The Swift CC is identical to Win64 CC with the exception of swift error
being passed in r12 which is a CSR. However, since this calling
convention is only used in swift -> swift code, it does not impact
interoperability and can be treated entirely as Win64 CC. We would
previously incorrectly lower the frame setup as we did not treat the
frame as conforming to Win64 specifications.
llvm-svn: 313813
Also add some tests that should be able to use v_mad_mixhi_f16,
but do not yet. This is trickier because we don't really model
the partial update of the register done by 16-bit instructions.
llvm-svn: 313806
Add adds support for naming data segments. This is useful
useful linkers so that they can merge similar sections.
Differential Revision: https://reviews.llvm.org/D37886
llvm-svn: 313795
Add support for passing SwiftError through a register on the Windows x64
calling convention. This allows the use of swifterror attributes on
parameters which is used by the swift front end for the `Error`
parameter. This partially enables building the swift standard library
for Windows x86_64.
llvm-svn: 313791
This enables readobj to output Windows resource files (.res). This way,
we'll be able to test .res outputs without comparing them byte-by-byte
with "magic binary files" generated by MS toolchain.
Differential Revision: https://reviews.llvm.org/D38058
llvm-svn: 313790
After r313775, it's easier to maintain a parallel BitVector of spilled
locations indexed by location number.
I wasn't able to build a good reduced test case for this iteration of
the bug, but I added a more direct assertion that spilled values must
use frame index locations. If this bug reappears, it won't only fire on
the NEON vector code that we detected it on, but on medium-sized
integer-only programs as well.
llvm-svn: 313786
This broke the buildbots, e.g.
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/391
> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask'
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Subscribers: mzolotukhin
>
> Reviewed By: ayal
>
> Differential Revision: https://reviews.llvm.org/D36130
>
> Review comments updated accordingly
>
> Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
>
> Added a TODO for sortLoadAccesses API
>
> Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
>
> Modified the TODO for sortLoadAccesses API
>
> Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
>
> Review comment update for using OpdNum to insert the mask in respective location
>
> Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
>
> Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
>
> Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313781
This patch implements the Darwin dwarfdump option --recurse-depth=<N>,
which limits the recursion depth when selectively printing DIEs at an
offset.
Differential Revision: https://reviews.llvm.org/D38064
llvm-svn: 313778
In these cases, two selects have constant selectable operands for
both the true and false components and have the same conditional
expression.
We then create two arithmetic operations of the same type and feed a
final select operation using the result of the true arithmetic for the true
operand and the result of the false arithmetic for the false operand and reuse
the original conditionl expression.
The arithmetic operations are naturally folded as a consequence, leaving
only the newly formed select to replace the old arithmetic operation.
Patch by: Michael Berg <michael_c_berg@apple.com>
Differential Revision: https://reviews.llvm.org/D37019
llvm-svn: 313774
I did not upload two binaries that I reference in tests.
This change adds support for sections involved in dynamic loading such
as SHT_DYNAMIC, SHT_DYNSYM, and allocated string tables.
The two added binaries used for tests can be downloaded here and here
Differential Revision: https://reviews.llvm.org/D36560
llvm-svn: 313772
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask'
jumbled accesses.
This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
Subscribers: mzolotukhin
Reviewed By: ayal
Differential Revision: https://reviews.llvm.org/D36130
Review comments updated accordingly
Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
Added a TODO for sortLoadAccesses API
Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
Modified the TODO for sortLoadAccesses API
Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
Review comment update for using OpdNum to insert the mask in respective location
Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313771
I overzealously landed this before I was sure that another change
wouldn't break the build that this change depends on.
This change adds support for sections involved in dynamic loading such
as SHT_DYNAMIC, SHT_DYNSYM, and allocated string tables.
The two added binaries used for tests can be downloaded here and here
Differential Revision: https://reviews.llvm.org/D36560
llvm-svn: 313767
Summary:
The fix for dead stripping analysis in the case of SamplePGO indirect
calls to local functions (r313151) introduced the possibility of an
infinite loop.
Make sure we check for the value being already live after we update it
for SamplePGO indirect call handling.
Reviewers: danielcdh
Subscribers: mehdi_amini, inglorion, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D38086
llvm-svn: 313766
Remove unneeded attributes from test/DebugInfo/Generic/imported-name-inlined.ll because it was causing failures on pure MIPS builds.
Patch by Miloš Stojanović!
Differential Revision: https://reviews.llvm.org/D38079
llvm-svn: 313762
This version of the patch fixes an off-by-one error causing PR34596. We
do not need to use std::next(BlockIter) when calling updateDepths, as
BlockIter already points to the next element.
Original commit message:
> For large basic blocks with lots of combinable instructions, the
> MachineTraceMetrics computations in MachineCombiner can dominate the compile
> time, as computing the trace information is quadratic in the number of
> instructions in a BB and it's relevant successors/predecessors.
> In most cases, knowing the instruction depth should be enough to make
> combination decisions. As we already iterate over all instructions in a basic
> block, the instruction depth can be computed incrementally. This reduces the
> cost of machine-combine drastically in cases where lots of instructions
> are combined. The major drawback is that AFAIK, computing the critical path
> length cannot be done incrementally. Therefore we only compute
> instruction depths incrementally, for basic blocks with more
> instructions than inc_threshold. The -machine-combiner-inc-threshold
> option can be used to set the threshold and allows for easier
> experimenting and checking if using incremental updates for all basic
> blocks has any impact on the performance.
>
> Reviewers: sanjoy, Gerolf, MatzeB, efriedma, fhahn
>
> Reviewed By: fhahn
>
> Subscribers: kiranchandramohan, javed.absar, efriedma, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D36619
llvm-svn: 313751
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.
