Re: [Qemu-devel] [PATCH 02/10] compiler.h: add QEMU_CACHELINE + QEMU_ALIGN() + QEMU_CACHELINE_ALIGNED

[Lluís Vilanova]

Richard Henderson writes:

> On 04/05/2016 12:02 PM, Lluís Vilanova wrote:
>> Peter Maydell writes:
>> 
>>> On 5 April 2016 at 17:31, Richard Henderson <address@hidden> wrote:
>>>> On 04/05/2016 09:23 AM, Lluís Vilanova wrote:
>>>>> 
>>>>> Got it!
>>>>> 
>>>>> gcc -march=native --help=params -v 2>&1 | grep "param
>>>>> l1-cache-line-size" | sed -e 's/.* --param l1-cache-line-size=\([0-9]\+\)
>>>>> .*/\1/'
>>>> 
>>>> 
>>>> That will only work on x86, where we can be pretty sure it's 64 anyway.
>> 
>> Oh, you mean l1-cache-line-size is an x86-only parameter in GCC?

> No, using -march=native to detect the host line size.

Ah. That's just an example. For cross-compilation you would use a different
march argument (or none to use the default target sub-arch) and get the
parameter for the target processor. This should already be known by configure as
part of the arguments to select the cross-compiler and target architecture
(e.g., CC).


Lluis