similar to: [LLVMdev] pseudo lowering

On Feb 17, 2013, at 1:01 PM, Reed Kotler <rkotler at mips.com> wrote: > On 02/17/2013 12:48 PM, Andrew Trick wrote: >> On Feb 16, 2013, at 1:31 PM, Cameron Zwarich <zwarich at apple.com> wrote: >> >>> That's exactly the right place. >> Really? You don't want the expansion to be optimized? You want to specify a machine model for the pseudo's

On Feb 16, 2013, at 1:31 PM, Cameron Zwarich <zwarich at apple.com> wrote: > That's exactly the right place. Really? You don't want the expansion to be optimized? You want to specify a machine model for the pseudo's as if they're real instructions? You don't want to schedule or register allocate the real instructions? -Andy > On Feb 16, 2013, at 1:08 PM, Reed

On 02/17/2013 01:08 PM, Andrew Trick wrote: > > On Feb 17, 2013, at 1:01 PM, Reed Kotler <rkotler at mips.com > <mailto:rkotler at mips.com>> wrote: > >> On 02/17/2013 12:48 PM, Andrew Trick wrote: >>> On Feb 16, 2013, at 1:31 PM, Cameron Zwarich<zwarich at apple.com> wrote: >>> >>>> That's exactly the right place.

On 02/17/2013 12:48 PM, Andrew Trick wrote: > On Feb 16, 2013, at 1:31 PM, Cameron Zwarich <zwarich at apple.com> wrote: > >> That's exactly the right place. > Really? You don't want the expansion to be optimized? You want to specify a machine model for the pseudo's as if they're real instructions? You don't want to schedule or register allocate the real

That's exactly the right place. Cameron On Feb 16, 2013, at 1:08 PM, Reed Kotler <rkotler at mips.com> wrote: > I have a bunch of pseudos that I want to lower right after instruction selection. > > Where is the best place to do that? > > I was planning to use expandPostRAPseudo. > > Is there a better place? > > TIA. > > Reed > > > >

You are trying to do a few different things here, and a uniform solution may not work for all of them. For a fixed instruction sequence, e.g. a special kind of move-and-branch sequence used for tail calls, you probably want a pseudo. If you are trying to combine arbitrary instructions together, e.g. Thumb IT blocks, you probably want to use bundles, even if the sequences are a fixed length. I

AFAIK, You have two choices: use a pseudo that is lowered into separate instructions later as part of asm emission, or use MI bundles. The former is generally what existing targets use for this sort of thing, but perhaps the second would work better for you. Cameron On Feb 16, 2013, at 8:37 PM, Reed Kotler <rkotler at mips.com> wrote: > Some of my pseudos do conditional branch .+4 and

One of my reasons for lowering things early is that I need to get an accurate count of the size of things. Some of the pseudos even have instructions like compare immediate, which in Mips 16 has two forms depending on the magnitude of the immediate field. Though I suppose it's possible to leave things as a pseudo and calculate their size, though I'm not sure where I could store the

Sounds like bundles will be the simplest to start with though I suppose I could just lower the pseudos after scheduling is done; for now. Bundles will prevent things from being able to be scheduled in more creative ways but for that I need to think more about the problem. So I can just create a bundle, insert instructions in it, and all will work more or less? I'm trying to take the next

On Feb 17, 2013, at 12:48 PM, Andrew Trick <atrick at apple.com> wrote: > On Feb 16, 2013, at 1:31 PM, Cameron Zwarich <zwarich at apple.com> wrote: > >> That's exactly the right place. > > Really? You don't want the expansion to be optimized? You want to specify a machine model for the pseudo's as if they're real instructions? You don't want to

This Pattern class says it's possible but seems just to not work or maybe I'm using it incorrectly. Probably I will go and fix it when I'm done with mips16. ________________________________________ From: Hal Finkel [hfinkel at anl.gov] Sent: Sunday, September 16, 2012 10:59 AM To: Anton Korobeynikov Cc: Kotler, Reed; LLVM-Dev ‎[llvmdev at cs.uiuc.edu]‎ Subject: Re: [LLVMdev] Pattern

Is there a simple way to just change the opcode of a machine instruction. I have a lot of long/short pairs where when I know the offset, i can replace the long version with the short version. Tia. REed

Some of my pseudos do conditional branch .+4 and such. I don't want the instruction scheduler to get creative on me. On 02/16/2013 07:20 PM, reed kotler wrote: > I have some pseudos that I am expanding in the Mips 16 port. Currently > they are blasted in one chunk as a multi line instruction sequence but I > am changing the code now to expand them > after register allocation.

I have some pseudos that I am expanding in the Mips 16 port. Currently they are blasted in one chunk as a multi line instruction sequence but I am changing the code now to expand them after register allocation. They are essentially macros and I need to make sure, at this time at least, that the individual instructions are not reordered or moved around. There are dependencies sometimes between

Here is a simple place I wanted to use it. ... On multiply, the result implicit is placed in a 64 bit hi/lo register. // // Format: MFLO rx MIPS16e // Purpose: Move From LO Register // To copy the special purpose LO register to a GPR. // def Mflo16: FRR16_M_ins<0b10010, "mflo", IIAlu> { let Uses = [LO]; let neverHasSideEffects = 1; } // // Pseudo Instruction for mult //

What have you tried? On Sun, Sep 16, 2012 at 3:34 PM, Kotler, Reed <rkotler at mips.com> wrote: > This Pattern class says it's possible but seems just to not work or maybe I'm using it incorrectly. > > Probably I will go and fix it when I'm done with mips16. > > > ________________________________________ > From: Hal Finkel [hfinkel at anl.gov] > Sent:

I understand that but falling back makes the compilation slower. I'm wondering what could be done to remove this restriction about fast-isel not being able to handle non legal types. ________________________________________ From: Anton Korobeynikov [anton at korobeynikov.info] Sent: Sunday, August 31, 2014 12:55 AM To: Reed Kotler Cc: LLVMdev at cs.uiuc.edu Subject: Re: [LLVMdev] lowering

After discussions last night, I'm leaning towards going legit with all my pseudo expansions in Mips 16. Some I think I can clearly do by just putting in the proper side effects of implicit registers (T8 the condition code register as used by mips 16). But I'm still left with some pseudos that have jmp .+4 type instructions in them. The original Mips port was to Mips I and Mips I,

Reed, Have a look at custom inserters. In particular, how they're used for atomics in the ARM backend. -Jim On Feb 17, 2013, at 12:51 PM, Reed Kotler <rkotler at mips.com> wrote: > After discussions last night, I'm leaning towards going legit with all my pseudo expansions in Mips 16. > > Some I think I can clearly do by just putting in the proper side effects of

Has anybody used the Pattern class. We all use Pat and ComplexPattern but I can't find any examples of Pattern. I have some instructions that I'm currently treating as pseudos but I'd like to treat them as patterns with several instructions but this does not seem to work, at least I can't get it to work so far. I get an error: Cannot handle instructions with temporaries yet!