This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh
Reviewed By: Ayal
Subscribers: mzolotukhin
Differential Revision: https://reviews.llvm.org/D36130
Commit after rebase for patch D36130
Change-Id: I8add1c265455669ef288d880f870a9522c8c08ab
llvm-svn: 313736
Also starts selecting global loads for constant address
in some cases. Some end up selecting to mubuf still, which
requires investigation.
We still get sub-optimal regalloc and extra waitcnts inserted
due to not really tracking the liveness of the separate register
halves.
llvm-svn: 313716
Summary:
With this change:
- Methods in LoopBase trip an assert if the receiver has been invalidated
- LoopBase::clear frees up the memory held the LoopBase instance
This change also shuffles things around as necessary to work with this stricter invariant.
Reviewers: chandlerc
Subscribers: mehdi_amini, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D38055
llvm-svn: 313708
This re-applies commit r313685, this time with the proper updates to
the test cases.
Original commit message:
Unreachable blocks in the machine instr representation are these
weird empty blocks with no successors.
The MIR printer used to not print empty lists of successors. However,
the MIR parser now treats non-printed list of successors as "please
guess it for me". As a result, the parser tries to guess the list of
successors and given the block is empty, just assumes it falls through
the next block (if any).
For instance, the following test case used to fail the verifier.
The MIR printer would print
entry
/ \
true (def) false (no list of successors)
|
split.true (use)
The MIR parser would understand this:
entry
/ \
true (def) false
| / <-- invalid edge
split.true (use)
Because of the invalid edge, we get the "def does not
dominate all uses" error.
The fix consists in printing empty successor lists, so that the parser
knows what to do for unreachable blocks.
rdar://problem/34022159
llvm-svn: 313696
Add adds support for naming data segments. This is useful
useful linkers so that they can merge similar sections.
Differential Revision: https://reviews.llvm.org/D37886
llvm-svn: 313692
Unreachable blocks in the machine instr representation are these
weird empty blocks with no successors.
The MIR printer used to not print empty lists of successors. However,
the MIR parser now treats non-printed list of successors as "please
guess it for me". As a result, the parser tries to guess the list of
successors and given the block is empty, just assumes it falls through
the next block (if any).
For instance, the following test case used to fail the verifier.
The MIR printer would print
entry
/ \
true (def) false (no list of successors)
|
split.true (use)
The MIR parser would understand this:
entry
/ \
true (def) false
| / <-- invalid edge
split.true (use)
Because of the invalid edge, we get the "def does not
dominate all uses" error.
The fix consists in printing empty successor lists, so that the parser
knows what to do for unreachable blocks.
rdar://problem/34022159
llvm-svn: 313685
I didn't initialize a pointer to be nullptr that I needed to.
This change adds support for nested and even overlapping segments. This means
that PT_PHDR, PT_GNU_RELRO, PT_TLS, and PT_DYNAMIC can be supported properly.
Differential Revision: https://reviews.llvm.org/D36558
llvm-svn: 313682
The ARM docs suggest in examples that the flags can have either case, and there
are applications in the wild that (libopencm3, for example) that expect to be
able to use the uppercase spelling.
https://reviews.llvm.org/D37953
llvm-svn: 313680
This reverts r313640, originally r313400, one more time for essentially
the same issue. My BitVector of spilled location numbers isn't working
because we coalesce identical DBG_VALUE locations as we rewrite them,
invalidating the location numbers used to index the BitVector.
llvm-svn: 313679
Summary: In the ThinLTO compilation, if a function is inlined in the profiling binary, we need to inline it before annotation. If the callee is not available in the primary module, a first step is needed to import that callee function. For the current implementation, if the call is an indirect call, which has been promoted to >1 targets and inlined, SamplePGO will only import one target with the largest sample count. This patch fixed the bug to import all targets instead.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D36637
llvm-svn: 313678
The pre-RA scheduler does load/store clustering, but post-RA
scheduler undoes it. Add mutation to prevent it.
Differential Revision: https://reviews.llvm.org/D38014
llvm-svn: 313670
SystemZTargetLowering::combineSTORE contains code to transform a
combination of STORE + BSWAP into a STRV type instruction.
This transformation is correct for regular stores, but not for
truncating stores. The routine neglected to check for that case.
Fixes a miscompilation of llvm-objcopy with clang, which caused
test suite failures in the SystemZ multistage build bot.
llvm-svn: 313669
This reverts commit SVN r313654. Seems that it is triggering an
assertion on Windows specifically. Revert until I can build on Windows
and look into what is happening there.
llvm-svn: 313668
Inputs should be placed local to the test (or possibly in a common
parent? I think we do that in some places - but the only common parent
between these two directories is 'test' which seems a bit overly broad).
llvm-svn: 313662
This change adds a test that checks the an error is produced when a hexagon
specific reserved section index is used but e_machine is not EM_HEXAGON.
Differential Revision: https://reviews.llvm.org/D38017
llvm-svn: 313661
Summary: Fix the bug when promoted call return type mismatches with the promoted function, we should not try to inline it. Otherwise it may lead to compiler crash.
Reviewers: davidxl, tejohnson, eraman
Reviewed By: tejohnson
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D38018
llvm-svn: 313658
This change adds support for nested and even overlapping segments. This means
that PT_PHDR, PT_GNU_RELRO, PT_TLS, and PT_DYNAMIC can be supported properly.
Differential Revision: https://reviews.llvm.org/D36558
llvm-svn: 313656
Add support for the R_AARCH64_ABS{16,32} relocations in the execution
engine. This is primarily used for DWARF debug information relocations
and needed by the LLVM JIT to support JITing for lldb.
Patch by Alex Langford!
llvm-svn: 313654
I forgot to zero out the BitVector when reusing it between UserValues.
Later uses of the same location number for a different UserValue would
falsely indicate that they were spilled. Usually this would lead to
incorrect debug info, but in some cases they would indicate something
nonsensical like a memory location based on a vector register (Q8 on
ARM).
llvm-svn: 313640
Two blocks prior to the join each perform an li and the the join block has an
add using the initialized register. Optimize each predecessor block to instead
use addi and delete the li's and add.
