBIN_HOOD_COUNT(x) #endif // all non-argument macros should use this facility. See // https://www.fluentcpp.com/2019/05/28/better-macros-better-flags/ #define ROBIN_HOOD(x) ROBIN_HOOD_PRIVATE_DEFINITION_##x() // mark unused members with this macro #define ROBIN_HOOD_UNUSED(identifier) // bitness #if SIZE_MAX == UINT32_MAX # define ROBIN_HOOD_PRIVATE_DEFINITION_BITNESS() 32 #elif SIZE_MAX == UINT64_MAX # define ROBIN_HOOD_PRIVATE_DEFINITION_BITNESS() 64 #else # error Unsupported bitness #endif // endianess #ifdef _MSC_VER # define ROBIN_HOOD_PRIVATE_DEFINITION_LITTLE_ENDIAN() 1 # define ROBIN_HOOD_PRIVATE_DEFINITION_BIG_ENDIAN() 0 #else # define ROBIN_HOOD_PRIVATE_DEFINITION_LITTLE_ENDIAN() \ (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) # define ROBIN_HOOD_PRIVATE_DEFINITION_BIG_ENDIAN() (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) #endif // inline #ifdef _MSC_VER # define ROBIN_HOOD_PRIVATE_DEFINITION_NOINLINE() __declspec(noinline) #else # define ROBIN_HOOD_PRIVATE_DEFINITION_NOINLINE() __attribute__((noinline)) #endif // exceptions #if !defined(__cpp_exceptions) && !defined(__EXCEPTIONS) && !defined(_CPPUNWIND) # define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_EXCEPTIONS() 0 #else # define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_EXCEPTIONS() 1 #endif // count leading/trailing bits #if !defined(ROBIN_HOOD_DISABLE_INTRINSICS) # ifdef _MSC_VER # if ROBIN_HOOD(BITNESS) == 32 # define ROBIN_HOOD_PRIVATE_DEFINITION_BITSCANFORWARD() _BitScanForward # else # define ROBIN_HOOD_PRIVATE_DEFINITION_BITSCANFORWARD() _BitScanForward64 # endif # include <intrin.h> # pragma intrinsic(ROBIN_HOOD(BITSCANFORWARD)) # define ROBIN_HOOD_COUNT_TRAILING_ZEROES(x) \ [](size_t mask) noexcept -> int { \ unsigned long index; \ return ROBIN_HOOD(BITSCANFORWARD)(&index, mask) ? static_cast<int>(index) \ : ROBIN_HOOD(BITNESS); \ }(x) # else # if ROBIN_HOOD(BITNESS) == 32 # define ROBIN_HOOD_PRIVATE_DEFINITION_CTZ() __builtin_ctzl # define ROBIN_HOOD_PRIVATE_DEFINITION_CLZ() __builtin_clzl # else # define ROBIN_HOOD_PRIVATE_DEFINITION_CTZ() __builtin_ctzll # define ROBIN_HOOD_PRIVATE_DEFINITION_CLZ() __builtin_clzll # endif # define ROBIN_HOOD_COUNT_LEADING_ZEROES(x) ((x) ? ROBIN_HOOD(CLZ)(x) : ROBIN_HOOD(BITNESS)) # define ROBIN_HOOD_COUNT_TRAILING_ZEROES(x) ((x) ? ROBIN_HOOD(CTZ)(x) : ROBIN_HOOD(BITNESS)) # endif #endif // fallthrough #ifndef __has_cpp_attribute // For backwards compatibility # define __has_cpp_attribute(x) 0 #endif #if __has_cpp_attribute(clang::fallthrough) # define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH() [[clang::fallthrough]] #elif __has_cpp_attribute(gnu::fallthrough) # define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH() [[gnu::fallthrough]] #else # define ROBIN_HOOD_PRIVATE_DEFINITION_FALLTHROUGH() #endif // likely/unlikely #ifdef _MSC_VER # define ROBIN_HOOD_LIKELY(condition) condition # define ROBIN_HOOD_UNLIKELY(condition) condition #else # define ROBIN_HOOD_LIKELY(condition) __builtin_expect(condition, 1) # define ROBIN_HOOD_UNLIKELY(condition) __builtin_expect(condition, 0) #endif // detect if native wchar_t type is availiable in MSVC #ifdef _MSC_VER # ifdef _NATIVE_WCHAR_T_DEFINED # define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 1 # else # define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 0 # endif #else # define ROBIN_HOOD_PRIVATE_DEFINITION_HAS_NATIVE_WCHART() 1 #endif // detect if MSVC supports the pair(std::piecewise_construct_t,...) consructor being constexpr #ifdef _MSC_VER # if _MSC_VER <= 1900 # define ROBIN_HOOD_PRIVATE_DEFINITION_BROKEN_CONSTEXPR() 1 # else # define ROBIN_HOOD_PRIVATE_DEFINITION_BROKEN_CONSTEXPR() 0 # endif #else # define ROBIN_HOOD_PRIVATE_DEFINITION_BROKEN_CONSTEXPR() 0 #endif // workaround missing "is_trivially_copyable" in g++ < 5.0 // See https://stackoverflow.com/a/31798726/48181 #if defined(__GNUC__) && __GNUC__ < 5 # define ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(...) __has_trivial_copy(__VA_ARGS__) #else # define ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(...) std::is_trivially_copyable<__VA_ARGS__>::value #endif // helpers for C++ versions, see https://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html #define ROBIN_HOOD_PRIVATE_DEFINITION_CXX() __cplusplus #define ROBIN_HOOD_PRIVATE_DEFINITION_CXX98() 199711L #define ROBIN_HOOD_PRIVATE_DEFINITION_CXX11() 201103L #define ROBIN_HOOD_PRIVATE_DEFINITION_CXX14() 201402L #define ROBIN_HOOD_PRIVATE_DEFINITION_CXX17() 201703L #if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX17) # define ROBIN_HOOD_PRIVATE_DEFINITION_NODISCARD() [[nodiscard]] #else # define ROBIN_HOOD_PRIVATE_DEFINITION_NODISCARD() #endif namespace robin_hood { #if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX14) # define ROBIN_HOOD_STD std #else // c++11 compatibility layer namespace ROBIN_HOOD_STD { template <class T> struct alignment_of : std::integral_constant<std::size_t, alignof(typename std::remove_all_extents<T>::type)> {}; template <class T, T... Ints> class integer_sequence { public: using value_type = T; static_assert(std::is_integral<value_type>::value, "not integral type"); static constexpr std::size_t size() noexcept { return sizeof...(Ints); } }; template <std::size_t... Inds> using index_sequence = integer_sequence<std::size_t, Inds...>; namespace detail_ { template <class T, T Begin, T End, bool> struct IntSeqImpl { using TValue = T; static_assert(std::is_integral<TValue>::value, "not integral type"); static_assert(Begin >= 0 && Begin < End, "unexpected argument (Begin<0 || Begin<=End)"); template <class, class> struct IntSeqCombiner; template <TValue... Inds0, TValue... Inds1> struct IntSeqCombiner<integer_sequence<TValue, Inds0...>, integer_sequence<TValue, Inds1...>> { using TResult = integer_sequence<TValue, Inds0..., Inds1...>; }; using TResult = typename IntSeqCombiner<typename IntSeqImpl<TValue, Begin, Begin + (End - Begin) / 2, (End - Begin) / 2 == 1>::TResult, typename IntSeqImpl<TValue, Begin + (End - Begin) / 2, End, (End - Begin + 1) / 2 == 1>::TResult>::TResult; }; template <class T, T Begin> struct IntSeqImpl<T, Begin, Begin, false> { using TValue = T; static_assert(std::is_integral<TValue>::value, "not integral type"); static_assert(Begin >= 0, "unexpected argument (Begin<0)"); using TResult = integer_sequence<TValue>; }; template <class T, T Begin, T End> struct IntSeqImpl<T, Begin, End, true> { using TValue = T; static_assert(std::is_integral<TValue>::value, "not integral type"); static_assert(Begin >= 0, "unexpected argument (Begin<0)"); using TResult = integer_sequence<TValue, Begin>; }; } // namespace detail_ template <class T, T N> using make_integer_sequence = typename detail_::IntSeqImpl<T, 0, N, (N - 0) == 1>::TResult; template <std::size_t N> using make_index_sequence = make_integer_sequence<std::size_t, N>; template <class... T> using index_sequence_for = make_index_sequence<sizeof...(T)>; } // namespace ROBIN_HOOD_STD #endif namespace detail { // make sure we static_cast to the correct type for hash_int #if ROBIN_HOOD(BITNESS) == 64 using SizeT = uint64_t; #else using SizeT = uint32_t; #endif template <typename T> T rotr(T x, unsigned k) { return (x >> k) | (x << (8U * sizeof(T) - k)); } // This cast gets rid of warnings like "cast from 'uint8_t*' {aka 'unsigned char*'} to // 'uint64_t*' {aka 'long unsigned int*'} increases required alignment of target type". Use with // care! template <typename T> inline T reinterpret_cast_no_cast_align_warning(void* ptr) noexcept { return reinterpret_cast<T>(ptr); } template <typename T> inline T reinterpret_cast_no_cast_align_warning(void const* ptr) noexcept { return reinterpret_cast<T>(ptr); } // make sure this is not inlined as it is slow and dramatically enlarges code, thus making other // inlinings more difficult. Throws are also generally the slow path. template <typename E, typename... Args> [[noreturn]] ROBIN_HOOD(NOINLINE) #if ROBIN_HOOD(HAS_EXCEPTIONS) void doThrow(Args&&... args) { // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-array-to-pointer-decay) throw E(std::forward<Args>(args)...); } #else void doThrow(Args&&... ROBIN_HOOD_UNUSED(args) /*unused*/) { abort(); } #endif template <typename E, typename T, typename... Args> T* assertNotNull(T* t, Args&&... args) { if (ROBIN_HOOD_UNLIKELY(nullptr == t)) { doThrow<E>(std::forward<Args>(args)...); } return t; } template <typename T> inline T unaligned_load(void const* ptr) noexcept { // using memcpy so we don't get into unaligned load problems. // compiler should optimize this very well anyways. T t; std::memcpy(&t, ptr, sizeof(T)); return t; } // Allocates bulks of memory for objects of type T. This deallocates the memory in the destructor, // and keeps a linked list of the allocated memory around. Overhead per allocation is the size of a // pointer. template <typename T, size_t MinNumAllocs = 4, size_t MaxNumAllocs = 256> class BulkPoolAllocator { public: BulkPoolAllocator() noexcept = default; // does not copy anything, just creates a new allocator. BulkPoolAllocator(const BulkPoolAllocator& ROBIN_HOOD_UNUSED(o) /*unused*/) noexcept : mHead(nullptr) , mListForFree(nullptr) {} BulkPoolAllocator(BulkPoolAllocator&& o) noexcept : mHead(o.mHead) , mListForFree(o.mListForFree) { o.mListForFree = nullptr; o.mHead = nullptr; } BulkPoolAllocator& operator=(BulkPoolAllocator&& o) noexcept { reset(); mHead = o.mHead; mListForFree = o.mListForFree; o.mListForFree = nullptr; o.mHead = nullptr; return *this; } BulkPoolAllocator& // NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp) operator=(const