similar to: [LLVMdev] Writing a backend basic information

Hello, Im back trying to finish my backend to a simple RISC cpu SABRE now that most of the tedious process of examining undergraduate students is out of the way. I have managed to describe the registers and the instructions in the architecture and have added support for 32 bit immediates (thanks to Christopher Lamb) as the instruction set only supports 17 bit immediates directly. Could

Hello, Im (trying) to write a backend for a simple 32bit processor architecture, with a single instruction format having no condition code registers. www.docm.mmu.ac.uk/STAFF/A.Nisbet/Sabre.pdf is the short 15 page document describing the architecture of Sabre. It is a Celoxica developed research/teaching processor, pages 5-8 contain relevant information for targetting it from a new compiler

Howdy, <---stuff deleted -----> Basically the architecture I want to compile to (SABRE) RISC does not support a conditional branch or a select instruction. It supports explicit branches of the form. blt %a, %b, imm // branch on less than iff %a < %b then pc = pc + imm So there are various branch instructions like .... ble, beq, bne, blt, bltu and bleu (unsigned) Im just

Is it legal to do something like a !strconcat on a non-string entity? That is, is there some operation that will let me do this (replace SOME_CONCAT with an appropriate operator): (WARNING! Hacked-up tablegen ahead!) multiclass sse_fp_binop_bitwise_rm<bits<8> opc, string OpcodeStr, SDNode OpNode> { // Vector operation emulating scalar (fp)

On Mar 23, 2009, at 5:56 PM, David Greene wrote: > Is it legal to do something like a !strconcat on a non-string > entity? That > is, is there some operation that will let me do this (replace > SOME_CONCAT with > an appropriate operator): I don't get it, can you try a simpler example on me? :) -Chris > > > (WARNING! Hacked-up tablegen ahead!) > >

Hi Hal, Thanks for your reply and it is helpful! I have a quick question: When I use BuildMI to build instructions in this case, do I have to add all three of the register operands explicitly (operand 0 and 1 are the same)? Thanks, Xiaochu On Tue, Nov 24, 2015 at 3:14 PM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> From: "Xiaochu Liu via

Hello all, I have two Tablegen questions in the context of an unconventional architecture. The pertinent details: the architecture has multiple register files that are selected via a bit in the instruction. One of the register files is a traditional one. The other is unconventional in that all source and dest registers are both read from and written to by the instructions. So add special0,

On Tue, Feb 10, 2009 at 8:27 AM, Villmow, Micah <Micah.Villmow at amd.com> wrote: > Bill, > Sorry if I wasn't clear enough. I wasn't referring to multiclass's that > define other classes, but with using patterns inside of a multiclass to > reduce redundant code. > For example: > multiclass IntSubtract<SDNode node> > { > def _i8 : Pat<(sub

Dear Alex, all, I was looking for fcvt.d.{w,l}{,u} in RISCVInstrInfoD and I'm not sure to understand the current definitions: 138 def FCVT_D_W : FPUnaryOp_r<0b1101001, 0b000, FPR64, GPR, "fcvt.d.w"> { 139 let rs2 = 0b00000; 140 } 141 142 def FCVT_D_WU : FPUnaryOp_r<0b1101001, 0b000, FPR64, GPR, "fcvt.d.wu"> { 143 let rs2 =

On Tuesday 24 March 2009 10:43, Chris Lattner wrote: > On Mar 23, 2009, at 5:56 PM, David Greene wrote: > > Is it legal to do something like a !strconcat on a non-string > > entity? That > > is, is there some operation that will let me do this (replace > > SOME_CONCAT with > > an appropriate operator): > > I don't get it, can you try a simpler example on

Dear there, I'm developing an instruction layout like: opcode | rd| ts and its semantics is: rd= rd opcode rs But when I describe it in td file like this: class R<bits<5> Op, string OpcodeStr, list<dag> Pattern> : InstV<(outs GPR:$rd), (ins GPR:$rd, GPR:$rs), !strconcat(OpcodeStr, "\t$rd, $rs"), Pattern> { bits<5> rd; bits<6> rs; let

On 8 November 2012 11:12, Cameron McInally <cameron.mcinally at nyu.edu> wrote: > On Wed, Nov 7, 2012 at 10:52 PM, Anitha Boyapati <anitha.boyapati at gmail.com> > wrote: > ... >> >> For the multiclass "fma4s", why is "mr" not inherited from "VEX_W" and >> "MemOp4" like those of "rm" or "rr" ? >

Here's the big RFC. A I've gone through and designed patterns for AVX, I quickly realized that the existing SSE pattern specification, while functional, is less than ideal in terms of maintenance. In particular, a number of nearly-identical patterns are specified all over for nearly-identical instructions. For example: let Constraints = "$src1 = $dst" in { multiclass

Hi, I have a simple question w.r.t the order of operands used in dag pattern matching in target files. Some of them seem intuitive. But I want to get it clarified anyway. I am using a pattern from X86InstrFMA.td in the below example. Consider FMA3 pattern (simplified). let Constraints = "$src1 = $dst" in { multiclass fma3s_rm<bits<8> opc, string OpcodeStr, X86MemOperand

On Jun 11, 2009, at 2:01 PM, David Greene wrote: > On Thursday 11 June 2009 12:28, Chris Lattner wrote: >>> >>> Yes. I want TableGen to be able to infer lots of stuff >>> programmatically. >>> This helps tremendously when specifying things like, oh, AVX. :) >> >> I don't see how this relates to regex's, and really don't want to

On 16 November 2012 13:41, Anitha B Gollamudi <anitha.boyapati at gmail.com> wrote: > Hi, > > I have a simple question w.r.t the order of operands used in dag > pattern matching in target files. Some of them seem intuitive. But I > want to get it clarified anyway. I am using a pattern from > X86InstrFMA.td in the below example. Consider FMA3 pattern > (simplified). >

Chris Lattner wrote: > However, I don't see any reason to base this off of strings. Instead > of passing down "f32" as a string, why not do something like this > pseudo code: > > class X86ValueType { > RegisterClass RegClass; > ... > } > > def X86_f32 : X86ValueType { > let RegClass = FR32; > ... }; > def X86_i32 :

Hello. I have extended the BPF back end with vector registers (inspiring from Mips MSA) - something like this: def MSA128D: RegisterClass<"Connex", [v128i16], 32, (sequence "Wh%u", 0, 31)>; I also added vector store and load instructions in the style of Mips MSA - see

Spills created at the end of the block (I assume you mean what fast regalloc does at -O0) are created long after instruction selection. In that case it sounds like your implementation of storeRegToStackSlot/loadRegFromStackSlot is broken -Matt On Tue, Oct 25, 2016 at 7:30 AM +0800, "Alex Susu via llvm-dev" <llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>>

You've unfortunately chosen a complex example. Your second question is needs be answered first. null_frag causes the pattern to be dropped. Now having covered that the reason the operands are in the order they are is because the only instruction that doesn't use null_frag is this one defm r213 : fma3s_rm<opc213, !strconcat(OpStr, !strconcat("213", PackTy)),