Differential Revision: https://reviews.llvm.org/D36734
llvm-svn: 313639
This is a preparatory step for D34515.
This change:
- makes nodes ISD::ADDCARRY and ISD::SUBCARRY legal for i32
- lowering is done by first converting the boolean value into the carry flag
using (_, C) ← (ARMISD::ADDC R, -1) and converted back to an integer value
using (R, _) ← (ARMISD::ADDE 0, 0, C). An ARMISD::ADDE between the two
operations does the actual addition.
- for subtraction, given that ISD::SUBCARRY second result is actually a
borrow, we need to invert the value of the second operand and result before
and after using ARMISD::SUBE. We need to invert the carry result of
ARMISD::SUBE to preserve the semantics.
- given that the generic combiner may lower ISD::ADDCARRY and
ISD::SUBCARRYinto ISD::UADDO and ISD::USUBO we need to update their lowering
as well otherwise i64 operations now would require branches. This implies
updating the corresponding test for unsigned.
- add new combiner to remove the redundant conversions from/to carry flags
to/from boolean values (ARMISD::ADDC (ARMISD::ADDE 0, 0, C), -1) → C
- fixes PR34045
- fixes PR34564
Differential Revision: https://reviews.llvm.org/D35192
llvm-svn: 313618
This patch adds the instruction scheduling information for the SkylakeClient (SKL) architecture target by adding the file X86SchedSkylakeClient.td located under the X86 Target.
We used the scheduling information retrieved from the Skylake architects in order to create the file.
The scheduling information includes latency, number of micro-Ops and used ports by each SKL instruction.
The patch continues the scheduling replacement and insertion effort started with the SNB target in r307529 and r310792 and for HSW in r311879.
Please expect some performance fluctuations due to code alignment effects.
Reviewers: craig.topper, zvi, chandlerc, igorb, aymanmus, RKSimon, delena
Differential Revision: https://reviews.llvm.org/D37294
llvm-svn: 313613
After clang started emitting deferred regions (r312818), llvm-cov has
had a hard time picking reasonable line execuction counts. There have
been one or two generic improvements in this area (e.g r310012), but
line counts can still report coverage for whitespace instead of code
(llvm.org/PR34612).
To fix the problem:
* Introduce a new region kind so that frontends can explicitly label
gap areas.
This is done by changing the encoding of the columnEnd field of
MappingRegion. This doesn't substantially increase binary size, and
makes it easy to maintain backwards-compatibility.
* Don't set the line count to a count from a gap area, unless the count
comes from a wrapped segment.
* Don't highlight gap areas as uncovered.
Fixes llvm.org/PR34612.
llvm-svn: 313597
This caused asserts in Chromium. See http://crbug.com/766261
> Summary:
> This comes up in optimized debug info for C++ programs that pass and
> return objects indirectly by address. In these programs,
> llvm.dbg.declare survives optimization, which causes us to emit indirect
> DBG_VALUE instructions. The fast register allocator knows to insert
> DW_OP_deref when spilling indirect DBG_VALUE instructions, but the
> LiveDebugVariables did not until this change.
>
> This fixes part of PR34513. I need to look into why this doesn't work at
> -O0 and I'll send follow up patches to handle that.
>
> Reviewers: aprantl, dblaikie, probinson
>
> Subscribers: qcolombet, hiraditya, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D37911
llvm-svn: 313589
If we have an AssertZext of a truncated value that has already been AssertZext'ed,
we can assert on the wider source op to improve the zext-y knowledge:
assert (trunc (assert X, i8) to iN), i1 --> trunc (assert X, i1) to iN
This moves a fold from being Mips-specific to general combining, and x86 shows
improvements.
Differential Revision: https://reviews.llvm.org/D37017
llvm-svn: 313577
rL310710 allowed store merging to occur after legalization to catch stores that are created late,
but this exposes a logic hole seen in PR34217:
https://bugs.llvm.org/show_bug.cgi?id=34217
We will miss merging stores if the target lowers vector extracts into target-specific operations.
This patch allows store merging to occur both before and after legalization if the target chooses
to get maximum merging.
I don't think the potential regressions in the other tests are relevant. The tests are for
correctness of weird IR constructs rather than perf tests, and I think those are still correct.
Differential Revision: https://reviews.llvm.org/D37987
llvm-svn: 313564
The AssertZext we might see in this case is only giving information about the lower 32 bits. It isn't providing information about the upper 32 bits. So we should emit a zext.
This fixes PR28540.
Differential Revision: https://reviews.llvm.org/D37729
llvm-svn: 313563
For cases where we are BITCASTing to vectors of smaller elements, then if the entire source was a splatted sign (src's NumSignBits == SrcBitWidth) we can say that the dst's NumSignBit == DstBitWidth, as we're just splitting those sign bits across multiple elements.
We could generalize this but at the moment the only use case I have is to peek through bitcasts to vector comparison results.
Differential Revision: https://reviews.llvm.org/D37849
llvm-svn: 313543
The shuffle combining and lowerVectorShuffleAsLanePermuteAndBlend were both still trying to use VPERM2XF128 for unary shuffles when AVX2 is enabled. VPERM2X128 takes two inputs meaning when we use it for a unary shuffle one of those inputs is left undefined creating a false dependency on whatever register gets allocated there.
If we have VPERMQ/PD we should prefer those since they only have a single input.
Differential Revision: https://reviews.llvm.org/D37947
llvm-svn: 313542
Add the missing hardware features the ProcA55 and ProcA75 feature.
These are already enabled via the target parser, but I had missed
them in the backend.
