Displaying 20 results from an estimated 24 matches for "isallocatable".
2012 Jun 08
0
[LLVMdev] Strong vs. default phi elimination and single-reg classes
...> %CTR8
> clang: /llvm-trunk/lib/CodeGen/LiveIntervalAnalysis.cpp:446:
> void llvm::LiveInterval
> s::handlePhysicalRegisterDef(llvm::MachineBasicBlock*,
> llvm::MachineBasicBlock::iterator, llvm::SlotIndex,
> llvm::MachineOperand&, llvm::LiveInt erval&): Assertion
> `!isAllocatable(interval.reg) && "Physregs shouldn't be live out!"'
> failed.
When machine code is still in SSA form, there are restrictions on what can be done with physical registers, which by their nature can't be in SSA form. Lang and I have been trying to come up with some r...
2012 Jun 08
2
[LLVMdev] Strong vs. default phi elimination and single-reg classes
...rts with:
register:
%CTR8
clang: /llvm-trunk/lib/CodeGen/LiveIntervalAnalysis.cpp:446:
void llvm::LiveInterval
s::handlePhysicalRegisterDef(llvm::MachineBasicBlock*,
llvm::MachineBasicBlock::iterator, llvm::SlotIndex,
llvm::MachineOperand&, llvm::LiveInt erval&): Assertion
`!isAllocatable(interval.reg) && "Physregs shouldn't be live out!"'
failed.
in this case the loop is quite simple:
944B BB#8: derived from LLVM BB %for.inc6, ADDRESS TAKEN
Live Ins: %CTR8
Predecessors according to CFG: BB#8 BB#3
960B BDNZ8 <BB#8&g...
2012 Apr 18
0
[LLVMdev] Conceptual difference between "Unallocatable" and "Reserved" registers.
...y for different sub-targets, and even different functions. The reserved registers for a function are computed by the TRI::getReservedRegs(MF) hook.
A register is allocatable if it belongs to at least one allocatable register class AND it is not reserved.
See RegisterClassInfo.h, in particular the isAllocatable() function.
The third set of unallocatable, unreserved registers usually only contains the flags. It is different from the reserved registers because the register allocator is still tracking liveness of these registers. The reserved registers are mostly ignored for liveness tracking.
/jakob
----...
2012 Apr 18
2
[LLVMdev] Conceptual difference between "Unallocatable" and "Reserved" registers.
Hi,
I'm writing to ask the differences between a "reserved" register and an
"unallocable" register. In X86 backend, for example, the stack pointer
register and instruction pointer are reserved but allocatable. In the
Doxygen document of function llvm::TargetRegisterInfo::getReservedRegs,
it says that a reserved register is one that *has particular uses and
should be
2019 Jun 02
2
Optimizing Compare instruction selection
...enuine instructions of my target architecture, they use the SR along with operands to produce a result.
As you can see ‘t30’ is used both before and after the function call, which is what I think that causes trouble. In particular, the assertion that I get is this:
Assertion failed: (RegClass->isAllocatable() && "Virtual register RegClass must be allocatable."), function createVirtualRegister, file /Users/joan/LLVM+CLANG/llvm-7.0.1.src/lib/CodeGen/MachineRegisterInfo.cpp, line 170.
If I remove the ‘isAllocatable=0’ setting on the SR register, then LLVM will try to spill the SR by ca...
2012 Jun 08
2
[LLVMdev] Strong vs. default phi elimination and single-reg classes
...llvm-trunk/lib/CodeGen/LiveIntervalAnalysis.cpp:446:
> > void llvm::LiveInterval
> > s::handlePhysicalRegisterDef(llvm::MachineBasicBlock*,
> > llvm::MachineBasicBlock::iterator, llvm::SlotIndex,
> > llvm::MachineOperand&, llvm::LiveInt erval&): Assertion
> > `!isAllocatable(interval.reg) && "Physregs shouldn't be live out!"'
> > failed.
FYI: I just committed the relevant code (disabled by default); and I
submitted a bug to track this issue:
http://llvm.org/bugs/show_bug.cgi?id=13057
(It seems that I was doing this as you were respondin...
2016 Feb 03
2
New register class and patterns
On Tue, Feb 2, 2016 at 8:42 PM, Matt Arsenault <arsenm2 at gmail.com> wrote:
>
> On Feb 2, 2016, at 16:52, Rail Shafigulin <rail at esenciatech.com> wrote:
>
> def SDT_EscalaSetFlag : SDTypeProfile<0, 3, [SDTCisSameAs<0, 1>]>;
>
>
> I think for setting an implicit register, you still need to have 1 result
> here.
>
> If you look at
2019 Jun 05
2
Optimizing Compare instruction selection
...my target architecture, they use the SR along with operands to produce a result.
>
> As you can see ‘t30’ is used both before and after the function call, which is what I think that causes trouble. In particular, the assertion that I get is this:
>
> Assertion failed: (RegClass->isAllocatable() && "Virtual register RegClass must be allocatable."), function createVirtualRegister, file /Users/joan/LLVM+CLANG/llvm-7.0.1.src/lib/CodeGen/MachineRegisterInfo.cpp, line 170.
>
> If I remove the ‘isAllocatable=0’ setting on the SR register, then LLVM will try to spill t...
2019 Jan 10
2
empty list assertion
In the definition of register classes, have you provided any value types
for each class?
