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
WASM
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 12.4.0
ARM GCC 13.1.0
ARM GCC 13.2.0
ARM GCC 13.2.0 (unknown-eabi)
ARM GCC 13.3.0
ARM GCC 13.3.0 (unknown-eabi)
ARM GCC 14.1.0
ARM GCC 14.1.0 (unknown-eabi)
ARM GCC 14.2.0
ARM GCC 14.2.0 (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 12.4.0
ARM64 gcc 13.1.0
ARM64 gcc 13.2.0
ARM64 gcc 13.3.0
ARM64 gcc 14.1.0
ARM64 gcc 14.2.0
ARM64 gcc 4.9.4
ARM64 gcc 5.4
ARM64 gcc 5.5.0
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 12.4.0
AVR gcc 13.1.0
AVR gcc 13.2.0
AVR gcc 13.3.0
AVR gcc 14.1.0
AVR gcc 14.2.0
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 13.3.0
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)
KVX ACB 5.0.0 (GCC 12.2.1)
LoongArch64 clang (trunk)
LoongArch64 clang 17.0.1
LoongArch64 clang 18.1.0
M68K gcc 13.1.0
M68K gcc 13.2.0
M68K gcc 13.3.0
M68K gcc 14.1.0
M68K gcc 14.2.0
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 12.4.0
RISC-V (32-bits) gcc 13.1.0
RISC-V (32-bits) gcc 13.2.0
RISC-V (32-bits) gcc 13.3.0
RISC-V (32-bits) gcc 14.1.0
RISC-V (32-bits) gcc 14.2.0
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 12.4.0
RISC-V (64-bits) gcc 13.1.0
RISC-V (64-bits) gcc 13.2.0
RISC-V (64-bits) gcc 13.3.0
RISC-V (64-bits) gcc 14.1.0
RISC-V (64-bits) gcc 14.2.0
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 12.4.0
SPARC LEON gcc 13.1.0
SPARC LEON gcc 13.2.0
SPARC LEON gcc 13.3.0
SPARC LEON gcc 14.1.0
SPARC LEON gcc 14.2.0
SPARC gcc 12.2.0
SPARC gcc 12.3.0
SPARC gcc 12.4.0
SPARC gcc 13.1.0
SPARC gcc 13.2.0
SPARC gcc 13.3.0
SPARC gcc 14.1.0
SPARC gcc 14.2.0
SPARC64 gcc 12.2.0
SPARC64 gcc 12.3.0
SPARC64 gcc 12.4.0
SPARC64 gcc 13.1.0
SPARC64 gcc 13.2.0
SPARC64 gcc 13.3.0
SPARC64 gcc 14.1.0
SPARC64 gcc 14.2.0
TI C6x gcc 12.2.0
TI C6x gcc 12.3.0
TI C6x gcc 12.4.0
TI C6x gcc 13.1.0
TI C6x gcc 13.2.0
TI C6x gcc 13.3.0
TI C6x gcc 14.1.0
TI C6x gcc 14.2.0
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 v19.20 VS16.0
arm64 msvc v19.21 VS16.1
arm64 msvc v19.22 VS16.2
arm64 msvc v19.23 VS16.3
arm64 msvc v19.24 VS16.4
arm64 msvc v19.25 VS16.5
arm64 msvc v19.27 VS16.7
arm64 msvc v19.28 VS16.8
arm64 msvc v19.28 VS16.9
arm64 msvc v19.29 VS16.10
arm64 msvc v19.29 VS16.11
arm64 msvc v19.30 VS17.0
arm64 msvc v19.31 VS17.1
arm64 msvc v19.32 VS17.2
arm64 msvc v19.33 VS17.3
arm64 msvc v19.34 VS17.4
arm64 msvc v19.35 VS17.5
arm64 msvc v19.36 VS17.6
arm64 msvc v19.37 VS17.7
arm64 msvc v19.38 VS17.8
arm64 msvc v19.39 VS17.9
arm64 msvc v19.40 VS17.10
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 12.0.0
armv7-a clang 12.0.1
armv7-a clang 13.0.0
armv7-a clang 13.0.1
armv7-a clang 14.0.0
armv7-a clang 15.0.0
armv7-a clang 16.0.0
armv7-a clang 17.0.1
armv7-a clang 18.1.0
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 12.4.0
loongarch64 gcc 13.1.0
loongarch64 gcc 13.2.0
loongarch64 gcc 13.3.0
loongarch64 gcc 14.1.0
loongarch64 gcc 14.2.0
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 12.4.0
mips gcc 13.1.0
mips gcc 13.2.0
mips gcc 13.3.0
mips gcc 14.1.0
mips gcc 14.2.0
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 12.4.0
mips64 (el) gcc 13.1.0
mips64 (el) gcc 13.2.0
mips64 (el) gcc 13.3.0
mips64 (el) gcc 14.1.0
mips64 (el) gcc 14.2.0
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 12.4.0
mips64 gcc 13.1.0
mips64 gcc 13.2.0
mips64 gcc 13.3.0
mips64 gcc 14.1.0
mips64 gcc 14.2.0
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 12.4.0
mipsel gcc 13.1.0
mipsel gcc 13.2.0
mipsel gcc 13.3.0
mipsel gcc 14.1.0
mipsel gcc 14.2.0
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 12.4.0
power gcc 13.1.0
power gcc 13.2.0
power gcc 13.3.0
power gcc 14.1.0
power gcc 14.2.0
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 12.4.0
power64 gcc 13.1.0
power64 gcc 13.2.0
power64 gcc 13.3.0
power64 gcc 14.1.0
power64 gcc 14.2.0
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 12.4.0