Differential Revision: https://reviews.llvm.org/D37974
llvm-svn: 313535
Implement the isTruncateFree hooks, lifted from AArch64, that are
used by TargetTransformInfo. This allows simplifycfg to reduce the
test case into a single basic block.
Differential Revision: https://reviews.llvm.org/D37516
llvm-svn: 313533
The indexed dot product instructions only accept the lower 16 D-registers as
the indexed register, but we were e.g. incorrectly accepting:
vudot.u8 d16,d16,d18[0]
Differential Revision: https://reviews.llvm.org/D37968
llvm-svn: 313531
This patch makes the `.eh_frame` extension an alias for `.debug_frame`.
Up till now it was only possible to dump the section using objdump, but
not with dwarfdump. Since the two are essentially interchangeable, we
dump whichever of the two is present.
As a workaround, this patch also adds parsing for 3 currently
unimplemented CFA instructions: `DW_CFA_def_cfa_expression`,
`DW_CFA_expression`, and `DW_CFA_val_expression`. Because I lack the
required knowledge, I just parse the fields without actually creating
the instructions.
Finally, this also fixes the typo in the `.debug_frame` section name
which incorrectly contained a trailing `s`.
Differential revision: https://reviews.llvm.org/D37852
llvm-svn: 313530
Summary:
Subregister liveness tracking is not implemented for X86 backend, so
sometimes the whole super register is said to be live, when only a
subregister is really live. That might happen if the def and the use
are located in different MBBs, see added fixup-bw-isnt.mir test.
However, using knowledge of the specific instructions handled by the
bw-fixup-pass we can get more precise liveness information which this
change does.
Reviewers: MatzeB, DavidKreitzer, ab, andrew.w.kaylor, craig.topper
Reviewed By: craig.topper
Subscribers: n.bozhenov, myatsina, llvm-commits, hiraditya
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Differential Revision: https://reviews.llvm.org/D37559
llvm-svn: 313524
Summary:
This change adds support for explicit tail-exit records to be written by
the XRay runtime. This lets us differentiate the tail exit
records/events in the log, and allows us to treat those exit events
especially in the future. For now we allow printing those out in YAML
(and reading them in).
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37964
llvm-svn: 313514
This Disassembly support allows for 'round-trip' testing, and rv32i-valid.s
has been updated appropriately.
Differential Revision: https://reviews.llvm.org/D23567
llvm-svn: 313486
This patch supports all RV32I instructions as described in the RISC-V manual.
A future patch will add support for pseudoinstructions and other instruction
expansions (e.g. 0-arg fence -> fence iorw, iorw).
Differential Revision: https://reviews.llvm.org/D23566
llvm-svn: 313485
This was a bug in the test that was only exposed as a result of
refactoring some code in lit configuration files. Previously,
llvm's lit configuration would only set the target-windows feature
if the system was also windows. Since cross-compilation is
a thing, this isn't correct. target-windows should be set
independently of system-windows.
Adding to that bug, this particular test then checked for
target-windows when it really meant "can I call a certain API on
the host machine", which is what system-windows is for.
Ultimately, this test only works if *both* the target and host
are Windows, so I've updated the test to reflect that.
llvm-svn: 313468
readelf tool reports an error when output contains the same section
in multiple COMDAT groups. That can be useful.
Path teaches llvm-readobj to do the same.
Differential revision: https://reviews.llvm.org/D37567
llvm-svn: 313459
This allows vector-sized store merging of constants in DAGCombiner using the existing code in MergeConsecutiveStores().
All of the twisted logic that decides exactly what vector operations are legal and fast for each particular CPU are
handled separately in there using the appropriate hooks.
For the motivating tests in merge-store-constants.ll, we already produce the same vector code in IR via the SLP vectorizer.
So this is just providing a backend backstop for code that doesn't go through that pass (-O1). More details in PR24449:
https://bugs.llvm.org/show_bug.cgi?id=24449 (this change should be the last step to resolve that bug)
Differential Revision: https://reviews.llvm.org/D37451
llvm-svn: 313458
We just need to toggle bits 1 and 5 of the immediate and swap the sources. The peephole pass could trigger commuting/folding for this later, but its easy enough to fix in isel.
Disable the peephole pass on the main vperm2x128 test so we know we're doing this through isel.
llvm-svn: 313455
I've moved the test cases from the InstCombine optimizations to the backend to keep the coverage we had there. It covered every possible immediate so I've preserved the resulting shuffle mask for each of those immediates.
llvm-svn: 313450
I'm going to autoupgrade these intrinsics in a future commit. This bit will never be set in the resulting output so pre-removing the bit.
llvm-svn: 313434
This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54.
There is a bug in this implementation where the string value of the
checksum is outputted, instead of the actual hex bytes. Therefore the
checksum is incorrect, and this prevent pdbs from being loaded by visual
studio. Revert this until the checksum is emitted correctly.
llvm-svn: 313431
It looks like this is going to be non-trivial to get working
in both Py2 and Py3, so for now I'm reverting until I have time
to fully test it under Python 3.
llvm-svn: 313429
This is the first of many commits that enable selectively dumping just
one record from the debug info.
This reapplies r313412 with some extra qualification to appease GCC and MSVC.
llvm-svn: 313419
* Fix an unsigned integer overflow in the logic that computes the
number of uncovered lines in a function.
* When aggregating region and line coverage summaries, take into account
that different instantiations may have a different number of regions.
The new test case provides test coverage for both bugs. I also verified
this change by preparing a coverage report for a stage2 build of llc --
the new assertions should detect any outstanding over-counting bugs.
Fixes PR34613.
llvm-svn: 313417
Static alloca usually doesn't generate any machine instructions, so it has 0 cost.
Differential Revision: https://reviews.llvm.org/D37879
llvm-svn: 313410
CostModel.
The original patch added support for horizontal min/max reductions to
the SLP vectorizer.
