rolfbjarne
commented
1 year ago This is great diagnostics!
I had a look at the symbols_SYSIOS.list files, and for all the symbols I checked that were in multiple files (around a dozen), almost all were bigger in .NET 7/8 (slightly smaller in .NET 8 vs .NET 7, but both significantly bigger than legacy Xamarin).
Selecting a symbol at random (AVFoundation_AVMediaTypesExtensions_get_AVMediaTypeClosedCaption), it's 124 bytes in legacy Xamarin, 176 bytes in .NET 7 and 172 bytes in .NET 8. While this doesn't seem significant, it'll add up if something similar happens to every symbol (there were a few that had the same size in all versions, but none that I checked were smaller in .NET than legacy Xamarin).
Then I checked the AOT-compiled code for this method, and this is what it shows (note that bulid settings might be different from the original reporter, so the actual assembly is likely different).
Legacy Xamarin
Size: 124 bytes
bin/iPhone/Release/testapp.app/testapp:
(__TEXT,__text) section
_Xamarin_iOS_AVFoundation_AVMediaTypesExtensions_get_AVMediaTypeClosedCaption:
00000001001b2944 stp x29, x30, [sp, #-0x10]!
00000001001b2948 adrp x8, 526 ; 0x1003c0000
00000001001b294c add x8, x8, #0x280
00000001001b2950 ldrb w8, [x8, #0x1aa]
00000001001b2954 cbz w8, 0x1001b2994
00000001001b2958 adrp x8, 551 ; 0x1003d9000
00000001001b295c add x8, x8, #0xe30
00000001001b2960 ldr x9, [x8, #0x610]
00000001001b2964 ldr x9, [x9]
00000001001b2968 cbz x9, 0x1001b29a0
00000001001b296c ldr w10, [x9, #0x18]
00000001001b2970 cmp w10, #0x3
00000001001b2974 b.ls 0x1001b29b0
00000001001b2978 ldr x10, [x8, #0x618]
00000001001b297c ldr x1, [x8, #0x638]
00000001001b2980 add x2, x9, #0x38
00000001001b2984 ldr x0, [x10]
00000001001b2988 bl _Xamarin_iOS_ObjCRuntime_Dlfcn_CachePointer_intptr_string_intptr_
00000001001b298c ldp x29, x30, [sp], #0x10
00000001001b2990 ret
00000001001b2994 mov w0, #0x1aa
00000001001b2998 bl _mono_aot_Xamarin_iOS_init_method
00000001001b299c b 0x1001b2958
00000001001b29a0 adr x1, #0x0
00000001001b29a4 nop
00000001001b29a8 orr w0, wzr, #0x7f
00000001001b29ac bl _p_2
00000001001b29b0 adr x1, #0x0
00000001001b29b4 nop
00000001001b29b8 mov w0, #0x6c
00000001001b29bc bl _p_2.NET 8
Size: 172 bytes
bin/Release/net8.0-ios/ios-arm64/MySimpleApp.app/MySimpleApp:
(__TEXT,__text) section
_Microsoft_iOS_AVFoundation_AVMediaTypesExtensions_get_AVMediaTypeClosedCaption:
0000000100f34338 stp x20, x19, [sp, #-0x20]!
0000000100f3433c stp x29, x30, [sp, #0x10]
0000000100f34340 adrp x8, 1471 ; 0x1014f3000
0000000100f34344 adrp x19, 1450 ; 0x1014de000
0000000100f34348 nop
0000000100f3434c ldrb w20, [x19, #0xb1e]
0000000100f34350 ldr x8, [x8, #0x868]
0000000100f34354 cbnz x8, 0x100f3439c
0000000100f34358 cbz w20, 0x100f343a4
0000000100f3435c adrp x8, 1449 ; 0x1014dd000
0000000100f34360 ldr x8, [x8, #0x348]
0000000100f34364 ldr x8, [x8]
0000000100f34368 ldr w9, [x8, #0x18]
0000000100f3436c cmp w9, #0x3
0000000100f34370 b.ls 0x100f343d0
0000000100f34374 adrp x9, 1449 ; 0x1014dd000
0000000100f34378 adrp x10, 1449 ; 0x1014dd000
0000000100f3437c add x2, x8, #0x38
0000000100f34380 ldr x9, [x9, #0x350]
0000000100f34384 ldr x1, [x10, #0x370]
0000000100f34388 ldr x0, [x9]
0000000100f3438c bl _Microsoft_iOS_ObjCRuntime_Dlfcn_CachePointer_intptr_string_intptr_
0000000100f34390 ldp x29, x30, [sp, #0x10]
