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任坤

2009-Mar-31 04:15 UTC

[LLVMdev] 转发: Re: Dear Evan Chang, Re: help: about how to use tblgen to constraint operand.

Dear Evan Chang:
I register incorrect Register class for MVT::f64. I have fixed it. Thanks your
advice.
"-view-legalize-dags" is very good option.
But I don't know why my LLC do not know "
-view-legalize-type-dags" option.
By the way, I use llvm 2.5 merged from llvm2.4.

Best Regards,

Ren Kun

--- 09年3月31日，周二, Evan Cheng <echeng at apple.com> 写道：
发件人: Evan Cheng <echeng at apple.com>
主题: Re: [LLVMdev] Dear Evan Chang, Re:  help: about how to use tblgen to
constraint operand.
收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List" <llvmdev
at cs.uiuc.edu>
日期: 2009,331,周二,1:04上午

This is probably instruction selection issue. I would look at
 the dag at various stafes of isel. Try -view-legalize-type-dags,
-view-legalize-dags, etc.
Evan
On Mar 29, 2009, at 11:54 PM, 任坤 wrote:
I try to define a register class
def GPR64 : RegisterClass<"mytarget", [i64], 64, [T0, T1.....]
to simulate even/odd pair of GPR32 register.
Actually, I just use GPR64 as a temporary register. 
My CPU just support i32 Integer type directly.
I use FDR to save f64.
def FDR : RegisterClass<"mytarget", [f64], 64,[FD0, FD1, ....]

When I move f64 to even/odd pair register, I first move f64 into GPR64,
 
then move to 2 GPR32 register.

It worked very well for register binding.

But When I test some case. I find a register class error.
--------------

11405   0x9321bc8: f64,ch = FLDI 0x93436f8, 0x9343c20, 0x9321ac0, 0x9343674
 --
                                                                     |
                                                                     |
11428         0x9321304: f64 = Register 
 #1066---------|                 |
153 11429         0x9321bc8: <multiple use>             |                
| 
154 11430       0x93447fc: ch = CopyToReg 0x9320fdc, 0x9321304, 0x9321bc8
<--|

---------------
When llc merge the result of FLDI and register #1066, It find #1066 is 
in GPR64 Register Class.
But I define FLDI to save it's result with FDR register at
mytargetInstructInfo.td file.
So a error given.
12493 VReg = 1066
12494 VReg RegClass     size = 8, align = 8
12495 Expected RegClass size = 8, align = 8
12496 Fatal error, aborting.
12497 0  
 llc       0x08bbc5cb
12498 1   llc       0x08bbc93c
12499 2             0x00110400 __kernel_sigreturn + 0
++++++++++++++++++++++++++++
I define register class in mytargetRegisterInfo.td. In here, I binding all
register class with supported variable type. 
I believe leaf node--Register is band with virtual register number at Initial
DAG.

But I do not know why LLC use my GPR64 register to save f64 type variable?

I want to know where pass or function llc binding type with register class?

I guess the initial DAG is created incorrectly. 

Which function first create IR--Register from *.bc and give it a virtual
register number ,  I want to debug it to find error reason.

Best Regards,

   Ren Kun




--- 09年2月21日，周六, Evan Cheng
 <evan.cheng at apple.com> 写道：
发件人: Evan Cheng <evan.cheng at apple.com>
主题: Re: [LLVMdev] help: about how to use tblgen to constraint operand.
收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List" <llvmdev
at cs.uiuc.edu>
日期: 2009,221,周六,2:51上午


On Feb 19, 2009, at 8:26 PM, 任坤 wrote:
hi, Dear Evan Cheng:

My cpu is i32 embeded CPU. I define pseudo register
 pair registers.

In mytargetRegisterInfo.td:
def T0: RegisterWithSubRegs<"t0",[R0,R1]>;
...
def GPR64 : RegisterClass<"mytarget", [i64], 64, [T0, T1.....]

In mytargetISelLowering.cpp:
I define i1, i8 , i16 and i32 are legal. 

