[AArch64] Mark mrs of TPIDR_EL0 (thread pointer) as *having* side effects.
This partially reverts r298851. The the underlying issue is that we don't
currently model the dependency between mrs (read system register) and
msr (write system register) instructions.
Something like the below should never be reordered:
The bitcode reader looks specifically for `__DATA, __objc_catlist` as a
section name. However, SVN r304661 removed the spaces (the two names
are functionally equivalent but do not compare equally
lexicographically). This causes compatibility issues. Add an
auto-upgrade path for removing the spaces as well as use the new name in
the LTO plugin.
------------------------------------------------------------------------
[AutoUpgrade] Fix a compatibility issue with module flag
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.
[DebugInfo] Fix potential CU mismatch for SubprogramScopeDIEs.
In constructAbstractSubprogramScopeDIE there can be a potential mismatch
between `this` and the CU of ContextDIE when a scope is shared between
two DISubprograms belonging to a different CU. In that case, `this` is
the CU that was specified in the IR, but the CU of ContextDIE is that of
the first subprogram that was emitted. This patch fixes the mismatch by
looking up the CU of ContextDIE, and switching to use that.
This fixes PR35212 (https://bugs.llvm.org/show_bug.cgi?id=35212)
Reland "[mips][mt][6/7] Add support for mftr, mttr instructions."
This adjusts the tests to hopfully pacify the
llvm-clang-x86_64-expensive-checks-win buildbot.
Unlike many other instructions, these instructions have aliases which
take coprocessor registers, gpr register, accumulator (and dsp accumulator)
registers, floating point registers, floating point control registers and
coprocessor 2 data and control operands.
For the moment, these aliases are treated as pseudo instructions which are
expanded into the underlying instruction. As a result, disassembling these
instructions shows the underlying instruction and not the alias.
[cmake] Stop putting the revision info in LLVM_VERSION_STRING
Summary:
This reduces the number of build actions after a no-op commit from
thousands to about six, which should be acceptable. If six actions is
still too many, developers can disable the LLVM_APPEND_VC_REV cmake
option.
llvm-config.h is a widely included header that should rarely change.
Before this patch, it would change after every re-configure. Very few
users of llvm-config.h need to know the precise version, and those that
do can migrate to incorporating LLVM_REVISION as provided by
llvm/Support/VCSRevision.h.
This should bring LLVM back to the behavior that it had before r306858
from June 30 2017. Most LLVM tools will now print a version string like
"6.0.0svn" instead of "6.0.0-git-c40c2a23de4".
formatv_object currently uses the implicitly defined move constructor,
but it is buggy. In typical use-cases, the problem doesn't show-up
because all calls to the move constructor are elided. Thus, the buggy
constructors are never invoked.
The issue especially shows-up when code is compiled using the
-fno-elide-constructors compiler flag. For instance, this is useful when
attempting to collect accurate code coverage statistics.
The exact issue is the following:
The Parameters data member is correctly moved, thus making the
parameters occupy a new memory location in the target
object. Unfortunately, the default copying of the Adapters blindly
copies the vector of pointers, leaving each of these pointers
referencing the parameters in the original object instead of the copied
one. These pointers quickly become dangling when the original object is
deleted. This quickly leads to crashes.
The solution is to update the Adapters pointers when performing a move.
The copy constructor isn't useful for format objects and can thus be
deleted.
Previously, the parsing of the 'subu $reg, ($reg,) imm' relied on a parser
which also rendered the operand to the instruction. In some cases the
general parser could construct an MCExpr which was not a MCConstantExpr
which MipsAsmParser was expecting.
Address this by altering the special handling to cope with unexpected inputs
and fine-tune the handling of cases where an register name that is not
available in the current ABI is regarded as not a match for the custom parser
but also not as an outright error.
Also enforces the binutils restriction that only constants are accepted.
MSA stores and loads to the stack are more likely to require an
emergency GPR spill slot due to the smaller offsets available
with those instructions.