0000000100f34394 ldp x20, x19, [sp], #0x20
0000000100f34398 ret
0000000100f3439c bl _mono_aot_Microsoft_iOS_icall_cold_wrapper_264
0000000100f343a0 cbnz w20, 0x100f3435c
0000000100f343a4 adrp x0, 920 ; 0x1012cc000
0000000100f343a8 add x0, x0, #0x19d
0000000100f343ac bl _mono_aot_Microsoft_iOS_init_method
0000000100f343b0 mov w8, #0x1
0000000100f343b4 strb w8, [x19, #0xb1e]
0000000100f343b8 b 0x100f3435c
0000000100f343bc adrp x1, 1267 ; 0x101427000
0000000100f343c0 mov w0, #0xeb
0000000100f343c4 ldr x1, [x1, #0xe40]
0000000100f343c8 bl plt_Microsoft_iOS__jit_icall_llvm_throw_corlib_exception_abs_trampoline
0000000100f343cc brk #0x1
0000000100f343d0 adrp x1, 1267 ; 0x101427000
0000000100f343d4 mov w0, #0xc9
0000000100f343d8 ldr x1, [x1, #0xe48]
0000000100f343dc bl plt_Microsoft_iOS__jit_icall_llvm_throw_corlib_exception_abs_trampoline
0000000100f343e0 brk #0x1This is the IL (identical between legacy Xamarin and .NET):
System.IntPtr AVFoundation.AVMediaTypesExtensions::get_AVMediaTypeClosedCaption () (internal compilercontrolled hidebysig reuseslot specialname static)
2 local variables:
System.IntPtr* V_0
System.IntPtr& V_1
IL_0000: ldsfld System.IntPtr[] AVFoundation.AVMediaTypesExtensions::values
IL_0005: ldc.i4.3
IL_0006: ldelema System.IntPtr
IL_000b: stloc.1
IL_000c: ldloc.1
IL_000d: conv.u
IL_000e: stloc.0
IL_000f: ldsfld System.IntPtr ObjCRuntime.Libraries/AVFoundation::Handle
IL_0014: ldstr "AVMediaTypeClosedCaption"
IL_0019: ldloc.0
IL_001a: call System.IntPtr ObjCRuntime.Dlfcn::CachePointer(System.IntPtr,System.String,System.IntPtr*)
IL_001f: ret@ivanpovazan not sure who would be able to explain this difference in the AOT-compiled size?
ivanpovazan
vargaz
AndreyFromGomel
Description
Context: Migrating game engine written in c# from legacy xamarin ios to .NET7.
After the migration, when comparing minimal engine project for ios ("EmptyProject") I noticed non neglectable increase in size of application (.NET7: 13.3MB , .NET8 10.8MB)
I built the project with legacy xamarin ios, net7 and net8 and tried to make some analysis and comparison. See Details section. Attachment contains built applications, debug symbols, MachO symbol dumps, some stats, binlogs, see Attachment section.
I understand there are a lot of issues on the matter and some growth is to be expected. But 10Mb (for net8) seems like too much, may be I made some mistakes, or there are methods to reduce application size I'm not aware of? (apart from TrimSafe on engine assembly)
Details
Main object of interest is predicted download size, since that is by what appstore limits availability of download over metered connections.
.app/.ipasize is not helpful in that regard, because afaik executable gets encrypted by appstore, making it compression-resistant. We predict download size as uncompressed executable size + everything else in ipa/app compressed size.bloaty was used to generate symbols:
bloaty -d segments,sections,symbols,compileunits --debug-file=./bin/Release/EmptyProject.app.dSYM/Contents/Resources/DWARF/EmptyProject ./bin/Release/EmptyProject.app/EmptyProject -n 0 --tsv > symbols.txtI used slightly modified (included in attachment) script by @ivanpovazan to generate stats. (mentioned here) Generated stats are also in attachment.
Script modifications are:
2.broke the diff, so diff is disabledEven so, the "OTHERS" section grew a lot.