-Krzysztof
On 1/9/2019 7:19 PM, m m via llvm-dev wrote:
> The file that is causing this assertion contains only 3 include statements
>
> |//===-- ABCOther.td - Describe the ABC Target Machine ----*- tablegen
> -*-===// // //
>
2013 Feb 17
4
[LLVMdev] keeping instructions in order and hidden dependencies
...nstruction that uses it, you want to model this dependency with an unallocatable physical register, e.g. the CPSR on ARM:
// Condition code registers.
def CCR : RegisterClass<"ARM", [i32], 32, (add CPSR)> {
let CopyCost = -1; // Don't allow copying of status registers.
let isAllocatable = 0;
}
This will require you to mark defs and uses (and kills), but if you're using it purely inside of a single basic block you won't have to worry about it too much. If you have instructions that may only generate this dependency in certain circumstances, you can use implicit def/use ope...
2013 Jul 23
0
[LLVMdev] Questions about MachineScheduler
...uery pressure for a specific set...
P = RPTracker.getPressureAfterInst(I)
diff = P[PsetID] - RPTracker.getRegSetPressureAtPos()[PSetID]
Note that how you define your target’s registers can make a big difference in the pressure set formation. Yours don’t look to bad, but in general remember to use isAllocatable=0 for any classes that don’t take part in regalloc.
-Andy
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2013 Jul 22
2
[LLVMdev] Questions about MachineScheduler
Hi,
I'm working on defining a SchedMachineModel for the Southern Islands
family of GPUs, and I have two questions related to the
MachineScheduler.
1. I have a resource that can process 15 instructions at the same time.
In the TableGen definitions, should I do:
def HWVMEM : ProcResource<15>;
or
let BufferSize = 15 in {
def HWVMEM : ProcResource<1>;
}
2. Southern Islands has
2017 May 05
2
problem with non-allocatable register classes
I am using some non-allocatable RegisterClasses to define lists of registers that are used for various non-allocation-related processing in the back end. For example, we have a post-allocation functional unit selection pass that is guided by the register assignment, which does things like 'myRegClass.contains(Reg)' to see if a register is in the set of registers accessible by a given unit.
2012 Jun 08
1
[LLVMdev] Strong vs. default phi elimination and single-reg classes
On Fri, 08 Jun 2012 09:24:16 -0700
Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote:
>
> On Jun 8, 2012, at 9:02 AM, Hal Finkel <hfinkel at anl.gov> wrote:
>
> > On Fri, 8 Jun 2012 08:49:32 -0700
> > Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote:
>
> >> When machine code is still in SSA form, there are restrictions on
> >> what can
2013 Feb 17
0
[LLVMdev] keeping instructions in order and hidden dependencies
...ou want to model this dependency with an unallocatable physical register, e.g. the CPSR on ARM:
>
> // Condition code registers.
> def CCR : RegisterClass<"ARM", [i32], 32, (add CPSR)> {
> let CopyCost = -1; // Don't allow copying of status registers.
> let isAllocatable = 0;
> }
>
> This will require you to mark defs and uses (and kills), but if you're using it purely inside of a single basic block you won't have to worry about it too much. If you have instructions that may only generate this dependency in certain circumstances, you can use implic...
2019 Jun 01
2
Optimizing Compare instruction selection
I attempt to optimize the use of the ‘CMP’ instruction on my architecture by removing the instruction instances where the Status Register already had the correct status flags.
The cmp instruction in my architecture is the typical one that compares two registers, or a register with an immediate, and sets the Status Flags accordingly. I implemented my ‘cmp’ instruction in LLVM by custom lowering
2016 Feb 05
3
New register class and patterns
...ciate if you could point out where in the code this
is happening.
I've also followed your advice and added i1 as a type for my SPR
def SPR : RegisterClass<"Esencia", [i1,i32], 32, (add SR)> {
let CopyCost = -1; // Don't allow copying of special purpose registers.
let isAllocatable = 0;
}
Then I changed an instruction class to return an explicit value
class SF_RR<bits<5> op2Val, string asmstr, PatLeaf Cond> :
InstRR<0x9, (outs), (ins GPR:$rA, GPR:$rB),
!strconcat(asmstr, "\t$rA, $rB"),
[(set SPR:$rC, (Esenciasetf...
2016 Feb 04
2
New register class and patterns
It does have an output register, it's just an implicit flag register. It
still has a DAG output. I'm not sure if the allocatable bit matters at this
point for selection purposes, but it does later. Not adding a type to the
register class can also be problematic (e.g. a flag register should have i1
added to regTypes for its class).
-Matt
>
Does LLVM make an assumption that there is an
2016 Feb 04
2
New register class and patterns
...> I already had 2 register classes before and everything was working. All
> I've done is that I had added an extra class. After that LLVM started to
> complain. And this is what puzzles me.
>
> Did you add a register class for a special condition register? Did you set
> it as isAllocatable = 0?
>
I think I'm slowly getting it. To answer your question, no I did not set
isAllocaable = 0 for the new register class. But I'm still confused.
Original instruction does not have an output register. It sets a flag in
the special purpose register. So why creating a new register clas...
2012 Jun 08
0
[LLVMdev] Strong vs. default phi elimination and single-reg classes
On Jun 7, 2012, at 7:31 PM, Hal Finkel wrote:
> 112B BB#1: derived from LLVM BB %for.body, ADDRESS TAKEN
> Predecessors according to CFG: BB#0 BB#1
> %vreg12<def> = PHI %vreg13, <BB#1>, %vreg11, <BB#0>;CTRRC8:%vreg12,%vreg13,%vreg11
> %vreg13<def> = COPY %vreg12<kill>; CTRRC8:%vreg13,%vreg12
> %vreg13<def> = BDNZ8 %vreg13,