53 lines
1.4 KiB
Markdown
53 lines
1.4 KiB
Markdown
|
# Build Options
|
||
|
|
|
||
|
|
- Compiler optimizations: /O3
|
||
|
|
- Link Time Optimization: /LTO
|
||
|
|
- Fast-Math(dangerous)
|
||
|
|
- Unity Builds
|
||
|
|
- Profile Guided optimizations
|
||
|
|
- Static Linking??
|
||
|
|
- LLVM Bolt
|
||
|
|
|
||
|
|
# C++ Options
|
||
|
|
|
||
|
|
## Annotations
|
||
|
|
constexpr
|
||
|
|
constinit
|
||
|
|
consteval(C++23)
|
||
|
|
const
|
||
|
|
static global variables/functions
|
||
|
|
|
||
|
|
## Attributes
|
||
|
|
\[\[noreturn]] => saves calls
|
||
|
|
\[\[likely]] => reorders branches
|
||
|
|
\[\[assume(condition)]] => UB if condition is false
|
||
|
|
__restrict => disallowes aliasing
|
||
|
|
\[\[gnu::pure]] => pure math functions, not supported in MSVC
|
||
|
|
|
||
|
|
## Avoid copies
|
||
|
|
using std::optional instead of nullable pointer
|
||
|
|
use smart pointers
|
||
|
|
if stealing, use rvalue ref
|
||
|
|
if need copy, use plain type
|
||
|
|
if modified, use lvalue ref
|
||
|
|
if cheap to copy, use plain type
|
||
|
|
if only reading, use const lvalue ref
|
||
|
|
if using a range and continous, use std::span
|
||
|
|
if can be arbitrary range, use std::ranges::***
|
||
|
|
if it needs to be a specific container, use the container
|
||
|
|
otherwise take iterator base
|
||
|
|
use std::string_view(readonly)
|
||
|
|
for invocables, try:
|
||
|
|
- std::invocable<\Args...> auto&& x
|
||
|
|
- return_t(*x)(Args...)
|
||
|
|
- std::move_only_function&&<\return_t(Args...)> x
|
||
|
|
- std::function<\return_t(Args...)> x
|
||
|
|
|
||
|
|
## Avoid allocation
|
||
|
|
dont allocate in loops
|
||
|
|
dont catch exceptions by value(use const lvalue ref)
|
||
|
|
use const lvalue refs also in range for loops, lambda captures and structured bindings
|
||
|
|
provide rvalue accessors T&& value() &&, C++23 provides this auto&& self
|
||
|
|
|
||
|
|
# Manual Hardware Optimizations
|