power64le gcc 13.1.0
power64le gcc 13.2.0
power64le gcc 13.3.0
power64le gcc 14.1.0
power64le gcc 14.2.0
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 12.4.0
s390x gcc 13.1.0
s390x gcc 13.2.0
s390x gcc 13.3.0
s390x gcc 14.1.0
s390x gcc 14.2.0
sh gcc 12.2.0
sh gcc 12.3.0
sh gcc 12.4.0
sh gcc 13.1.0
sh gcc 13.2.0
sh gcc 13.3.0
sh gcc 14.1.0
sh gcc 14.2.0
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 (WINE)
x64 msvc v19.20 VS16.0
x64 msvc v19.21 VS16.1
x64 msvc v19.22 VS16.2
x64 msvc v19.23 VS16.3
x64 msvc v19.24 VS16.4
x64 msvc v19.25 VS16.5
x64 msvc v19.27 VS16.7
x64 msvc v19.28 VS16.8
x64 msvc v19.28 VS16.9
x64 msvc v19.29 VS16.10
x64 msvc v19.29 VS16.11
x64 msvc v19.30 VS17.0
x64 msvc v19.31 VS17.1
x64 msvc v19.32 VS17.2
x64 msvc v19.33 VS17.3
x64 msvc v19.34 VS17.4
x64 msvc v19.35 VS17.5
x64 msvc v19.36 VS17.6
x64 msvc v19.37 VS17.7
x64 msvc v19.38 VS17.8
x64 msvc v19.39 VS17.9
x64 msvc v19.40 VS17.10
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 (WINE)
x86 msvc v19.20 VS16.0
x86 msvc v19.21 VS16.1
x86 msvc v19.22 VS16.2
x86 msvc v19.23 VS16.3
x86 msvc v19.24 VS16.4
x86 msvc v19.25 VS16.5
x86 msvc v19.27 VS16.7
x86 msvc v19.28 VS16.8
x86 msvc v19.28 VS16.9
x86 msvc v19.29 VS16.10
x86 msvc v19.29 VS16.11
x86 msvc v19.30 VS17.0
x86 msvc v19.31 VS17.1
x86 msvc v19.32 VS17.2
x86 msvc v19.33 VS17.3
x86 msvc v19.34 VS17.4
x86 msvc v19.35 VS17.5
x86 msvc v19.36 VS17.6
x86 msvc v19.37 VS17.7
x86 msvc v19.38 VS17.8
x86 msvc v19.39 VS17.9
x86 msvc v19.40 VS17.10
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 nvc++ 24.5
x86 nvc++ 24.7
x86-64 Zapcc 190308
x86-64 clang (EricWF contracts)
x86-64 clang (amd-staging)
x86-64 clang (assertions trunk)
x86-64 clang (clangir)
x86-64 clang (dascandy contracts)
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 P3068)
x86-64 clang (experimental P3309)
x86-64 clang (experimental P3367)
x86-64 clang (experimental P3372)
x86-64 clang (experimental metaprogramming - P2632)
x86-64 clang (experimental pattern matching)
x86-64 clang (old concepts branch)
x86-64 clang (p1974)
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 clang rocm-6.0.2
x86-64 clang rocm-6.1.2
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 12.4
x86-64 gcc 13.1
x86-64 gcc 13.2
x86-64 gcc 13.3
x86-64 gcc 14.1
x86-64 gcc 14.2
x86-64 gcc 3.4.6
x86-64 gcc 4.0.4
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 6.5
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
x86-64 icx 2024.1.0
x86-64 icx 2024.2.0
zig c++ 0.10.0
zig c++ 0.11.0
zig c++ 0.12.0
zig c++ 0.12.1
zig c++ 0.13.0
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
#include <array> #include <iostream> #include <ranges> #include <range/v3/view/cartesian_product.hpp> #include <range/v3/view/indices.hpp> #include <tuple> #include <https://raw.githubusercontent.com/kokkos/mdspan/single-header/mdspan.hpp> namespace stdex = std::experimental; ////////////////////////////////////////////////////////////////////////// // Part 1: Compile-time iteration ////////////////////////////////////////////////////////////////////////// // C++20 lets you write lambdas with explicitly named template parameters // (vs. C++14 lambdas with "auto" parameters). // If you have a lambda templated on <std::size_t ... Indices> // that takes a std::index_sequence<Indices...