RFR: Add support for ARMv6 to ARM JIT

[Andrew Haley]

On 22/01/15 09:53, Edward Nevill wrote:
> On Wed, Jan 21, 2015 at 5:16 PM, Andrew Haley <aph at redhat.com> wrote:
> 
>> On 01/21/2015 05:06 PM, Edward Nevill wrote:
>>
>>> Because of the size of the changes I have introduced a new file
>>> arm32JIT.cpp rather than modifying the existing thumb2.cpp. This is
>>> switched on a symbol ARM32JIT. By default it will continue to build
>>> the Thumb2 JIT. To change it to build the ARM32 JIT by default add
>>> -DARM32JIT to CFLAGS in zeroshark.make as in the following patch.
>>
>> I don't get this.  Surely we should have both, switchable at runtime.
> 
> arm32jit.cpp supports generation for ARMV6, ARMV6K and ARMV6T2+.
> 
> For ARMV6 and ARMV6K it will generate 32 bit ARM instructions.
> 
> For ARMV6T2 and later it will generate Thumb2 instructions by defaulty, but
> this can be changed by setting the T2_COMPILE_ARM environment variable.

So what is thumb2.cpp for?  I still don't get it.

Andrew.