Handle this by overestimating the size of the stack by determining
the largest offset presuming that all callee save registers are
spilled and accounting of incoming arguments when determining
whether an emergency spill slot is required.
Linker: Create a function declaration when moving a non-prevailing alias of function type.
We were previously creating a global variable of function type,
which is invalid IR. This issue was exposed by r304690, in which we
started asserting that global variables were of a valid type.
[ConstantFold] Fix a crash when folding a GEP that has vector index
LLVM crashes when factoring out an out-of-bound index into preceding dimension
and the preceding dimension uses vector index. Simply bail out now when this
case happens.
Previously, on long branches (relative jumps of >4 kB), an assertion
failure was hit, as AVRInstrInfo::insertIndirectBranch was not
implemented. Despite its name, it is called by the branch relaxator
for *all* unconditional jumps.
Patch by Thomas Backman.
------------------------------------------------------------------------
In some cases, the code generator attempts to generate instructions such as:
lddw r24, Y+63
which expands to:
ldd r24, Y+63
ldd r25, Y+64 # Oops! This is actually ld r25, Y in the binary
This commit limits the first offset to 62, and thus the second to 63.
It also updates some asserts in AVRExpandPseudoInsts.cpp, including for
INW and OUTW, which appear to be unused.
Patch by Thomas Backman.
------------------------------------------------------------------------
[TTI] Fix getGEPCost() for geps with a single operand.
Previously this would sporadically crash as TargetType
was never initialized. We special-case the single-operand
case returning earlier and trying to mimic the behaviour of
isLegalAddressingMode as closely as possible.
[X86] Don't create i64 constants on 32-bit targets when lowering v64i1 constant build vectors
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.
Previously, on long branches (relative jumps of >4 kB), an assertion
failure was hit, as AVRInstrInfo::insertIndirectBranch was not
implemented. Despite its name, it is called by the branch relaxator
for *all* unconditional jumps.
Patch by Thomas Backman.
------------------------------------------------------------------------
Renato Golin [Tue, 3 Oct 2017 13:13:34 +0000 (13:13 +0000)]
[release_50] Merging r313916
[AArch64] Fix bug in store of vector 0 DAGCombine.
Summary:
Avoid using XZR/WZR directly as operands to split stores of zero
vectors. Doing so can lead to the XZR/WZR being used by an instruction
that doesn't allow it (e.g. add).
LiveIntervalAnalysis: Fix alias regunit reserved definition
A register in CodeGen can be marked as reserved: In that case we
consider the register always live and do not use (or rather ignore)
kill/dead/undef operand flags.
LiveIntervalAnalysis however tracks liveness per register unit (not per
register). We already needed adjustments for this in r292871 to deal
with super/sub registers. However I did not look at aliased register
there. Looking at ARM:
FPSCR (regunits FPSCR, FPSCR~FPSCR_NZCV) aliases with FPSCR_NZCV
(regunits FPSCR_NZCV, FPSCR~FPSCR_NZCV) hence they share a register unit
(FPSCR~FPSCR_NZCV) that represents the aliased parts of the registers.
This shared register unit was previously considered non-reserved,
however given that we uses of the reserved FPSCR potentially violate
some rules (like uses without defs) we should make FPSCR~FPSCR_NZCV
reserved too and stop tracking liveness for it.
This patch:
- Defines a register unit as reserved when: At least for one root
register, the root register and all its super registers are reserved.
- Adjust LiveIntervals::computeRegUnitRange() for new reserved
definition.
- Add MachineRegisterInfo::isReservedRegUnit() to have a canonical way
of testing.
- Stop computing LiveRanges for reserved register units in HMEditor even
with UpdateFlags enabled.
- Skip verification of uses of reserved reg units in the machine
verifier (this usually didn't happen because there would be no cached
liverange but there is no guarantee for that and I would run into this
case before the HMEditor tweak, so may as well fix the verifier too).