> parameter, // you can then call the lambda // with the result of std::make_index_sequence<N>. // This calls the lambda with the template arguments 0, 1, 2, ..., N-1. // You can then use these as "loop indices" to "iterate" // at compile time over a parameter pack. // // If you don't have C++20, you can replace the lambda // with a separate, named helper function. // I learned this trick from Daisy Hollman, Queen of Templates. // // Another approach would be to write a reusable "template for each". // I didn't do that, but it could be useful for backporting // or for documenting intent. // Print all the elements of a parameter pack. // // This is a lambda and not a function because // you can't straightforwardly use std::apply // on templated nonmember functions // (as it doesn't know which overload to use), // but you can use it on generic lambdas. // See the example here: // // https://en.cppreference.com/w/cpp/utility/apply auto print_pack = []<class ... InputTypes>(InputTypes&& ... input) { auto print_all = [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { auto print_one = [&] (std::size_t index, auto&& in) { std::cout << in; if(index + 1 < sizeof...(Indices)) { std::cout << ", "; } }; (print_one(Indices, input), ...); }; std::cout << '('; print_all(std::make_index_sequence<sizeof...(InputTypes)>()); std::cout << ")\n"; }; // Invoke the function f for each multidimensional index in e. // Here we use cartesian_product of multiple iota. // Not all compilers implement iota_view yet, so we use ranges-v3. // // You'll notice that the rightmost index varies the fastest. // We call this "row major" by analogy with layout_right. template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents(Callable&& f, stdex::extents<IndexType, Extents...> e) { [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { auto v = ranges::views::cartesian_product( ranges::views::iota(IndexType(0), e.extent(Indices))...); for(const auto& tuple_of_indices : v) { std::apply(std::forward<Callable>(f), tuple_of_indices); } }(std::make_index_sequence<sizeof...(Extents)>()); } // This does the same thing as for_each_in_extents, // but spells out explicitly what std::apply does. template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_2(Callable&& f, stdex::extents<IndexType, Extents...> e) { [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { auto v = ranges::views::cartesian_product( ranges::views::iota(IndexType(0), e.extent(Indices))...); for(const auto& tuple_of_indices : v) { [&]<std::size_t ... InnerIndices>( std::index_sequence<InnerIndices...> ) { std::forward<Callable>(f)(std::get<InnerIndices>(tuple_of_indices)...); }( std::make_index_sequence<sizeof...(Extents)>() ); } }( std::make_index_sequence<sizeof...(Extents)>() ); } ////////////////////////////////////////////////////////////////////////// // Part 2: Splitting extents // // extents<class /* integral not bool */ IndexType, size_t Extents...> // is part of mdspan. It can mix run-time and compile-time extents values. // // We can express multidimensional iteration recursively // by splitting an extents object into two parts (left and right), // and iterating over one part while fixing the other. ////////////////////////////////////////////////////////////////////////// // Returns a new extents object representing all but the leftmost extent of e. // extents<int, 2, 3, 4> -> extents<int, 3, 4> // extents<int, dynamic_extent, 3, 4> -> extents<int, 3, 4> // // This example shows that you can do index arithmetic on an index sequence. template<class IndexType, std::size_t ... Extents> auto right_extents( stdex::extents<IndexType, Extents...> e ) { static_assert(sizeof...(Extents) != 0); return [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { return stdex::extents<IndexType, e.static_extent(Indices + 1)...>{ e.extent(Indices + 1)... }; }( std::make_index_sequence<sizeof...(Extents) - 1>() ); } /* mdspan<float[][2][][3][][4]> extents<dynamic_extent, 2, dynamic_extent, 3, dynamic_extent, 4> span<float, 4> if constexpr (e.static_extent(r) == dynamic_extent) { } extents<std::integral_constant<int, 2>, std::integral_constant<int, 3>, int> extents<std::integral_constant<int, 2>, std::integral_constant<int, 3>, uint64_t, ...