A set of function attributes is required in any function that uses constrained
floating point intrinsics. None of our tests use these attributes.
This patch fixes this.
These tests have been tested against the IR verifier changes in D68233.
Reviewed by: andrew.w.kaylor, cameron.mcinally, uweigand
Approved by: andrew.w.kaylor
Differential Revision: https://reviews.llvm.org/D67925
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373761 91177308-0d34-0410-b5e6-96231b3b80d8
SystemZPostRewrite needs to be run before (it may emit COPYs) the Post-RA
pseudo pass also at -O0, so it should be added in addPostRegAlloc().
Review: Ulrich Weigand
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373182 91177308-0d34-0410-b5e6-96231b3b80d8
These two test cases use -march=systemz instead of a triple. In
particular, the used file format is then based on the default host
triple. This leads to different behaviour on different platforms.
The SystemZ implementation uses the integrated assembler for a
long time now. The mature-mc-support test can be fully enabled.
Differential Revision: https://reviews.llvm.org/D68129
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373098 91177308-0d34-0410-b5e6-96231b3b80d8
Merge more Select pseudo instructions in emitSelect() by allowing other
instructions between them as long as they do not clobber CC.
Debug value instructions are now moved down to below the new PHIs instead of
erasing them.
Review: Ulrich Weigand
https://reviews.llvm.org/D67619
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372873 91177308-0d34-0410-b5e6-96231b3b80d8
The recently announced IBM z15 processor implements the architecture
already supported as "arch13" in LLVM. This patch adds support for
"z15" as an alternate architecture name for arch13.
The patch also uses z15 in a number of places where we used arch13
as long as the official name was not yet announced.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372435 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.llvm.org/D65945 for reference,
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: MatzeB, qcolombet, dschuff, arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, s.egerton, pzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67433
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371608 91177308-0d34-0410-b5e6-96231b3b80d8
Since NaN is very rare in normal programs, so the probability for floating point unordered comparison should be extremely small. Current probability is 3/8, it is too large, this patch changes it to a tiny number.
Differential Revision: https://reviews.llvm.org/D65303
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371541 91177308-0d34-0410-b5e6-96231b3b80d8
SystemZInstrInfo::analyzeBranch() needs to check for INLINEASM_BR
instructions, or it will crash.
Review: Ulrich Weigand
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370753 91177308-0d34-0410-b5e6-96231b3b80d8
Now that constrained fpto[su]i intrinsic are available,
add codegen support to the SystemZ backend.
In addition to pure back-end changes, I've also needed
to add the strict_fp_to_[su]int and any_fp_to_[su]int
pattern fragments in the obvious way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370674 91177308-0d34-0410-b5e6-96231b3b80d8
This patch introduces the DAG version of SimplifyMultipleUseDemandedBits, which attempts to peek through ops (mainly and/or/xor so far) that don't contribute to the demandedbits/elts of a node - which means we can do this even in cases where we have multiple uses of an op, which normally requires us to demanded all bits/elts. The intention is to remove a similar instruction - SelectionDAG::GetDemandedBits - once SimplifyMultipleUseDemandedBits has matured.
The InstCombine version of SimplifyMultipleUseDemandedBits can constant fold which I haven't added here yet, and so far I've only wired this up to some basic binops (and/or/xor/add/sub/mul) to demonstrate its use.
We do see a couple of regressions that need to be addressed:
AMDGPU unsigned dot product codegen retains an AND mask (for ZERO_EXTEND) that it previously removed (but otherwise the dotproduct codegen is a lot better).
X86/AVX2 has poor handling of vector ANY_EXTEND/ANY_EXTEND_VECTOR_INREG - it prematurely gets converted to ZERO_EXTEND_VECTOR_INREG.
The code owners have confirmed its ok for these cases to fixed up in future patches.
Differential Revision: https://reviews.llvm.org/D63281
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366799 91177308-0d34-0410-b5e6-96231b3b80d8
Reimplement scheduling constraints for strict FP instructions in
ScheduleDAGInstrs::buildSchedGraph to allow for more relaxed
scheduling. Specifially, allow one strict FP instruction to
be scheduled across another, as long as it is not moved across
any global barrier.
