[WTF] Annotate Seconds' member functions and operators with constexpr

https://bugs.webkit.org/show_bug.cgi?id=170662

Reviewed by Daniel Bates.

Source/WebCore:

* page/Frame.cpp:

Source/WTF:

Annotate Seconds' member functions and operators with constexpr.
It allows us to use Seconds calculation in compile time and use these
calculation for static const global variables.

operator% is an exception: it uses fmod and it is not offered as constexpr.

* wtf/MathExtras.h:
(defaultMinimumForClamp):
(defaultMaximumForClamp):
(clampToAccepting64):
Super unfortunate ugly code. This is because GCC 4.9 does not support C++14 relaxed constexpr.

* wtf/Seconds.h:
(WTF::Seconds::Seconds):
(WTF::Seconds::value):
(WTF::Seconds::minutes):
(WTF::Seconds::seconds):
(WTF::Seconds::milliseconds):
(WTF::Seconds::microseconds):
(WTF::Seconds::nanoseconds):
(WTF::Seconds::operator bool):
(WTF::Seconds::operator+):
(WTF::Seconds::operator-):
(WTF::Seconds::operator*):
(WTF::Seconds::operator/):
(WTF::Seconds::operator==):
(WTF::Seconds::operator!=):
(WTF::Seconds::operator<):
(WTF::Seconds::operator>):
(WTF::Seconds::operator<=):
(WTF::Seconds::operator>=):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@215169 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Source/WTF/ChangeLog b/Source/WTF/ChangeLog
index 7dd564b..e1da7fd 100644 (file)
--- a/Source/WTF/ChangeLog
+++ b/Source/WTF/ChangeLog
@@ -1,3 +1,42 @@
+2017-04-09  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        [WTF] Annotate Seconds' member functions and operators with constexpr
+        https://bugs.webkit.org/show_bug.cgi?id=170662
+
+        Reviewed by Daniel Bates.
+
+        Annotate Seconds' member functions and operators with constexpr.
+        It allows us to use Seconds calculation in compile time and use these
+        calculation for static const global variables.
+
+        operator% is an exception: it uses fmod and it is not offered as constexpr.
+
+        * wtf/MathExtras.h:
+        (defaultMinimumForClamp):
+        (defaultMaximumForClamp):
+        (clampToAccepting64):
+        Super unfortunate ugly code. This is because GCC 4.9 does not support C++14 relaxed constexpr.
+
+        * wtf/Seconds.h:
+        (WTF::Seconds::Seconds):
+        (WTF::Seconds::value):
+        (WTF::Seconds::minutes):
+        (WTF::Seconds::seconds):
+        (WTF::Seconds::milliseconds):
+        (WTF::Seconds::microseconds):
+        (WTF::Seconds::nanoseconds):
+        (WTF::Seconds::operator bool):
+        (WTF::Seconds::operator+):
+        (WTF::Seconds::operator-):
+        (WTF::Seconds::operator*):
+        (WTF::Seconds::operator/):
+        (WTF::Seconds::operator==):
+        (WTF::Seconds::operator!=):
+        (WTF::Seconds::operator<):
+        (WTF::Seconds::operator>):
+        (WTF::Seconds::operator<=):
+        (WTF::Seconds::operator>=):
+
 2017-04-09  Chris Dumez  <cdumez@apple.com>
 
         Start dropping Timer API dealing with double

diff --git a/Source/WTF/wtf/MathExtras.h b/Source/WTF/wtf/MathExtras.h
index 40c77e3..dcef394 100644 (file)
--- a/Source/WTF/wtf/MathExtras.h
+++ b/Source/WTF/wtf/MathExtras.h
@@ -141,10 +141,10 @@ inline float rad2grad(float r) { return r * 200.0f / piFloat; }
 inline float grad2rad(float g) { return g * piFloat / 200.0f; }
 
 // std::numeric_limits<T>::min() returns the smallest positive value for floating point types
-template<typename T> inline T defaultMinimumForClamp() { return std::numeric_limits<T>::min(); }
-template<> inline float defaultMinimumForClamp() { return -std::numeric_limits<float>::max(); }
-template<> inline double defaultMinimumForClamp() { return -std::numeric_limits<double>::max(); }
-template<typename T> inline T defaultMaximumForClamp() { return std::numeric_limits<T>::max(); }
+template<typename T> constexpr inline T defaultMinimumForClamp() { return std::numeric_limits<T>::min(); }
+template<> constexpr inline float defaultMinimumForClamp() { return -std::numeric_limits<float>::max(); }
+template<> constexpr inline double defaultMinimumForClamp() { return -std::numeric_limits<double>::max(); }
+template<typename T> constexpr inline T defaultMaximumForClamp() { return std::numeric_limits<T>::max(); }
 
 template<typename T> inline T clampTo(double value, T min = defaultMinimumForClamp<T>(), T max = defaultMaximumForClamp<T>())
 {
@@ -195,13 +195,9 @@ inline int clampToInteger(T x)
 
