Displaying 20 results from an estimated 1000 matches similar to: "Different SelectionDAGs for same CPU"
2019 Jan 26
2
Different SelectionDAGs for same CPU
Hi Tim,
>That C++ function is probably what looks for an FrameIndex node and
>has been taught that it can be folded into the load.
How do you teach a function that a node can be folded into an instruction?
________________________________
From: Tim Northover <t.p.northover at gmail.com>
Sent: Monday, January 21, 2019 11:52 PM
To: Josh Sharp
Cc: via llvm-dev
Subject: Re: [llvm-dev]
2019 Jun 24
3
How to handle ISD::STORE when both operands are FrameIndex?
Hello.
After "Initial selection DAG" stage I get a DAG with node
t14: ch = store<(store 4 into %ir.p45, align 8, addrspace 1)> t10,
FrameIndex:i32<2>, FrameIndex:i32<3>, undef:i32
1. Where does it come from? Can I do anything to make it not appear?
2. If not, how do I change it so that the operand being stored would be
first loaded into a register, and that register
2016 Jul 30
1
Instruction selection bug for vector store with FixedStack
Hello.
Could you please help me solve the following LLC bug happening at instruction
selection time:
ISEL: Starting pattern match on root node: t172: ch = store<ST64[FixedStack6]>
t0, t6, FrameIndex:i64<6>, undef:i64
Initial Opcode index to 157
Skipped scope entry (due to false predicate) at index 162, continuing at 236
Match failed at
2010 Sep 29
1
[LLVMdev] comparison pattern trouble - might be a bug in LLVM 2.8?
On 29 Sep 2010, at 06:25, Heikki Kultala wrote:
> Our architecture has 1-bit boolean predicate registers.
>
> I've defined comparison
>
>
> def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set I1Regs:$op3, (setne I32Regs:$op1, I32Regs:$op2))]>;
>
>
>
>
> But then I end up having the following bug:
>
>
2019 Jun 25
2
How to handle ISD::STORE when both operands are FrameIndex?
On Mon, Jun 24, 2019 at 4:08 PM Tim Northover <t.p.northover at gmail.com>
wrote:
> On Mon, 24 Jun 2019 at 12:16, Gleb Popov via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > 1. Where does it come from? Can I do anything to make it not appear?
>
> It comes from something like:
>
> %ptr = alloca i8
> %var = alloca i8*
> store i8* %ptr, i8**
2010 Sep 29
0
[LLVMdev] comparison pattern trouble - might be a bug in LLVM 2.8?
On Sep 29, 2010, at 12:36 AM, Heikki Kultala wrote:
> On 29 Sep 2010, at 06:25, Heikki Kultala wrote:
>
>> Our architecture has 1-bit boolean predicate registers.
>>
>> I've defined comparison
>>
>> def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set I1Regs:$op3, (setne I32Regs:$op1, I32Regs:$op2))]>;
2010 Sep 30
4
[LLVMdev] Illegal optimization in LLVM 2.8 during SelectionDAG? (Re: comparison pattern trouble - might be a bug in LLVM 2.8?)
Bill Wendling wrote:
> On Sep 29, 2010, at 12:36 AM, Heikki Kultala wrote:
>
>> On 29 Sep 2010, at 06:25, Heikki Kultala wrote:
>>
>>> Our architecture has 1-bit boolean predicate registers.
>>>
>>> I've defined comparison
>>>
>>> def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set
2009 Mar 18
2
[LLVMdev] Selecting FrameIndex
Hi All
I'm having nightmares with FrameIndexes during my backend development :(
I have ComplexPatterns defined for my two addressing modes (RR and
RI). Most of the time, FrameIndex operands appear to be on load/store
nodes, in which case everything works fine as my custom addressing
modes matchers work fine.
Unfortunately, I now have an add node which has a FrameIndex operand
(this results
2010 Oct 01
0
[LLVMdev] Illegal optimization in LLVM 2.8 during SelectionDAG? (Re: comparison pattern trouble - might be a bug in LLVM 2.8?)
On Sep 30, 2010, at 2:13 AM, Heikki Kultala wrote:
> Bill Wendling wrote:
>> On Sep 29, 2010, at 12:36 AM, Heikki Kultala wrote:
>>
>>> On 29 Sep 2010, at 06:25, Heikki Kultala wrote:
>>>
>>>> Our architecture has 1-bit boolean predicate registers.