> if constexpr (! std::is_empty_v<decltype(e.static_extent(r))> { } */ // Return two things: // // * the leftmost extent as an extents object, and // * all the other (right) extents as a (single) extents object. // // Encoding the leftmost extent as an extents object // lets us preserve its compile-time-ness. // // This needs to be a lambda or function object, not a templated function. auto split_extents_at_leftmost = []<class IndexType, std::size_t... Extents>(stdex::extents<IndexType, Extents...> e) { static_assert(sizeof...(Extents) != 0); stdex::extents<IndexType, e.static_extent(0)> left_ext( e.extent(0)); return std::tuple{left_ext, right_extents(e)}; }; // right_extents can be implemented by overloading for // extents<IndexType, LeftExtent, RightExtents...>. // That approach doesn't work for left_extents. // Returns a new extents object representing all but the rightmost extent of e. template<class IndexType, std::size_t ... Extents> auto left_extents( stdex::extents<IndexType, Extents...> e ) { static_assert(sizeof...(Extents) != 0); return [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { return stdex::extents<IndexType, e.static_extent(Indices)...>{ e.extent(Indices)... }; }( std::make_index_sequence<sizeof...(Extents) - 1>() ); } // This needs to be a lambda or function object, not a templated function. auto split_extents_at_rightmost = []<class IndexType, std::size_t ... Extents>(stdex::extents<IndexType, Extents...> e) { static_assert(sizeof...(Extents) != 0); stdex::extents<IndexType, e.static_extent(e.rank() - 1)> right_ext( e.extent(e.rank() - 1)); return std::tuple{left_extents(e), right_ext}; }; ////////////////////////////////////////////////////////////////////////// // Part 3: Recursing on extents ////////////////////////////////////////////////////////////////////////// // This is a loop over one extent (dimension). // By packaging up lambdas that fix other extents, // we can use this as a building block // for iterating over all the extents of a multidimensional array. // // This could also serve as a hook for passing along // optimization information -- e.g., whether we want // to apply "#pragma omp simd" to a particular extent. template<class Callable, class IndexType, std::size_t Extent> void for_each_one_extent(Callable&& callable, stdex::extents<IndexType, Extent> ext) { // If it's a run-time extent, do a run-time loop. if constexpr(ext.static_extent(0) == stdex::dynamic_extent) { for(IndexType index = 0; index < ext.extent(0); ++index) { std::forward<Callable>(callable)(index); } } else { // It's a compile-time extent, so use a fold expression // to "iterate at compile time." // This effectively unrolls the loop. // // Since we know the extent at compile time, // we could also apply other optimizations here, // like unrolling for specific SIMD widths. [&]<std::size_t ... Indices> ( std::index_sequence<Indices...> ) { (std::forward<Callable>(callable)(Indices), ...); }( std::make_index_sequence<Extent>() ); } } // Call callable on each multidimensional index in the extents, // iterating in row-major order. template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_row_major( Callable&& callable, stdex::extents<IndexType, Extents...> ext) { if constexpr(ext.rank() == 0) { return; } else if constexpr(ext.rank() == 1) { for_each_one_extent(callable, ext); } else { auto [left_exts, right_exts] = split_extents_at_leftmost(ext); auto inner = [&](auto... left_indices) { auto next = [&] (auto... right_indices) { // left_indices is really only one index here, // but it's still a parameter pack. // Writing the code this way suggests a more general approach. std::forward<Callable>(callable)(left_indices..., right_indices...); }; for_each_in_extents_row_major(next, right_exts); }; for_each_one_extent(inner, left_exts); } } // Call callable on each multidimensional index in the extents, // iterating in column-major order. // // The implementation differs in only two places from the row-major version. // This suggests a way to generalize. // // Overloading on stdex::extents<IndexType, LeftExtents..., RightExtent> // works fine for the row major case, but not for the column major case. template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_col_major( Callable&& callable, stdex::extents<IndexType, Extents...