Support COPYs involving higher FP16 regs (like F24H) with a new pseudo
instruction 'VLR16'.
This is needed with -O0/regalloc=fast, and probably in more cases as
well.
Fixes#178788.
This PR enables the option `-fpatchable-function-entry` for SystemZ. It
utilizes existing common code and just adds the emission of nops after
the function label in the backend.
SystemZ provides multiple nop options of varying length, making the
semantics of this option somewhat ambiguous. In order to align with what
`gcc` does with that same option, we#re choosing `nopr` as the
canoonical nop for this purpose.
For test, this adapts an existing test file from aarch64.
This Change makes `RegState` into an enum class, with bitwise operators.
It also:
- Updates declarations of flag variables/arguments/returns from
`unsigned` to `RegState`.
- Updates empty RegState initializers from 0 to `{}`.
If this is causing problems in downstream code:
- Adopt the `RegState getXXXRegState(bool)` functions instead of using a
ternary operator such as `bool ? RegState::XXX : 0`.
- Adopt the `bool hasRegState(RegState, RegState)` function instead of
using a bitwise check of the flags.
This preparatory patch introduces an additional argument to the target hook
loadRegFromStackSlot. Ths is essential for targets to handle subregister-specific
reload in the future. See how this is used for AMDGPU target with PR #175002.
Adding support for serializing the ada entry flags helps with mir based
test cases. Without this change, the flags are simple displayed as being
"unkmown".
Both conceptually belong to the same subtarget, so it should not
be necessary to pass in the context TargetRegisterInfo to any
TargetInstrInfo member. Add this reference so those superfluous
arguments can be removed.
Most targets placed their TargetRegisterInfo as a member
in TargetInstrInfo. A few had this owned by the TargetSubtargetInfo,
so unify all targets to look the same.
This will make it possible for tablegen to make subtarget
dependent decisions without adding new arguments to every
target.
---------
Co-authored-by: Sergei Barannikov <barannikov88@gmail.com>
- _Float16 is now accepted by Clang.
- The half IR type is fully handled by the backend.
- These values are passed in FP registers and converted to/from float around
each operation.
- Compiler-rt conversion functions are now built for s390x including the missing
extendhfdf2 which was added.
Fixes#50374
In 236f938ef, I introduced a generic version of this routine. I believe
that the SystemZ specific version of this is less general than the
generic version, and is thus unrequired. I wasn't 100% given the
difference in sub-register, multiple use and defs, but from the SystemZ
code, it looks like those cases simply don't arise?
As part of an effort to enable instr-ref-based debug value tracking,
this PR implements `SystemZInstrInfo::isLoadFromStackSlotPostFE`, as
well as `SystemZInstrInfo::isStoreToStackSlotPostFE`. The implementation
relies upon the presence of MachineMemoryOperands on the relevant
`MachineInstr`s in order to access the `FrameIndex` post frame index
elimination.
Since these new functions are only meant to be called after frame-index
elimination, they assert against the present of a frame index on the
base register operand of the instruction.
Outside of the utility of these functions to enable instr-ref-based
debug value tracking, they also changes the behavior of the AsmPrinter,
since it will now be able to properly detect non-folded spills and
reloads, so this changes a number of tests that were checking
specifically for folded reloads.
Note that there are some tests that still check for `vst` and `vl` as
folded spills/reloads even though they should be straight reloads. This
will be addressed in a future PR.
Co-authored-by: Dominik Steenken <dominik.steenken@gmail.com>
As a first step toward implementing SystemZ support for instr-ref-based
debug info tracking, this commit adds a basic implementation for the
previously absent `SystemZInstrInfo::isCopyInstrImpl`.
This is accomplished by adding a new flag called `isMoveReg` on the
relevant instructions and calling upon that bit of information to
implement the function. Which instructions to add the flag to was based
on the implementation of `SystemZInstrInfo::copyPhysReg`. The full list
of instructions is as follows:
#### General-Purpose Registers
- `lr`
- `lgr`
#### Floating Point Registers
- `ler`
- `ldr`
- `lxr`
#### Vector Registers
- `vlr`
NVPTX, SPIRV, and WebAssembly pass virtual registers to this function
since they don't perform register allocation. We need to use Register to
avoid a virtual register being converted to MCRegister by the caller.