Note that this should only affect ARMs FPSCR/FPSCR_NZCV registers today;
aliased registers are rarely used, the only other cases are hexagons
P0-P3/P3_0 and C8/USR pairs which are not mixing reserved/non-reserved
registers in an alias.
[AArch64][Falkor] Fix bug in falkor prefetcher fix pass.
Summary:
In rare cases, loads that don't get prefetched that were marked as
strided loads could cause a crash if they occurred in a loop with other
colliding loads.
[AArch64][Falkor] Fix correctness bug in falkor prefetcher fix pass and correct some opcode tag computations.
Summary:
This addresses a correctness bug for LD[1234]*_POST opcodes that have
the prefetcher fix applied to them: the base register was not being
written back from the temp after being incremented, so it would appear
to never be incremented.
Also, fix some opcode tag computations based on some updated HW details
to get better tag avoidance and thus better prefetcher performance.
[AArch64][Falkor] Fix bug in Falkor HWPF tag collision avoidance
LDPDi was incorrectly marked as ignoring the destination register in the
prefetcher tag.
------------------------------------------------------------------------
ARMv4 doesn't support the "BX" instruction, which has been introduced
with ARMv4t. Adjust the call lowering and tail call implementation
accordingly.
Further changes are necessary to ensure that presence of the v4t feature
is correctly set. Most importantly, the "generic" CPU for thumb-*
triples should include ARMv4t, since thumb mode without thumb support
would naturally be pointless.
Add a couple of asserts to ensure thumb instructions are not emitted
without CPU support.
This fixes the avr-rust issue (#75) with floating-point comparisons generating broken code.
By default, LLVM assumes these comparisons return 32-bit values, but ours are 8-bit.
Patch By Thomas Backman.
------------------------------------------------------------------------
These functions are automaticalled called by the CRT if they are
declared.
We need these to be called otherwise RAM will start completely
uninitialised, even though we need to copy RAM variables from progmem to
RAM.
------------------------------------------------------------------------
AMDGPU: IMPLICIT_DEFs and DBG_VALUEs do not contribute to wait states
Summary:
This fixes a bug that was exposed on gfx9 in various
GL45-CTS.shaders.loops.*_iterations.select_iteration_count_fragment tests,
e.g. GL45-CTS.shaders.loops.do_while_uniform_iterations.select_iteration_count_fragment
AMDGPU: IMPLICIT_DEFs and DBG_VALUEs do not contribute to wait states
Summary:
This fixes a bug that was exposed on gfx9 in various
GL45-CTS.shaders.loops.*_iterations.select_iteration_count_fragment tests,
e.g. GL45-CTS.shaders.loops.do_while_uniform_iterations.select_iteration_count_fragment
[X86] Don't pull carry through X86ISD::ADD carryin, -1 if we can't guranteed we're really using the carry flag from the add.
Prior to this patch we had a DAG combine that tried to bypass an X86ISD::ADD with -1 being added to the carry flag of some previous operation. We would then pass the carry flag directly to user.
But this is only safe if the user is looking for the carry flag and not the zero flag.
So we need to only do this combine in a context where we know what flag the consumer is using.
Hans Wennborg [Tue, 29 Aug 2017 21:38:44 +0000 (21:38 +0000)]
Merging r312022:
------------------------------------------------------------------------
r312022 | hans | 2017-08-29 11:41:00 -0700 (Tue, 29 Aug 2017) | 10 lines
[DAG] Bound loop dependence check in merge optimization.
The loop dependence check looks for dependencies between store merge
candidates not captured by the chain sub-DAG doing a check of
predecessors which may be very large. Conservatively bound number of
nodes checked for compilation time. (Resolves PR34326).
Landing on behalf of Nirav Dave to unblock the 5.0.0 release.
