[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for X
From: |
Weddington, Eric |
Subject: |
Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB. |
Date: |
Mon, 19 Nov 2012 15:57:38 +0000 |
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On
> Behalf Of Thomas, George
> Sent: Monday, November 19, 2012 4:32 AM
> To: address@hidden
> Subject: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for
> Xmegas with USB.
>
> Section 20.13.7 of the Xmega manual speaks about the requirement of 16 bit
> alignment.
>
> http://www.atmel.com/images/doc8331.pdf
>
> As the MAXIMUM_ALIGNMENT in avr.h is set to 1, it throws an error when
> trying to compile.
>
> I have attached a patch which sets it to 2 by default in the compiler.
> I have also attached a case which fails.
>
> Would this be an acceptable change ?
Hi George,
No, this would not be an acceptable change, because it is changing the data
alignment for the whole compiler, when there is only a restriction on a data
structure for a single peripheral for a small subset of the AVR processors.
This is why the data attribute "aligned" exists. Just do this for your data
structure:
__attribute__ ((aligned (2)))
Eric
- [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Thomas, George, 2012/11/19
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Georg-Johann Lay, 2012/11/19
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB.,
Weddington, Eric <=
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Weddington, Eric, 2012/11/19
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Georg-Johann Lay, 2012/11/19
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Thomas, George, 2012/11/19
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Thomas, George, 2012/11/21
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Georg-Johann Lay, 2012/11/21
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., David Brown, 2012/11/22
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., Georg-Johann Lay, 2012/11/22
- Re: [avr-gcc-list] Align attribute in gcc requiring alignment of 2 for Xmegas with USB., David Brown, 2012/11/22