I'm guessing based on tablegen definitions. I also don't
really understand how this could have been missing.
This defends against regressions in a future peephole-opt
patch.
This patch is in preparation to enable setting the MachineInstr::MIFlag
flags, i.e. FrameSetup/FrameDestroy, on callee saved register
spill/reload instructions in prologue/epilogue. This eventually helps in
setting the prologue_end and epilogue_begin markers more accurately.
The DWARF Spec in "6.4 Call Frame Information" says:
The code that allocates space on the call frame stack and performs the
save
operation is called the subroutine’s prologue, and the code that
performs
the restore operation and deallocates the frame is called its epilogue.
which means the callee saved register spills and reloads are part of
prologue (a.k.a frame setup) and epilogue (a.k.a frame destruction),
respectively. And, IIUC, LLVM backend uses FrameSetup/FrameDestroy flags
to identify instructions that are part of call frame setup and
destruction.
In the trunk, while most targets consistently set
FrameSetup/FrameDestroy on save/restore call frame information (CFI)
instructions of callee saved registers, they do not consistently set
those flags on the actual callee saved register spill/reload
instructions.
I believe this patch provides a clean mechanism to set
FrameSetup/FrameDestroy flags on the actual callee saved register
spill/reload instructions as needed. And, by having default argument of
MachineInstr::NoFlags for Flags, this patch is a NFC.
With this patch, the targets have to just pass FrameSetup/FrameDestroy
flag to the storeRegToStackSlot/loadRegFromStackSlot calls from the
target derived spillCalleeSavedRegisters and restoreCalleeSavedRegisters
to set those flags on callee saved register spill/reload instructions.
Also, this patch makes it very easy to set the source line information
on callee saved register spill/reload instructions which is needed by
the DwarfDebug.cpp implementation to set prologue_end and epilogue_begin
markers more accurately.
As per DwarfDebug.cpp implementation:
prologue_end is the first known non-DBG_VALUE and non-FrameSetup
location
that marks the beginning of the function body
epilogue_begin is the first FrameDestroy location that has been seen in
the
epilogue basic block
With this patch, the targets have to just do the following to set the
source line information on callee saved register spill/reload
instructions, without hampering the LLVM's efforts to avoid adding
source line information on the artificial code generated by the
compiler.
<Foo>InstrInfo::storeRegToStackSlot() {
...
DebugLoc DL =
Flags & MachineInstr::FrameSetup ? DebugLoc() : MBB.findDebugLoc(I);
...
}
<Foo>InstrInfo::loadRegFromStackSlot() {
...
DebugLoc DL =
Flags & MachineInstr::FrameDestroy ? MBB.findDebugLoc(I) : DebugLoc();
...
}
While I understand this patch would break out-of-tree backend builds, I
think it is in the right direction.
One immediate use case that can benefit from this patch is fixing
#120553 becomes simpler.
The renamable flag is useful during MachineCopyPropagation but renamable
flag will be dropped after lowerCopy in some case.
This patch introduces extra arguments to pass the renamable flag to
copyPhysReg.
When expanding an L128 (which is used to reload i128) it is
possible that the quadword destination register clobbers an
address register. This patch adds an assertion against the case
where both of the expanded parts clobber the address, and in the
case where one of the expanded parts do so puts it last.
Fixes#91437
This reverts commit a415b4dfcc02e3e82b8c8a7836f7c04b9d65dc9b.
Modify the instruction in place to transform it into a REG_SEQUENCE,
which is what other implementations of foldImmediate do. Also start
erasing the def instruction if there are no other uses.
Fixes#91110.
If materializing a constant in a vector register that is just
going to be copied to general registers, directly materialize
the immediate in the gpr. This will avoid a few lit test regressions
in a future commit.
Enable MachineCombining for FP add, sub and mul.