Stats:
legacy xamarin ios
``` -------------------------------------------------------------------------------- Stats for symbols from __TEXT,__text: -------------------------------------------------------------------------------- Total number of _infos: 0 Total number of plts: 35625 Total number of wrappers: 3155 Total number of icus: 0 Total number of Globalizations: 1496 Total number of generics: 10383 -------------------------------------------------------------------------------- Total size of _infos: 0 Total size of plts: 712672 Total size of wrappers: 606384 Total size of icus: 0 Total size of Globalizations: 290856 Total size of generics: 2400912 -------------------------------------------------------------------------------- Total symbols: 102682 Total corelib: 16840 16.40% Total sysios: 2504 2.44% Total mono: 7023 6.84% Total others: 26769 26.07% Total game and engine: 49546 48.25% Total size: 19778536 Total corelib: 3716896 18.79% Total sysios: 337796 1.71% Total mono: 3117024 15.76% Total others: 2240916 11.33% Total game and engine: 10365904 52.41% -------------------------------------------------------------------------------- ```net7
``` -------------------------------------------------------------------------------- Stats for symbols from __TEXT,__text: -------------------------------------------------------------------------------- Total number of _infos: 0 Total number of plts: 34430 Total number of wrappers: 4171 Total number of icus: 5648 Total number of Globalizations: 1904 Total number of generics: 19493 -------------------------------------------------------------------------------- Total size of _infos: 0 Total size of plts: 688912 Total size of wrappers: 1049952 Total size of icus: 872852 Total size of Globalizations: 382336 Total size of generics: 5410680 -------------------------------------------------------------------------------- Total symbols: 142057 Total corelib: 37509 26.40% Total sysios: 3032 2.13% Total mono: 6696 4.71% Total others: 43358 30.52% Total game and engine: 51462 36.23% Total size: 30762632 Total corelib: 9797056 31.85% Total sysios: 528448 1.72% Total mono: 4327068 14.07% Total others: 4056944 13.19% Total game and engine: 12053116 39.18% -------------------------------------------------------------------------------- ```net8
``` -------------------------------------------------------------------------------- Stats for symbols from __TEXT,__text: -------------------------------------------------------------------------------- Total number of _infos: 0 Total number of plts: 1 Total number of wrappers: 3604 Total number of icus: 5621 Total number of Globalizations: 1323 Total number of generics: 10026 -------------------------------------------------------------------------------- Total size of _infos: 0 Total size of plts: 140 Total size of wrappers: 861976 Total size of icus: 872424 Total size of Globalizations: 533484 Total size of generics: 3182648 -------------------------------------------------------------------------------- Total symbols: 103924 Total corelib: 34695 33.38% Total sysios: 2618 2.52% Total mono: 6379 6.14% Total others: 30602 29.45% Total game and engine: 29630 28.51% Total size: 27785504 Total corelib: 9430576 33.94% Total sysios: 414288 1.49% Total mono: 3943104 14.19% Total others: 4024752 14.49% Total game and engine: 9972784 35.89% -------------------------------------------------------------------------------- ```MachO sections comparison:
Environment
Version information
``` Visual Studio Community 2022 for Mac Version 17.6.6 (build 408) Installation UUID: 7571e8bb-d341-4541-a456-2451824e8830 Runtime .NET 7.0.3 (64-bit) Architecture: X64 Microsoft.macOS.Sdk 13.1.1007; git-rev-head:8afca776a0a96613dfb7200e0917bb57f9ed5583; git-branch:release/7.0.1xx-xcode14.2 Roslyn (Language Service) 5.6.0-3.23180.6+99e956e42697a6dd886d1e12478ea2b27cceacfa NuGet Version: 6.4.0.117 Xamarin Designer Version: 17.6.3.9 Hash: 2648399ae8 Branch: remotes/origin/d17-6 Build date: 2023-10-23 17:40:07 UTC .NET SDK (x64) SDK: /usr/local/share/dotnet/sdk/7.0.403/Sdks SDK Version: 7.0.403 MSBuild SDKs: /Applications/Visual Studio.app/Contents/MonoBundle/MSBuild/Current/bin/Sdks .NET Runtime (x64) Runtime: /usr/local/share/dotnet/dotnet Runtime Version: 7.0.13 Xamarin.Profiler Version: 1.8.0.49 Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler Updater Version: 11 Xamarin.Android Not Installed Microsoft Build of OpenJDK Java SDK: Not Found Eclipse Temurin JDK Java SDK: Not Found Android SDK Manager Version: 17.6.0.50 Hash: a715dca Branch: HEAD Build date: 2023-10-23 17:40:12 UTC Android Device Manager Version: 0.0.0.1309 Hash: 06e3e77 Branch: HEAD Build date: 2023-10-23 17:40:12 UTC Apple Developer Tools Xcode: 15.0 22265 Build: 15A240d Xamarin.Mac Version: 9.3.0.18 Visual Studio Community Hash: 9d266025e Branch: xcode14.3 Build date: 2023-09-06 19:52:26-0400 Xamarin.iOS Version: 16.4.0.18 Visual Studio Community Hash: 9d266025e Branch: xcode14.3 Build date: 2023-09-06 19:52:27-0400 Build Information Release ID: 1706060408 Git revision: 3912eca6712af97335aa3a782abaa75ff86ec74a Build date: 2023-10-23 17:38:20+00 Build branch: release-17.6 Build lane: release-17.6 Operating System Mac OS X 14.0.0 Darwin 23.0.0 Darwin Kernel Version 23.0.0 Fri Sep 15 14:42:42 PDT 2023 root:xnu-10002.1.13~1/RELEASE_X86_64 x86_64 ```Attachment
I'm sorry for the attachment format, max upload size is 20MB and there's extension whitelist.
.00xand.zipin the name of each filenet-ios-app-size-analysis.001.zip net-ios-app-size-analysis.002.zip net-ios-app-size-analysis.003.zip net-ios-app-size-analysis.004.zip net-ios-app-size-analysis.005.zip