Displaying 20 results from an estimated 900 matches similar to: "[LLVMdev] selecting select_cc"
2006 Aug 22
0
[LLVMdev] selecting select_cc
Hi Rafael,
> I am trying to add support for select_cc. In ARM it can be implemented
> with:
>
> mov $dst, $falseVal
> cmp $a, $b
> moveq $dst, $trueVal
The more normal ARM code, as produced by assembly writers and compilers
that I've seen, is
cmp $a, $b
moveq $dst, $trueVal
movne $dst, $falseVal
e.g. at the end of a function returning r0
orr r0, r0, #0x40
2017 Mar 07
2
Specifying conditional blocks for the back end
Hello.
Because I experience optimizations (DCE, OoO schedule) which mess the correct
semantics of the list of instructions lowered in ISelLowering from the VSELECT LLVM
instruction, and these bad transformations happen even before scheduling, at later I-sel
subpasses, I try to fix this problem by lowering VSELECT to only one pseudo-instruction
and LATER translate it to a list of
2007 Oct 26
2
[LLVMdev] LLVM Newbie. Questions about backend.
Hello,
I have been studying LLVM and started to create a new backend for a
new RISC architecture. Now I need some help to get forward with my
project. I'm quite new to compiling techniques so I'm sorry for the
stupid questions.
Question 1:
My idea is to lower the select SDNode as follows:
%res1 = %falseVal
%res2 = setc %trueVal, %condition
Where setc is conditional mov. The
2012 Aug 19
1
[LLVMdev] MBlaze select_cc lowering question.
Can someone explain how the condition code is passed from the
MBlazeTargetLowering::LowerSELECT_CC to
MBlazeTargetLowering::EmitCustomSelect custom inserter? In
LowerSELECT_CC the condition code is never accessed (Op.GetOperand(4))
and I don't see how it ends up getting correctly passed to the
MBlazeTargetLowering::EmitCustomSelect.
> SDValue
2006 Nov 27
1
R.DLL mapping by P/Invoke
After a long processing, I was able to create a version of a small C# class
that was able to emulate the rproxy by P/Invoke. This is mostly to find a
workaround a performance problem of the StatConnector.
It's almost work but ... I have strange memory exception when I call the
print function. The variable seems to not survive from one call to the
other.
As there is no debug symbol for
2008 Sep 12
2
[LLVMdev] Selection Condition Codes
Eli, Thanks for the tips.
I've been able to get something working using a custom instruction
inserter, however, I'm still having the problem of linking together the
setcc and the select_cc commands. I want to turn the setcc into a
comparison and use the results in the select_cc register. However, the
comparison information is in the select_cc instruction and the result of
the comparison
2008 Sep 12
0
[LLVMdev] Selection Condition Codes
On Thu, Sep 11, 2008 at 6:14 PM, Villmow, Micah <Micah.Villmow at amd.com> wrote:
> I am attempting to lower the selectCC instruction to the instruction set of
> the backend I'm working on and I cannot seem to find a way to correctly
> implement this instruction. I know how this instruction should get
> implemented; I just have yet to find a way to do it. I want the select_cc
2007 Jan 09
2
[LLVMdev] Pattern matching questions
On Tue, 9 Jan 2007, Evan Cheng wrote:
>> - How does one deal with multiple instruction sequences in a pattern?
>> To load a constant is a two instruction sequence, but both
>> instructions only take two operands (assume that r3 is a 32-bit
>> register):
>>
>> ilhu $3, 45 # r3 = (45 << 16)
>> iohl $3, 5 # r3 |= 5
2008 Sep 12
2
[LLVMdev] Selection Condition Codes
I am attempting to lower the selectCC instruction to the instruction set
of the backend I'm working on and I cannot seem to find a way to
correctly implement this instruction. I know how this instruction should
get implemented; I just have yet to find a way to do it. I want the
select_cc instruction to be lowered into a comparison followed by a
conditional move. I've attempted to use a
2008 Jul 08
0
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
PPCTargetLowering::EmitInstrWithCustomInserter has a reference
to the current MachineFunction for other purposes. Can you use
MachineFunction::getRegInfo instead?
Dan
On Jul 8, 2008, at 1:56 PM, Gary Benson wrote:
> Would it be acceptable to change MachineInstr::getRegInfo from private
> to public so I can use it from
> PPCTargetLowering::EmitInstrWithCustomInserter?
>
>
2008 Jul 11
0
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Hi Gary,
This does not patch cleanly for me (PPCISelLowering.cpp). Can you
prepare a updated patch?