This patch causes LLVM to miscompile fairly simple signed min
reductions. I have attached a test progrom to http://llvm.org/PR34635
that shows the behavior change after this patch. We found this in a test
for the open source Eigen library, but also in other code.
Unfortunately, the revert is moderately challenging. It required
reverting:
r313042: [SLP] Test with multiple uses of conditional op and wrong parent.
r312853: [SLP] Fix buildbots, NFC.
r312793: [SLP] Fix the warning about paths not returning the value, NFC.
r312791: [SLP] Support for horizontal min/max reduction.
And even then, I had to completely skip reverting the changes to TTI and
CostModel because r312832 rewrote so much of this code. Plus, the cost
modeling changes aren implicated in the miscompile, so they should be
fine and will just not be used until this gets re-introduced.
llvm-svn: 313409
This is a resubmission of r313270. It broke standalone builds of
compiler-rt because we were not correctly generating the llvm-lit
script in the standalone build directory.
The fixes incorporated here attempt to find llvm/utils/llvm-lit
from the source tree returned by llvm-config. If present, it
will generate llvm-lit into the output directory. Regardless,
the user can specify -DLLVM_EXTERNAL_LIT to point to a specific
lit.py on their file system. This supports the use case of
someone installing lit via a package manager. If it cannot find
a source tree, and -DLLVM_EXTERNAL_LIT is either unspecified or
invalid, then we print a warning that tests will not be able
to run.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313407
Summary:
This comes up in optimized debug info for C++ programs that pass and
return objects indirectly by address. In these programs,
llvm.dbg.declare survives optimization, which causes us to emit indirect
DBG_VALUE instructions. The fast register allocator knows to insert
DW_OP_deref when spilling indirect DBG_VALUE instructions, but the
LiveDebugVariables did not until this change.
This fixes part of PR34513. I need to look into why this doesn't work at
-O0 and I'll send follow up patches to handle that.
Reviewers: aprantl, dblaikie, probinson
Subscribers: qcolombet, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D37911
llvm-svn: 313400
Summary:
Fixes PR34513.
Indirect DBG_VALUEs typically come from dbg.declares of non-trivially
copyable C++ objects that must be passed by address. We were already
handling the case where the virtual register gets allocated to a
physical register and is later spilled. That's what usually happens for
normal parameters that aren't NRVO variables: they usually appear in
physical register parameters, and are spilled later in the function,
which would correctly add deref.
NRVO variables are different because the dbg.declare can come much later
after earlier instructions cause the incoming virtual register to be
spilled.
Also, clean up this code. We only need to look at the first operand of a
DBG_VALUE, which eliminates the operand loop.
Reviewers: aprantl, dblaikie, probinson
Subscribers: MatzeB, qcolombet, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37929
llvm-svn: 313399
Summary:
After r304661, module flag to record objective-c image info section is
encoded without whitespaces after comma. The new name is equivalent to
the old one, except that when LTO a module built by old compiler and a
module built by a new compiler, it will fail with conflicting values.
Fix the issue by removing whitespaces in bitcode upgrade path.
rdar://problem/34416934
Reviewers: compnerd
Reviewed By: compnerd
Subscribers: mehdi_amini, hans, llvm-commits
Differential Revision: https://reviews.llvm.org/D37909
llvm-svn: 313398
This means that we can honor -fdata-sections rather than
always creating a segment for each symbol.
It also allows for a followup change to add .init_array and friends.
Differential Revision: https://reviews.llvm.org/D37876
llvm-svn: 313395
As Eli pointed out (and I got wrong in the first place), langref says: "The
getelementptr returns a vector of pointers, instead of a single address, when one
or more of its arguments is a vector. In such cases, all vector arguments should
have the same number of elements, and every scalar argument will be effectively
broadcast into a vector during address calculation."
Costantfold for gep doesn't really take in account this paragraph, returning a
pointer instead of a vector of pointer which triggers an assertion in RAUW,
as we're trying to replace values with mistmatching types.
Differential Revision: https://reviews.llvm.org/D37928
llvm-svn: 313394
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled.
However LLVM-C API users can still provide callback function for diagnostic handler.
llvm-svn: 313390
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled.
However LLVM-C API users can still provide callback function for diagnostic handler.
llvm-svn: 313382
- Create helper function for resolving weak references.
- Add test that preproduces the crash.
Differential Revision: https://reviews.llvm.org/D37916
llvm-svn: 313381
This caused PR34629: asserts firing when building Chromium. It also broke some
buildbots building test-suite as reported on the commit thread.
> Summary:
> 1/ Operand folding during complex pattern matching for LEAs has been
> extended, such that it promotes Scale to accommodate similar operand
> appearing in the DAG.
> e.g.
> T1 = A + B
> T2 = T1 + 10
> T3 = T2 + A
> For above DAG rooted at T3, X86AddressMode will no look like
> Base = B , Index = A , Scale = 2 , Disp = 10
>
> 2/ During OptimizeLEAPass down the pipeline factorization is now performed over LEAs
> so that if there is an opportunity then complex LEAs (having 3 operands)
> could be factored out.
> e.g.
> leal 1(%rax,%rcx,1), %rdx
> leal 1(%rax,%rcx,2), %rcx
> will be factored as following
> leal 1(%rax,%rcx,1), %rdx
> leal (%rdx,%rcx) , %edx
>
> 3/ Aggressive operand folding for AM based selection for LEAs is sensitive to loops,
> thus avoiding creation of any complex LEAs within a loop.
>
> Reviewers: lsaba, RKSimon, craig.topper, qcolombet
>
> Reviewed By: lsaba
>
> Subscribers: spatel, igorb, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D35014
llvm-svn: 313376
Summary:
The checksums had already been placed in the IR, this patch allows
MCCodeView to actually write it out to an MCStreamer.
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37157
llvm-svn: 313374
The early out for AVX2 in lowerV2X128VectorShuffle is positioned in a weird spot below some shuffle mask equivalency checks.
