Optimize division by constant after AND or RSZ

[pentp]

If the dividend operand is AND or RSZ with a constant then the number of input bits can be reduced which helps generate more optimal magic numbers.
Also adopted a couple more functions to use unsigned division.

Diff example:

 G_M59169_IG02:
        48B8FFFFFFFFFFFFFF3F mov      rax, 0x3FFFFFFFFFFFFFFF
        488BD0               mov      rdx, rax
        482311               and      rdx, qword ptr [rcx]
        48B94B598638D6C56D34 mov      rcx, 0x346DC5D63886594B
        488BC2               mov      rax, rdx
        48F7E1               mul      rdx:rax, rcx
        488BCA               mov      rcx, rdx
        48C1E90B             shr      rcx, 11
-       48BACFF753E3A59BC420 mov      rdx, 0x20C49BA5E353F7CF
+       48BAF0A7C64B37894100 mov      rdx, 0x4189374BC6A7F0
        488BC1               mov      rax, rcx
-       48C1E803             shr      rax, 3
        48F7E2               mul      rdx:rax, rdx
-       48C1EA04             shr      rdx, 4
        4869C2E8030000       imul     rax, rdx, 0x3E8
        482BC8               sub      rcx, rax
        8BC1                 mov      eax, ecx
-						;; bbWeight=1    PerfScore 13.75
+						;; bbWeight=1    PerfScore 12.75
 G_M59169_IG03:
        C3                   ret      
 						;; bbWeight=1    PerfScore 1.00
 
-; Total bytes of code 76, prolog size 0, PerfScore 22.35, instruction count 17, allocated bytes for code 76 (MethodHash=439618de) for method DateTime:get_Millisecond():int:this
+; Total bytes of code 68, prolog size 0, PerfScore 20.55, instruction count 15, allocated bytes for code 68 (MethodHash=439618de) for method DateTime:get_Millisecond():int:this

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[pentp]

Moved inlining changes to separate PR #56466

[kunalspathak]

Changes looks good. Thank you!
Did you run superpmi and can you share the diff numbers across benchmarks/libraries/asp?

[kunalspathak]

How does this cast help?

[pentp]

It changes the division from signed to unsigned.

[SingleAccretion]

Another possible source of reducing bits would be small types (don't think it is worth doing it now though, you could leave a TODO for someone to take a second look if/after #55186 is merged).

[pentp]

PMI diffs for System.Private.CoreLib:

Summary of Code Size diffs:
(Lower is better)

Total bytes of base: 5563217
Total bytes of diff: 5563112
Total bytes of delta: -105 (-0,00% of base)
Total relative delta: -0,67
    diff is an improvement.
    relative diff is an improvement.

Detailed diffs for win-x64

Top method improvements (bytes):
         -16 (-0,88% of base) : System.Private.CoreLib.dasm - StringSerializer:GetNextTransitionTimeValue():TransitionTime:this
          -9 (-0,13% of base) : System.Private.CoreLib.dasm - DateTimeFormat:FormatCustomized(DateTime,ReadOnlySpan`1,DateTimeFormatInfo,TimeSpan,StringBuilder):StringBuilder
          -8 (-9,52% of base) : System.Private.CoreLib.dasm - Calendar:GetMilliseconds(DateTime):double:this
          -8 (-10,53% of base) : System.Private.CoreLib.dasm - DateTime:get_Millisecond():int:this
          -8 (-9,30% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Millisecond():int:this
          -8 (-0,40% of base) : System.Private.CoreLib.dasm - TimeZoneInfo:TransitionTimeFromTimeZoneInformation(byref,byref,bool):bool
          -4 (-6,06% of base) : System.Private.CoreLib.dasm - Calendar:GetMinute(DateTime):int:this
          -4 (-6,06% of base) : System.Private.CoreLib.dasm - Calendar:GetSecond(DateTime):int:this
          -4 (-5,80% of base) : System.Private.CoreLib.dasm - DateTime:get_Minute():int:this
          -4 (-5,80% of base) : System.Private.CoreLib.dasm - DateTime:get_Second():int:this
          -4 (-0,54% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,int,Calendar,TimeSpan):this
          -4 (-0,44% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,int,TimeSpan):this
          -4 (-0,45% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,TimeSpan):this
          -4 (-5,06% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Minute():int:this
          -4 (-5,06% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Second():int:this
          -4 (-0,38% of base) : System.Private.CoreLib.dasm - EastAsianLunisolarCalendar:ToDateTime(int,int,int,int,int,int,int,int):DateTime:this
          -4 (-0,51% of base) : System.Private.CoreLib.dasm - GregorianCalendar:ToDateTime(int,int,int,int,int,int,int,int):DateTime:this
          -4 (-0,40% of base) : System.Private.CoreLib.dasm - HebrewCalendar:HebrewToGregorian(int,int,int,int,int,int,int):DateTime

Top method improvements (percentages):
          -8 (-10,53% of base) : System.Private.CoreLib.dasm - DateTime:get_Millisecond():int:this
          -8 (-9,52% of base) : System.Private.CoreLib.dasm - Calendar:GetMilliseconds(DateTime):double:this
          -8 (-9,30% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Millisecond():int:this
          -4 (-6,06% of base) : System.Private.CoreLib.dasm - Calendar:GetMinute(DateTime):int:this
          -4 (-6,06% of base) : System.Private.CoreLib.dasm - Calendar:GetSecond(DateTime):int:this
          -4 (-5,80% of base) : System.Private.CoreLib.dasm - DateTime:get_Minute():int:this
          -4 (-5,80% of base) : System.Private.CoreLib.dasm - DateTime:get_Second():int:this
          -4 (-5,06% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Minute():int:this
          -4 (-5,06% of base) : System.Private.CoreLib.dasm - DateTimeOffset:get_Second():int:this
         -16 (-0,88% of base) : System.Private.CoreLib.dasm - StringSerializer:GetNextTransitionTimeValue():TransitionTime:this
          -4 (-0,54% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,int,Calendar,TimeSpan):this
          -4 (-0,51% of base) : System.Private.CoreLib.dasm - GregorianCalendar:ToDateTime(int,int,int,int,int,int,int,int):DateTime:this
          -4 (-0,45% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,TimeSpan):this
          -4 (-0,44% of base) : System.Private.CoreLib.dasm - DateTimeOffset:.ctor(int,int,int,int,int,int,int,TimeSpan):this
          -4 (-0,40% of base) : System.Private.CoreLib.dasm - HebrewCalendar:HebrewToGregorian(int,int,int,int,int,int,int):DateTime
          -8 (-0,40% of base) : System.Private.CoreLib.dasm - TimeZoneInfo:TransitionTimeFromTimeZoneInformation(byref,byref,bool):bool
          -4 (-0,38% of base) : System.Private.CoreLib.dasm - EastAsianLunisolarCalendar:ToDateTime(int,int,int,int,int,int,int,int):DateTime:this
          -9 (-0,13% of base) : System.Private.CoreLib.dasm - DateTimeFormat:FormatCustomized(DateTime,ReadOnlySpan`1,DateTimeFormatInfo,TimeSpan,StringBuilder):StringBuilder

18 total methods with Code Size differences (18 improved, 0 regressed), 26172 unchanged.

[kunalspathak]

LGTM