1. I still have problem. I save my function return double  value in R0 and R1. 
 It is expanded into two i32. But my GPR64 is defined to save i64. llvm finds
 I have i64 GPR register. It will automatically decide not to expand i64 to two
i32.

2. I guess I need a special pseudo instruction to move between GPR32 and GPR64.
How to move R0, R1 to T1( R2, R3 pair). and don't convert two i32 to i64?
Could I  use MyTargetInstrInfo::copyRegToReg() to handle this logic issue?
No. copyRegToReg only supports copying registers of the same (or compatible
register classes).


3. Maybe I can  study INSERT_SUBREG/EXTRACT_SUBREG at X86 porting file.
Yes.


I will  do some research more deeply. I think the best way is that TableGen has
register pair TypeProfile feature. :(
 
It's not a tablegen issue. It's easy to add the constraint to tablegen
but the register allocator has to be able to allocate register pairs. That is
definitely not a trivial task.
Evan





But I find i64 data will not be ex
--- 09年2月20日，周五, Evan Cheng <echeng at apple.com> 写道：
发件人: Evan Cheng
 <echeng at apple.com>
主题: Re: [LLVMdev] help: about how to use tblgen to constraint operand.
收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List" <llvmdev
at cs.uiuc.edu>
日期: 2009,220,周五,1:11上午

Currently there is no constraint that tells the register allocator to allocate a
consecutive register pair. What I would suggest you do is to declare pseudo
register pair registers (and corresponding register class, say PAIR_GPR). In
this case, your myFMDRR would take one input of  PAIR_GPR class. The asm printer
should be taught to print a PAIR_GPR register as two GPR registers (you should
also teach the JIT of the same thing).
A PAIR_GPR register should be a super
 register of two GPR registers. e.g. r0r1_pair is a super register of r0 and r1.
In order to *construct* a PAIR_GPR register, you have to use two INSERT_SUBREG.
To extract out a GPR from a PAIR_GPR, you need to issue EXTRACT_SUBREG. In most
cases, these will be nop's. In other cases, they are copies.
Evan
On Feb 19, 2009, at 2:00 AM, 任坤 wrote:
I define a pattern to move two 32bits gpr to 64bits fpr. like arm instructure 
fmdrr.
But I need to use an even/odd register pair to save  its 2 operands.
I define in mytarget.td:

myfmdrr:
 SDTypeProfile<1, 2, [SDTCisVT<0, f64>, SDTCisVT<1, i32>,

     SDTCisSameAs<1, 2>]>;
def my_fmdrr : ...........
def myFMDRR : ....
                      (outs FPR: $result), ins(GPR: $op1, GPR:$op2 )
                       [(setFPR: $result, (my_fmdrr GPR: $op1, GPR:$op2) )]

I create myfmdrr instructure in mytargetISelLowering.cpp. and its operands are
in R0 and R1.
But after optimization, the operands are save R2 and R1. I know optimization
pass does not
know myfmdrr operands constraint. But How I tell optimzition pass by tblgen??

Could I can control operand constraint in mytargetiSelLowering.cpp? How do I
control??


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http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev


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 list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev





        好玩贺卡等你发，邮箱贺卡全新上线！_______________________________________________
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LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev





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Arnold Schwaighofer

2009-Mar-31 09:34 UTC

head link

[LLVMdev] Re: [LLVMdev] 转发: Re: Dear Evan Chang, Re: help: about how to use tblgen to constraint operand.