But I think we want to allow VPERMQ for any unary shuffle.
Differential Revision: https://reviews.llvm.org/D37893
llvm-svn: 313373
When handling a v64i1 build vector of constants on 32-bit targets we were creating an illegal i64 constant that we then bitcasted back to v64i1. We need to instead create two 32-bit constants, bitcast them to v32i1 and concat the result. We should also take care to handle the halves being all zeros/ones after the split.
This patch splits the build vector and then recursively lowers the two pieces. This allows us to handle the all ones and all zeros cases with minimal effort. Ideally we'd just do the split and concat, and let lowering get called again on the new nodes, but getNode has special handling for CONCAT_VECTORS that reassembles the pieces back into a single BUILD_VECTOR. Hopefully the two temporary BUILD_VECTORS we had to create to do this that don't get returned don't cause any issues.
Fixes PR34605.
Differential Revision: https://reviews.llvm.org/D37858
llvm-svn: 313366
Currently if we're inserting 0s into the upper elements of a vector register we insert an explicit move of the smaller register to implicitly zero the upper bits. But if we can prove that they are already zero we can skip that. This is based on a similar idea of what we do to avoid emitting explicit zero extends for GR32->GR64.
Unfortunately, this is harder for vector registers because there are several opcodes that don't have VEX equivalent instructions, but can write to XMM registers. Among these are SHA instructions and a MMX->XMM move. Bitcasts can also get in the way.
So for now I'm starting with explicitly allowing only VPMADDWD because we emit zeros in combineLoopMAddPattern. So that is placing extra instruction into the reduction loop.
I'd like to allow PSADBW as well after D37453, but that's currently blocked by a bitcast. We either need to peek through bitcasts or canonicalize insert_subvectors with zeros to remove bitcasts on the value being inserted.
Longer term we should probably have a cleanup pass that removes superfluous zeroing moves even when the producer is in another basic block which is something these isel tricks can't do. See PR32544.
Differential Revision: https://reviews.llvm.org/D37653
llvm-svn: 313365
Add a profitability heuristic to enable runtime unrolling of multi-exit
loop: There can be atmost two unique exit blocks for the loop and the
second exit block should be a deoptimizing block. Also, there can be one
other exiting block other than the latch exiting block. The reason for
the latter is so that we limit the number of branches in the unrolled
code to being at most the unroll factor. Deoptimizing blocks are rarely
taken so these additional number of branches created due to the
unrolling are predictable, since one of their target is the deopt block.
Reviewers: apilipenko, reames, evstupac, mkuper
Subscribers: llvm-commits
Reviewed by: reames
Differential Revision: https://reviews.llvm.org/D35380
llvm-svn: 313363
During runtime unrolling on loops with multiple exits, we update the
exit blocks with the correct phi values from both original and remainder
loop.
In this process, we lookup the VMap for the mapped incoming phi values,
but did not update the VMap if a default entry was generated in the VMap
during the lookup. This default value is generated when constants or
values outside the current loop are looked up.
This patch fixes the assertion failure when null entries are present in
the VMap because of this lookup. Added a testcase that showcases the
problem.
llvm-svn: 313358
This adds support for allowing v8f16 vector types, thus avoiding conversions
from/to single precision for these types. This is a follow up patch of
commits r311154 and r312104, which added support for scalars and v4f16
types, respectively.
Differential Revision: https://reviews.llvm.org/D37802
llvm-svn: 313351
Patch tries to improve vectorization of the following code:
void add1(int * __restrict dst, const int * __restrict src) {
*dst++ = *src++;
*dst++ = *src++ + 1;
*dst++ = *src++ + 2;
*dst++ = *src++ + 3;
}
Allows to vectorize even if the very first operation is not a binary add, but just a load.
Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev, davide
Subscribers: llvm-commits, RKSimon
Differential Revision: https://reviews.llvm.org/D28907
llvm-svn: 313348
Summary:
1/ Operand folding during complex pattern matching for LEAs has been
extended, such that it promotes Scale to accommodate similar operand
appearing in the DAG.
e.g.
T1 = A + B
T2 = T1 + 10
T3 = T2 + A
For above DAG rooted at T3, X86AddressMode will no look like
Base = B , Index = A , Scale = 2 , Disp = 10
2/ During OptimizeLEAPass down the pipeline factorization is now performed over LEAs
so that if there is an opportunity then complex LEAs (having 3 operands)
could be factored out.
e.g.
leal 1(%rax,%rcx,1), %rdx
leal 1(%rax,%rcx,2), %rcx
will be factored as following
leal 1(%rax,%rcx,1), %rdx
leal (%rdx,%rcx) , %edx
3/ Aggressive operand folding for AM based selection for LEAs is sensitive to loops,
thus avoiding creation of any complex LEAs within a loop.
Reviewers: lsaba, RKSimon, craig.topper, qcolombet
Reviewed By: lsaba
Subscribers: spatel, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D35014
llvm-svn: 313343
This patch is still breaking several multi-stage compiler-rt bots.
I already know what the fix is, but I want to get the bots green
for now and then try re-applying in the morning.
llvm-svn: 313335
To further reduce duplicate code, this patch introduces a module
that configs can simply import and get access to a lot of useful
functionality such as setting up paths, adding features that are
useful across all projects, and other utility-type functions.
For now this only updates llvm's suite to use this new library,
but subsequent patches will update other projects.
Differential Revision: https://reviews.llvm.org/D37778
llvm-svn: 313325
This is stepping stone towards honoring -fdata-sections
and letting the assembler decide how many wasm data
segments to create.
Differential Revision: https://reviews.llvm.org/D37834
llvm-svn: 313313
For instructions that unlikely generate machine instructions, they should also have 0 latency.
