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
With XPLINK, dynamic stack allocations requires calling
a runtime function, which allocates the stack memory,
moves the register save area, and returns the new
stack pointer.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D119732
The XPLINK return `b 2(7)` has size 4 bytes, while the Linux return
`br 7` only has size 2 bytes. Thus a new alias is required to have correct
instruction byte count. It also fixes the conditional return code.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D119437
By reordering the objects on the stack frame after looking at the users, a
better utilization of displacement operands will result. This means less
needed Load Address instructions for the accessing of these objects.
This is important for very large functions where otherwise small changes
could cause a lot more/less accesses go out of range.
Note: this is not yet enabled for SystemZXPLINKFrameLowering, but should be.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D115690
Delegate updating of LiveIntervals to each target's
convertToThreeAddress implementation, instead of repairing LiveIntervals
after the fact in TwoAddressInstruction::convertInstTo3Addr.
Differential Revision: https://reviews.llvm.org/D113493
All instructions must have a correct size value close to emission when
SystemZLongBranch runs, or a necessary branch relaxation may be missed.
This patch also adds an assert for instruction sizes in SystemZLongBranch.
Review: Ulrich Weigand
This simplifies the API and addresses a FIXME in
TwoAddressInstructionPass::convertInstTo3Addr.
Differential Revision: https://reviews.llvm.org/D110229
The backend generally uses 64-bit immediates (e.g. what
MachineOperand::getImm() returns), so use that for analyzeCompare()
and optimizeCompareInst() as well. This avoids truncation for
targets that support immediates larger 32-bit. In particular, we
can avoid the bugprone value normalization hack in the AArch64
target.
This is a followup to D108076.
Differential Revision: https://reviews.llvm.org/D108875
This patch adds the abstract class SystemZCallingConventionRegisters
which is a SystemZ-specific class detailing special registers used
by calling conventions on the target. SystemZELFRegisters and
SystemZXPLINK64Registers implement this class for ELF and XPLINK64
respectively.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D102370
Rename ELF specific variables, making it easier to add the XPLink
variables in future patches.
Reviewed By: abhina.sreeskantharajan, Kai
Differential Revision: https://reviews.llvm.org/D98199
Indirect sibling calls need to use %r1 to hold the target address.
This is currently hard-coded in many places. This is not only
unnecessary, but makes future changes in this area difficult.
This patch now encodes the target address as operand without
hard coding a register in most places throughout the MI back-end.
Code generation still always uses %r1, but this is now decided
solely in one place in SystemZTargetLowering::LowerCall.
NFC intended.
Use FP-mem instructions when folding reloads into single lane (W..) vector
instructions.
Only do this when all other operands of the instruction have already been
allocated to an FP (F0-F15) register.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D76705
A spilled load of an immediate can use MVHI/MVGHI instead.
A compare of a spilled register against an immediate can use CHSI/CGHSI.
A logical compare can use CLFHSI/CLGHSI.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D76055
Swap the compare operands if LHS is spilled while updating the CCMask:s of
the CC users. This is relatively straight forward since the live-in lists for
the CC register can be assumed to be correct during register allocation
(thanks to 659efa2).
Also fold a spilled operand of an LOCR/SELR into an LOC(G).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D67437
On SystemZ there are a set of "access registers" that can be copied in and
out of 32-bit GPRs with special instructions. These instructions can only
perform the copy using low 32-bit parts of the 64-bit GPRs. However, the
default register class for 32-bit integers is GRX32, which also contains the
high 32-bit part registers.
In order to never end up with a case of such a COPY into a high reg, this
patch adds a new simple pre-RA pass that selects such COPYs into target
instructions.
This pass also handles COPYs from CC (Condition Code register), and COPYs to
CC can now also be emitted from a high reg in copyPhysReg().
Fixes: https://bugs.llvm.org/show_bug.cgi?id=44254
Review: Ulrich Weigand.
Differential Revision: https://reviews.llvm.org/D75014
In GlobalISel we may in some unfortunate circumstances generate PHIs with
operands that are on separate banks. If-conversion doesn't currently check for
that case and ends up generating a CSEL on AArch64 with incorrect register
operands.
Differential Revision: https://reviews.llvm.org/D72961
It was recently discovered that the handling of CC values was actually broken
since overflow was not properly handled ('nsw' flag not checked for).
Add and sub instructions now have a new target specific instruction flag
named SystemZII::CCIfNoSignedWrap. It means that the CC result can be used
instead of a compare with 0, but only if the instruction has the 'nsw' flag
set.
This patch also adds the improvements of conversion to logical instructions
and the analyzing of add with immediates, to be able to eliminate more
compares.
Review: Ulrich Weigand
https://reviews.llvm.org/D66868
Now that the machine verifier will check for cases of register/immediate
MachineOperands and their correspondence to the MC instruction descriptor,
this patch adds the operand types to the descriptors where they were
previously missing. All MCOI::OPERAND_UNKNOWN operand types have been handled
to get a known type, except for G_... (global isel) instructions.
Review: Ulrich Weigand
https://reviews.llvm.org/D71494
SystemZExpandPseudo:s only job was to expand LOCRMux instructions into jump
sequences. This needs to be done if expandLOCRPseudo() or expandSELRPseudo()
fails to find a legal opcode (all registers "high" or "low"). This task has
now been moved to SystemZPostRewrite while removing the SystemZExpandPseudo
pass.
It is in fact preferred to expand these pseudos directly after register
allocation in SystemZPostRewrite since the hinted register combinations are
then not subject to later optimizations.
Review: Ulrich Weigand
https://reviews.llvm.org/D67432
llvm-svn: 371959