Hans Wennborg [Thu, 24 Aug 2017 16:16:07 +0000 (16:16 +0000)]
Merging r311623:
------------------------------------------------------------------------
r311623 | hans | 2017-08-23 18:08:27 -0700 (Wed, 23 Aug 2017) | 11 lines
[DAG] Fix Node Replacement in PromoteIntBinOp
When one operand is a user of another in a promoted binary operation
we may replace and delete the returned value before returning
triggering an assertion. Reorder node replacements to prevent this.
Hans Wennborg [Wed, 23 Aug 2017 21:30:37 +0000 (21:30 +0000)]
Merging r311565:
------------------------------------------------------------------------
r311565 | hans | 2017-08-23 08:43:28 -0700 (Wed, 23 Aug 2017) | 8 lines
LowerAtomic: Don't skip optnone functions; atomic still need lowering (PR34020)
The lowering isn't really an optimization, so optnone shouldn't make a
difference. ARM relies on the pass running when using "-mthread-model
single", because in that mode, it doesn't run AtomicExpand. See bug for
more details.
[IR] AutoUpgrade ModuleFlagBehavior for PIC and PIE level
Summary:
From r303590, ModuleFlagBehavior for PIC and PIE level is changed from
Error to Max. This will cause bitcode compatibility issue when linking
against a bitcode static archive built with old compiler.
Add an auto-ugprade path to upgrade the the ModuleFlagBehavior in the
old bitcode to match the new one so IRLinker can link them.
Hans Wennborg [Tue, 22 Aug 2017 17:44:59 +0000 (17:44 +0000)]
Merging r311263:
------------------------------------------------------------------------
r311263 | ctopper | 2017-08-19 15:02:02 -0700 (Sat, 19 Aug 2017) | 1 line
[AVX512] Use alignedstore256 in a pattern that's emitting a 256-bit movaps from an extract subvector operation.
------------------------------------------------------------------------
[X86] Prevent several calls to ISD::isConstantSplatVector from returning a narrower APInt than the original scalar type
ISD::isConstantSplatVector can shrink to the smallest splat width. But we don't check the size of the resulting APInt at all. This can cause us to misinterpret the results.
This patch just adds a flag to prevent the APInt from changing width.
When lowering a VLA, we emit a __chstk call. However, this call can
internally clobber CPSR. We did not mark this register as an ImpDef,
which could potentially allow a comparison to be hoisted above the call
to `__chkstk`. In such a case, the CPSR could be clobbered, and the
check invalidated. When the support was initially added, it seemed that
the call would take care of preventing CPSR from being clobbered, but
this is not the case. Mark the register as clobbered to fix a possible
state corruption.
------------------------------------------------------------------------
[SelectionDAG] Teach the vector-types operand scalarizer about SETCC
When v1i1 is legal (e.g. AVX512) the legalizer can reach
a case where a v1i1 SETCC with an illgeal vector type operand
wasn't scalarized (since v1i1 is legal) but its operands does
have to be scalarized. This used to assert because SETCC was
missing from the vector operand scalarizer.
This patch attemps to teach the legalizer to handle these cases
by scalazring the operands, converting the node into a scalar
SETCC node.
[llvm-dlltool] Fix creating stdcall/fastcall import libraries for i386
Hook up the -k option (that in the original GNU dlltool removes the
@n suffix from the symbol that the final executable ends up linked to).
In llvm-dlltool, make sure that functions end up with the undecorate
name type if this option is set and they are decorated. In mingw, when
creating import libraries from def files instead of creating an import
library as a side effect of linking a DLL, the symbol names in the def
contain the stdcall/fastcall decoration (but no leading underscore).
By setting the undecorate name type, a linker linking to the import
library will omit the decoration from the DLL import entry.
With this in place, mingw-w64 for i386 built with llvm-dlltool/clang
produces import libraries that actually work.
[cmake] Expose the dependencies of ExecutionEngine as PUBLIC
Expose the dependencies of LLVMExecutionEngine library as PUBLIC rather
than PRIVATE when building a shared library. This is necessary because
the library is not contained but exposes API of other LLVM libraries via
its headers.