BulkPoolAllocator& ROBIN_HOOD_UNUSED(o) /*unused*/) noexcept { // does not do anything return *this; } ~BulkPoolAllocator() noexcept { reset(); } // Deallocates all allocated memory. void reset() noexcept { while (mListForFree) { T* tmp = *mListForFree; ROBIN_HOOD_LOG("std::free") std::free(mListForFree); mListForFree = reinterpret_cast_no_cast_align_warning<T**>(tmp); } mHead = nullptr; } // allocates, but does NOT initialize. Use in-place new constructor, e.g. // T* obj = pool.allocate(); // ::new (static_cast<void*>(obj)) T(); T* allocate() { T* tmp = mHead; if (!tmp) { tmp = performAllocation(); } mHead = *reinterpret_cast_no_cast_align_warning<T**>(tmp); return tmp; } // does not actually deallocate but puts it in store. // make sure you have already called the destructor! e.g. with // obj->~T(); // pool.deallocate(obj); void deallocate(T* obj) noexcept { *reinterpret_cast_no_cast_align_warning<T**>(obj) = mHead; mHead = obj; } // Adds an already allocated block of memory to the allocator. This allocator is from now on // responsible for freeing the data (with free()). If the provided data is not large enough to // make use of, it is immediately freed. Otherwise it is reused and freed in the destructor. void addOrFree(void* ptr, const size_t numBytes) noexcept { // calculate number of available elements in ptr if (numBytes < ALIGNMENT + ALIGNED_SIZE) { // not enough data for at least one element. Free and return. ROBIN_HOOD_LOG("std::free") std::free(ptr); } else { ROBIN_HOOD_LOG("add to buffer") add(ptr, numBytes); } } void swap(BulkPoolAllocator<T, MinNumAllocs, MaxNumAllocs>& other) noexcept { using std::swap; swap(mHead, other.mHead); swap(mListForFree, other.mListForFree); } private: // iterates the list of allocated memory to calculate how many to alloc next. // Recalculating this each time saves us a size_t member. // This ignores the fact that memory blocks might have been added manually with addOrFree. In // practice, this should not matter much. ROBIN_HOOD(NODISCARD) size_t calcNumElementsToAlloc() const noexcept { auto tmp = mListForFree; size_t numAllocs = MinNumAllocs; while (numAllocs * 2 <= MaxNumAllocs && tmp) { auto x = reinterpret_cast<T***>(tmp); tmp = *x; numAllocs *= 2; } return numAllocs; } // WARNING: Underflow if numBytes < ALIGNMENT! This is guarded in addOrFree(). void add(void* ptr, const size_t numBytes) noexcept { const size_t numElements = (numBytes - ALIGNMENT) / ALIGNED_SIZE; auto data = reinterpret_cast<T**>(ptr); // link free list auto x = reinterpret_cast<T***>(data); *x = mListForFree; mListForFree = data; // create linked list for newly allocated data auto* const headT = reinterpret_cast_no_cast_align_warning<T*>(reinterpret_cast<char*>(ptr) + ALIGNMENT); auto* const head = reinterpret_cast<char*>(headT); // Visual Studio compiler automatically unrolls this loop, which is pretty cool for (size_t i = 0; i < numElements; ++i) { *reinterpret_cast_no_cast_align_warning<char**>(head + i * ALIGNED_SIZE) = head + (i + 1) * ALIGNED_SIZE; } // last one points to 0 *reinterpret_cast_no_cast_align_warning<T**>(head + (numElements - 1) * ALIGNED_SIZE) = mHead; mHead = headT; } // Called when no memory is available (mHead == 0). // Don't inline this slow path. ROBIN_HOOD(NOINLINE) T* performAllocation() { size_t const numElementsToAlloc = calcNumElementsToAlloc(); // alloc new memory: [prev |T, T, ... T] size_t const bytes = ALIGNMENT + ALIGNED_SIZE * numElementsToAlloc; ROBIN_HOOD_LOG("std::malloc " << bytes << " = " << ALIGNMENT << " + " << ALIGNED_SIZE << " * " << numElementsToAlloc) add(assertNotNull<std::bad_alloc>(std::malloc(bytes)), bytes); return mHead; } // enforce byte alignment of the T's #if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX14) static constexpr size_t ALIGNMENT = (std::max)(std::alignment_of<T>::value, std::alignment_of<T*>::value); #else static const size_t ALIGNMENT = (ROBIN_HOOD_STD::alignment_of<T>::value > ROBIN_HOOD_STD::alignment_of<T*>::value) ? ROBIN_HOOD_STD::alignment_of<T>::value : +ROBIN_HOOD_STD::alignment_of<T*>::value; // the + is for walkarround #endif static constexpr size_t ALIGNED_SIZE = ((sizeof(T) - 1) / ALIGNMENT + 1) * ALIGNMENT; static_assert(MinNumAllocs >= 1, "MinNumAllocs"); static_assert(MaxNumAllocs >= MinNumAllocs, "MaxNumAllocs"); static_assert(ALIGNED_SIZE >= sizeof(T*), "ALIGNED_SIZE"); static_assert(0 == (ALIGNED_SIZE % sizeof(T*)), "ALIGNED_SIZE mod"); static_assert(ALIGNMENT >= sizeof(T*), "ALIGNMENT"); T* mHead{nullptr}; T** mListForFree{nullptr}; }; template <typename T, size_t MinSize, size_t MaxSize, bool IsFlat> struct NodeAllocator; // dummy allocator that does nothing template <typename T, size_t MinSize, size_t MaxSize> struct NodeAllocator<T, MinSize, MaxSize, true> { // we are not using the data, so just free it. void addOrFree(void* ptr, size_t ROBIN_HOOD_UNUSED(numBytes) /*unused*/) noexcept { ROBIN_HOOD_LOG("std::free") std::free(ptr); } }; template <typename T, size_t MinSize, size_t MaxSize> struct NodeAllocator<T, MinSize, MaxSize, false> : public BulkPoolAllocator<T, MinSize, MaxSize> {}; // c++14 doesn't have is_nothrow_swappable, and clang++ 6.0.1 doesn't like it either, so I'm making // my own here. namespace swappable { #if ROBIN_HOOD(CXX) < ROBIN_HOOD(CXX17) using std::swap; template <typename T> struct nothrow { static const bool value = noexcept(swap(std::declval<T&>(), std::declval<T&>())); }; #else template <typename T> struct nothrow { static const bool value = std::is_nothrow_swappable<T>::value; }; #endif } // namespace swappable } // namespace detail struct is_transparent_tag {}; // A custom pair implementation is used in the map because std::pair is not is_trivially_copyable, // which means it would not be allowed to be used in std::memcpy. This struct is copyable, which is // also tested. template <typename T1, typename T2> struct pair { using first_type = T1; using second_type = T2; template <typename U1 = T1, typename U2 = T2, typename = typename std::enable_if<std::is_default_constructible<U1>::value && std::is_default_constructible<U2>::value>::type> constexpr pair() noexcept(noexcept(U1()) && noexcept(U2())) : first() , second() {} // pair constructors are explicit so we don't accidentally call this ctor when we don't have to. explicit constexpr pair(std::pair<T1, T2> const& o) noexcept( noexcept(T1(std::declval<T1 const&>())) && noexcept(T2(std::declval<T2 const&>()))) : first(o.first) , second(o.second) {} // pair constructors are explicit so we don't accidentally call this ctor when we don't have to. explicit constexpr pair(std::pair<T1, T2>&& o) noexcept(noexcept( T1(std::move(std::declval<T1&&>()))) && noexcept(T2(std::move(std::declval<T2&&>())))) : first(std::move(o.first)) , second(std::move(o.second)) {} constexpr pair(T1&& a, T2&& b) noexcept(noexcept( T1(std::move(std::declval<T1&&>()))) && noexcept(T2(std::move(std::declval<T2&&>())))) : first(std::move(a)) , second(std::move(b)) {} template <typename U1, typename U2> constexpr pair(U1&& a, U2&& b) noexcept(noexcept(T1(std::forward<U1>( std::declval<U1&&>()))) && noexcept(T2(std::forward<U2>(std::declval<U2&&>())))) : first(std::forward<U1>(a)) , second(std::forward<U2>(b)) {} template <typename... U1, typename... U2> // MSVC 2015 produces error "C2476: ‘constexpr’ constructor does not initialize all members" // if this constructor is constexpr #if !ROBIN_HOOD(BROKEN_CONSTEXPR) constexpr #endif pair(std::piecewise_construct_t /*unused*/, std::tuple<U1...> a, std::tuple<U2...> b) noexcept(noexcept(pair(std::declval<std::tuple<U1...>&>(), std::declval<std::tuple<U2...>&>(), ROBIN_HOOD_STD::index_sequence_for<U1...>(), ROBIN_HOOD_STD::index_sequence_for<U2...>()))) : pair(a, b, ROBIN_HOOD_STD::index_sequence_for<U1...>(), ROBIN_HOOD_STD::index_sequence_for<U2...>()) { } // constructor called from the std::piecewise_construct_t ctor template <typename... U1, size_t... I1, typename... U2, size_t... I2> pair(std::tuple<U1...>& a, std::tuple<U2...>& b, ROBIN_HOOD_STD::index_sequence<I1...> /*unused*/, ROBIN_HOOD_STD::index_sequence<I2...> /*unused*/) noexcept( noexcept(T1(std::forward<U1>(std::get<I1>( std::declval<std::tuple< U1...>&>()))...)) && noexcept(T2(std:: forward<U2>(std::get<I2>( std::declval<std::tuple<U2...>&>()))...))) : first(std::forward<U1>(std::get<I1>(a))...) , second(std::forward<U2>(std::get<I2>(b))...) { // make visual studio compiler happy about warning about unused a & b. // Visual studio's pair implementation disables warning 4100. (void)a; (void)b; } void swap(pair<T1, T2>& o) noexcept((detail::swappable::nothrow<T1>::value) && (detail::swappable::nothrow<T2>::value)) { using std::swap; swap(first, o.first); swap(second, o.second); } T1 first; // NOLINT(misc-non-private-member-variables-in-classes) T2 second; // NOLINT(misc-non-private-member-variables-in-classes) }; template <typename A, typename B> inline void swap(pair<A, B>& a, pair<A, B>& b) noexcept( noexcept(std::declval<pair<A, B>&>().swap(std::declval<pair<A, B>&>()))) { a.swap(b); } template <typename A, typename B> inline constexpr bool operator==(pair<A, B> const& x, pair<A, B> const& y) { return (x.first == y.first) && (x.second == y.second); } template <typename A, typename B> inline constexpr bool operator!=(pair<A, B> const& x, pair<A, B> const& y) { return !(x == y); } template <typename A, typename B> inline constexpr bool operator<(pair<A, B> const& x, pair<A, B> const& y) noexcept(noexcept( std::declval<A const&>() < std::declval<A const&>()) && noexcept(std::declval<B const&>() < std::declval<B const&>())) { return x.first < y.first || (!