Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-19 Thread Carrot Wei
Could anybody help to review the small patch http://gcc.gnu.org/ml/gcc-patches/2010-01/msg00531.html thanks Guozhi On Sat, Jan 9, 2010 at 7:25 PM, Carrot Wei wrote: > OK, I filed a bug to trace it. > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42671 > > thanks > Guozhi > > On Thu, Jan 7, 2010 at

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-09 Thread Carrot Wei
OK, I filed a bug to trace it. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42671 thanks Guozhi On Thu, Jan 7, 2010 at 6:23 PM, Richard Earnshaw wrote: > > On Wed, 2010-01-06 at 18:26 +, Paul Brook wrote: >> On Wednesday 06 January 2010, Carrot Wei wrote: >> > So thumb2 can also use the instr

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-07 Thread Paul Brook
On Thursday 07 January 2010, Richard Earnshaw wrote: > On Wed, 2010-01-06 at 18:26 +, Paul Brook wrote: > > On Wednesday 06 January 2010, Carrot Wei wrote: > > > So thumb2 can also use the instructions similar to thumb1, right? It > > > potentially has better performance and smaller code size.

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-07 Thread Richard Earnshaw
On Wed, 2010-01-06 at 18:26 +, Paul Brook wrote: > On Wednesday 06 January 2010, Carrot Wei wrote: > > So thumb2 can also use the instructions similar to thumb1, right? It > > potentially has better performance and smaller code size. > > Technically yes, however in ARMv7 the relevant instruct

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-06 Thread Laurent Desnogues
On Thu, Jan 7, 2010 at 2:10 AM, Carrot Wei wrote: > Does "deprecated" mean it works currently but may not work in future versions? > > In chapter A8.6.6 of document > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0406b/index.html > I can't find it is mentioned that (add.n , pc) is

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-06 Thread Carrot Wei
Does "deprecated" mean it works currently but may not work in future versions? In chapter A8.6.6 of document http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0406b/index.html I can't find it is mentioned that (add.n , pc) is deprecated. thanks Carrot On Thu, Jan 7, 2010 at 2:26 AM,

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-06 Thread Paul Brook
On Wednesday 06 January 2010, Carrot Wei wrote: > So thumb2 can also use the instructions similar to thumb1, right? It > potentially has better performance and smaller code size. Technically yes, however in ARMv7 the relevant instruction (add.n , pc) is deprecated. Paul

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-06 Thread Carrot Wei
So thumb2 can also use the instructions similar to thumb1, right? It potentially has better performance and smaller code size. thanks Carrot On Tue, Jan 5, 2010 at 7:06 PM, Richard Earnshaw wrote: > > On Tue, 2010-01-05 at 15:42 +0800, Carrot Wei wrote: >> Hi >> >> In function arm_load_pic_regis

Re: Why Thumb-2 only allows very limited access to the PC?

2010-01-05 Thread Richard Earnshaw
On Tue, 2010-01-05 at 15:42 +0800, Carrot Wei wrote: > Hi > > In function arm_load_pic_register in file arm.c there are following code: > > if (TARGET_ARM) > { > ... > } > else if (TARGET_THUMB2) > { > /* Thumb-2 only allows very limited access

Why Thumb-2 only allows very limited access to the PC?

2010-01-04 Thread Carrot Wei
Hi In function arm_load_pic_register in file arm.c there are following code: if (TARGET_ARM) { ... } else if (TARGET_THUMB2) { /* Thumb-2 only allows very limited access to the PC. Calculate the address in a temporary reg