Differential Revision: https://reviews.llvm.org/D64412
Reviewed By: cameron.mcinally
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366222 91177308-0d34-0410-b5e6-96231b3b80d8
This patch series adds support for the next-generation arch13
CPU architecture to the SystemZ backend.
This includes:
- Basic support for the new processor and its features.
- Assembler/disassembler support for new instructions.
- CodeGen for new instructions, including new LLVM intrinsics.
- Scheduler description for the new processor.
- Detection of arch13 as host processor.
Note: No currently available Z system supports the arch13
architecture. Once new systems become available, the
official system name will be added as supported -march name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365932 91177308-0d34-0410-b5e6-96231b3b80d8
Although removeCopyByCommutingDef deals with full copies, it is still
possible to copy undef lanes and thus, we wouldn't have any a value
number for these lanes.
This fixes PR40215.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365256 91177308-0d34-0410-b5e6-96231b3b80d8
This implements a small enhancement to https://reviews.llvm.org/D55506
Specifically, while we were able to match strict FP nodes for
floating-point extend operations with a register as source, this
did not work for operations with memory as source.
That is because from regular operations, this is represented as
a combined "extload" node (which is a variant of a load SD node);
but there is no equivalent using a strict FP operation.
However, it turns out that even in the absence of an extload
node, we can still just match the operations explicitly, e.g.
(strict_fpextend (f32 (load node:$ptr))
This patch implements that method to match the LDEB/LXEB/LXDB
SystemZ instructions even when the extend uses a strict-FP node.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364450 91177308-0d34-0410-b5e6-96231b3b80d8
Vector load/store instructions support an optional alignment field
that the compiler can use to provide known alignment info to the
hardware. If the field is used (and the information is correct),
the hardware may be able (on some models) to perform faster memory
accesses than otherwise.
This patch adds support for alignment hints in the assembler and
disassembler, and fills in known alignment during codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363806 91177308-0d34-0410-b5e6-96231b3b80d8
This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.
Patch by Matthias Braun
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363757 91177308-0d34-0410-b5e6-96231b3b80d8
Some GEPs were not being split, presumably because that split would just be
undone by the DAGCombiner. Not performing those splits can prevent important
optimizations, such as preventing the element indices / member offsets from
being (partially) folded into load/store instruction immediates. This patch:
- Makes the splits also occur in the cases where the base address and the GEP
are in the same BB.
- Ensures that the DAGCombiner doesn't reassociate them back again.
Differential Revision: https://reviews.llvm.org/D60294
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363544 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.
This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.
Reviewers: arsenm, thegameg, qcolombet
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D60137
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363533 91177308-0d34-0410-b5e6-96231b3b80d8
Current findBestLoopTop can find and move one kind of block to top, a latch block has one successor. Another common case is:
* a latch block
* it has two successors, one is loop header, another is exit
* it has more than one predecessors
If it is below one of its predecessors P, only P can fall through to it, all other predecessors need a jump to it, and another conditional jump to loop header. If it is moved before loop header, all its predecessors jump to it, then fall through to loop header. So all its predecessors except P can reduce one taken branch.
Differential Revision: https://reviews.llvm.org/D43256
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363471 91177308-0d34-0410-b5e6-96231b3b80d8
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.
This re-enables it for FastISel with the corresponding fix.
This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.
FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.
This fix moves the replacement of registers before the emission of
copies for the live-ins.
The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).
A few tests are affected by this:
* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed
Differential Revision: https://reviews.llvm.org/D62361
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362963 91177308-0d34-0410-b5e6-96231b3b80d8
This patch aims to reduce spilling and register moves by using the 3-address
versions of instructions per default instead of the 2-address equivalent
ones. It seems that both spilling and register moves are improved noticeably
generally.
Regalloc hints are passed to increase conversions to 2-address instructions
which are done in SystemZShortenInst.cpp (after regalloc).
Since the SystemZ reg/mem instructions are 2-address (dst and lhs regs are
the same), foldMemoryOperandImpl() can no longer trivially fold a spilled
source register since the reg/reg instruction is now 3-address. In order to
remedy this, new 3-address pseudo memory instructions are used to perform the
folding only when the dst and lhs virtual registers are known to be allocated
to the same physreg. In order to not let MachineCopyPropagation run and
change registers on these transformed instructions (making it 3-address), a
new target pass called SystemZPostRewrite.cpp is run just after
VirtRegRewriter, that immediately lowers the pseudo to a target instruction.