(y.first < x.first) && x.second < y.second); } template <typename A, typename B> inline constexpr bool operator>(pair<A, B> const& x, pair<A, B> const& y) { return y < x; } template <typename A, typename B> inline constexpr bool operator<=(pair<A, B> const& x, pair<A, B> const& y) { return !(x > y); } template <typename A, typename B> inline constexpr bool operator>=(pair<A, B> const& x, pair<A, B> const& y) { return !(x < y); } inline size_t hash_bytes(void const* ptr, size_t len) noexcept { static constexpr uint64_t m = UINT64_C(0xc6a4a7935bd1e995); static constexpr uint64_t seed = UINT64_C(0xe17a1465); static constexpr unsigned int r = 47; auto const* const data64 = static_cast<uint64_t const*>(ptr); uint64_t h = seed ^ (len * m); size_t const n_blocks = len / 8; for (size_t i = 0; i < n_blocks; ++i) { auto k = detail::unaligned_load<uint64_t>(data64 + i); k *= m; k ^= k >> r; k *= m; h ^= k; h *= m; } auto const* const data8 = reinterpret_cast<uint8_t const*>(data64 + n_blocks); switch (len & 7U) { case 7: h ^= static_cast<uint64_t>(data8[6]) << 48U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 6: h ^= static_cast<uint64_t>(data8[5]) << 40U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 5: h ^= static_cast<uint64_t>(data8[4]) << 32U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 4: h ^= static_cast<uint64_t>(data8[3]) << 24U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 3: h ^= static_cast<uint64_t>(data8[2]) << 16U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 2: h ^= static_cast<uint64_t>(data8[1]) << 8U; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH case 1: h ^= static_cast<uint64_t>(data8[0]); h *= m; ROBIN_HOOD(FALLTHROUGH); // FALLTHROUGH default: break; } h ^= h >> r; // not doing the final step here, because this will be done by keyToIdx anyways // h *= m; // h ^= h >> r; return static_cast<size_t>(h); } inline size_t hash_int(uint64_t x) noexcept { // tried lots of different hashes, let's stick with murmurhash3. It's simple, fast, well tested, // and doesn't need any special 128bit operations. x ^= x >> 33U; x *= UINT64_C(0xff51afd7ed558ccd); x ^= x >> 33U; // not doing the final step here, because this will be done by keyToIdx anyways // x *= UINT64_C(0xc4ceb9fe1a85ec53); // x ^= x >> 33U; return static_cast<size_t>(x); } // A thin wrapper around std::hash, performing an additional simple mixing step of the result. template <typename T, typename Enable = void> struct hash : public std::hash<T> { size_t operator()(T const& obj) const noexcept(noexcept(std::declval<std::hash<T>>().operator()(std::declval<T const&>()))) { // call base hash auto result = std::hash<T>::operator()(obj); // return mixed of that, to be save against identity has return hash_int(static_cast<detail::SizeT>(result)); } }; template <typename CharT> struct hash<std::basic_string<CharT>> { size_t operator()(std::basic_string<CharT> const& str) const noexcept { return hash_bytes(str.data(), sizeof(CharT) * str.size()); } }; #if ROBIN_HOOD(CXX) >= ROBIN_HOOD(CXX17) template <typename CharT> struct hash<std::basic_string_view<CharT>> { size_t operator()(std::basic_string_view<CharT> const& sv) const noexcept { return hash_bytes(sv.data(), sizeof(CharT) * sv.size()); } }; #endif template <class T> struct hash<T*> { size_t operator()(T* ptr) const noexcept { return hash_int(reinterpret_cast<detail::SizeT>(ptr)); } }; template <class T> struct hash<std::unique_ptr<T>> { size_t operator()(std::unique_ptr<T> const& ptr) const noexcept { return hash_int(reinterpret_cast<detail::SizeT>(ptr.get())); } }; template <class T> struct hash<std::shared_ptr<T>> { size_t operator()(std::shared_ptr<T> const& ptr) const noexcept { return hash_int(reinterpret_cast<detail::SizeT>(ptr.get())); } }; template <typename Enum> struct hash<Enum, typename std::enable_if<std::is_enum<Enum>::value>::type> { size_t operator()(Enum e) const noexcept { using Underlying = typename std::underlying_type<Enum>::type; return hash<Underlying>{}(static_cast<Underlying>(e)); } }; #define ROBIN_HOOD_HASH_INT(T) \ template <> \ struct hash<T> { \ size_t operator()(T const& obj) const noexcept { \ return hash_int(static_cast<uint64_t>(obj)); \ } \ } #if defined(__GNUC__) && !defined(__clang__) # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wuseless-cast" #endif // see https://en.cppreference.com/w/cpp/utility/hash ROBIN_HOOD_HASH_INT(bool); ROBIN_HOOD_HASH_INT(char); ROBIN_HOOD_HASH_INT(signed char); ROBIN_HOOD_HASH_INT(unsigned char); ROBIN_HOOD_HASH_INT(char16_t); ROBIN_HOOD_HASH_INT(char32_t); #if ROBIN_HOOD(HAS_NATIVE_WCHART) ROBIN_HOOD_HASH_INT(wchar_t); #endif ROBIN_HOOD_HASH_INT(short); ROBIN_HOOD_HASH_INT(unsigned short); ROBIN_HOOD_HASH_INT(int); ROBIN_HOOD_HASH_INT(unsigned int); ROBIN_HOOD_HASH_INT(long); ROBIN_HOOD_HASH_INT(long long); ROBIN_HOOD_HASH_INT(unsigned long); ROBIN_HOOD_HASH_INT(unsigned long long); #if defined(__GNUC__) && !defined(__clang__) # pragma GCC diagnostic pop #endif namespace detail { template <typename T> struct void_type { using type = void; }; template <typename T, typename = void> struct has_is_transparent : public std::false_type {}; template <typename T> struct has_is_transparent<T, typename void_type<typename T::is_transparent>::type> : public std::true_type {}; // using wrapper classes for hash and key_equal prevents the diamond problem when the same type // is used. see https://stackoverflow.com/a/28771920/48181 template <typename T> struct WrapHash : public T { WrapHash() = default; explicit WrapHash(T const& o) noexcept(noexcept(T(std::declval<T const&>()))) : T(o) {} }; template <typename T> struct WrapKeyEqual : public T { WrapKeyEqual() = default; explicit WrapKeyEqual(T const& o) noexcept(noexcept(T(std::declval<T const&>()))) : T(o) {} }; // A highly optimized hashmap implementation, using the Robin Hood algorithm. // // In most cases, this map should be usable as a drop-in replacement for std::unordered_map, but // be about 2x faster in most cases and require much less allocations. // // This implementation uses the following memory layout: // // [Node, Node, ... Node | info, info, ... infoSentinel ] // // * Node: either a DataNode that directly has the std::pair<key, val> as member, // or a DataNode with a pointer to std::pair<key,val>. Which DataNode representation to use // depends on how fast the swap() operation is. Heuristically, this is automatically choosen // based on sizeof(). there are always 2^n Nodes. // // * info: Each Node in the map has a corresponding info byte, so there are 2^n info bytes. // Each byte is initialized to 0, meaning the corresponding Node is empty. Set to 1 means the // corresponding node contains data. Set to 2 means the corresponding Node is filled, but it // actually belongs to the previous position and was pushed out because that place is already // taken. // // * infoSentinel: Sentinel byte set to 1, so that iterator's ++ can stop at end() without the // need for a idx variable. // // According to STL, order of templates has effect on throughput. That's why I've moved the // boolean to the front. // https://www.reddit.com/r/cpp/comments/ahp6iu/compile_time_binary_size_reductions_and_cs_future/eeguck4/ template <bool IsFlat, size_t MaxLoadFactor100, typename Key, typename T, typename Hash, typename KeyEqual> class Table : public WrapHash<Hash>, public WrapKeyEqual<KeyEqual>, detail::NodeAllocator< typename std::conditional< std::is_void<T>::value, Key, robin_hood::pair<typename std::conditional<IsFlat, Key, Key const>::type, T>>::type, 4, 16384, IsFlat> { public: static constexpr bool is_flat = IsFlat; static constexpr bool is_map = !std::is_void<T>::value; static constexpr bool is_set = !is_map; static constexpr bool is_transparent = has_is_transparent<Hash>::value && has_is_transparent<KeyEqual>::value; using key_type = Key; using mapped_type = T; using value_type = typename std::conditional< is_set, Key, robin_hood::pair<typename std::conditional<is_flat, Key, Key const>::type, T>>::type; using size_type = size_t; using hasher = Hash; using key_equal = KeyEqual; using Self = Table<IsFlat, MaxLoadFactor100, key_type, mapped_type, hasher, key_equal>; private: static_assert(MaxLoadFactor100 > 10 && MaxLoadFactor100 < 100, "MaxLoadFactor100 needs to be >10 && < 100"); using WHash = WrapHash<Hash>; using WKeyEqual = WrapKeyEqual<KeyEqual>; // configuration defaults // make sure we have 8 elements, needed to quickly rehash mInfo static constexpr size_t InitialNumElements = sizeof(uint64_t); static constexpr uint32_t InitialInfoNumBits = 5; static constexpr uint8_t InitialInfoInc = 1U << InitialInfoNumBits; static constexpr size_t InfoMask = InitialInfoInc - 1U; static constexpr uint8_t InitialInfoHashShift = 0; using DataPool = detail::NodeAllocator<value_type, 4, 16384, IsFlat>; // type needs to be wider than uint8_t. using InfoType = uint32_t; // DataNode //////////////////////////////////////////////////////// // Primary template for the data node. We have special implementations for small and big // objects. For large objects it is assumed that swap() is fairly slow, so we allocate these // on the heap so swap merely swaps a pointer. template <typename M, bool> class DataNode {}; // Small: just allocate on the stack. template <typename M> class DataNode<M, true> final { public: template <typename... Args> explicit DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, Args&&... args) noexcept( noexcept(value_type(std::forward<Args>(args)...))) : mData(std::forward<Args>(args)...) {} DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, DataNode<M, true>&& n) noexcept( std::is_nothrow_move_constructible<value_type>::value) : mData(std::move(n.mData)) {} // doesn't