Xcode instruction Set Settings

There are currently several instruction sets for iOS:

I386:mac
ARMV6:IPHONE,IPHONE2,IPHONE3G, first generation and second generation ipod Touch
Armv7:iphone 3GS, iphone 4, iphone 4s, IPod 3g/4g/5g, ipad, ipad 2, ipad 3, ipad Mini
ARMV7S:IPHONE5,IPHONE5C, IPad 4
Armv8/arm64:iphone 6 (Plus), IPhone 5s, ipad Air (2), Retina ipad Mini (2,3)

  The machine's support for the instruction set is backwards compatible, so the armv7 instruction set can be run in iphone5s, but it's not that high--

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Architecture: Refers to the set of instructions you want to support.

Valid architectures: Refers to the set of instructions that will be compiled.

Build Active Architecture only: Compiles only the currently applicable instruction set.

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 This is the beginning of 2014, in fact, 4 and 4S users are quite a lot, and iphone3 and other machines almost no, so our instruction set minimum must be based on ARMV7.

Therefore, the value of architecture is selected: ARMv7 armv7s arm64

PS: Minimum support required when selecting Arm64 5.1.1:

Convert Your App to a 64-bit Binary after Updating It for IOS 7

nsinteger  and cgfloat  types needs to be carefully examined.

Start by building the app for the 64-bit runtime, fixing to warnings that occur as well as searching your code for SPECIF IC 64-bit issues. For example:

• Make sure all function calls has a proper prototype.

• Avoid truncating 64-bit values by accidentally assigning them to a 32-bit data type.

• Ensure that calculations is performed correctly in the 64-bit version of the Your app.

• Create data structures whose layouts is identical in the 32-bit and 64-bit versions of your apps (such as when you write a Data file to ICloud).

1, if you want your app to be able to run most efficiently on each machine, you need to change build Active Architecture only to No,valid architectures select the corresponding instruction set: ARMv7 armv7s arm64. This will compile the corresponding code for each instruction set, so the final IPA volume is roughly 3 times times, and the release version must be No.

2, if you want to keep the app volume is minimal, then the current stage should choose valid architectures as ARMV7, so build Active Architecture only Select Yes or no does not matter

Support for 64-bit

Apple Next February Mandatory --Bit support

For support 64-bit, we can set architectures as standard architectures, on the latest Xcode 6, which includes ARMV7 and arm64.

Get apps to support 32-bit and 64-bit basic steps

1. Make sure that the Xcode version number >=5.0.1

2. Update project settings, minimum deployment target >= 5.1.1

3. Change architectures to standard architectures (include 64-bit)

4. Run the test code, resolve the compilation warnings and errors, and make changes to the appropriate location against this document or the Official document 64-bit Transition Guide for Cocoa touch. (The compiler can't tell us everything)

5. Test on the real 64-bit machine.

6. Use instruments to view memory usage issues.

Major changes in 64-bit

The 64-bit runtime environment and the 32-bit runtime environment are mainly the following two points different:

Changes in data types

Changes on the method call

Changes in data types

Xcode instruction Set Settings