search for: fixedleninstructiondecod

Hi Kurt, Jim, I took the liberty of working on this today. The patch has become a bit of a frankenpatch, for the reasons listed out below and so I won't be able to submit it until tomorrow. The actual fix itself was very straightforward, but exposed a failing in the FixedLenInstructionDecoder in that it does not support instruction predicates such as "IsThumb2". Generally this is fine, however MRS has different encodings in v{6,7}m and v{6,7}{a,r} - the encodings are not sufficiently different to deterministically tell them apart without subtarget specific information. I c...

...> > I took the liberty of working on this today. > > The patch has become a bit of a frankenpatch, for the reasons listed out below > and so I won't be able to submit it until tomorrow. > > The actual fix itself was very straightforward, but exposed a failing in the > FixedLenInstructionDecoder in that it does not support instruction predicates > such as "IsThumb2". > > Generally this is fine, however MRS has different encodings in v{6,7}m and > v{6,7}{a,r} - the encodings are not sufficiently different to deterministically > tell them apart without subtarget s...

Hi Kurt, The assembly parser doesn't (yet) handle these, you're right. Currently, the MRS instruction is split into two variants in the ARMInstrThumb2.td file, t2MRS and t2MRSsys, one for the user mode version reading cpsr and one for the system mode version reading spsr. MSR, by contrast, has a custom parse method for the mask operand since it's a bit more complex than an either/or.

I was attempting to compile some code with a recent (r138716) version of llvm/clang, targeting a cortex-m4 processor. And I get an error like this: CC: sched_garbage.c In file included from sched_garbage.c:43: In file included from ./os_internal.h:48: In file included from /p/nuttx/trunk/nuttx/include/sched.h:47: In file included from /p/nuttx/trunk/nuttx/include/nuttx/sched.h:54: In file