>>>>
>>>> I've defined comparison
>>>>
>>>> def
2007 Dec 03
2
[LLVMdev] Using frameindex in a pattern
Suppose I have a target that does not have register+constant
addressing mode. Then, I have DAG like:
(store ..., (frameindex))
Targets like SPARC have the following patterns to catch this:
def ADDRri : ComplexPattern<i32, 2,
"SelectADDRri", [frameindex], []>;
def STri : F3_2<3, 0b000100,
(outs), (ins MEMri:$addr, IntRegs:$src),
2007 Dec 04
1
[LLVMdev] Using frameindex in a pattern
Evan Cheng wrote:
>
> On Dec 3, 2007, at 12:53 PM, Vladimir Prus wrote:
>
>>
>> Suppose I have a target that does not have register+constant
>> addressing mode. Then, I have DAG like:
>>
>> (store ..., (frameindex))
>>
>> Targets like SPARC have the following patterns to catch this:
>>
>> def ADDRri : ComplexPattern<i32, 2,
2007 Dec 04
0
[LLVMdev] Using frameindex in a pattern
On Dec 3, 2007, at 12:53 PM, Vladimir Prus wrote:
>
> Suppose I have a target that does not have register+constant
> addressing mode. Then, I have DAG like:
>
> (store ..., (frameindex))
>
> Targets like SPARC have the following patterns to catch this:
>
> def ADDRri : ComplexPattern<i32, 2,
> "SelectADDRri", [frameindex], []>;
> def STri :
2010 Sep 29
2
[LLVMdev] comparison pattern trouble
Our architecture has 1-bit boolean predicate registers.
I've defined comparison
def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set I1Regs:$op3, (setne I32Regs:$op1, I32Regs:$op2))]>;
But then I end up having the following bug:
Code
%0 = zext i8 %data to i32
%1 = zext i16 %crc to i32
%2 = xor i32 %1, %0
%3 = and i32 %2, 1
%4 =
2017 Sep 20
1
Store lowering -> Cannot select FrameIndex.
Hi,
I'm try to lower the store LLVM-IR instruction as per the following LLVM IR program:
*** IR Dump After Module Verifier ***
define void @storeloadi32() {
%ptr = alloca i32
store volatile i32 12, i32* %ptr
ret void
}
The target instruction is associated to the store like this:
def MOVSUTO_A_iSLr : CLPFPU_A_iSLr<0b1000001101,
2019 Jun 26
2
How to handle ISD::STORE when both operands are FrameIndex?
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
2014 Jun 07
3
[LLVMdev] Load/Store Instruction Error
Hi all,
I started to write an LLVM backend for custom CPU. I created XXXInstrInfo
but there are some problems. I searched for it but I couldn't find
anything. Can anyone help me?
include "XXXInstrFormats.td"
def simm16 : Operand<i32> {
let DecoderMethod = "DecodeSimm16";
}
def mem : Operand<i32> {
let PrintMethod = "printMemOperand";
let
2014 Dec 05
2
[LLVMdev] illegal code generated for special architecture
Hi!
I'm making a strange observation in my backend, that ends in illegal code:
Version 1:
- I lower FrameIndex to TargetFrameIndex (nothing special)
- I generate a special address-register ADD instruction in eliminateFrameIndex() to write FramePointer + offset into a new address-register
- I use explicit load and store and address-registers in my target instruction patterns:
eg (store
2008 Oct 06
1
[LLVMdev] sign extensions on loads?
I have a simple test case that my code generator handles fine when using
optimizations, but when I disable optimizations, It turns into a
sequence of instructions that I can't figure out what to setup to get it
to generate the correct code.
The instructions in question are:
%tmp1 = load float* %test ; <float> [#uses=1]
%conv = fpext float %tmp1 to double ;
2016 Jun 22
2
LLVM Backend Issues
Thanks Anton and Krzysztof!
Here is the dump using the -debug flag. At this point I am not making much
sense of this, would it be too much to ask if one of you could walk me
through one of these lines?
One thing that I didn't point out is that I never defined any separate
floating point registers, not sure if this will pose any issue?
Thanks again for your time!
Jeff
jeff at
2015 Jun 27
3
[LLVMdev] Legalizing SelectionDAGs with illegal pointer type
Hi,
I recently started helping with the LLVM AVR backend [1]. The AVR is an 8 bit core with pointer type i16. That makes pointers illegal in the SelectionDAG. As far as I understand it, it is the backends job to legalize these nodes by using the ReplaceNodeResults/LowerOperation callbacks. Is that about right?
I have the feeling that the symbolic nodes carrying pointers, like FrameIndex are