Evo at least requires a C++03 (ideally C++11) compliant compiler.

Without C++11, Evo uses some compiler specific features, most notably with threads and atomic operations.

Optimization

Evo uses optimizations that take advantage of SSE 4.2 and SSE 2 CPU instructions (via compiler intrinsics). These are mainly used for string scanning/parsing and bit manipulation.

Most compilers enable at least SSE 2 instructions by default, which is supported by all x64 CPUs
Evo follows the compiler options by default (using macros set by compiler) – defaults are generally preferred, but you may fine-tune for more specific hardware
- Note that Evo uses SSE 4.2 by default when AVX or AVX2 is enabled with the compiler
When fine tuning for best performance, testing and benchmarking is recommended as results may vary

Notes for best performance:

GCC & Clang
- Compile with -msse4.2 to enable optimizations for SSE 4.2 instructions (if requiring a CPU with SSE 4.2 support is acceptable)
- You can also optimize further for current or specific hardware with -march= and -tune=
- See: https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html
- Tools like valgrind may have issues with SSE 4.2 instructions, with errors like: Unknown instruction/opcode
MSVC:
- Code Generation is configured under C/C++ configuration for project, or with /arch option
  - MSVC doesn't have an option to enable SSE 4.2 – if needed enable this by defining EVO_USE_SSE42 (before including Evo headers) (if requiring a CPU with SSE 4.2 support is acceptable)
  - You can also enable Evo SSE 4.2 use by enabling AVX code generation (if requiring a CPU with AVX support is acceptable)
- See: https://docs.microsoft.com/en-us/cpp/build/reference/arch-minimum-cpu-architecture?view=vs-2017

Testing

Tested on the following systems and compilers:

Ubuntu

18.04: gcc 7.4.0, clang 6.0.0, valgrind 3.13.0 – Intel Core i7
16.04: gcc 5.4.0, clang 3.8.0, valgrind 3.11.0 – Intel Core i7
14.04: gcc 4.8.4, clang 3.4.0, valgrind 3.10.1 – VM
- Also: gcc 4.6.4, gcc 4.7.3

CentOS – VM

7.6: gcc 4.8.5, clang 3.4.2, valgrind 3.13.0
6.10: gcc 4.4.7, clang 3.4.2

FreeBSD – VM

12.0: clang 6.0.1, valgrind 3.10.1

MacOS – Intel Core i5

10.13.6: Apple LLVM 10.0.0 (clang 1000-10.44.4)

Windows 10 – Intel Core i7

MSVC 2017 Community 15.9.11, libevent 2.1.8, libevent 2.0.22
MSVC 2015 Community Update 3

Windows 7 SP1 32-bit – VM

MSVC 2013 Community Update 5, libevent 2.1.8, libevent 2.0.22
cygwin 3.0.6: gcc 7.4.0

Notes

All tested systems are 64-bit, unless otherwise noted
Microsoft Visual C++:
- Before 2015: Static var initialization is not thread-safe ("magic statics")
- 2013: Atomic or AtomicPtr with const template param causes release build compiler error
- Before 2012: Atomics not supported, but Evo will try to emulate atomics with a mutex (this may not work well)
Cygwin:
- For C++11 (or newer), enable with the gnu++ option variant to avoid compile errors, ex: g++ -std=gnu++11
Older compilers (like gcc 4.4 or clang 3.4) should use -fno-strict-aliasing to avoid warnings and stability issues
- RedHat GCC 4.4 on CentOS 6 has a vtable optimization bug, see here
See also: Build Dependencies