Differential Revision: https://reviews.llvm.org/D37833
llvm-svn: 313288
Because the stack growth direction and addressing is done
in the same direction, modifying SP at the beginning of the
call sequence was incorrect. If we had a stack passed argument,
we would end up skipping that number of bytes before pushing
arguments, leaving unused/inconsistent space.
The callee creates fixed stack objects in its frame, so
the space necessary for these is already logically allocated
in the callee, so we just let the callee increment SP if
it really requires it.
llvm-svn: 313279
Summary: SampleProfileLoader inlines hot functions if it is inlined in the profiled binary. However, the inline needs to be guarded by legality check, otherwise it could lead to correctness issues.
Reviewers: eraman, davidxl
Reviewed By: eraman
Subscribers: vitalybuka, sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D37779
llvm-svn: 313277
The other members of the dext family of instructions (dextm, dextu) are
traditionally handled by the assembler selecting the right variant of
'dext' depending on the values of the position and size operands.
When these instructions are disassembled, rather than reporting the
actual instruction, an equivalent aliased form of 'dext' is generated
and is reported. This is to mimic the behaviour of binutils.
Reviewers: slthakur, nitesh.jain, atanasyan
Differential Revision: https://reviews.llvm.org/D34887
llvm-svn: 313276
Using SplitCSR for the frame register was very broken. Often
the copies in the prolog and epilog were optimized out, in addition
to them being inserted after the true prolog where the FP
was clobbered.
I have a hacky solution which works that continues to use
split CSR, but for now this is simpler and will get to working
programs.
llvm-svn: 313274
This replaces TableGen's type inference to operate on parameterized
types instead of MVTs, and as a consequence, some interfaces have
changed:
- Uses of MVTs are replaced by ValueTypeByHwMode.
- EEVT::TypeSet is replaced by TypeSetByHwMode.
This affects the way that types and type sets are printed, and the
tests relying on that have been updated.
There are certain users of the inferred types outside of TableGen
itself, namely FastISel and GlobalISel. For those users, the way
that the types are accessed have changed. For typical scenarios,
these replacements can be used:
- TreePatternNode::getType(ResNo) -> getSimpleType(ResNo)
- TreePatternNode::hasTypeSet(ResNo) -> hasConcreteType(ResNo)
- TypeSet::isConcrete -> TypeSetByHwMode::isValueTypeByHwMode(false)
For more information, please refer to the review page.
Differential Revision: https://reviews.llvm.org/D31951
llvm-svn: 313271
This patch simplifies LLVM's lit infrastructure by enforcing an ordering
that a site config is always run before a source-tree config.
A significant amount of the complexity from lit config files arises from
the fact that inside of a source-tree config file, we don't yet know if
the site config has been run. However it is *always* required to run
a site config first, because it passes various variables down through
CMake that the main config depends on. As a result, every config
file has to do a bunch of magic to try to reverse-engineer the location
of the site config file if they detect (heuristically) that the site
config file has not yet been run.
This patch solves the problem by emitting a mapping from source tree
config file to binary tree site config file in llvm-lit.py. Then, during
discovery when we find a config file, we check to see if we have a
target mapping for it, and if so we use that instead.
This mechanism is generic enough that it does not affect external users
of lit. They will just not have a config mapping defined, and everything
will work as normal.
On the other hand, for us it allows us to make many simplifications:
* We are guaranteed that a site config will be executed first
* Inside of a main config, we no longer have to assume that attributes
might not be present and use getattr everywhere.
* We no longer have to pass parameters such as --param llvm_site_config=<path>
on the command line.
* It is future-proof, meaning you don't have to edit llvm-lit.in to add
support for new projects.
* All of the duplicated logic of trying various fallback mechanisms of
finding a site config from the main config are now gone.
One potentially noteworthy thing that was required to implement this
change is that whereas the ninja check targets previously used the first
method to spawn lit, they now use the second. In particular, you can no
longer run lit.py against the source tree while specifying the various
`foo_site_config=<path>` parameters. Instead, you need to run
llvm-lit.py.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313270
Traditionally GAS has provided automatic selection between dins, dinsm and
dinsu. Binutils also disassembles all instructions in that family as 'dins'
rather than the actual instruction.
Reviewers: slthakur
Differential Revision: https://reviews.llvm.org/D34877
llvm-svn: 313267
This should bring signed div/rem analysis up to the same level as unsigned.
We use icmp simplification to determine when the divisor is known greater than the dividend.
Each positive test is followed by a negative test to show that we're not overstepping the boundaries of the known bits.
There are extra tests for the signed-min-value special cases.
Alive proofs:
http://rise4fun.com/Alive/WI5
Differential Revision: https://reviews.llvm.org/D37713
llvm-svn: 313264
This patch complements D16810 "[mips] Make isel select the correct DEXT variant
up front.". Now ISel picks the right variant of DINS, so now there is no need
to replace DINS with the appropriate variant during
MipsMCCodeEmitter::encodeInstruction().
This patch also enables target specific instruction verification for ins, dins,
dinsm, dinsu, ext, dext, dextm, dextu. These instructions have constraints that
are checked when generating MipsISD::Ins and MipsISD::Ext nodes, but these
constraints are not checked during instruction selection. Adding machine
verification should catch outstanding cases.
Finally, correct a bug that instruction verification uncovered, where the
position operand of a DINSU generated during lowering was being silently
and accidently corrected to the correct value.
Reviewers: slthakur
Differential Revision: https://reviews.llvm.org/D34809
llvm-svn: 313254
We already have a combine for this pattern when the input to shl is add, so we just need to enable the transformation when the input is or.
Original patch by @tstellar
Differential Revision: https://reviews.llvm.org/D19325
llvm-svn: 313251
invalidated SCCs even when we do not have an updated SCC to redirect
towards.