This causes other libraries to fail to link if the linker verifies for
correctness of -l flags (i.e. fails on indirect dependencies). This e.g.
happens when building LLDB against shared LLVM:
lib64/liblldbExpression.a(IRExecutionUnit.cpp.o):(.data.rel.ro._ZTIN4llvm18MCJITMemoryManagerE[_ZTIN4llvm18MCJITMemoryManagerE]+0x10): undefined reference to `typeinfo for llvm::RuntimeDyld::MemoryManager'
lib64/liblldbExpression.a(IRExecutionUnit.cpp.o):(.data.rel.ro._ZTVN4llvm18MCJITMemoryManagerE[_ZTVN4llvm18MCJITMemoryManagerE]+0x60): undefined reference to `llvm::RuntimeDyld::MemoryManager::anchor()'
lib64/liblldbExpression.a(IRExecutionUnit.cpp.o):(.data.rel.ro._ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE[_ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE]+0x48): undefined reference to `llvm::RTDyldMemoryManager::deregisterEHFrames()'
lib64/liblldbExpression.a(IRExecutionUnit.cpp.o):(.data.rel.ro._ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE[_ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE]+0x60): undefined reference to `llvm::RuntimeDyld::MemoryManager::anchor()'
lib64/liblldbExpression.a(IRExecutionUnit.cpp.o):(.data.rel.ro._ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE[_ZTVN12lldb_private15IRExecutionUnit13MemoryManagerE]+0xd0): undefined reference to `llvm::JITSymbolResolver::anchor()'
collect2: error: ld returned 1 exit status
Declaring the dependencies as PUBLIC guarantees that any package using
the ExecutionEngine library will also get explicit -l flags for
the dependent libraries guaranteeing that the symbols exposed in headers
could be resolved.
[Inliner] Fix a nasty bug when inlining a non-recursive trace of
a function into itself.
We tried to fix this before in r306495 but that got reverted as the
assert was actually hit.
This fixes the original bug (which we seem to have lost track of with
the revert) by blocking a second remapping when the function being
inlined is also the caller and the remapping could succeed but
erroneously.
The included test case would actually load from an inlined copy of the
alloca before this change, failing to load the stored value and
miscompiling.
Many thanks to Richard Smith for diagnosing a user miscompile to this
bug, and to Kyle for the first attempt and initial analysis and David Li
for remembering the issue and how to fix it and suggesting the patch.
I'm just stitching it together and landing it. =]
------------------------------------------------------------------------
[ARM] Check the right order for halves of VZIP/VUZP if both parts are used
This is the exact same fix as in SVN r247254. In that commit, the fix was
applied only for isVTRNMask and isVTRN_v_undef_Mask, but the same issue
is present for VZIP/VUZP as well.
[dfsan] Add explicit zero extensions for shadow parameters in function wrappers.
In the case where dfsan provides a custom wrapper for a function,
shadow parameters are added for each parameter of the function.
These parameters are i16s. For targets which do not consider this
a legal type, the lack of sign extension information would cause
LLVM to generate anyexts around their usage with phi variables
and calling convention logic.
Address this by introducing zero exts for each shadow parameter.
[X86][AVX512] Choose correct registers in vpbroadcastb/w
Fixes the vpbroadcastb/w instructions which use GPRs as source operands, to use the correct registers.
The full GPR should be used, and not the subregister, as it happens before the patch.
[VirtRegRewriter] Properly model the register liveness on undef subreg definition
Undef subreg definition means that the content of the super register
doesn't matter at this point. While that's true for virtual registers,
this may not hold when replacing them with actual physical registers.
Indeed, some part of the physical register may be coalesced with the
related virtual register and thus, the values for those parts matter and
must be live.
The fix consists in checking whether or not subregs of the physical register
being assigned to an undef subreg definition are live through that def and
insert an implicit use if they are. Doing so, will keep them alive until
that point like they should be.