Hi Ren Kun,

it is "-view-legalize-types-dags" not
"-view-legalize-type-dags"
(there is a "s" missing at the end of "type"). So that is
probably why
it does not work.

llc -help-hidden displays all hidden options that you can pass to llc.

regards
arnold

2009/3/31 任坤 <hbrenkun at yahoo.cn>:> Dear Evan Chang:
> I register incorrect Register class for MVT::f64. I have fixed it. Thanks
> your advice.
> "-view-legalize-dags" is very good option.
> But I don't know why my LLC do not know "
-view-legalize-type-dags" option.
> By the way, I use llvm 2.5 merged from llvm2.4.
>
> Best Regards,
>
> Ren Kun
>
> --- 09年3月31日，周二, Evan Cheng <echeng at apple.com> 写道：
>
> 发件人: Evan Cheng <echeng at apple.com>
> 主题: Re: [LLVMdev] Dear Evan Chang, Re: help: about how to use tblgen to
> constraint operand.
> 收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List"
<llvmdev at cs.uiuc.edu>
> 日期: 2009,331,周二,1:04上午
>
> This is probably instruction selection issue. I would look at the dag at
> various stafes of isel. Try -view-legalize-type-dags, -view-legalize-dags,
> etc.
> Evan
> On Mar 29, 2009, at 11:54 PM, 任坤 wrote:
>
> I try to define a register class
> def GPR64 : RegisterClass<"mytarget", [i64], 64, [T0, T1.....]
> to simulate even/odd pair of GPR32 register.
> Actually, I just use GPR64 as a temporary register.
> My CPU just support i32 Integer type directly.
> I use FDR to save f64.
> def FDR : RegisterClass<"mytarget", [f64], 64,[FD0, FD1, ....]
>
> When I move f64 to even/odd pair register, I first move f64 into GPR64,
> then move to 2 GPR32 register.
>
> It worked very well for register binding.
>
> But When I test some case. I find a register class error.
> --------------
>
> 11405   0x9321bc8: f64,ch = FLDI 0x93436f8, 0x9343c20, 0x9321ac0, 0x9343674
> --
>                                                                      |
>                                                                      |
> 11428         0x9321304: f64 = Register  #1066---------|                 |
> 153 11429         0x9321bc8: <multiple use>             |            
|
> 154 11430       0x93447fc: ch = CopyToReg 0x9320fdc, 0x9321304, 0x9321bc8
> <--|
>
> ---------------
> When llc merge the result of FLDI and register #1066, It find #1066 is
> in GPR64 Register Class.
> But I define FLDI to save it's result with FDR register at
> mytargetInstructInfo.td file.
> So a error given.
> 12493 VReg = 1066
> 12494 VReg RegClass     size = 8, align = 8
> 12495 Expected RegClass size = 8, align = 8
> 12496 Fatal error, aborting.
> 12497 0   llc       0x08bbc5cb
> 12498 1   llc       0x08bbc93c
> 12499 2             0x00110400 __kernel_sigreturn + 0
> ++++++++++++++++++++++++++++
> I define register class in mytargetRegisterInfo.td. In here, I binding all
> register class with supported variable type.
> I believe leaf node--Register is band with virtual register number at
> Initial DAG.
>
> But I do not know why LLC use my GPR64 register to save f64 type variable?
>
> I want to know where pass or function llc binding type with register class?
>
> I guess the initial DAG is created incorrectly.
>
> Which function first create IR--Register from *.bc and give it a virtual
> register number ,  I want to debug it to find error reason.
>
> Best Regards,
>
>    Ren Kun
>
>
>
>
> --- 09年2月21日，周六, Evan Cheng <evan.cheng at apple.com> 写道：
>
> 发件人: Evan Cheng <evan.cheng at apple.com>
> 主题: Re: [LLVMdev] help: about how to use tblgen to constraint operand.
> 收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List"
<llvmdev at cs.uiuc.edu>
> 日期: 2009,221,周六,2:51上午
>
>
> On Feb 19, 2009, at 8:26 PM, 任坤 wrote:
>
> hi, Dear Evan Cheng:
>
> My cpu is i32 embeded CPU. I define pseudo register pair registers.
>
> In mytargetRegisterInfo.td:
> def T0: RegisterWithSubRegs<"t0",[R0,R1]>;
> ...
> def GPR64 : RegisterClass<"mytarget", [i64], 64, [T0, T1.....]
>
> In mytargetISelLowering.cpp:
> I define i1, i8 , i16 and i32 are legal.
>
> 1. I still have problem. I save my function return double  value in R0 and
> R1.
> It is expanded into two i32. But my GPR64 is defined to save i64. llvm
finds
> I have i64 GPR register. It will automatically decide not to expand i64 to
> two i32.
>
> 2. I guess I need a special pseudo instruction to move between GPR32 and
> GPR64.
> How to move R0, R1 to T1( R2, R3 pair). and don't convert two i32 to
i64?
> Could I use MyTargetInstrInfo::copyRegToReg() to handle this logic issue?
>
> No. copyRegToReg only supports copying registers of the same (or compatible
> register classes).
>
>
> 3. Maybe I can study INSERT_SUBREG/EXTRACT_SUBREG at X86 porting file.
>
> Yes.
>
>
> I will do some research more deeply. I think the best way is that TableGen
> has register pair TypeProfile feature. :(
>
> It's not a tablegen issue. It's easy to add the constraint to
tablegen but
> the register allocator has to be able to allocate register pairs. That is
> definitely not a trivial task.
> Evan
>
>
>
>
>
> But I find i64 data will not be ex
> --- 09年2月20日，周五, Evan Cheng <echeng at apple.com> 写道：
>
> 发件人: Evan Cheng <echeng at apple.com>
> 主题: Re: [LLVMdev] help: about how to use tblgen to constraint operand.
> 收件人: hbrenkun at yahoo.cn, "LLVM Developers Mailing List"
<llvmdev at cs.uiuc.edu>
> 日期: 2009,220,周五,1:11上午
>
> Currently there is no constraint that tells the register allocator to
> allocate a consecutive register pair. What I would suggest you do is to
> declare pseudo register pair registers (and corresponding register class,
> say PAIR_GPR). In this case, your myFMDRR would take one input of PAIR_GPR
> class. The asm printer should be taught to print a PAIR_GPR register as two
> GPR registers (you should also teach the JIT of the same thing).
> A PAIR_GPR register should be a super register of two GPR registers. e.g.
> r0r1_pair is a super register of r0 and r1. In order to *construct* a
> PAIR_GPR register, you have to use two INSERT_SUBREG. To extract out a GPR
> from a PAIR_GPR, you need to issue EXTRACT_SUBREG. In most cases, these
will
> be nop's. In other cases, they are copies.
> Evan
> On Feb 19, 2009, at 2:00 AM, 任坤 wrote:
>
> I define a pattern to move two 32bits gpr to 64bits fpr. like arm
> instructure fmdrr.
> But I need to use an even/odd register pair to save its 2 operands.
> I define in mytarget.td:
>
> myfmdrr:
> SDTypeProfile<1, 2, [SDTCisVT<0, f64>, SDTCisVT<1, i32>,
>     SDTCisSameAs<1, 2>]>;
> def my_fmdrr : ...........
> def myFMDRR : ....
>                       (outs FPR: $result), ins(GPR: $op1, GPR:$op2 )
>                        [(setFPR: $result, (my_fmdrr GPR: $op1, GPR:$op2) )]
>
> I create myfmdrr instructure in mytargetISelLowering.cpp. and its operands
> are in R0 and R1.
> But after optimization, the operands are save R2 and R1. I know
optimization
> pass does not
> know myfmdrr operands constraint. But How I tell optimzition pass by
> tblgen??
>
> Could I can control operand constraint in mytargetiSelLowering.cpp? How do
I
> control??
>
>
> ________________________________
> 好玩贺卡等你发，邮箱贺卡全新上线！_______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
> ________________________________
> 好玩贺卡等你发，邮箱贺卡全新上线！_______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
> ________________________________
> 好玩贺卡等你发，邮箱贺卡全新上线！_______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
> ________________________________
> 好玩贺卡等你发，邮箱贺卡全新上线！
>
> ________________________________
> 好玩贺卡等你发，邮箱贺卡全新上线！
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>

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