If it would have been possibe to insert a COPY instruction and change a
register operand (convert to 2-address) in foldMemoryOperandImpl() while
trusting that the caller (e.g. InlineSpiller) would update/repair the
involved LiveIntervals, the solution involving pseudo instructions would not
have been needed. This is perhaps a potential improvement (see Phabricator
post).
Common code changes:
* A new hook TargetPassConfig::addPostRewrite() is utilized to be able to run a
target pass immediately before MachineCopyPropagation.
* VirtRegMap is passed as an argument to foldMemoryOperand().
Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D60888
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362868 91177308-0d34-0410-b5e6-96231b3b80d8
The ISD::STRICT_ nodes used to implement the constrained floating-point
intrinsics are currently never passed to the target back-end, which makes
it impossible to handle them correctly (e.g. mark instructions are depending
on a floating-point status and control register, or mark instructions as
possibly trapping).
This patch allows the target to use setOperationAction to switch the action
on ISD::STRICT_ nodes to Legal. If this is done, the SelectionDAG common code
will stop converting the STRICT nodes to regular floating-point nodes, but
instead pass the STRICT nodes to the target using normal SelectionDAG
matching rules.
To avoid having the back-end duplicate all the floating-point instruction
patterns to handle both strict and non-strict variants, we make the MI
codegen explicitly aware of the floating-point exceptions by introducing
two new concepts:
- A new MCID flag "mayRaiseFPException" that the target should set on any
instruction that possibly can raise FP exception according to the
architecture definition.
- A new MI flag FPExcept that CodeGen/SelectionDAG will set on any MI
instruction resulting from expansion of any constrained FP intrinsic.
Any MI instruction that is *both* marked as mayRaiseFPException *and*
FPExcept then needs to be considered as raising exceptions by MI-level
codegen (e.g. scheduling).
Setting those two new flags is straightforward. The mayRaiseFPException
flag is simply set via TableGen by marking all relevant instruction
patterns in the .td files.
The FPExcept flag is set in SDNodeFlags when creating the STRICT_ nodes
in the SelectionDAG, and gets inherited in the MachineSDNode nodes created
from it during instruction selection. The flag is then transfered to an
MIFlag when creating the MI from the MachineSDNode. This is handled just
like fast-math flags like no-nans are handled today.
This patch includes both common code changes required to implement the
new features, and the SystemZ implementation.
Reviewed By: andrew.w.kaylor
Differential Revision: https://reviews.llvm.org/D55506
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362663 91177308-0d34-0410-b5e6-96231b3b80d8
[FPEnv] Added a special UnrollVectorOp method to deal with the chain on StrictFP opcodes
This change creates UnrollVectorOp_StrictFP. The purpose of this is to address a failure that consistently occurs when calling StrictFP functions on vectors whose number of elements is 3 + 2n on most platforms, such as PowerPC or SystemZ. The old UnrollVectorOp method does not expect that the vector that it will unroll will have a chain, so it has an assert that prevents it from running if this is the case. This new StrictFP version of the method deals with the chain while unrolling the vector. With this new function in place during vector widending, llc can run vector-constrained-fp-intrinsics.ll for SystemZ successfully.
Submitted by: Drew Wock <drew.wock@sas.com>
Reviewed by: Cameron McInally, Kevin P. Neal
Approved by: Cameron McInally
Differential Revision: https://reviews.llvm.org/D62546
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362241 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?
The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`
https://rise4fun.com/Alive/ffh
This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.
Reviewers: RKSimon, craig.topper, spatel, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62252
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362143 91177308-0d34-0410-b5e6-96231b3b80d8
This change creates UnrollVectorOp_StrictFP. The purpose of this is to address a failure that consistently occurs when calling StrictFP functions on vectors whose number of elements is 3 + 2n on most platforms, such as PowerPC or SystemZ. The old UnrollVectorOp method does not expect that the vector that it will unroll will have a chain, so it has an assert that prevents it from running if this is the case. This new StrictFP version of the method deals with the chain while unrolling the vector. With this new function in place during vector widending, llc can run vector-constrained-fp-intrinsics.ll for SystemZ successfully.
