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

[Silviu Baranga]

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: swp.diff
Type: application/octet-stream
Size: 2581 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: AI1_cmp.diff
Type: application/octet-stream
Size: 2405 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: cdp2.diff
Type: application/octet-stream
Size: 1655 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mrrc.diff
Type: application/octet-stream
Size: 4581 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment-0003.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mrs.diff
Type: application/octet-stream
Size: 2154 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120417/578dc3ce/attachment-0004.obj>