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Add noexcept specifier to fixed point operations

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This commit is contained in:
Myles Busig 2024-08-03 16:18:20 -06:00
parent 82d6d64829
commit 0e0884cce9
2 changed files with 19 additions and 19 deletions
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36
include/mtl/fixed.hpp
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@ -17,12 +17,12 @@ namespace mtl {
* Valid values are in the range ~[-33'554'431.01, 33'554'432.98]
*
* Has a maximum error of +/- 1/128 (~0.0078), integers are always
* exactly.
* exactly represented.
*
* \par ARM
*
* All functions are compiled in ARM mode because some operators (notably
* multiplication and division) use ARM-only instructions. For optimal
* All functions are compiled in ARM-mode because some operators (notably
* multiplication and division) are much faster in ARM-mode. For optimal
* performance, fixed point numbers should only be used in ARM-mode
* code to enable as much inlining as possible.
*/
@ -44,10 +44,10 @@ private:
* DO NOT use to set the fixed number to an integer value, use
* the public constructor instead.
*/
constexpr fixed(int32_t _x, bool) : x(_x) {}
constexpr fixed(int32_t _x, bool) noexcept : x(_x) {}
public:
constexpr fixed() : x(0) {}
constexpr fixed() noexcept : x(0) {}
/**
* \brief Integer constructor
*
@ -56,7 +56,7 @@ public:
* the class description for more detail.
*/
template <typename T, std::enable_if_t<std::is_integral_v<T>, bool> = true>
constexpr fixed(T _i) : x(_i * 64) {}
constexpr fixed(T _i) noexcept : x(_i * 64) {}
/**
* \brief Floating point constructor
*
@ -69,7 +69,7 @@ public:
* float.
*/
template <typename T, std::enable_if_t<std::is_floating_point_v<T>, bool> = true>
constexpr fixed(T _f)
constexpr fixed(T _f) noexcept
// 0.5 offset accounts for truncating to integer, round instead
: x((_f * 64) + 0.5f) {}
@ -82,7 +82,7 @@ public:
*
* Should not be used unless absolutely needed.
*/
static constexpr fixed from_raw(int32_t x) {
static constexpr fixed from_raw(int32_t x) noexcept {
return fixed(x, true);
}
@ -92,7 +92,7 @@ public:
* Gets the raw value of the fixed point number. i.e. The fixed point
* number multiplied by 64.
*/
constexpr int32_t raw() const {
constexpr int32_t raw() const noexcept {
return x;
}
@ -102,34 +102,34 @@ public:
* Addition with fixed point numbers is the same as with a 32-bit
* integer, so should be extremely quick.
*/
constexpr fixed operator+(fixed rhs) const {
constexpr fixed operator+(fixed rhs) const noexcept {
return from_raw(x + rhs.x);
}
constexpr fixed& operator+=(fixed rhs) {
constexpr fixed& operator+=(fixed rhs) noexcept {
x += rhs.x;
return *this;
}
/**
* \brief Fixed point subtraction
*/
constexpr fixed operator-(fixed rhs) const {
constexpr fixed operator-(fixed rhs) const noexcept {
return from_raw(x - rhs.x);
}
constexpr fixed& operator-=(fixed rhs) {
constexpr fixed& operator-=(fixed rhs) noexcept {
x -= rhs.x;
return *this;
}
constexpr fixed operator-() const {
constexpr fixed operator-() const noexcept {
return from_raw(-x);
}
/**
* \brief Fixed point multiplication
*/
constexpr fixed operator*(fixed rhs) const {
constexpr fixed operator*(fixed rhs) const noexcept {
return from_raw(((int64_t)x * rhs.x) >> 6);
}
constexpr fixed& operator*=(fixed rhs) {
constexpr fixed& operator*=(fixed rhs) noexcept {
*this = *this * rhs;
return *this;
}
@ -149,8 +149,8 @@ public:
*
* Placed in IWRAM
*/
GBA_IWRAM fixed operator/(fixed rhs) const;
fixed& operator/=(fixed rhs) {
GBA_IWRAM fixed operator/(fixed rhs) const noexcept;
fixed& operator/=(fixed rhs) noexcept {
*this = *this / rhs;
return *this;
}

2
src/gba/fixed.cpp
View File

@ -6,7 +6,7 @@ TARGET_ARM_MODE
namespace mtl {
fixed fixed::operator/(fixed rhs) const {
fixed fixed::operator/(fixed rhs) const noexcept {
int32_t raw_result;
asm(
// This division implementation has two methods it can use.