Thanks,
Evan
On Jul 10, 2008, at 11:45 AM, Gary Benson wrote:
> Cool, that worked. New patch attached...
>
> Cheers,
> Gary
>
> Evan Cheng wrote:
>> Just cast both values to const TargetRegisterClass*.
>>
>> Evan
>>
>> On Jul 10, 2008, at 7:36
2008 Jun 30
2
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Chris Lattner wrote:
> On Jun 27, 2008, at 8:27 AM, Gary Benson wrote:
> > def CMP_UNRESw : Pseudo<(outs), (ins GPRC:$rA, GPRC:$rB, i32imm:
> > $label),
> > "cmpw $rA, $rB\n\tbne- La${label}_exit",
> > [(PPCcmp_unres GPRC:$rA, GPRC:$rB, imm:
> > $label)]>;
> > }
> >
> > ...and
2008 Jun 30
0
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
You need to insert new basic blocks and update CFG to accomplish this.
There is a hackish way to do this right now. Add a pseudo instruction
to represent this operation and mark it usesCustomDAGSchedInserter.
This means the intrinsic is mapped to a single (pseudo) node. But it
is then expanded into instructions that can span multiple basic
blocks. See
2008 Jul 10
0
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Just cast both values to const TargetRegisterClass*.
Evan
On Jul 10, 2008, at 7:36 AM, Gary Benson wrote:
> Evan Cheng wrote:
>> How about?
>>
>> const TargetRegisterClass *RC = is64Bit ? &PPC:GPRCRegClass :
>> &PPC:G8RCRegClass;
>> unsigned TmpReg = RegInfo.createVirtualRegister(RC);
>
> I tried something like that yesterday:
>
> const
2008 Jul 10
2
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Evan Cheng wrote:
> How about?
>
> const TargetRegisterClass *RC = is64Bit ? &PPC:GPRCRegClass :
> &PPC:G8RCRegClass;
> unsigned TmpReg = RegInfo.createVirtualRegister(RC);
I tried something like that yesterday:
const TargetRegisterClass *RC =
is64bit ? &PPC::GPRCRegClass : &PPC::G8RCRegClass;
but I kept getting this error no matter how I arranged it:
2008 Jul 10
2
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Cool, that worked. New patch attached...
Cheers,
Gary
Evan Cheng wrote:
> Just cast both values to const TargetRegisterClass*.
>
> Evan
>
> On Jul 10, 2008, at 7:36 AM, Gary Benson wrote:
> > Evan Cheng wrote:
> > > How about?
> > >
> > > const TargetRegisterClass *RC = is64Bit ? &PPC:GPRCRegClass :
> > > &PPC:G8RCRegClass;
>
2008 Jul 08
2
[LLVMdev] Implementing llvm.atomic.cmp.swap.i32 on PowerPC
Would it be acceptable to change MachineInstr::getRegInfo from private
to public so I can use it from PPCTargetLowering::EmitInstrWithCustomInserter?
Cheers,
Gary
Evan Cheng wrote:
> Look for createVirtualRegister. These are examples in
> PPCISelLowering.cpp.
>
> Evan
> On Jul 8, 2008, at 8:24 AM, Gary Benson wrote:
>
> > Hi Evan,
> >
> > Evan Cheng wrote:
2007 Jan 09
3
[LLVMdev] Pattern matching questions
I was able to resolve my previous question about dealing with custom
loads/stores, and following Chris' suggestion, the IBM Cell SPU backend
can generate code for "int main(void) { return 0; }" without crashing
llc. There's a lot of work still to be done... like getting frame
offsets correctly computed and hauling in the raft of intrinsics that
the Cell SDK defines.
Three quick
2009 Apr 16
2
[LLVMdev] How do I model MUL with multiply-accumulate instruction?
The only multiplication instruction on my target CPU is
multiply-and-accumulate. The result goes into a special register that
can destructively read at the end of a sequence of multiply-adds. The
following sequence is required to so a simple multiply:
acc r0 # clear accumulator, discarding its value (r0 reads as 0,
and sinks writes)
mac rSRC1, rSRC2 # multiply sources, store
2013 May 13
3
[LLVMdev] Q: When is a boolean not a boolean?
A: When the types are created in different contexts.
I've been running into a module validation error related to phi nodes
produced by the GVN pass, where the types of the incoming values aren't the
same instance of IntegerType i1.
I'm not certain I've found the root cause of the problem yet, it's probably
due to my handling of LLVMContext & Module life cycles, and this