E.g., let vreg14 being assigned to R0_R1 then
%vreg14:gsub_0<def,read-undef> = COPY %R0 ; <-- R1 is still live here
%vreg14:gsub_1<def> = COPY %R1
Before this changes, the rewriter would change the code into:
%R0<def> = KILL %R0, %R0_R1<imp-def> ; <-- this tells R1 is redefined
%R1<def> = KILL %R1, %R0_R1<imp-def>, %R0_R1<imp-use> ; this value of this R1
; is believed to come
; from the previous
; instruction
Because of this invalid liveness, later pass could make wrong choices and in
particular clobber live register as it happened with the register scavenger in
llvm.org/PR34107
Now we would generate:
%R0<def> = KILL %R0, %R0_R1<imp-def>, %R0_R1<imp-use> ; This tells R1 needs to
; reach this point
%R1<def> = KILL %R1, %R0_R1<imp-def>, %R0_R1<imp-use>
The bug has been here forever, it got exposed recently because the register
scavenger got smarter.
When creating an import library from lld, the cases with
Name != ExtName shouldn't end up as a weak alias, but as a real
export of the new name, which is what actually is exported from
the DLL.
This restores the behaviour of renamed exports to what it was in
4.0.
The other half of this commit, including test, goes into lld.
test-release.sh: Move test-suite setup to beginning of the script
Summary:
We want to catch failures early before do the full 3 stage build.
The goal here is to avoid running through the whole build process and have
it fail at the end (and not create the binary packages), just because
some prerequisites failed to install.
Remove RISCV from LLVM_ALL_TARGETS in CMakeLists.txt
It was mistakenly added to that list in D23560 (committed in rL285712). RISCV
is an experimental backend and should never have been in that list, I
mistakenly interpreted LLVM_ALL_TARGETS as a list of all targets rather than
targets to build by default. Unfortunately, because of this the RISCV backend
has been building by default when it shouldn't be.
This commet adds a description comment, which should help to avoid such
mistakes in the future.
See my message to llvm-dev for more information and analysis
<http://lists.llvm.org/pipermail/llvm-dev/2017-August/116347.html>.
[X86] When handling addcarry intrinsic, create the flag result with the correct type so we don't crash if we use a memory instruction
Summary:
Previously we were creating the flag result with MVT::Other which is interpretted as a Chain node. If we used a memory form of the instruction we would end up with a copyToReg that consumed the chain result of the adcx instruction instead of the flag result.
Pretty sure we should be using MVT::i32 here, that's what we do other places we create these node types.
[BDCE] clear poison generators after turning a value into zero (PR33695, PR34037)
nsw, nuw, and exact carry implicit assumptions about their operands, so we need
to clear those after trivializing a value. We decided there was no danger for
llvm.assume or metadata, so there's just a comment about that.
This fixes miscompiles as shown in:
https://bugs.llvm.org/show_bug.cgi?id=33695
https://bugs.llvm.org/show_bug.cgi?id=34037
The assert was added with r310779 and is usually correct,
but as the test shows, not always. The 'volatile' on the
load is needed to expose the faulty path because without
it, DemandedBits would return that the load is just dead
rather than not demanded, and so we wouldn't hit the
bogus assert.
Also, since the lambda is just a single-line now, get rid
of it and inline the DB.isAllOnesValue() calls.
This should fix (prevent execution of a faulty assert):
https://bugs.llvm.org/show_bug.cgi?id=34179
[lit] Fix UnboundLocalError for invalid shtest redirects
Replace the incorrect variable reference when invalid redirect is used.
This fixes the following issue:
File "/usr/src/llvm/utils/lit/lit/TestRunner.py", line 316, in processRedirects
raise InternalShellError(cmd, "Unsupported redirect: %r" % (r,))
UnboundLocalError: local variable 'r' referenced before assignment
which in turn broke shtest-shell.py and max-failures.py lit tests.
The breakage was introduced during refactoring in rL307310.
