Skip to content

30% optimization of DateTime.GetDate()/.Year/.Month/.Day/.DayOfYear by 'Euclidean affine functions' #72712

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
danmoseley merged 9 commits into from
Jul 31, 2022
Merged

30% optimization of DateTime.GetDate()/.Year/.Month/.Day/.DayOfYear by 'Euclidean affine functions' #72712

Changes from 1 commit
Commits
Show all changes
9 commits
Select commit Hold shift + click to select a range
5cc9503
Optimize DateTime.GetDate()/.GetDatePart() by 'Euclidean affine funct…
SergeiPavlov Jul 23, 2022
4293bfd
Code style
SergeiPavlov Jul 23, 2022
163509c
Refactoring: avoid switch and 'var' keyword; add March1BasedDayOfNewY…
SergeiPavlov Jul 24, 2022
dfd20c6
Fix build
SergeiPavlov Jul 24, 2022
06cdd8f
Add [MethodImpl(MethodImplOptions.AggressiveInlining)] to GetDatePart()
SergeiPavlov Jul 24, 2022
e5e0ded
revert relevant comments from original code
SergeiPavlov Jul 25, 2022
7503120
Inline calculations into properties: Year, Month, Day, DayOfYear inst…
SergeiPavlov Jul 28, 2022
8f48de6
Fix indentation
SergeiPavlov Jul 28, 2022
7a5531e
align comment
SergeiPavlov Jul 28, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
revert relevant comments from original code
  • Loading branch information
@SergeiPavlov
SergeiPavlov committed Jul 25, 2022
commit e5e0ded7c3aef0e4989d2f257e4ac8c23e8a2bf0
5 changes: 4 additions & 1 deletion src/libraries/System.Private.CoreLib/src/System/DateTime.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1367,14 +1367,16 @@ private int GetDatePart(int part)
ulong u2 = (ulong)Math.BigMul(2939745, (int)r1 | 3);
ushort daySinceMarch1 = (ushort)((uint)u2 / 11758980);
int n3 = 2141 * daySinceMarch1 + 197913;
// Return 1-based day-of-month
if (part == DatePartDay)
return (ushort)n3 / 2141 + 1;
// If month was requested, return it
if (part == DatePartMonth)
return (ushort)(n3 >> 16) - (daySinceMarch1 >= March1BasedDayOfNewYear ? 12 : 0);

int year = (int)(100 * y400 + (uint)(u2 >> 32)) + (daySinceMarch1 >= March1BasedDayOfNewYear ? 1 : 0);
return part == DatePartYear
? year
? year // If year was requested, compute and return it
: daySinceMarch1 >= March1BasedDayOfNewYear // DatePartDayOfYear case
? daySinceMarch1 - March1BasedDayOfNewYear + 1 // rollover December 31
: daySinceMarch1 + (366 - March1BasedDayOfNewYear) + (IsLeapYear(year) ? 1 : 0);
Expand All @@ -1392,6 +1394,7 @@ internal void GetDate(out int year, out int month, out int day)
ushort daySinceMarch1 = (ushort)((uint)u2 / 11758980);
int n3 = 2141 * daySinceMarch1 + 197913;
year = (int)(100 * y400 + (uint)(u2 >> 32));
// compute month and day
month = (ushort)(n3 >> 16);
day = (ushort)n3 / 2141 + 1;

Expand Down