similar to: [LLVMdev] Constraints

On Wednesday 18 June 2008 01:30, Evan Cheng wrote: > On Jun 17, 2008, at 1:36 PM, David Greene wrote: > > Can someone explain the Constraints system in X86*.td? > > > > For example: > > > > let Constraints = "$src1 = $dst" > > > > This replaces isTwoAddress (according to svn logs), which I gather > > is how > > two-address

On Jun 17, 2008, at 1:36 PM, David Greene wrote: > Can someone explain the Constraints system in X86*.td? > > For example: > > let Constraints = "$src1 = $dst" > > This replaces isTwoAddress (according to svn logs), which I gather > is how > two-address instructions used to be marked for X86. You're right. This is the same as isTwoAddress, just more

> It doesn't look like TableGen supports Constraints beyond EARLY_CLOBBER > and TIED_TO. We would need to add a constraint such as "$dst != $src1, > $dst != $mask, $src1 != $mask" to the current patterns to enforce the > rules. You can emulate such constraints via early clobbing. Just mark dst as early clobbing. > Is there another mechanism to suport a constraint

>> It doesn't look like TableGen supports Constraints beyond EARLY_CLOBBER >> and TIED_TO. We would need to add a constraint such as "$dst != $src1, >> $dst != $mask, $src1 != $mask" to the current patterns to enforce the >> rules. > You can emulate such constraints via early clobbing. Just mark dst as > early clobbing. How would that (or any early

We've discovered a problem in the AVX2 gather patterns X86InstrSSE.td. According to the AVX2 manual, no two of the destination register, vector index register and mask register can be the same. The patterns in X86InstrSSE.td are missing this constraint and it's possible to generate an illegal instruction. It doesn't look like TableGen supports Constraints beyond EARLY_CLOBBER and

sanjiv gupta wrote: > I have a question: > In the pattern below from X86 > > def INC8r : I<0xFE, MRM0r, (outs GR8 :$dst), (ins GR8 :$src), > "inc{b}\tdst", > [(set GR8:$dst, (add GR8:$src, 1))]>; > > Since we are emitting only "inc $dst", > What makes sure that the $src and $dst are same register? > > - Sanjiv It's enclosed

On Wed, Jan 23, 2013 at 4:40 PM, Tim Northover <t.p.northover at gmail.com>wrote: > >> It doesn't look like TableGen supports Constraints beyond EARLY_CLOBBER > >> and TIED_TO. We would need to add a constraint such as "$dst != $src1, > >> $dst != $mask, $src1 != $mask" to the current patterns to enforce the > >> rules. > > You can

On Thu, 1 Mar 2007, Christopher Lamb wrote: > I see in the x86 InstInfo.td the following for the INC instructions: > > def INC8r : I<0xFE, MRM0r, (ops GR8 :$dst, GR8 :$src), "inc{b} $dst", > [(set GR8:$dst, (add GR8:$src, 1))]>; > > Which seem to have the same restriction that I'm trying to implement, > but I don't understand how this

Anton Korobeynikov <anton at korobeynikov.info> writes: >> It doesn't look like TableGen supports Constraints beyond EARLY_CLOBBER >> and TIED_TO. We would need to add a constraint such as "$dst != $src1, >> $dst != $mask, $src1 != $mask" to the current patterns to enforce the >> rules. > You can emulate such constraints via early clobbing. Just

Hi, I've come across a problem while working on an LLVM backend for a new target architecture. This architecture has two single-ported register files. Each instruction can only read one operand from each register file, but can write to either. I tried implementing it naïvely in TableGen with two definitions per instruction, so I had: def AllRegs : RegisterClass< ... (add interleave

Hi,every one. I' in trouble again. I want add a new intrinsic mapping a new instruction. I add the int_x86_max_qb as fllowing: def int_x86_max_qb: GCCBuiltin<"__builtin_x86_max_qb">, Intrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i32_ty], [Commutative]>; BUILTIN(__builtin_x86_max_qb, "iii", "") I define the intrinsic as Pseudo instruction,it

I have a question: In the pattern below from X86 def INC8r : I<0xFE, MRM0r, (outs GR8 :$dst), (ins GR8 :$src), "inc{b}\tdst", [(set GR8:$dst, (add GR8:$src, 1))]>; Since we are emitting only "inc $dst", What makes sure that the $src and $dst are same register? - Sanjiv

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

Chris Lattner wrote: > On Thu, 2 Dec 2004, Brent Monroe wrote: > >>I'm trying to add the xadd instruction to the X86 back end. >>xadd r/m32, r32 >>exchanges r/m32 and r32, and loads the sum into r/m32. I'm >>interested in the case where the destination operand is a >>memory location. >> >>I've added the following entry to

I need to implement an instruction which has 2 read-write registers, so I added let Constraints = "$src1 = $dst, $mask = $mask_wb" in { ... def rm : AVX28I<opc, MRMSrcMem, (outs VR128:$dst, VR128:$mask_wb), (ins VR128:$src1, v128mem:$src2, VR128:$mask), ... } There is a problem since MRMSrcMem assumes the 2nd physical operand is a memory operand. See the section about

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

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). >

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 GPRI8:$src0, GPRI8:$src1), (ADD_i8 GPRI8:$src0, (NEGATE_i8 GPRI8:$src1))>; def _i32 : Pat<(sub

--------- Forwarded Message --------- From： Tianhao Shen <17862703959 at 163.com> Date： 11/14/2018 09:31 To： craig.topper at gmail.com <craig.topper at gmail.com> Subject： Re: [llvm-dev] How to define an instruction Hi, Craig Thank you for replying to me. I guess that you misunderstand my meaning about "can'r run". I just want to run my instruction by LLVM using the

In BPF, an ADD instruction is defined as a 2 register instruction: 0x0f. add dst, src. dst += src In BPFInstrInfo.td this kind of ALU instruction is defined with: def _rr : ALU_RR<BPF_ALU64, Opc, (outs GPR:$dst), (ins GPR:$src2, GPR:$src), "$dst "#OpcodeStr#" $src", [(set