do anything void destroy(M& ROBIN_HOOD_UNUSED(map) /*unused*/) noexcept {} void destroyDoNotDeallocate() noexcept {} value_type const* operator->() const noexcept { return &mData; } value_type* operator->() noexcept { return &mData; } const value_type& operator*() const noexcept { return mData; } value_type& operator*() noexcept { return mData; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, typename VT::first_type&>::type getFirst() noexcept { return mData.first; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_set, VT&>::type getFirst() noexcept { return mData; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, typename VT::first_type const&>::type getFirst() const noexcept { return mData.first; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_set, VT const&>::type getFirst() const noexcept { return mData; } template <typename MT = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, MT&>::type getSecond() noexcept { return mData.second; } template <typename MT = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_set, MT const&>::type getSecond() const noexcept { return mData.second; } void swap(DataNode<M, true>& o) noexcept( noexcept(std::declval<value_type>().swap(std::declval<value_type>()))) { mData.swap(o.mData); } private: value_type mData; }; // big object: allocate on heap. template <typename M> class DataNode<M, false> { public: template <typename... Args> explicit DataNode(M& map, Args&&... args) : mData(map.allocate()) { ::new (static_cast<void*>(mData)) value_type(std::forward<Args>(args)...); } DataNode(M& ROBIN_HOOD_UNUSED(map) /*unused*/, DataNode<M, false>&& n) noexcept : mData(std::move(n.mData)) {} void destroy(M& map) noexcept { // don't deallocate, just put it into list of datapool. mData->~value_type(); map.deallocate(mData); } void destroyDoNotDeallocate() noexcept { mData->~value_type(); } value_type const* operator->() const noexcept { return mData; } value_type* operator->() noexcept { return mData; } const value_type& operator*() const { return *mData; } value_type& operator*() { return *mData; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, typename VT::first_type&>::type getFirst() noexcept { return mData->first; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_set, VT&>::type getFirst() noexcept { return *mData; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, typename VT::first_type const&>::type getFirst() const noexcept { return mData->first; } template <typename VT = value_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_set, VT const&>::type getFirst() const noexcept { return *mData; } template <typename MT = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, MT&>::type getSecond() noexcept { return mData->second; } template <typename MT = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<is_map, MT const&>::type getSecond() const noexcept { return mData->second; } void swap(DataNode<M, false>& o) noexcept { using std::swap; swap(mData, o.mData); } private: value_type* mData; }; using Node = DataNode<Self, IsFlat>; // helpers for insertKeyPrepareEmptySpot: extract first entry (only const required) ROBIN_HOOD(NODISCARD) key_type const& getFirstConst(Node const& n) const noexcept { return n.getFirst(); } // in case we have void mapped_type, we are not using a pair, thus we just route k through. // No need to disable this because it's just not used if not applicable. ROBIN_HOOD(NODISCARD) key_type const& getFirstConst(key_type const& k) const noexcept { return k; } // in case we have non-void mapped_type, we have a standard robin_hood::pair template <typename Q = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<!std::is_void<Q>::value, key_type const&>::type getFirstConst(value_type const& vt) const noexcept { return vt.first; } // Cloner ////////////////////////////////////////////////////////// template <typename M, bool UseMemcpy> struct Cloner; // fast path: Just copy data, without allocating anything. template <typename M> struct Cloner<M, true> { void operator()(M const& source, M& target) const { auto const* const src = reinterpret_cast<char const*>(source.mKeyVals); auto* tgt = reinterpret_cast<char*>(target.mKeyVals); auto const numElementsWithBuffer = target.calcNumElementsWithBuffer(target.mMask + 1); std::copy(src, src + target.calcNumBytesTotal(numElementsWithBuffer), tgt); } }; template <typename M> struct Cloner<M, false> { void operator()(M const& s, M& t) const { auto const numElementsWithBuffer = t.calcNumElementsWithBuffer(t.mMask + 1); std::copy(s.mInfo, s.mInfo + t.calcNumBytesInfo(numElementsWithBuffer), t.mInfo); for (size_t i = 0; i < numElementsWithBuffer; ++i) { if (t.mInfo[i]) { ::new (static_cast<void*>(t.mKeyVals + i)) Node(t, *s.mKeyVals[i]); } } } }; // Destroyer /////////////////////////////////////////////////////// template <typename M, bool IsFlatAndTrivial> struct Destroyer {}; template <typename M> struct Destroyer<M, true> { void nodes(M& m) const noexcept { m.mNumElements = 0; } void nodesDoNotDeallocate(M& m) const noexcept { m.mNumElements = 0; } }; template <typename M> struct Destroyer<M, false> { void nodes(M& m) const noexcept { m.mNumElements = 0; // clear also resets mInfo to 0, that's sometimes not necessary. auto const numElementsWithBuffer = m.calcNumElementsWithBuffer(m.mMask + 1); for (size_t idx = 0; idx < numElementsWithBuffer; ++idx) { if (0 != m.mInfo[idx]) { Node& n = m.mKeyVals[idx]; n.destroy(m); n.~Node(); } } } void nodesDoNotDeallocate(M& m) const noexcept { m.mNumElements = 0; // clear also resets mInfo to 0, that's sometimes not necessary. auto const numElementsWithBuffer = m.calcNumElementsWithBuffer(m.mMask + 1); for (size_t idx = 0; idx < numElementsWithBuffer; ++idx) { if (0 != m.mInfo[idx]) { Node& n = m.mKeyVals[idx]; n.destroyDoNotDeallocate(); n.~Node(); } } } }; // Iter //////////////////////////////////////////////////////////// struct fast_forward_tag {}; // generic iterator for both const_iterator and iterator. template <bool IsConst> // NOLINTNEXTLINE(hicpp-special-member-functions,cppcoreguidelines-special-member-functions) class Iter { private: using NodePtr = typename std::conditional<IsConst, Node const*, Node*>::type; public: using difference_type = std::ptrdiff_t; using value_type = typename Self::value_type; using reference = typename std::conditional<IsConst, value_type const&, value_type&>::type; using pointer = typename std::conditional<IsConst, value_type const*, value_type*>::type; using iterator_category = std::forward_iterator_tag; // default constructed iterator can be compared to itself, but WON'T return true when // compared to end(). Iter() = default; // Rule of zero: nothing specified. The conversion constructor is only enabled for // iterator to const_iterator, so it doesn't accidentally work as a copy ctor. // Conversion constructor from iterator to const_iterator. template <bool OtherIsConst, typename = typename std::enable_if<IsConst && !OtherIsConst>::type> // NOLINTNEXTLINE(hicpp-explicit-conversions) Iter(Iter<OtherIsConst> const& other) noexcept : mKeyVals(other.mKeyVals) , mInfo(other.mInfo) {} Iter(NodePtr valPtr, uint8_t const* infoPtr) noexcept : mKeyVals(valPtr) , mInfo(infoPtr) {} Iter(NodePtr valPtr, uint8_t const* infoPtr, fast_forward_tag ROBIN_HOOD_UNUSED(tag) /*unused*/) noexcept : mKeyVals(valPtr) , mInfo(infoPtr) { fastForward(); } template <bool OtherIsConst, typename = typename std::enable_if<IsConst && !OtherIsConst>::type> Iter& operator=(Iter<OtherIsConst> const& other) noexcept { mKeyVals = other.mKeyVals; mInfo = other.mInfo; return *this; } // prefix increment. Undefined behavior if we are at end()! Iter& operator++() noexcept { mInfo++; mKeyVals++; fastForward(); return *this; } Iter operator++(int) noexcept { Iter tmp = *this; ++(*this); return tmp; } reference operator*() const { return **mKeyVals; } pointer operator->() const { return &**mKeyVals; } template <bool O> bool operator==(Iter<O> const& o) const noexcept { return mKeyVals == o.mKeyVals; } template <bool O> bool operator!