機器對指令集的支持是向下兼容的,所以armv7的指令集是能夠運行在iphone5S的,只是效率沒那麼高而已~html
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Architecture : 指你想支持的指令集。app
Valid architectures : 指即將編譯的指令集。iphone
Build Active Architecture Only : 只是否只編譯當前適用的指令集。ide
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如今是2014年初,其實4和4S的用戶仍是蠻多的,而iphone3之類的機器幾乎沒有了,因此咱們的指令集最低必須基於armv7.spa
所以,Architecture的值選擇:armv7 armv7s arm64prototype
PS:選arm64時須要最低支持5.1.1:code
Xcode 5.0.1 can build your app with both 32-bit and 64-bit binaries included. This combined binary requires a minimum deployment target of iOS 5.1.1 or later. The 64-bit binary runs only on 64-bit devices running iOS 7.0.3 and later. If you have an existing app, you should first update your app for iOS 7 and then port it to run on 64-bit processors. By updating it first for iOS 7, you can remove deprecated code paths and use modern practices. If you’re creating a new app, target iOS 7 and compile 32-bit and 64-bit versions of your app.orm
The architecture for 64-bit apps on iOS is almost identical to the architecture for OS X apps, making it easy to create a common code base that runs in both operating systems. Converting a Cocoa Touch app to 64-bit follows a similar transition process as the one for Cocoa apps on OS X. Pointers and some common C types change from 32 bits to 64 bits. Code that relies on the NSInteger
and CGFloat
types needs to be carefully examined.
Start by building the app for the 64-bit runtime, fixing any warnings that occur as well as searching your code for specific 64-bit issues. For example:
Make sure all function calls have a proper prototype.
Avoid truncating 64-bit values by accidentally assigning them to a 32-bit data type.
Ensure that calculations are performed correctly in the 64-bit version of your app.
Create data structures whose layouts are identical in the 32-bit and 64-bit versions of your app (such as when you write a data file to iCloud).
1,若是想本身的app在各個機器都可以最高效率的運行,則須要將Build Active Architecture Only改成NO,Valid architectures選擇對應的指令集:armv7 armv7s arm64。這個會爲各個指令集編譯對應的代碼,所以最後的 ipa體積基本翻了3倍,Release版本必須NO。
2,若是想讓app體積保持最小,則現階段應該選擇Valid architectures爲armv7,這樣Build Active Architecture Only選YES或NO就無所謂了
經常使用命令:
一、查看支持構架的命令是lipo -info xxxxx.a二、合併真機和模擬器的庫的命令是 lipo -create xxxx_iphoneos.a xxxx_simulator.a -output xxxx.a