Re: [PATCH] Make ARM GAS accept valid STR instruction

[Jie Zhang <jie at codesourcery dot com>]

On 08/25/2010 01:26 PM, Jie Zhang wrote:
> On 08/25/2010 10:58 AM, Daniel Jacobowitz wrote:
> > On Mon, Aug 23, 2010 at 11:38:59PM +0800, Jie Zhang wrote:
> > > On 08/21/2010 05:03 AM, Daniel Jacobowitz wrote:
> > > > On Wed, Aug 18, 2010 at 04:28:07PM +0800, Jie Zhang wrote:
> > > > > `str r0,[pc,#4]' is a valid instruction although the use of PC is
> > > > > deprecated. But currently GAS rejects this instruction. This patch
> > > > > should fix it. Tested using GAS testsuite for arm-none-eabi target.
> > > > > Is it OK?
> > > >
> > > > Where (on what architectures) is the use of PC deprecated? It's
> > > > documented as fine in the ARM v5 reference; I do not think we should
> > > > warn unconditionally, but then, some other code in gas does. At least
> > > > check warn_on_deprecated.
> > > >
> > > > swp{b} warns only of armv6 or later, that might be the right model
> > > > here.
> > > Thanks! That's a good idea. I checked the manuals. It's deprecated
> > > since ARMv7-A. So I changed my patch accordingly. The new patch is
> > > attached. In the new patch, I just removed the valid instruction from
> > > the test and inserted a blank line to keep the line numbers of the
> > > following lines unchanged to avoid massive line number changes in
> > > test dump file. Compared to the last version of the patch, I added
> > > the valid str instruction to the new test added by the this patch.
> > >
> > > Tested GAS for arm-none-eabi, no regressions found.
> > >
> > > Is it OK now?
> >
> > Yes. Please tweak the architecture test though: it's deprecated for
> > all ARM v7. It doesn't matter for M-profile because the ARM
> > instruction set is missing there, but v7-R is the same as v7-A here.
> Thanks. The patch attached is what I have committed.
I forgot to update the comment. This patch does it. Committed.


--
Jie Zhang
CodeSourcery

	* config/tc-arm.c (encode_arm_addr_mode_2): Fix comment.

Index: config/tc-arm.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-arm.c,v
retrieving revision 1.453
diff -u -p -r1.453 tc-arm.c
--- config/tc-arm.c	25 Aug 2010 05:25:08 -0000	1.453
+++ config/tc-arm.c	25 Aug 2010 05:57:24 -0000
@@ -6826,7 +6826,7 @@ encode_arm_addr_mode_2 (int i, bfd_boole
 	  constraint ((is_t || inst.operands[i].writeback),
 		      BAD_PC_ADDRESSING);
 
-	  /* Use of PC in str is deprecated for ARMv7-A.  */
+	  /* Use of PC in str is deprecated for ARMv7.  */
 	  if (warn_on_deprecated
 	      && !is_load
 	      && ARM_CPU_HAS_FEATURE (selected_cpu, arm_ext_v7))