> ext) { if constexpr(ext.rank() == 0) { return; } else if constexpr (ext.rank() == 1) { for_each_one_extent(callable, ext); } else { // 1. Split rightmost instead of leftmost. auto [left_exts, right_exts] = split_extents_at_rightmost(ext); auto inner = [&](auto... right_indices) { // 2. Put the left indices in the inner loop, // instead of the right indices. auto next = [&] (auto... left_indices) { std::forward<Callable>(callable)(left_indices..., right_indices...); }; for_each_in_extents_col_major(next, left_exts); }; for_each_in_extents_col_major(inner, right_exts); } } ////////////////////////////////////////////////////////////////////////// // Part 4: Generalize iteration order, pass 1 ////////////////////////////////////////////////////////////////////////// enum class WhichSideIsInnermost { LEFT, RIGHT }; // This parameterizes iteration by how the extents are split. // // Using split_extents_at_leftmost and LEFT results in row-major iteration; // using split_extents_at_rightmost and RIGHT results in column-major iteration. template<class Callable, class IndexType, std::size_t ... Extents, class ExtentsSplitter> void for_each_in_extents_3_impl(Callable&& callable, stdex::extents<IndexType, Extents...> ext, ExtentsSplitter split_extents, const WhichSideIsInnermost which_side) { if constexpr(ext.rank() == 0) { return; } else if constexpr(ext.rank() == 1) { for_each_one_extent(callable, ext); } else { auto [left_exts, right_exts] = split_extents(ext); // I can't come up with a simple way to generalize more. // If we use the same code for both and just reverse the order // of split_extents return values for the column-major case, // then we'll have to re-reverse the indices in the tuple. if (which_side == WhichSideIsInnermost::RIGHT) { auto inner = [&](auto... left_indices) { auto next = [&] (auto... right_indices) { std::forward<Callable>(callable)(left_indices..., right_indices...); }; for_each_in_extents_3_impl(next, right_exts, split_extents, which_side); }; for_each_in_extents_3_impl(inner, left_exts, split_extents, which_side); } else { auto inner = [&](auto... right_indices) { auto next = [&] (auto... left_indices) { std::forward<Callable>(callable)(left_indices..., right_indices...); }; for_each_in_extents_3_impl(next, left_exts, split_extents, which_side); }; for_each_in_extents_3_impl(inner, right_exts, split_extents, which_side); } } } template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_3(Callable&& callable, stdex::extents<IndexType, Extents...> ext, stdex::layout_right) { for_each_in_extents_3_impl(std::forward<Callable>(callable), ext, split_extents_at_leftmost, WhichSideIsInnermost::RIGHT); } template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_3(Callable&& callable, stdex::extents<IndexType, Extents...> ext, stdex::layout_left) { for_each_in_extents_3_impl(std::forward<Callable>(callable), ext, split_extents_at_rightmost, WhichSideIsInnermost::LEFT); } ////////////////////////////////////////////////////////////////////////// // Part 5: Generalize iteration order, pass 2 ////////////////////////////////////////////////////////////////////////// // Cris Cecka suggested revising the above example // by picking one iteration order as canonical // (we've chosen row-major order above), // and implementing other orders // by changing the orders of extents and indices. template<class Callable, class IndexType, std::size_t ... Extents, class ExtentsReorderer, class ExtentsSplitter, class IndicesReorderer> void for_each_in_extents_4_impl(Callable&& callable, stdex::extents<IndexType, Extents...