similar to: [LLVMdev] matching "ret 0"

On Sun, 1 Oct 2006, Roman Levenstein wrote: > I'm trying to implement a new backend for an embedded CISC processor. > Therefore I thought that it makes sense to take X86 target as a basis, > to save some time. Ok. Note that the X86 backend is one of the most complex though, because it supports several subtargets and ABIs, which makes it more complex than some other targets. >

I want to generate the instruction like addi 40, r3 ! i.e. r3 = r3 + 40 The format i wrote is def ADDI : F1<opcode, (outs IntRegs:$dst), (ins IntRegs:$dst, i32imm:$imm) "addi $imm, $dst", [(set $IntRegs:$dst, (add $IntRegs:$dst, i32imm:$c))] but it is not compiling. what should be the format. vikram -- View this message

Hi! I'm writing a new back-end for a new architecture. First, I'll do some "tests" with an existing back-end (I chose the Sparc back-end). My architecture has special address-registers and I want to add such new address-registers to my Sparc back-end. 1) I defined a new register call AddrRegs 2) I registered the class AddrRegs (addRegisterClass(MVT::iPTR, .. )) 3) I

Hi Vikram, The error message would be helpful, but the most likely problem is the duplication of $dst. It should probably be: def ADDI : F1<opcode, (outs IntRegs:$dst), (ins IntRegs:$src, i32imm:$imm) "addi $imm, $dst", [(set $IntRegs:$dst, (add $IntRegs:$src, i32imm:$c))]> { let Constraints = "$src = $dst"; } i.e. separate

I have changed the way in which the ARM backend generates a function return. Instead of expanding a RET to a CopyToReg;RETFLAG, it now expands into a CopyToReg;BRIND. I haven't commit it yet, but the patch is attached. In my opinion the resulting code is easier to understand, but I have some questions: Why all backends use RETFLAG? Why it is named RETFLAG? Why the Copy that places the

Hi, I'm trying to implement a new backend for an embedded CISC processor. Therefore I thought that it makes sense to take X86 target as a basis, to save some time. But when I look into the X86InstrInfo.td, I have a very strong feeling that it is one of the most complex instruction set descriptions compared to other targets. I can imagine that this is due to the complexity of X86's

Hi, I am working on a backend for a CGRA architecture with advanced predicate support (as on EPIC machines and as first used in the OpenIMPACT compiler). Until last month, the backend was working fine, but since the r161643 commit by stoklund, my backend doesn't work anymore. I think I noticed some related commits later on, and the assertion I get on the latest trunk (r164162) differs from

On Tue, Jun 25, 2019 at 9:59 AM Tim Northover <t.p.northover at gmail.com> wrote: > On Tue, 25 Jun 2019 at 06:26, Gleb Popov via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > >> While the store is being selected LLVM will just treat the value being > >> stored as a generic pointer-width integer unless you have written a > >> specific pattern for

On Oct 19, 2007, at 8:15 AM, Boris Boesler wrote: > Hi! > > I'm writing a new back-end for a new architecture. First, I'll do > some "tests" with an existing back-end (I chose the Sparc back-end). > My architecture has special address-registers and I want to add such > new address-registers to my Sparc back-end. > > 1) I defined a new register call

Hi Chris, Thanks a lot for your answer! Chris Lattner wrote: >> 1. Why does X86 instruction set description provide different >> descriptions for the same instructions, which differ only in the size >> of operands? >> E.g. >> >> def MOV8rm : I<0x8A, MRMSrcMem, (ops GR8 :$dst, i8mem :$src), >> "mov{b} {$src, $dst|$dst, $src}",

On Thu, Mar 21, 2013 at 2:26 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk>wrote: > Currently, instruction selection patterns are defined like this: > > def : Pat<(and (not GR32:$src1), GR32:$src2), > (ANDN32rr GR32:$src1, GR32:$src2)>; > def : Pat<(and (not GR64:$src1), GR64:$src2), > (ANDN64rr GR64:$src1, GR64:$src2)>; > >

Hi David, > [(set GR32:$rD, globaladdr:$addr)] > It seems to have somehow managed to create a cycle in the DAG, which is > of course wrong. But how? When I write a similar pattern into the ARM .td files and look at (from the build directory) lib/Target/ARM/ARMGenDAGISel.inc, I see: /*56478*/ /*SwitchOpcode*/ 13, TARGET_VAL(ISD::GlobalAddress),// ->56494 /*56481*/

Hi Arnold, Thanks for the patch. Some questions and commons: 1. Have you test it against the llvm test suite? Does it work if fp elimination optimization is turned off? 2. Please follow llvm coding convention and make sure every line fits in 80 columns. 3. enum NameDecorationStyle { None, StdCall, - FastCall + FastCall, + FastCC // the normal fastcc calling convention }; Why is

I have an llvm ir, which generates the following machine code using llc (llvm 3.0 on win32) after # *** IR Dump After X86 DAG->DAG Instruction Selection ***: The first three lines and the last two lines alone together are used to compute "sin" for some double number. - line 1: move the stack pointer down 8 - line 2: copy the updated stack pointer to a base register - line 3: copy a

On Tue, 30 May 2006, [UTF-8] Rafael Esp?ndola wrote: > I have changed the way in which the ARM backend generates a function > return. Instead of expanding a RET to a CopyToReg;RETFLAG, it now > expands into a CopyToReg;BRIND. I haven't commit it yet, but the patch > is attached. Ok, I haven't looked at the code, but you're free to do whatever make sense. > In my

Hi, While working some more on the backend, I've added callee register saving and have come across something odd (I assume its because i've not implemented something), this is with optimisations which makes it even more odd : MOV.L [R7+ 12], R1 ; 4-byte Folded Spill MOV.L [R7+ 8], R2 ; 4-byte Folded Spill ADD.L R0,R0 + R1 ADD.L

On Sep 18, 2012, at 1:45 PM, Bjorn De Sutter <bjorn.desutter at elis.ugent.be> wrote: > I am working on a backend for a CGRA architecture with advanced predicate support (as on EPIC machines and as first used in the OpenIMPACT compiler). Until last month, the backend was working fine, but since the r161643 commit by stoklund, my backend doesn't work anymore. I think I noticed some

The phi instruction is irrelevant; just the way I think about things. The question is if the allocator believes that t0 and t2 interfere. Perhaps the coalescing example was too simple. In the general case, we can't coalesce without a notion of interference. My worry is that looking at interference by ranges of instruction numbers leads to inaccuracies when a range is introduced by a copy.

> On Sep 10, 2018, at 5:25 PM, Matthias Braun <mbraun at apple.com> wrote: > > > >> On Sep 10, 2018, at 5:11 PM, Preston Briggs <preston.briggs at gmail.com <mailto:preston.briggs at gmail.com>> wrote: >> >> The phi instruction is irrelevant; just the way I think about things. >> The question is if the allocator believes that t0 and t2

On 8 March 2014 00:53, Owen Anderson <resistor at mac.com> wrote: > ISDOpcodes.h contains what documentation there is on the semantics of each > opcode. And TargetOpcodes.h for a few of the post-ISel ones (mostly they're in MachineInstr form, but you'll see them with -view-sched-dags, and occasionally before). Tim.