In order for this to work, the default instruction selection of reg/mem opcodes is disabled for ISD nodes that carry the flags that allow reassociation. The reg/mem folding is instead done after MachineCombiner by PeepholeOptimizer. SystemZInstrInfo optimizeLoadInstr() and foldMemoryOperandImpl() ("LoadMI version") have been implemented for this purpose also by this patch.
Fixes#82659
There are some functions, such as `findRegisterDefOperandIdx` and `findRegisterDefOperand`, that have too many default parameters. As a result, we have encountered some issues due to the lack of TRI parameters, as shown in issue #82411.
Following @RKSimon 's suggestion, this patch refactors 9 functions, including `{reads, kills, defines, modifies}Register`, `registerDefIsDead`, and `findRegister{UseOperandIdx, UseOperand, DefOperandIdx, DefOperand}`, adjusting the order of the TRI parameter and making it required. In addition, all the places that call these functions have also been updated correctly to ensure no additional impact.
After this, the caller of these functions should explicitly know whether to pass the `TargetRegisterInfo` or just a `nullptr`.
On SystemZ, the outgoing argument area which is big enough for all calls
in the function is created once during the prolog, as opposed to
adjusting the stack around each call. The call-sequence instructions are
therefore not really useful any more than to compute the maximum call
frame size, which has so far been done by PEI, but can just as well be
done at an earlier point.
This patch removes the mapping of the CallFrameSetupOpcode and
CallFrameDestroyOpcode and instead computes the MaxCallFrameSize
directly after instruction selection and then removes the ADJCALLSTACK
pseudos. This removes the confusing pseudos and also avoids the problem
of having to keep the call frame size accurate when creating new MBBs.
This fixes#76618 which exposed the need to maintain the call frame size
when splitting blocks (which was not done).
This is part of #70452 that changes the type used for the external
interface of MMO to LocationSize as opposed to uint64_t. This means the
constructors take LocationSize, and convert ~UINT64_C(0) to
LocationSize::beforeOrAfter(). The getSize methods return a
LocationSize.
This allows us to be more precise with unknown sizes, not accidentally
treating them as unsigned values, and in the future should allow us to
add proper scalable vector support but none of that is included in this
patch. It should mostly be an NFC.
Global ISel is still expected to use the underlying LLT as it needs, and
are not expected to see unknown sizes for generic operations. Most of
the changes are hopefully fairly mechanical, adding a lot of getValue()
calls and protecting them with hasValue() where needed.
This only converts the instances where all that is needed is to change
the variable type name.
Basically, anything that involves a function that LiveRegUnits does not
directly have was skipped to play it safe.
Reverts
7a0e222a17
The usage of FP Load and Test instructions as a comparison against zero
with the assumption that the dest reg will always reflect the source reg is
actually incorrect: Unfortunately, a SNaN will be converted to a QNaN, so the
instruction may actually change the value as opposed to being a pure register
move with a test.
This patch
- changes instruction selection to always emit FP LT with a scratch def
reg, which will typically be allocated to the same reg if dead.
- Removes the conversions into FP LT in SystemZElimcompare.
Change MCInstrDesc::operands to return an ArrayRef so we can easily use
it everywhere instead of the (IMHO ugly) opInfo_begin and opInfo_end.
A future patch will remove opInfo_begin and opInfo_end.
Also use it instead of raw access to the OpInfo pointer. A future patch
will remove this pointer.
Differential Revision: https://reviews.llvm.org/D142213
With D134950, targets get notified when a virtual register is created and/or
cloned. Targets can do the needful with the delegate callback. AMDGPU propagates
the virtual register flags maintained in the target file itself. They are useful
to identify a certain type of machine operands while inserting spill stores and
reloads. Since RegAllocFast spills the physical register itself, there is no way
its virtual register can be mapped back to retrieve the flags. It can be solved
by passing the virtual register as an additional argument. This argument has no
use when the spill interfaces are called during the greedy allocator or even the
PrologEpilogInserter and can pass a null register in such cases.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D138656
When e.g. a VR64 register is spilled to a stack slot requiring a long
(20-bit) displacement, it is possible to use an FP opcode if the allocated
phys reg allows it. This eliminates the use of a separate LAY instruction.
Reviewed By: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D115406
This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169