=(Iter<O> const& o) const noexcept { return mKeyVals != o.mKeyVals; } private: // fast forward to the next non-free info byte // I've tried a few variants that don't depend on intrinsics, but unfortunately they are // quite a bit slower than this one. So I've reverted that change again. See map_benchmark. void fastForward() noexcept { size_t n = 0; while (0U == (n = detail::unaligned_load<size_t>(mInfo))) { mInfo += sizeof(size_t); mKeyVals += sizeof(size_t); } #if defined(ROBIN_HOOD_DISABLE_INTRINSICS) // we know for certain that within the next 8 bytes we'll find a non-zero one. if (ROBIN_HOOD_UNLIKELY(0U == detail::unaligned_load<uint32_t>(mInfo))) { mInfo += 4; mKeyVals += 4; } if (ROBIN_HOOD_UNLIKELY(0U == detail::unaligned_load<uint16_t>(mInfo))) { mInfo += 2; mKeyVals += 2; } if (ROBIN_HOOD_UNLIKELY(0U == *mInfo)) { mInfo += 1; mKeyVals += 1; } #else # if ROBIN_HOOD(LITTLE_ENDIAN) auto inc = ROBIN_HOOD_COUNT_TRAILING_ZEROES(n) / 8; # else auto inc = ROBIN_HOOD_COUNT_LEADING_ZEROES(n) / 8; # endif mInfo += inc; mKeyVals += inc; #endif } friend class Table<IsFlat, MaxLoadFactor100, key_type, mapped_type, hasher, key_equal>; NodePtr mKeyVals{nullptr}; uint8_t const* mInfo{nullptr}; }; //////////////////////////////////////////////////////////////////// // highly performance relevant code. // Lower bits are used for indexing into the array (2^n size) // The upper 1-5 bits need to be a reasonable good hash, to save comparisons. template <typename HashKey> void keyToIdx(HashKey&& key, size_t* idx, InfoType* info) const { // In addition to whatever hash is used, add another mul & shift so we get better hashing. // This serves as a bad hash prevention, if the given data is // badly mixed. auto h = static_cast<uint64_t>(WHash::operator()(key)); h *= mHashMultiplier; h ^= h >> 33U; // the lower InitialInfoNumBits are reserved for info. *info = mInfoInc + static_cast<InfoType>((h & InfoMask) >> mInfoHashShift); *idx = (static_cast<size_t>(h) >> InitialInfoNumBits) & mMask; } // forwards the index by one, wrapping around at the end void next(InfoType* info, size_t* idx) const noexcept { *idx = *idx + 1; *info += mInfoInc; } void nextWhileLess(InfoType* info, size_t* idx) const noexcept { // unrolling this by hand did not bring any speedups. while (*info < mInfo[*idx]) { next(info, idx); } } // Shift everything up by one element. Tries to move stuff around. void shiftUp(size_t startIdx, size_t const insertion_idx) noexcept(std::is_nothrow_move_assignable<Node>::value) { auto idx = startIdx; ::new (static_cast<void*>(mKeyVals + idx)) Node(std::move(mKeyVals[idx - 1])); while (--idx != insertion_idx) { mKeyVals[idx] = std::move(mKeyVals[idx - 1]); } idx = startIdx; while (idx != insertion_idx) { ROBIN_HOOD_COUNT(shiftUp) mInfo[idx] = static_cast<uint8_t>(mInfo[idx - 1] + mInfoInc); if (ROBIN_HOOD_UNLIKELY(mInfo[idx] + mInfoInc > 0xFF)) { mMaxNumElementsAllowed = 0; } --idx; } } void shiftDown(size_t idx) noexcept(std::is_nothrow_move_assignable<Node>::value) { // until we find one that is either empty or has zero offset. // TODO(martinus) we don't need to move everything, just the last one for the same // bucket. mKeyVals[idx].destroy(*this); // until we find one that is either empty or has zero offset. while (mInfo[idx + 1] >= 2 * mInfoInc) { ROBIN_HOOD_COUNT(shiftDown) mInfo[idx] = static_cast<uint8_t>(mInfo[idx + 1] - mInfoInc); mKeyVals[idx] = std::move(mKeyVals[idx + 1]); ++idx; } mInfo[idx] = 0; // don't destroy, we've moved it // mKeyVals[idx].destroy(*this); mKeyVals[idx].~Node(); } // copy of find(), except that it returns iterator instead of const_iterator. template <typename Other> ROBIN_HOOD(NODISCARD) size_t findIdx(Other const& key) const { size_t idx{}; InfoType info{}; keyToIdx(key, &idx, &info); do { // unrolling this twice gives a bit of a speedup. More unrolling did not help. if (info == mInfo[idx] && ROBIN_HOOD_LIKELY(WKeyEqual::operator()(key, mKeyVals[idx].getFirst()))) { return idx; } next(&info, &idx); if (info == mInfo[idx] && ROBIN_HOOD_LIKELY(WKeyEqual::operator()(key, mKeyVals[idx].getFirst()))) { return idx; } next(&info, &idx); } while (info <= mInfo[idx]); // nothing found! return mMask == 0 ? 0 : static_cast<size_t>(std::distance( mKeyVals, reinterpret_cast_no_cast_align_warning<Node*>(mInfo))); } void cloneData(const Table& o) { Cloner<Table, IsFlat && ROBIN_HOOD_IS_TRIVIALLY_COPYABLE(Node)>()(o, *this); } // inserts a keyval that is guaranteed to be new, e.g. when the hashmap is resized. // @return True on success, false if something went wrong void insert_move(Node&& keyval) { // we don't retry, fail if overflowing // don't need to check max num elements if (0 == mMaxNumElementsAllowed && !try_increase_info()) { throwOverflowError(); } size_t idx{}; InfoType info{}; keyToIdx(keyval.getFirst(), &idx, &info); // skip forward. Use <= because we are certain that the element is not there. while (info <= mInfo[idx]) { idx = idx + 1; info += mInfoInc; } // key not found, so we are now exactly where we want to insert it. auto const insertion_idx = idx; auto const insertion_info = static_cast<uint8_t>(info); if (ROBIN_HOOD_UNLIKELY(insertion_info + mInfoInc > 0xFF)) { mMaxNumElementsAllowed = 0; } // find an empty spot while (0 != mInfo[idx]) { next(&info, &idx); } auto& l = mKeyVals[insertion_idx]; if (idx == insertion_idx) { ::new (static_cast<void*>(&l)) Node(std::move(keyval)); } else { shiftUp(idx, insertion_idx); l = std::move(keyval); } // put at empty spot mInfo[insertion_idx] = insertion_info; ++mNumElements; } public: using iterator = Iter<false>; using const_iterator = Iter<true>; Table() noexcept(noexcept(Hash()) && noexcept(KeyEqual())) : WHash() , WKeyEqual() { ROBIN_HOOD_TRACE(this) } // Creates an empty hash map. Nothing is allocated yet, this happens at the first insert. // This tremendously speeds up ctor & dtor of a map that never receives an element. The // penalty is payed at the first insert, and not before. Lookup of this empty map works // because everybody points to DummyInfoByte::b. parameter bucket_count is dictated by the // standard, but we can ignore it. explicit Table( size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/, const Hash& h = Hash{}, const KeyEqual& equal = KeyEqual{}) noexcept(noexcept(Hash(h)) && noexcept(KeyEqual(equal))) : WHash(h) , WKeyEqual(equal) { ROBIN_HOOD_TRACE(this) } template <typename Iter> Table(Iter first, Iter last, size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/ = 0, const Hash& h = Hash{}, const KeyEqual& equal = KeyEqual{}) : WHash(h) , WKeyEqual(equal) { ROBIN_HOOD_TRACE(this) insert(first, last); } Table(std::initializer_list<value_type> initlist, size_t ROBIN_HOOD_UNUSED(bucket_count) /*unused*/ = 0, const Hash& h = Hash{}, const KeyEqual& equal = KeyEqual{}) : WHash(h) , WKeyEqual(equal) { ROBIN_HOOD_TRACE(this) insert(initlist.begin(), initlist.end()); } Table(Table&& o) noexcept : WHash(std::move(static_cast<WHash&>(o))) , WKeyEqual(std::move(static_cast<WKeyEqual&>(o))) , DataPool(std::move(static_cast<DataPool&>(o))) { ROBIN_HOOD_TRACE(this) if (o.mMask) { mHashMultiplier = std::move(o.mHashMultiplier); mKeyVals = std::move(o.mKeyVals); mInfo = std::move(o.mInfo); mNumElements = std::move(o.mNumElements); mMask = std::move(o.mMask); mMaxNumElementsAllowed = std::move(o.mMaxNumElementsAllowed); mInfoInc = std::move(o.mInfoInc); mInfoHashShift = std::move(o.mInfoHashShift); // set other's mask to 0 so its destructor won't do anything o.init(); } } Table& operator=(Table&& o) noexcept { ROBIN_HOOD_TRACE(this) if (&o != this) { if (o.mMask) { // only move stuff if the other map actually has some data destroy(); mHashMultiplier = std::move(o.mHashMultiplier); mKeyVals = std::move(o.mKeyVals); mInfo = std::move(o.mInfo); mNumElements = std::move(o.mNumElements); mMask = std::move(o.mMask); mMaxNumElementsAllowed = std::move(o.mMaxNumElementsAllowed); mInfoInc = std::move(o.mInfoInc); mInfoHashShift = std::move(o.mInfoHashShift); WHash::operator=(std::move(static_cast<WHash&>(o))); WKeyEqual::operator=(std::move(static_cast<WKeyEqual&>(o))); DataPool::operator=(std::move(static_cast<DataPool&>(o))); o.init(); } else { // nothing in the other map => just clear us. clear(); } } return *this; } Table(const Table& o) : WHash(static_cast<const WHash&>(o)) , WKeyEqual(static_cast<const WKeyEqual&>(o)) , DataPool(static_cast<const DataPool&>(o)) { ROBIN_HOOD_TRACE(this) if (!o.empty()) { // not empty: create an exact copy. it is also possible to just iterate through all // elements and insert them, but copying is probably faster. auto const numElementsWithBuffer = calcNumElementsWithBuffer(o.mMask + 1); auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer); ROBIN_HOOD_LOG("std::malloc " << numBytesTotal << " = calcNumBytesTotal(" << numElementsWithBuffer << ")") mHashMultiplier = o.mHashMultiplier; mKeyVals = static_cast<Node*>( detail::assertNotNull<std::bad_alloc>(std::malloc(numBytesTotal))); // no need for calloc because clonData does memcpy mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer); mNumElements = o.mNumElements; mMask = o.mMask; mMaxNumElementsAllowed = o.mMaxNumElementsAllowed; mInfoInc = o.mInfoInc; mInfoHashShift = o.mInfoHashShift; cloneData(o); } } // Creates a copy of the given map. Copy constructor of each entry is used. // Not sure why clang-tidy thinks this doesn't handle self assignment, it does // NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp) Table& operator=(Table const& o) { ROBIN_HOOD_TRACE(this) if (&o == this) { // prevent assigning of itself return *this; } // we keep using the old allocator and not assign the new one, because we want to keep // the memory available. when it is the same size. if (o.empty()) { if (0 == mMask) { // nothing to do, we are empty too return *this; } // not empty: destroy what we have there // clear also resets mInfo to 0, that's sometimes not necessary. destroy(); init(); WHash::operator=(static_cast<const WHash&>(o)); WKeyEqual::operator=(static_cast<const WKeyEqual&>(o)); DataPool::operator=(static_cast<DataPool const&>(o)); return *this; } // clean up old stuff Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{}.nodes(*this); if (mMask != o.mMask) { // no luck: we don't have the same array size allocated, so we need to realloc. if (0 != mMask) { // only deallocate if we actually have data! ROBIN_HOOD_LOG("std::free") std::free(mKeyVals); } auto const numElementsWithBuffer = calcNumElementsWithBuffer(o.mMask + 1); auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer); ROBIN_HOOD_LOG("std::malloc " << numBytesTotal << " = calcNumBytesTotal(" << numElementsWithBuffer << ")") mKeyVals = static_cast<Node*>( detail::assertNotNull<std::bad_alloc>(std::malloc(numBytesTotal))); // no need for calloc here because cloneData performs a memcpy. mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer); // sentinel is set in cloneData } WHash::operator=(static_cast<const WHash&>(o)); WKeyEqual::operator=(static_cast<const WKeyEqual&>(o)); DataPool::operator=(static_cast<DataPool const&>(o)); mHashMultiplier = o.mHashMultiplier; mNumElements = o.mNumElements; mMask = o.mMask; mMaxNumElementsAllowed = o.mMaxNumElementsAllowed; mInfoInc = o.mInfoInc; mInfoHashShift = o.mInfoHashShift; cloneData(o); return *this; } // Swaps everything between the two maps. void swap(Table& o) { ROBIN_HOOD_TRACE(this) using std::swap; swap(o, *this); } // Clears all data, without resizing. void clear() { ROBIN_HOOD_TRACE(this) if (empty()) { // don't do anything! also important because we don't want to write to // DummyInfoByte::b, even though we would just write 0 to it. return; } Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{}.nodes(*this); auto const numElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1); // clear everything, then set the sentinel again uint8_t const z = 0; std::fill(mInfo, mInfo + calcNumBytesInfo(numElementsWithBuffer), z); mInfo[numElementsWithBuffer] = 1; mInfoInc = InitialInfoInc; mInfoHashShift = InitialInfoHashShift; } // Destroys the map and all it's contents. ~Table() { ROBIN_HOOD_TRACE(this) destroy(); } // Checks if both tables contain the same entries. Order is irrelevant. bool operator==(const Table& other) const { ROBIN_HOOD_TRACE(this) if (other.size() != size()) { return false; } for (auto const& otherEntry : other) { if (!has(otherEntry)) { return false; } } return true; } bool operator!