This comes up in a fairly subtle and surprising circumstance: we need to
have a connected but internal node in the call graph which later becomes
a disconnected island, and then gets deleted. All of this needs to
happen mid-CGSCC walk. Because it is disconnected, we have no way of
computing a new "current" SCC when it gets deleted. Instead, we need to
explicitly check for a deleted "current" SCC and bail out of the current
CGSCC step. This will bubble all the way up to the post-order walk and
then resume correctly.
I've included minimal tests for this bug. The specific behavior
matches something we've seen in the wild with the new PM combined with
ThinLTO and sample PGO, but I've not yet confirmed whether this is the
only issue there.
llvm-svn: 313242
This breaks bootstrap builds, and is actually unnecessary. Tested
locally and it seems we can remove -debug-comile just fine.
Follow-up to D37791.
llvm-svn: 313238
This patch fixes pr34283, which exposed that the computation of
maximum legal width for vectorization was wrong, because it relied
on MaxInterleaveFactor to obtain the maximum stride used in the loop,
however not all strided accesses in the loop have an interleave-group
associated with them.
Instead of recording the maximum stride in the loop, which can be over
conservative (e.g. if the access with the maximum stride is not involved
in the dependence limitation), this patch tracks the actual maximum legal
width imposed by accesses that are involved in dependencies.
Differential Revision: https://reviews.llvm.org/D37507
llvm-svn: 313237
Summary:
XRay had been assuming that the previous section is the "text" section
of the function when lowering the instrumentation map. Unfortunately
this is not a safe assumption, because we may be coming from lowering
debug type information for the function being lowered.
This fixes an issue with combining -gsplit-dwarf, -generate-type-units,
-debug-compile and -fxray-instrument for sole member functions. When the
split dwarf section is stripped, we're left with references from the
xray_instr_map to the debug section. The change now uses the function's
symbol instead of the previous section's start symbol.
We found the bug while attempting to strip the split debug sections off
an XRay-instrumented object file, which had a peculiar edge-case for
single-function classes where the single function is being lowered.
Because XRay had assocaited the instrumentation map for a function to
the debug types section instead of the function's section, the objcopy
call will fail due to the misplaced reference from the xray_instr_map
section.
Reviewers: pcc, dblaikie, echristo
Subscribers: llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D37791
llvm-svn: 313233
This reland includes a fix for the LowerTypeTests pass so that it
looks past aliases when determining which type identifiers are live.
Differential Revision: https://reviews.llvm.org/D37842
llvm-svn: 313229
This broke Chromium's CFI build; see crbug.com/765004.
> We were previously handling aliases during dead stripping by adding
> the aliased global's "original name" GUID to the worklist. This will
> lead to incorrect behaviour if the global has local linkage because
> the original name GUID will not correspond to the global's GUID in
> the summary.
>
> Because an alias is just another name for the global that it
> references, there is no need to mark the referenced global as used,
> or to follow references from any other copies of the global. So all
> we need to do is to follow references from the aliasee's summary
> instead of the alias.
>
> Differential Revision: https://reviews.llvm.org/D37789
llvm-svn: 313222
This caused PR34596.
> [MachineCombiner] Update instruction depths incrementally for large BBs.
>
> Summary:
> For large basic blocks with lots of combinable instructions, the
> MachineTraceMetrics computations in MachineCombiner can dominate the compile
> time, as computing the trace information is quadratic in the number of
> instructions in a BB and it's relevant successors/predecessors.
>
> In most cases, knowing the instruction depth should be enough to make
> combination decisions. As we already iterate over all instructions in a basic
> block, the instruction depth can be computed incrementally. This reduces the
> cost of machine-combine drastically in cases where lots of instructions
> are combined. The major drawback is that AFAIK, computing the critical path
> length cannot be done incrementally. Therefore we only compute
> instruction depths incrementally, for basic blocks with more
> instructions than inc_threshold. The -machine-combiner-inc-threshold
> option can be used to set the threshold and allows for easier
> experimenting and checking if using incremental updates for all basic
> blocks has any impact on the performance.
>
> Reviewers: sanjoy, Gerolf, MatzeB, efriedma, fhahn
>
> Reviewed By: fhahn
>
> Subscribers: kiranchandramohan, javed.absar, efriedma, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D36619
llvm-svn: 313213
MachineScheduler when clustering loads or stores checks if base
pointers point to the same memory. This check is done through
comparison of base registers of two memory instructions. This
works fine when instructions have separate offset operand. If
they require a full calculated pointer such instructions can
never be clustered according to such logic.
Changed shouldClusterMemOps to accept base registers as well and
let it decide what to do about it.
Differential Revision: https://reviews.llvm.org/D37698
llvm-svn: 313208
Since users typically don't really care about the .dwo / non.dwo
distinction, this patch makes it so dwarfdump --debug-<info,...> dumps
.debug_info and (if available) also .debug_info.dwo. This simplifies
the command line interface (I've removed all dwo-specific dump
options) and makes the tool friendlier to use.
Differential Revision: https://reviews.llvm.org/D37771
llvm-svn: 313207
Previously we used a size of '1' for VLAs because we weren't sure what
MSVC did. However, MSVC does support declaring an array without a size,
for which it emits an array type with a size of zero. Clang emits the
same DI metadata for VLAs and arrays without bound, so we would describe
arrays without bound as having one element. This lead to Microsoft
debuggers only printing a single element.
Emitting a size of zero appears to cause these debuggers to search the
symbol information to find a definition of the variable with accurate
array bounds.
Fixes http://crbug.com/763580
llvm-svn: 313203
This is to fix PR34502. After rL311401, the live range of spilled vreg will be
cleared. HoistSpill need to use the live range of the original vreg before splitting
to know the moving range of the spills. The patch saves a copy of live interval for
the spilled vreg inside of HoistSpillHelper.
Differential Revision: https://reviews.llvm.org/D37578
llvm-svn: 313197