> ext, ExtentsReorderer reorder_extents, ExtentsSplitter split_extents, IndicesReorderer reorder_indices) { if constexpr(ext.rank() == 0) { return; } else if constexpr(ext.rank() == 1) { for_each_one_extent(callable, ext); } else { // 1. Reorder the input extents. auto reordered_extents = reorder_extents(ext); // 2. Split into "left" and "right." // For row-major and column-major, the resulting left_exts // should always have rank 1 (i.e., only contain one extent). auto [left_exts, right_exts] = split_extents(reordered_extents); // 3. Create a lambda that loops over the right extents, // and takes the left extent(s) as input. auto inner = [&] (auto... left_indices) { auto next = [&] (auto... right_indices) { // 4. "Fix" the order of indices to match // the above reordering of extents. std::apply(std::forward<Callable>(callable), reorder_indices(left_indices..., right_indices...)); }; for_each_in_extents_4_impl(next, right_exts, reorder_extents, split_extents, reorder_indices); }; // 5. Take the above lambda and loop over the left extent(s). for_each_in_extents_4_impl(inner, left_exts, reorder_extents, split_extents, reorder_indices); } } auto extents_identity = []<class IndexType, std::size_t ... Extents>( stdex::extents<IndexType, Extents...> ext) { return ext; }; auto extents_reverse = []<class IndexType, std::size_t ... Extents>( stdex::extents<IndexType, Extents...> ext) { constexpr std::size_t N = ext.rank(); return [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { return stdex::extents< IndexType, ext.static_extent(N - 1 - Indices)... >{ ext.extent(N - 1 - Indices)... }; }( std::make_index_sequence<N>() ); }; // Return a parameter pack as a tuple. auto indices_identity = [](auto... indices) { return std::tuple{indices...}; }; // Get the n-th item in a parameter pack, // where n is a compile-time value. template<std::size_t n, class ... Args> auto get_pack(Args... args) { std::common_type_t<decltype(args)...> result; std::size_t i = 0; return ((i++ == n ? (result = args, true) : false) || ...); } // Return the reverse of a parameter pack as a std::tuple. auto indices_reverse = [](auto... args) { constexpr std::size_t N = sizeof...(args); return [&]<std::size_t ... Indices>( std::index_sequence<Indices...> ) { return std::tuple{ get_pack<N - 1 - Indices>(args)... }; }( std::make_index_sequence<N>() ); }; // Row-major iteration template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_4(Callable&& callable, stdex::extents<IndexType, Extents...> ext, stdex::layout_right) { for_each_in_extents_4_impl(std::forward<Callable>(callable), ext, extents_identity, split_extents_at_leftmost, indices_identity); } // Column-major iteration template<class Callable, class IndexType, std::size_t ... Extents> void for_each_in_extents_4(Callable&& callable, stdex::extents<IndexType, Extents...> ext, stdex::layout_left) { for_each_in_extents_4_impl(std::forward<Callable>(callable), ext, extents_reverse, split_extents_at_rightmost, indices_reverse); } int main() { //stdex::extents<int, 3, 4, 5> e; //stdex::dextents<int, 3> e{3, 4, 5}; stdex::extents<int, 3, stdex::dynamic_extent, 5> e{4}; std::cout << "for_each_in_extents:\n"; for_each_in_extents(print_pack, e); std::cout << "\nfor_each_in_extents_2:\n"; for_each_in_extents_2(print_pack, e); std::cout << "\nRow major:\n"; for_each_in_extents_row_major(print_pack, e); std::cout << "\nColumn major\n"; for_each_in_extents_col_major(print_pack, e); std::cout << "\nfor_each_in_extents_3: row major:\n"; for_each_in_extents_3(print_pack, e, stdex::layout_right{}); std::cout << "\nfor_each_in_extents_3: column major:\n"; for_each_in_extents_3(print_pack, e, stdex::layout_left{}); std::cout << "\nfor_each_in_extents_4: row major:\n"; for_each_in_extents_4(print_pack, e, stdex::layout_right{}); std::cout << "\nfor_each_in_extents_4: column major:\n"; for_each_in_extents_4(print_pack, e, stdex::layout_left{}); 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