Revert "[lit] Remove dead code not referenced in the LLVM SVN repo."
Summary:
This reverts rL306623, which removed `FileBasedTest`, an abstract base class,
but did not also remove the usages of that class in the lit unit tests.
The revert fixes four test failures in the lit unit test suite.
Test plan:
As per the instructions in `utils/lit/README.txt`, run the lit unit
test suite:
Summary:
Whereas rL299560 and rL309071 call `parallelism_groups.items()`, under the
assumption that `parallelism_groups` is a `dict` type, the default
parameter for that attribute is a `list`. Change the default to a
`dict` for type correctness.
This regression in the unit tests would have been caught if the
unit tests were being run continously. It also would have been caught
if the lit project used a Python type checker such as `mypy`.
Test Plan:
As per the instructions in `utils/lit/README.txt`, run the lit unit
test suite:
[lit] Fix race between shtest-shell and max-failures tests
Previously these tests would use the same Output directory leading to
flaky non-deterministic failures.
------------------------------------------------------------------------
[SelectionDAG] When scalarizing vselect, don't assert on
a legal cond operand.
When scalarizing the result of a vselect, the legalizer currently expects
to already have scalarized the operands. While this is true for the true/false
operands (which have the same type as the result), it is not case for the
condition operand. On X86 AVX512, v1i1 is legal - this leads to operations such
as '< N x type> vselect < N x i1> < N x type> < N x type>' where < N x type > is
illegal to hit an assertion during the scalarization.
The handling is similar to r205625.
This also exposes the fact that (v1i1 extract_subvector) should be legal
and selectable on AVX512 - We do this by custom lowering to vector_extract_elt.
This still leaves us in some cases with redundant dag nodes which will be
combined in a separate soon to come patch.
Hans Wennborg [Thu, 10 Aug 2017 17:33:55 +0000 (17:33 +0000)]
Merging r310481, r310492 and r310510:
------------------------------------------------------------------------
r310481 | davide | 2017-08-09 08:13:50 -0700 (Wed, 09 Aug 2017) | 8 lines
[ValueTracking] Honour recursion limit.
The recently improved support for `icmp` in ValueTracking
(r307304) exposes the fact that `isImplied` condition doesn't
really bail out if we hit the recursion limit (and calls
`computeKnownBits` which increases the depth and asserts).
[SCEV] Limit max size of AddRecExpr during evolving
When SCEV calculates product of two SCEVAddRecs from the same loop, it
tries to combine them into one big AddRecExpr. If the sizes of the initial
SCEVs were `S1` and `S2`, the size of their product is `S1 + S2 - 1`, and every
operand of the resulting SCEV is combined from operands of initial SCEV and
has much higher complexity than they have.
As result, if we try to calculate something like:
%x1 = {a,+,b}
%x2 = mul i32 %x1, %x1
%x3 = mul i32 %x2, %x1
%x4 = mul i32 %x3, %x2
...
The size of such SCEVs grows as `2^N`, and the arguments
become more and more complex as we go forth. This leads
to long compilation and huge memory consumption.
This patch sets a limit after which we don't try to combine two
`SCEVAddRecExpr`s into one. By default, max allowed size of the
resulting AddRecExpr is set to 16.
Clean up after my misguided attempt in r304267 to "fix" CMP_SWAP
returning an uninitialized status value.
- I was always using tMOVi8 to zero the status register which cannot
encode higher register numbers and llvm would silently miscompile)
- Nobody was ever looking at that status value outside the expansion.
ARMDAGToDAGISel::SelectCMP_SWAP() the only place creating CMP_SWAP
instructions was not mapping anything to it. (The cmpxchg status value
from llvm IR is lowered to a manual comparison after the CMP_SWAP)
So this:
- Renames the register from "status" to "temp" it make it obvious that
it isn't used outside the expansion.
- Remove the zeroing status/temp register.
- Keep the live-in list improvements from r304267
projects / llvm / log