[llvm-commits] [patch] Patches for some unpredictable instructions on ARM

[Owen Anderson]

These looks fine to be, but please clean up trailing whitespace before committing.

--Owen

On Apr 17, 2012, at 9:12 AM, Silviu Baranga <silbar01 at arm.com> wrote:

> Hi,
>  
> Here are some patches that address the decoding of some unpredictable instructions
> on the ARM backend. All patches add regression tests.
>  
> swp.diff - The swp/swpb instructions have some corner cases in which they have
>                     unpredictable behaviour. The patch adds checks for these cases and
>                     regression tests.
> AI1_cmp.diff - Sets the unpredictable field for all the cmp, tst, teq, cmnz instructions and adds
>                     the unpredictability condition for the register-shifted register form when any of the
>                     register operands are the pc register.
> cdp2.diff - The CDP2 instruction has no restriction on the coprocessor number parameter,
>                    but in the current implementation the instruction is undefined if the value of the
>                    coprocessor number is in {1010, 1011}. To fix this we add a new operand type for the coprocessor
>                    number, which doesn't have that restriction. We replace the coprocessor operand type in
>                    the CDP2 instruction with the new operand.
> mrrc.diff - The MCRR2/MRRC2 instructions are unpredictable when the coprocessor is in 101X or
>                    Rt==Rt2 or Rt==15 or Rt2==15. The patch adds C++ code to handle these cases and a
>                    regression test.
> mrs.diff - The patch adds the soft fail behavior when disassembling MRS instructions. There
>                    appears to be a collision between the space of unpredictable MRS instructions and
>                    the space of predictable CPS instructions. The workaround for this was to not set the
>                    16th bit in the unpredictability mask of the MRS instruction.  
>  
>  
> Please review these patches.
>  
> Thanks,
> Silviu
> <swp.diff><AI1_cmp.diff><cdp2.diff><mrrc.diff><mrs.diff>_______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/4590325d/attachment.html>