similar to: [LLVMdev] mips16 hard float puzzle

On Fri, Jan 4, 2013 at 6:28 PM, reed kotler <rkotler at mips.com> wrote: > On 01/04/2013 06:08 PM, Eli Friedman wrote: >> >> On Fri, Jan 4, 2013 at 4:08 PM, reed kotler <rkotler at mips.com> wrote: >>> >>> I'm working on mips16 hard float which at a first approximation is just >>> soft >>> float but calls different library

On 01/04/2013 06:08 PM, Eli Friedman wrote: > On Fri, Jan 4, 2013 at 4:08 PM, reed kotler <rkotler at mips.com> wrote: >> I'm working on mips16 hard float which at a first approximation is just soft >> float but calls different library routines. Those different library routines >> are just an implementation (in mips32 mode) of soft float using mips32 >>

On Fri, Jan 4, 2013 at 4:08 PM, reed kotler <rkotler at mips.com> wrote: > I'm working on mips16 hard float which at a first approximation is just soft > float but calls different library routines. Those different library routines > are just an implementation (in mips32 mode) of soft float using mips32 > hardware instructions. This part is already done. (mips16 mode has no

On 01/04/2013 07:45 PM, Eli Friedman wrote: > On Fri, Jan 4, 2013 at 6:28 PM, reed kotler <rkotler at mips.com> wrote: >> On 01/04/2013 06:08 PM, Eli Friedman wrote: >>> On Fri, Jan 4, 2013 at 4:08 PM, reed kotler <rkotler at mips.com> wrote: >>>> I'm working on mips16 hard float which at a first approximation is just >>>> soft

On Mon, Jan 7, 2013 at 4:16 PM, reed kotler <rkotler at mips.com> wrote: > On 01/04/2013 07:45 PM, Eli Friedman wrote: >> >> On Fri, Jan 4, 2013 at 6:28 PM, reed kotler <rkotler at mips.com> wrote: >>> >>> On 01/04/2013 06:08 PM, Eli Friedman wrote: >>>> >>>> On Fri, Jan 4, 2013 at 4:08 PM, reed kotler <rkotler at mips.com>

For example: /home/rkotler/llvm/install/bin/llc -mcpu=mips16 hf16_2.ll -march=mipsel -relocation-model=pic -o hf16_2.s -O3 -mips16-hard-float -soft-float On 01/04/2013 07:45 PM, Eli Friedman wrote: > On Fri, Jan 4, 2013 at 6:28 PM, reed kotler <rkotler at mips.com> wrote: >> On 01/04/2013 06:08 PM, Eli Friedman wrote: >>> On Fri, Jan 4, 2013 at 4:08 PM, reed kotler

Reed, It's not clear to me that you need to do anything special here. If you define your MIPS16 register class as not containing SP, then any MIPS16 instructions that get selected and want to read from SP should get a COPY inserted from SP to a MIPS16 vreg. The coalescer should, ideally, get rid of extraneous copies for you. --Owen On Sep 20, 2012, at 10:48 PM, Reed Kotler <rkotler at

On 01/08/2013 01:48 PM, Eli Friedman wrote: > On Mon, Jan 7, 2013 at 6:07 PM, reed kotler <rkotler at mips.com> wrote: >> For example: >> >> /home/rkotler/llvm/install/bin/llc -mcpu=mips16 hf16_2.ll -march=mipsel >> -relocation-model=pic -o hf16_2.s -O3 -mips16-hard-float -soft-float > Try something like the following: > > float f; > double test(void*

Actually, SP is already not in the mips 16 register class but there is some C++ code that is common to mips32, mips64 and mips16 that is wanting to use SP. It's kind of awkward but does work except in this case of load/store haflword and byte to stack objects. Maybe I'm shooting myself in the foot there. I don't know that code too well so maybe I need to look into it. There are

Trying to think of a clever way to do something.... On Mips 16, the SP (stack pointer) is not a directly accessible register in most instructions. There is a way to move to and from mips 16 registers (subset of mips32) and mips32 registers. For the load/store word instructions, there are forms which implicitly take SP. However, for store/load byte and store/load halfword, there is no such

On Sep 20, 2012, at 11:44 PM, Reed Kotler <rkotler at mips.com> wrote: > Actually, SP is already not in the mips 16 register class but there is some C++ code that is common to mips32, mips64 and mips16 that is wanting to use SP. It's kind of awkward but does work except in this case of load/store haflword and byte to stack objects. > ARM has a similar problem. The InstrInfo

On Tue, Jan 8, 2013 at 6:33 PM, reed kotler <rkotler at mips.com> wrote: > On 01/08/2013 01:48 PM, Eli Friedman wrote: >> >> On Mon, Jan 7, 2013 at 6:07 PM, reed kotler <rkotler at mips.com> wrote: >>> >>> For example: >>> >>> /home/rkotler/llvm/install/bin/llc -mcpu=mips16 hf16_2.ll -march=mipsel >>> -relocation-model=pic -o

On Mon, Jan 7, 2013 at 6:07 PM, reed kotler <rkotler at mips.com> wrote: > > For example: > > /home/rkotler/llvm/install/bin/llc -mcpu=mips16 hf16_2.ll -march=mipsel > -relocation-model=pic -o hf16_2.s -O3 -mips16-hard-float -soft-float Try something like the following: float f; double test(void* fptr) { f = ((float(*)(float,float))fptr)(1.0, 1.0); } -Eli

On Fri, Jan 20, 2012 at 1:59 PM, reed kotler <rkotler at mips.com> wrote: > We are starting to look at the mips16 and micro mips ports. > > There are various design issues that people may have some good input on. > Especially in how to structure the TD files and other optimizer issues. > > Mips16 is sort of like thumb and Micro Mips like thumb2 as far as I > understand.

I'm implementing this unusual gcc form of mips16 hard float. I ran into one unexpected wrinkle. It effects efficiency as opposed to correctness but I'd like to figure out the best way to resolve it. The signatures for the libcall routines have floating point arguments in at least some situations. I have not fully examined if it's all of them. So in callinfo while I'm lowering

We are starting to look at the mips16 and micro mips ports. There are various design issues that people may have some good input on. Especially in how to structure the TD files and other optimizer issues. Mips16 is sort of like thumb and Micro Mips like thumb2 as far as I understand. Mips16 or Micro Mips can live inside of either MIPS32 or MIPS64. In gcc, it's possible using attributes to

Turned out to be a rather simple fix. Just copied SP to a virtual register in the beginning of the function. Then added an extra operand to the DAGs with stack reference load/store, with the extra operand equal to this virtual register if the Parent of the address is a LOAD/STORE of an 8 or 16 bit quantity. It worked fine. When needed SP got copied to a mips 16 register and when the SP alias

What happens here is that the code that is doing the "softening", generates a libcall On closer inspection, llvm is doing half of this correctly. The signature for the soft float function for extending a float to double is of the form: i64 xxx_extendsfdf2(float); But it should be i64 xxx_extendsfdf2(i32) This particular paradigm is duplicated many times in the the float type

I'm working on the mips16. Mips16 is a mode of the Mips32 (or Mips64) processor. For the most part, it is a compressed form of the MIPS32 instruction set, though not all instructions are supported. Most of the same opcodes and formats are present though sometimes with some restriction. (The micro mips architecture is a true 16 bit compressed form of MIps32 though also with some

Ok. That's a somewhat different problem, then. Devil will be in the details of what you want to do. A few options. First is to always have a standard frame pointer register available and reference off of that. Caveat: dynamic stack realignment and vararrays muck with that more than a bit. Second is what gcc is doing and reserve a register just for this in addition to the frame register.