Submitted by: Drew Wock <drew.wock@sas.com>
Reviewed by: Cameron McInally, Kevin P. Neal
Approved by: Cameron McInally
Differential Revision: http://reviews.llvm.org/D62546
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362112 91177308-0d34-0410-b5e6-96231b3b80d8
I was looking into an endless combine loop the uncommitted follow-up patch
was causing, and it appears even these patches can exibit such an
endless loop. The root cause is that we try to hoist one binop (add/sub) with
constant operand, and if we get two such binops both of which are
eligible for this hoisting, we get stuck.
Some cases may highlight missing constant-folds.
Reverts r361871,r361872,r361873,r361874.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362109 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?
The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`
https://rise4fun.com/Alive/ffh
This is a recommit, originally committed in rL361853, but reverted
to investigate test-suite compile-time hangs.
Reviewers: RKSimon, craig.topper, spatel, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62252
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361872 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?
The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`
https://rise4fun.com/Alive/ffh
Reviewers: RKSimon, craig.topper, spatel, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62252
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361853 91177308-0d34-0410-b5e6-96231b3b80d8
The check lines are being affected by an upcoming patch,
regenerate the checklines to visualize the changes better.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361380 91177308-0d34-0410-b5e6-96231b3b80d8
This adds the FPC (floating-point control register) as a reserved
physical register and models its use by SystemZ instructions.
Note that only the current rounding modes and the IEEE exception
masks are modeled. *Changes* of the FPC due to exceptions (in
particular the IEEE exception flags and the DXC) are not modeled.
At this point, this patch is mostly NFC, but it will prevent
scheduling of floating-point instructions across SPFC/LFPC etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360570 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Extract the logic for doing reassociations
from DAGCombiner::reassociateOps into a helper
function DAGCombiner::reassociateOpsCommutative,
and use that helper to trigger reassociation
on the original operand order, or the commuted
operand order.
Codegen is not identical since the operand order will
be different when doing the reassociations for the
commuted case. That causes some unfortunate churn in
some test cases. Apart from that this should be NFC.
Reviewers: spatel, craig.topper, tstellar
Reviewed By: spatel
Subscribers: dmgreen, dschuff, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61199
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359476 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.
Refactors a few subclasses to support the target independent %a, %c, and
%n.
The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.
It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.
Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449
Reviewers: echristo, void
Reviewed By: void
Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60887
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359337 91177308-0d34-0410-b5e6-96231b3b80d8
Certain optimisations from ConstantHoisting and CGP rely on Selection DAG not
seeing through to the constant in other blocks. Revert this patch while we come
up with a better way to handle that.
I will try to follow this up with some better tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358113 91177308-0d34-0410-b5e6-96231b3b80d8
This lines up with what we do for regular subtract and it matches up better with X86 assumptions in isel patterns that add with immediate is more canonical than sub with immediate.
Differential Revision: https://reviews.llvm.org/D60020
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358027 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Teach SelectionDAG how to compute known bits of ISD::CopyFromReg if
the virtual reg used has one def only.
This can be particularly useful when calling isBaseWithConstantOffset()
with the ISD::CopyFromReg argument, as more optimizations may get enabled
in the result.
Also add a missing truncation on X86, found by testing of this patch.
Change-Id: Id1c9fceec862d118c54a5b53adf72ada5d6daefa
Reviewers: bogner, craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: lebedev.ri, nemanjai, jvesely, nhaehnle, javed.absar, jsji, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59535
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357745 91177308-0d34-0410-b5e6-96231b3b80d8
This function is responsible for checking the legality of fusing an instance
of load -> op -> store into a single operation. In the SystemZ backend the
check was incomplete and a test case emerged with a cycle in the instruction
selection DAG as a result.
Instead of using the NodeIds to determine node relationships,
hasPredecessorHelper() now is used just like in the X86 backend. This handled
the failing tests and as well gave a few additional transformations on
benchmarks.
The SystemZ isFusableLoadOpStorePattern() is now a very near copy of the X86
function, and it seems this could be made a utility function in common code
instead.
Review: Ulrich Weigand
https://reviews.llvm.org/D60255
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357688 91177308-0d34-0410-b5e6-96231b3b80d8