=(const Table& other) const { ROBIN_HOOD_TRACE(this) return !operator==(other); } template <typename Q = mapped_type> typename std::enable_if<!std::is_void<Q>::value, Q&>::type operator[](const key_type& key) { ROBIN_HOOD_TRACE(this) auto idxAndState = insertKeyPrepareEmptySpot(key); switch (idxAndState.second) { case InsertionState::key_found: break; case InsertionState::new_node: ::new (static_cast<void*>(&mKeyVals[idxAndState.first])) Node(*this, std::piecewise_construct, std::forward_as_tuple(key), std::forward_as_tuple()); break; case InsertionState::overwrite_node: mKeyVals[idxAndState.first] = Node(*this, std::piecewise_construct, std::forward_as_tuple(key), std::forward_as_tuple()); break; case InsertionState::overflow_error: throwOverflowError(); } return mKeyVals[idxAndState.first].getSecond(); } template <typename Q = mapped_type> typename std::enable_if<!std::is_void<Q>::value, Q&>::type operator[](key_type&& key) { ROBIN_HOOD_TRACE(this) auto idxAndState = insertKeyPrepareEmptySpot(key); switch (idxAndState.second) { case InsertionState::key_found: break; case InsertionState::new_node: ::new (static_cast<void*>(&mKeyVals[idxAndState.first])) Node(*this, std::piecewise_construct, std::forward_as_tuple(std::move(key)), std::forward_as_tuple()); break; case InsertionState::overwrite_node: mKeyVals[idxAndState.first] = Node(*this, std::piecewise_construct, std::forward_as_tuple(std::move(key)), std::forward_as_tuple()); break; case InsertionState::overflow_error: throwOverflowError(); } return mKeyVals[idxAndState.first].getSecond(); } template <typename Iter> void insert(Iter first, Iter last) { for (; first != last; ++first) { // value_type ctor needed because this might be called with std::pair's insert(value_type(*first)); } } void insert(std::initializer_list<value_type> ilist) { for (auto&& vt : ilist) { insert(std::move(vt)); } } template <typename... Args> std::pair<iterator, bool> emplace(Args&&... args) { ROBIN_HOOD_TRACE(this) Node n{*this, std::forward<Args>(args)...}; auto idxAndState = insertKeyPrepareEmptySpot(getFirstConst(n)); switch (idxAndState.second) { case InsertionState::key_found: n.destroy(*this); break; case InsertionState::new_node: ::new (static_cast<void*>(&mKeyVals[idxAndState.first])) Node(*this, std::move(n)); break; case InsertionState::overwrite_node: mKeyVals[idxAndState.first] = std::move(n); break; case InsertionState::overflow_error: n.destroy(*this); throwOverflowError(); break; } return std::make_pair(iterator(mKeyVals + idxAndState.first, mInfo + idxAndState.first), InsertionState::key_found != idxAndState.second); } template <typename... Args> iterator emplace_hint(const_iterator position, Args&&... args) { (void)position; return emplace(std::forward<Args>(args)...).first; } template <typename... Args> std::pair<iterator, bool> try_emplace(const key_type& key, Args&&... args) { return try_emplace_impl(key, std::forward<Args>(args)...); } template <typename... Args> std::pair<iterator, bool> try_emplace(key_type&& key, Args&&... args) { return try_emplace_impl(std::move(key), std::forward<Args>(args)...); } template <typename... Args> iterator try_emplace(const_iterator hint, const key_type& key, Args&&... args) { (void)hint; return try_emplace_impl(key, std::forward<Args>(args)...).first; } template <typename... Args> iterator try_emplace(const_iterator hint, key_type&& key, Args&&... args) { (void)hint; return try_emplace_impl(std::move(key), std::forward<Args>(args)...).first; } template <typename Mapped> std::pair<iterator, bool> insert_or_assign(const key_type& key, Mapped&& obj) { return insertOrAssignImpl(key, std::forward<Mapped>(obj)); } template <typename Mapped> std::pair<iterator, bool> insert_or_assign(key_type&& key, Mapped&& obj) { return insertOrAssignImpl(std::move(key), std::forward<Mapped>(obj)); } template <typename Mapped> iterator insert_or_assign(const_iterator hint, const key_type& key, Mapped&& obj) { (void)hint; return insertOrAssignImpl(key, std::forward<Mapped>(obj)).first; } template <typename Mapped> iterator insert_or_assign(const_iterator hint, key_type&& key, Mapped&& obj) { (void)hint; return insertOrAssignImpl(std::move(key), std::forward<Mapped>(obj)).first; } std::pair<iterator, bool> insert(const value_type& keyval) { ROBIN_HOOD_TRACE(this) return emplace(keyval); } iterator insert(const_iterator hint, const value_type& keyval) { (void)hint; return emplace(keyval).first; } std::pair<iterator, bool> insert(value_type&& keyval) { return emplace(std::move(keyval)); } iterator insert(const_iterator hint, value_type&& keyval) { (void)hint; return emplace(std::move(keyval)).first; } // Returns 1 if key is found, 0 otherwise. size_t count(const key_type& key) const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) auto kv = mKeyVals + findIdx(key); if (kv != reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) { return 1; } return 0; } template <typename OtherKey, typename Self_ = Self> // NOLINTNEXTLINE(modernize-use-nodiscard) typename std::enable_if<Self_::is_transparent, size_t>::type count(const OtherKey& key) const { ROBIN_HOOD_TRACE(this) auto kv = mKeyVals + findIdx(key); if (kv != reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) { return 1; } return 0; } bool contains(const key_type& key) const { // NOLINT(modernize-use-nodiscard) return 1U == count(key); } template <typename OtherKey, typename Self_ = Self> // NOLINTNEXTLINE(modernize-use-nodiscard) typename std::enable_if<Self_::is_transparent, bool>::type contains(const OtherKey& key) const { return 1U == count(key); } // Returns a reference to the value found for key. // Throws std::out_of_range if element cannot be found template <typename Q = mapped_type> // NOLINTNEXTLINE(modernize-use-nodiscard) typename std::enable_if<!std::is_void<Q>::value, Q&>::type at(key_type const& key) { ROBIN_HOOD_TRACE(this) auto kv = mKeyVals + findIdx(key); if (kv == reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) { doThrow<std::out_of_range>("key not found"); } return kv->getSecond(); } // Returns a reference to the value found for key. // Throws std::out_of_range if element cannot be found template <typename Q = mapped_type> // NOLINTNEXTLINE(modernize-use-nodiscard) typename std::enable_if<!std::is_void<Q>::value, Q const&>::type at(key_type const& key) const { ROBIN_HOOD_TRACE(this) auto kv = mKeyVals + findIdx(key); if (kv == reinterpret_cast_no_cast_align_warning<Node*>(mInfo)) { doThrow<std::out_of_range>("key not found"); } return kv->getSecond(); } const_iterator find(const key_type& key) const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return const_iterator{mKeyVals + idx, mInfo + idx}; } template <typename OtherKey> const_iterator find(const OtherKey& key, is_transparent_tag /*unused*/) const { ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return const_iterator{mKeyVals + idx, mInfo + idx}; } template <typename OtherKey, typename Self_ = Self> typename std::enable_if<Self_::is_transparent, // NOLINT(modernize-use-nodiscard) const_iterator>::type // NOLINT(modernize-use-nodiscard) find(const OtherKey& key) const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return const_iterator{mKeyVals + idx, mInfo + idx}; } iterator find(const key_type& key) { ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return iterator{mKeyVals + idx, mInfo + idx}; } template <typename OtherKey> iterator find(const OtherKey& key, is_transparent_tag /*unused*/) { ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return iterator{mKeyVals + idx, mInfo + idx}; } template <typename OtherKey, typename Self_ = Self> typename std::enable_if<Self_::is_transparent, iterator>::type find(const OtherKey& key) { ROBIN_HOOD_TRACE(this) const size_t idx = findIdx(key); return iterator{mKeyVals + idx, mInfo + idx}; } iterator begin() { ROBIN_HOOD_TRACE(this) if (empty()) { return end(); } return iterator(mKeyVals, mInfo, fast_forward_tag{}); } const_iterator begin() const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return cbegin(); } const_iterator cbegin() const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) if (empty()) { return cend(); } return const_iterator(mKeyVals, mInfo, fast_forward_tag{}); } iterator