 // Explicitly accept 64bit result when clamping double value.
 // Keep in mind that double can only represent 53bit integer precisely.
-template<typename T> inline T clampToAccepting64(double value, T min = defaultMinimumForClamp<T>(), T max = defaultMaximumForClamp<T>())
+template<typename T> constexpr inline T clampToAccepting64(double value, T min = defaultMinimumForClamp<T>(), T max = defaultMaximumForClamp<T>())
 {
-    if (value >= static_cast<double>(max))
-        return max;
-    if (value <= static_cast<double>(min))
-        return min;
-    return static_cast<T>(value);
+    return (value >= static_cast<double>(max)) ? max : ((value <= static_cast<double>(min)) ? min : static_cast<T>(value));
 }
 
 inline bool isWithinIntRange(float x)

diff --git a/Source/WTF/wtf/Seconds.h b/Source/WTF/wtf/Seconds.h
index d07ffef..48483f2 100644 (file)
--- a/Source/WTF/wtf/Seconds.h
+++ b/Source/WTF/wtf/Seconds.h
@@ -37,20 +37,20 @@ class WallTime;
 
 class Seconds {
 public:
-    Seconds() { }
+    constexpr Seconds() { }
     
     explicit constexpr Seconds(double value)
         : m_value(value)
     {
     }
     
-    double value() const { return m_value; }
+    constexpr double value() const { return m_value; }
     
-    double minutes() const { return m_value / 60; }
-    double seconds() const { return m_value; }
-    double milliseconds() const { return seconds() * 1000; }
-    double microseconds() const { return milliseconds() * 1000; }
-    double nanoseconds() const { return microseconds() * 1000; }
+    constexpr double minutes() const { return m_value / 60; }
+    constexpr double seconds() const { return m_value; }
+    constexpr double milliseconds() const { return seconds() * 1000; }
+    constexpr double microseconds() const { return milliseconds() * 1000; }
+    constexpr double nanoseconds() const { return microseconds() * 1000; }
 
     // Keep in mind that Seconds is held in double. If the value is not in range of 53bit integer, the result may not be precise.
     template<typename T> T minutesAs() const { static_assert(std::is_integral<T>::value, ""); return clampToAccepting64<T>(minutes()); }
@@ -89,37 +89,37 @@ public:
         return Seconds(std::numeric_limits<double>::infinity());
     }
     
-    explicit operator bool() const { return !!m_value; }
+    explicit constexpr operator bool() const { return !!m_value; }
     
-    Seconds operator+(Seconds other) const
+    constexpr Seconds operator+(Seconds other) const
     {
         return Seconds(value() + other.value());
     }
     
-    Seconds operator-(Seconds other) const
+    constexpr Seconds operator-(Seconds other) const
     {
         return Seconds(value() - other.value());
     }
     
-    Seconds operator-() const
+    constexpr Seconds operator-() const
     {
         return Seconds(-value());
     }
     
     // It makes sense to consider scaling a duration, like, "I want to wait 5 times as long as
     // last time!".
-    Seconds operator*(double scalar) const
+    constexpr Seconds operator*(double scalar) const
     {
         return Seconds(value() * scalar);
     }
     
-    Seconds operator/(double scalar) const
+    constexpr Seconds operator/(double scalar) const
     {
         return Seconds(value() / scalar);
     }
     
     // It's reasonable to think about ratios between Seconds.
-    double operator/(Seconds other) const
+    constexpr double operator/(Seconds other) const
     {
         return value() / other.value();
     }
@@ -177,32 +177,32 @@ public:
     WTF_EXPORT_PRIVATE MonotonicTime operator-(MonotonicTime) const;
     WTF_EXPORT_PRIVATE TimeWithDynamicClockType operator-(const TimeWithDynamicClockType&) const;
     
-    bool operator==(Seconds other) const
+    constexpr bool operator==(Seconds other) const
     {
         return m_value == other.m_value;
     }
     
-    bool operator!=(Seconds other) const
+    constexpr bool operator!=(Seconds other) const
     {
         return m_value != other.m_value;
     }
     
-    bool operator<(Seconds other) const
+    constexpr bool operator<(Seconds other) const
     {
         return m_value < other.m_value;
     }
     
-    bool operator>(Seconds other) const
+    constexpr bool operator>(Seconds other) const
     {
         return m_value > other.m_value;
     }
     
-    bool operator<=(Seconds other) const
+    constexpr bool operator<=(Seconds other) const
     {
         return m_value <= other.m_value;
     }
     
-    bool operator>=(Seconds other) const
+    constexpr bool operator>=(Seconds other) const
     {
         return m_value >= other.m_value;
     }

diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index f6838ca..6566a90 100644 (file)
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,12 @@
+2017-04-09  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        [WTF] Annotate Seconds' member functions and operators with constexpr
+        https://bugs.webkit.org/show_bug.cgi?id=170662
+
+        Reviewed by Daniel Bates.
+
+        * page/Frame.cpp:
+
 2017-04-09  Chris Dumez  <cdumez@apple.com>
 
         Drop Timer::startRepeating() overload taking a double

diff --git a/Source/WebCore/page/Frame.cpp b/Source/WebCore/page/Frame.cpp
index 47560ed..4ed9124 100644 (file)
--- a/Source/WebCore/page/Frame.cpp
+++ b/Source/WebCore/page/Frame.cpp
@@ -121,7 +121,7 @@ namespace WebCore {
 using namespace HTMLNames;
 
 #if PLATFORM(IOS)
-static const Seconds scrollFrequency { 1000 / 60. };
+static const Seconds scrollFrequency { 1000_s / 60. };
 #endif
 
 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, frameCounter, ("Frame"));