end() { ROBIN_HOOD_TRACE(this) // no need to supply valid info pointer: end() must not be dereferenced, and only node // pointer is compared. return iterator{reinterpret_cast_no_cast_align_warning<Node*>(mInfo), nullptr}; } const_iterator end() const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return cend(); } const_iterator cend() const { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return const_iterator{reinterpret_cast_no_cast_align_warning<Node*>(mInfo), nullptr}; } iterator erase(const_iterator pos) { ROBIN_HOOD_TRACE(this) // its safe to perform const cast here // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast) return erase(iterator{const_cast<Node*>(pos.mKeyVals), const_cast<uint8_t*>(pos.mInfo)}); } // Erases element at pos, returns iterator to the next element. iterator erase(iterator pos) { ROBIN_HOOD_TRACE(this) // we assume that pos always points to a valid entry, and not end(). auto const idx = static_cast<size_t>(pos.mKeyVals - mKeyVals); shiftDown(idx); --mNumElements; if (*pos.mInfo) { // we've backward shifted, return this again return pos; } // no backward shift, return next element return ++pos; } size_t erase(const key_type& key) { ROBIN_HOOD_TRACE(this) size_t idx{}; InfoType info{}; keyToIdx(key, &idx, &info); // check while info matches with the source idx do { if (info == mInfo[idx] && WKeyEqual::operator()(key, mKeyVals[idx].getFirst())) { shiftDown(idx); --mNumElements; return 1; } next(&info, &idx); } while (info <= mInfo[idx]); // nothing found to delete return 0; } // reserves space for the specified number of elements. Makes sure the old data fits. // exactly the same as reserve(c). void rehash(size_t c) { // forces a reserve reserve(c, true); } // reserves space for the specified number of elements. Makes sure the old data fits. // Exactly the same as rehash(c). Use rehash(0) to shrink to fit. void reserve(size_t c) { // reserve, but don't force rehash reserve(c, false); } // If possible reallocates the map to a smaller one. This frees the underlying table. // Does not do anything if load_factor is too large for decreasing the table's size. void compact() { ROBIN_HOOD_TRACE(this) auto newSize = InitialNumElements; while (calcMaxNumElementsAllowed(newSize) < mNumElements && newSize != 0) { newSize *= 2; } if (ROBIN_HOOD_UNLIKELY(newSize == 0)) { throwOverflowError(); } ROBIN_HOOD_LOG("newSize > mMask + 1: " << newSize << " > " << mMask << " + 1") // only actually do anything when the new size is bigger than the old one. This prevents to // continuously allocate for each reserve() call. if (newSize < mMask + 1) { rehashPowerOfTwo(newSize, true); } } size_type size() const noexcept { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return mNumElements; } size_type max_size() const noexcept { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return static_cast<size_type>(-1); } ROBIN_HOOD(NODISCARD) bool empty() const noexcept { ROBIN_HOOD_TRACE(this) return 0 == mNumElements; } float max_load_factor() const noexcept { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return MaxLoadFactor100 / 100.0F; } // Average number of elements per bucket. Since we allow only 1 per bucket float load_factor() const noexcept { // NOLINT(modernize-use-nodiscard) ROBIN_HOOD_TRACE(this) return static_cast<float>(size()) / static_cast<float>(mMask + 1); } ROBIN_HOOD(NODISCARD) size_t mask() const noexcept { ROBIN_HOOD_TRACE(this) return mMask; } ROBIN_HOOD(NODISCARD) size_t calcMaxNumElementsAllowed(size_t maxElements) const noexcept { if (ROBIN_HOOD_LIKELY(maxElements <= (std::numeric_limits<size_t>::max)() / 100)) { return maxElements * MaxLoadFactor100 / 100; } // we might be a bit inprecise, but since maxElements is quite large that doesn't matter return (maxElements / 100) * MaxLoadFactor100; } ROBIN_HOOD(NODISCARD) size_t calcNumBytesInfo(size_t numElements) const noexcept { // we add a uint64_t, which houses the sentinel (first byte) and padding so we can load // 64bit types. return numElements + sizeof(uint64_t); } ROBIN_HOOD(NODISCARD) size_t calcNumElementsWithBuffer(size_t numElements) const noexcept { auto maxNumElementsAllowed = calcMaxNumElementsAllowed(numElements); return numElements + (std::min)(maxNumElementsAllowed, (static_cast<size_t>(0xFF))); } // calculation only allowed for 2^n values ROBIN_HOOD(NODISCARD) size_t calcNumBytesTotal(size_t numElements) const { #if ROBIN_HOOD(BITNESS) == 64 return numElements * sizeof(Node) + calcNumBytesInfo(numElements); #else // make sure we're doing 64bit operations, so we are at least safe against 32bit overflows. auto const ne = static_cast<uint64_t>(numElements); auto const s = static_cast<uint64_t>(sizeof(Node)); auto const infos = static_cast<uint64_t>(calcNumBytesInfo(numElements)); auto const total64 = ne * s + infos; auto const total = static_cast<size_t>(total64); if (ROBIN_HOOD_UNLIKELY(static_cast<uint64_t>(total) != total64)) { throwOverflowError(); } return total; #endif } private: template <typename Q = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<!std::is_void<Q>::value, bool>::type has(const value_type& e) const { ROBIN_HOOD_TRACE(this) auto it = find(e.first); return it != end() && it->second == e.second; } template <typename Q = mapped_type> ROBIN_HOOD(NODISCARD) typename std::enable_if<std::is_void<Q>::value, bool>::type has(const value_type& e) const { ROBIN_HOOD_TRACE(this) return find(e) != end(); } void reserve(size_t c, bool forceRehash) { ROBIN_HOOD_TRACE(this) auto const minElementsAllowed = (std::max)(c, mNumElements); auto newSize = InitialNumElements; while (calcMaxNumElementsAllowed(newSize) < minElementsAllowed && newSize != 0) { newSize *= 2; } if (ROBIN_HOOD_UNLIKELY(newSize == 0)) { throwOverflowError(); } ROBIN_HOOD_LOG("newSize > mMask + 1: " << newSize << " > " << mMask << " + 1") // only actually do anything when the new size is bigger than the old one. This prevents to // continuously allocate for each reserve() call. if (forceRehash || newSize > mMask + 1) { rehashPowerOfTwo(newSize, false); } } // reserves space for at least the specified number of elements. // only works if numBuckets if power of two // True on success, false otherwise void rehashPowerOfTwo(size_t numBuckets, bool forceFree) { ROBIN_HOOD_TRACE(this) Node* const oldKeyVals = mKeyVals; uint8_t const* const oldInfo = mInfo; const size_t oldMaxElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1); // resize operation: move stuff initData(numBuckets); if (oldMaxElementsWithBuffer > 1) { for (size_t i = 0; i < oldMaxElementsWithBuffer; ++i) { if (oldInfo[i] != 0) { // might throw an exception, which is really bad since we are in the middle of // moving stuff. insert_move(std::move(oldKeyVals[i])); // destroy the node but DON'T destroy the data. oldKeyVals[i].~Node(); } } // this check is not necessary as it's guarded by the previous if, but it helps // silence g++'s overeager "attempt to free a non-heap object 'map' // [-Werror=free-nonheap-object]" warning. if (oldKeyVals != reinterpret_cast_no_cast_align_warning<Node*>(&mMask)) { // don't destroy old data: put it into the pool instead if (forceFree) { std::free(oldKeyVals); } else { DataPool::addOrFree(oldKeyVals, calcNumBytesTotal(oldMaxElementsWithBuffer)); } } } } ROBIN_HOOD(NOINLINE) void throwOverflowError() const { #if ROBIN_HOOD(HAS_EXCEPTIONS) throw std::overflow_error("robin_hood::map overflow"); #else abort(); #endif } template <typename OtherKey, typename... Args> std::pair<iterator, bool> try_emplace_impl(OtherKey&& key, Args&&... args) { ROBIN_HOOD_TRACE(this) auto idxAndState = insertKeyPrepareEmptySpot(key); switch (idxAndState.second) { case InsertionState::key_found: break; case InsertionState::new_node: ::new (static_cast<void*>(&mKeyVals[idxAndState.first])) Node( *this, std::piecewise_construct, std::forward_as_tuple(std::forward<OtherKey>(key)), std::forward_as_tuple(std::forward<Args>(args)...)); break; case InsertionState::overwrite_node: mKeyVals[idxAndState.first] = Node(*this, std::piecewise_construct, std::forward_as_tuple(std::forward<OtherKey>(key)), std::forward_as_tuple(std::forward<Args>(args)...)); break; case InsertionState::overflow_error: throwOverflowError(); break; } return std::make_pair(iterator(mKeyVals + idxAndState.first, mInfo + idxAndState.first), InsertionState::key_found != idxAndState.second); } template <typename OtherKey, typename Mapped> std::pair<iterator, bool> insertOrAssignImpl(OtherKey&& key, Mapped&& obj) { ROBIN_HOOD_TRACE(this) auto idxAndState = insertKeyPrepareEmptySpot(key); switch (idxAndState.second) { case InsertionState::key_found: mKeyVals[idxAndState.first].getSecond() = std::forward<Mapped>(obj); break; case InsertionState::new_node: ::new (static_cast<void*>(&mKeyVals[idxAndState.first])) Node( *this, std::piecewise_construct, std::forward_as_tuple(std::forward<OtherKey>(key)), std::forward_as_tuple(std::forward<Mapped>(obj))); break; case InsertionState::overwrite_node: mKeyVals[idxAndState.first] = Node(*this, std::piecewise_construct, std::forward_as_tuple(std::forward<OtherKey>(key)), std::forward_as_tuple(std::forward<Mapped>(obj))); break; case InsertionState::overflow_error: throwOverflowError(); break; } return std::make_pair(iterator(mKeyVals + idxAndState.first, mInfo + idxAndState.first), InsertionState::key_found != idxAndState.second); } void initData(size_t max_elements) { mNumElements = 0; mMask = max_elements - 1; mMaxNumElementsAllowed = calcMaxNumElementsAllowed(max_elements); auto const numElementsWithBuffer = calcNumElementsWithBuffer(max_elements); // malloc & zero mInfo. Faster than calloc everything. auto const numBytesTotal = calcNumBytesTotal(numElementsWithBuffer); ROBIN_HOOD_LOG("std::calloc " << numBytesTotal << " = calcNumBytesTotal(" << numElementsWithBuffer << ")") mKeyVals = reinterpret_cast<Node*>( detail::assertNotNull<std::bad_alloc>(std::malloc(numBytesTotal))); mInfo = reinterpret_cast<uint8_t*>(mKeyVals + numElementsWithBuffer); std::memset(mInfo, 0, numBytesTotal - numElementsWithBuffer * sizeof(Node)); // set sentinel mInfo[numElementsWithBuffer] = 1; mInfoInc = InitialInfoInc; mInfoHashShift = InitialInfoHashShift; } enum class InsertionState { overflow_error, key_found, new_node, overwrite_node }; // Finds key, and if not already present prepares a spot where to pot the key & value. // This potentially shifts nodes out of the way, updates mInfo and number of inserted // elements, so the only operation left to do is create/assign a new node at that spot. template <typename OtherKey> std::pair<size_t, InsertionState> insertKeyPrepareEmptySpot(OtherKey&& key) { for (int i = 0; i < 256; ++i) { size_t idx{}; InfoType info{}; keyToIdx(key, &idx, &info); nextWhileLess(&info, &idx); // while we potentially have a match while (info == mInfo[idx]) { if (WKeyEqual::operator()(key, mKeyVals[idx].getFirst())) { // key already exists, do NOT insert. // see http://en.cppreference.com/w/cpp/container/unordered_map/insert return std::make_pair(idx, InsertionState::key_found); } next(&info, &idx); } // unlikely that this evaluates to true if (ROBIN_HOOD_UNLIKELY(mNumElements >= mMaxNumElementsAllowed)) { if (!increase_size()) { return std::make_pair(size_t(0), InsertionState::overflow_error); } continue; } // key not found, so we are now exactly where we want to insert it. auto const insertion_idx = idx; auto const insertion_info = info; if (ROBIN_HOOD_UNLIKELY(insertion_info + mInfoInc > 0xFF)) { mMaxNumElementsAllowed = 0; } // find an empty spot while (0 != mInfo[idx]) { next(&info, &idx); } if (idx != insertion_idx) { shiftUp(idx, insertion_idx); } // put at empty spot mInfo[insertion_idx] = static_cast<uint8_t>(insertion_info); ++mNumElements; return std::make_pair(insertion_idx, idx == insertion_idx ? InsertionState::new_node : InsertionState::overwrite_node); } // enough attempts failed, so finally give up. return std::make_pair(size_t(0), InsertionState::overflow_error); } bool try_increase_info() { ROBIN_HOOD_LOG("mInfoInc=" << mInfoInc << ", numElements=" << mNumElements << ", maxNumElementsAllowed=" << calcMaxNumElementsAllowed(mMask + 1)) if (mInfoInc <= 2) { // need to be > 2 so that shift works (otherwise undefined behavior!) return false; } // we got space left, try to make info smaller mInfoInc = static_cast<uint8_t>(mInfoInc >> 1U); // remove one bit of the hash, leaving more space for the distance info. // This is extremely fast because we can operate on 8 bytes at once. ++mInfoHashShift; auto const numElementsWithBuffer = calcNumElementsWithBuffer(mMask + 1); for (size_t i = 0; i < numElementsWithBuffer; i += 8) { auto val = unaligned_load<uint64_t>(mInfo + i); val = (val >> 1U) & UINT64_C(0x7f7f7f7f7f7f7f7f); std::memcpy(mInfo + i, &val, sizeof(val)); } // update sentinel, which might have been cleared out! mInfo[numElementsWithBuffer] = 1; mMaxNumElementsAllowed = calcMaxNumElementsAllowed(mMask + 1); return true; } // True if resize was possible, false otherwise bool increase_size() { // nothing allocated yet? just allocate InitialNumElements if (0 == mMask) { initData(InitialNumElements); return true; } auto const maxNumElementsAllowed = calcMaxNumElementsAllowed(mMask + 1); if (mNumElements < maxNumElementsAllowed && try_increase_info()) { return true; } ROBIN_HOOD_LOG("mNumElements=" << mNumElements << ", maxNumElementsAllowed=" << maxNumElementsAllowed << ", load=" << (static_cast<double>(mNumElements) * 100.0 / (static_cast<double>(mMask) + 1))) if (mNumElements * 2 < calcMaxNumElementsAllowed(mMask + 1)) { // we have to resize, even though there would still be plenty of space left! // Try to rehash instead. Delete freed memory so we don't steadyily increase mem in case // we have to rehash a few times nextHashMultiplier(); rehashPowerOfTwo(mMask + 1, true); } else { // we've reached the capacity of the map, so the hash seems to work nice. Keep using it. rehashPowerOfTwo((mMask + 1) * 2, false); } return true; } void nextHashMultiplier() { // adding an *even* number, so that the multiplier will always stay odd. This is necessary // so that the hash stays a mixing function (and thus doesn't have any information loss). mHashMultiplier += UINT64_C(0xc4ceb9fe1a85ec54); } void destroy() { if (0 == mMask) { // don't deallocate! return; } Destroyer<Self, IsFlat && std::is_trivially_destructible<Node>::value>{} .nodesDoNotDeallocate(*this); // This protection against not deleting mMask shouldn't be needed as it's sufficiently // protected with the 0==mMask check, but I have this anyways because g++ 7 otherwise // reports a compile error: attempt to free a non-heap object 'fm' // [-Werror=free-nonheap-object] if (mKeyVals != reinterpret_cast_no_cast_align_warning<Node*>(&mMask)) { ROBIN_HOOD_LOG("std::free") std::free(mKeyVals); } } void init() noexcept { mKeyVals = reinterpret_cast_no_cast_align_warning<Node*>(&mMask); mInfo = reinterpret_cast<uint8_t*>(&mMask); mNumElements = 0; mMask = 0; mMaxNumElementsAllowed = 0; mInfoInc = InitialInfoInc; mInfoHashShift = InitialInfoHashShift; } // members are sorted so no padding occurs uint64_t mHashMultiplier = UINT64_C(0xc4ceb9fe1a85ec53); // 8 byte 8 Node* mKeyVals = reinterpret_cast_no_cast_align_warning<Node*>(&mMask); // 8 byte 16 uint8_t* mInfo = reinterpret_cast<uint8_t*>(&mMask); // 8 byte 24 size_t mNumElements = 0; // 8 byte 32 size_t mMask = 0; // 8 byte 40 size_t mMaxNumElementsAllowed = 0; // 8 byte 48 InfoType mInfoInc = InitialInfoInc; // 4 byte 52 InfoType mInfoHashShift = InitialInfoHashShift; // 4 byte 56 // 16 byte 56 if NodeAllocator }; } // namespace detail // map template <typename Key, typename T, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_flat_map = detail::Table<true, MaxLoadFactor100, Key, T, Hash, KeyEqual>; template <typename Key, typename T, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_node_map = detail::Table<false, MaxLoadFactor100, Key, T, Hash, KeyEqual>; template <typename Key, typename T, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_map = detail::Table<sizeof(robin_hood::pair<Key, T>) <= sizeof(size_t) * 6 && std::is_nothrow_move_constructible<robin_hood::pair<Key, T>>::value && std::is_nothrow_move_assignable<robin_hood::pair<Key, T>>::value, MaxLoadFactor100, Key, T, Hash, KeyEqual>; // set template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_flat_set = detail::Table<true, MaxLoadFactor100, Key, void, Hash, KeyEqual>; template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_node_set = detail::Table<false, MaxLoadFactor100, Key, void, Hash, KeyEqual>; template <typename Key, typename Hash = hash<Key>, typename KeyEqual = std::equal_to<Key>, size_t MaxLoadFactor100 = 80> using unordered_set = detail::Table<sizeof(Key) <= sizeof(size_t) * 6 && std::is_nothrow_move_constructible<Key>::value && std::is_nothrow_move_assignable<Key>::value, MaxLoadFactor100, Key, void, Hash, KeyEqual>; } // namespace robin_hood #endif namespace{ void parseMemoryValue(const char* buf , const char* prefix , unsigned int& val) { const std::size_t prefixLen = strlen(prefix); if(strncmp(buf , prefix , prefixLen) == 0 ) { val = static_cast<unsigned>(atoi(buf + prefixLen)); } } int getMemory(unsigned int& currentRealMem, unsigned int& peakRealMemory , unsigned int& currentVirtualMemory, unsigned int& peakVirtualMemory) { static constexpr int bufferSize = 1024; char buf[bufferSize]; std::ifstream stream; stream.open("/proc/self/status"); if(!stream.is_open()) return -1; while(!stream.getline(buf,bufferSize).eof()) { const char* pos = strstr(buf , "Vm"); if(pos == nullptr) continue; pos+=2; parseMemoryValue(pos , "RSS:" , currentRealMem); parseMemoryValue(pos , "HWM:" , peakRealMemory); parseMemoryValue(pos , "Size:" , currentVirtualMemory); parseMemoryValue(pos , "Peak:" , peakVirtualMemory); } stream.close(); return 0 ; } void printMemory(const std::string& title) { unsigned currentReal = 0 ; unsigned realPeak = 0 ; unsigned currentVirtual = 0 ; unsigned virtualPeak = 0 ; if(getMemory(currentReal , realPeak , currentVirtual , virtualPeak)) { return ; } std::cout<<"Printing "<<title << std::endl; std::cout<<std::endl; std::cout<<"Current Real " <<currentReal / 1.0e3 << " MB"<<std::endl; std::cout<<"Peak Real "<<realPeak / 1.0e3 << " MB"<<std::endl; std::cout<<"Current Virual "<<currentVirtual / 1.0e3 << " MB"<<std::endl; std::cout<<"Peak Virtual "<<virtualPeak / 1.0e3 << " MB"<<std::endl; std::cout<<std::endl; } } int main() { struct Value { int arr[20]; }; using Container = robin_hood::unordered_map<int , Value>; robin_hood::unordered_map<int , Container> containers; unsigned numMapElements = 1'000; for(unsigned k =0 ; k < 8 ; ++k) { printMemory("Memory at the start of iteration " + std::to_string(k)); for(unsigned i =0 ; i < numMapElements ; ++i) { Container tmp; containers[i] = tmp; for(unsigned j =0 ; j < 50 ; ++j) { containers[i].emplace(j , Value()); } } printMemory("Memory at the end of iteration " + std::to_string(k)); } return 0 ; }
Become a Patron
Sponsor on GitHub
Donate via PayPal
Source on GitHub
Mailing list
Installed libraries
Wiki
Report an issue
How it works
Contact the author
CE on Mastodon
About the author
Statistics
Changelog
Version tree