Issues addressed since original review:
- Moved removal of dead instructions found by
LiveIntervals::shrinkToUses() outside of loop iterating over
instructions to avoid instructions being deleted while pointed to by
iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312328 91177308-0d34-0410-b5e6-96231b3b80d8
It caused PR34387: Assertion failed: (RegNo < NumRegs && "Attempting to access record for invalid register number!")
> Issues identified by buildbots addressed since original review:
> - Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
> - The pass no longer forwards COPYs to physical register uses, since
> doing so can break code that implicitly relies on the physical
> register number of the use.
> - The pass no longer forwards COPYs to undef uses, since doing so
> can break the machine verifier by creating LiveRanges that don't
> end on a use (since the undef operand is not considered a use).
>
> [MachineCopyPropagation] Extend pass to do COPY source forwarding
>
> This change extends MachineCopyPropagation to do COPY source forwarding.
>
> This change also extends the MachineCopyPropagation pass to be able to
> be run during register allocation, after physical registers have been
> assigned, but before the virtual registers have been re-written, which
> allows it to remove virtual register COPY LiveIntervals that become dead
> through the forwarding of all of their uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312178 91177308-0d34-0410-b5e6-96231b3b80d8
Issues identified by buildbots addressed since original review:
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312154 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r311135.
sanitizer-x86_64-linux-android buildbot is timing out with just this
patch applied.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311142 91177308-0d34-0410-b5e6-96231b3b80d8
Two issues identified by buildbots were addressed:
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
Reviewers: qcolombet, javed.absar, MatzeB, jonpa
Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny
Differential Revision: https://reviews.llvm.org/D30751
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311135 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r311038.
Several buildbots are breaking, and at least one appears to be due to
the forwarding of physical regs enabled by this change. Reverting while
I investigate further.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311062 91177308-0d34-0410-b5e6-96231b3b80d8
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
Reviewers: qcolombet, javed.absar, MatzeB, jonpa
Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny
Differential Revision: https://reviews.llvm.org/D30751
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311038 91177308-0d34-0410-b5e6-96231b3b80d8
CFI instructions that set appropriate cfa offset and cfa register are now
inserted in emitEpilogue() in X86FrameLowering.
Majority of the changes in this patch:
1. Ensure that CFI instructions do not affect code generation.
2. Enable maintaining correct information about cfa offset and cfa register
in a function when basic blocks are reordered, merged, split, duplicated.
These changes are target independent and described below.
Changed CFI instructions so that they:
1. are duplicable
2. are not counted as instructions when tail duplicating or tail merging
3. can be compared as equal
Add information to each MachineBasicBlock about cfa offset and cfa register
that are valid at its entry and exit (incoming and outgoing CFI info). Add
support for updating this information when basic blocks are merged, split,
duplicated, created. Add a verification pass (CFIInfoVerifier) that checks
that outgoing cfa offset and register of predecessor blocks match incoming
values of their successors.
Incoming and outgoing CFI information is used by a late pass
(CFIInstrInserter) that corrects CFA calculation rule for a basic block if
needed. That means that additional CFI instructions get inserted at basic
block beginning to correct the rule for calculating CFA. Having CFI
instructions in function epilogue can cause incorrect CFA calculation rule
for some basic blocks. This can happen if, due to basic block reordering,
or the existence of multiple epilogue blocks, some of the blocks have wrong
cfa offset and register values set by the epilogue block above them.
Patch by Violeta Vukobrat.
Differential Revision: https://reviews.llvm.org/D18046
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306529 91177308-0d34-0410-b5e6-96231b3b80d8
We currently generate BUILD_VECTOR as a tree of UNPCKL shuffles of the same type:
e.g. for v4f32:
Step 1: unpcklps 0, 2 ==> X: <?, ?, 2, 0>
: unpcklps 1, 3 ==> Y: <?, ?, 3, 1>
Step 2: unpcklps X, Y ==> <3, 2, 1, 0>
The issue is because we are not placing sequential vector elements together early enough, we fail to recognise many combinable patterns - consecutive scalar loads, extractions etc.
Instead, this patch unpacks progressively larger sequential vector elements together:
e.g. for v4f32:
Step 1: unpcklps 0, 2 ==> X: <?, ?, 1, 0>
: unpcklps 1, 3 ==> Y: <?, ?, 3, 2>
Step 2: unpcklpd X, Y ==> <3, 2, 1, 0>
This does mean that we are creating UNPCKL shuffle of different value types, but the relevant combines that benefit from this are quite capable of handling the additional BITCASTs that are now included in the shuffle tree.
Differential Revision: https://reviews.llvm.org/D33864
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304688 91177308-0d34-0410-b5e6-96231b3b80d8
It can be costly to transfer from the gprs to the xmm registers and can prevent loads merging.
This patch splits vXi16/vXi32/vXi64 BUILD_VECTORS that use the same operand in multiple elements into a BUILD_VECTOR with only a single insertion of each of those elements and then performs an unary shuffle to duplicate the values.
There are a couple of minor regressions this patch unearths due to some missing MOVDDUP/BROADCAST folds that I will address in a future patch.
Note: Now that vector shuffle lowering and combining is pretty good we should be reusing that instead of duplicating so much in LowerBUILD_VECTOR - this is the first of several patches to address this.
Differential Revision: https://reviews.llvm.org/D31373
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299387 91177308-0d34-0410-b5e6-96231b3b80d8
Up until now, vpmovm2 instruction described its destination operand size
by the source operand size. This patch adds new pattern for the vpmovm2
instruction. The node describes new expansion of the destination (from
{128|256} to 512).
Differential Revision: https://reviews.llvm.org/D30654
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298586 91177308-0d34-0410-b5e6-96231b3b80d8
Only do this for integer types currently - floats types (in particular insertps) load folding often fails with this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295208 91177308-0d34-0410-b5e6-96231b3b80d8
Choosing a "cfi" name makes the intend a bit clearer in an assembly dump
and more importantly the assembly dumps are slightly more stable as the
numbers don't move around anymore when unrelated code calls
createTempSymbol() more or less often.
As they are temp labels the name doesn't influence the generated object
code.
Differential Revision: https://reviews.llvm.org/D27244
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288290 91177308-0d34-0410-b5e6-96231b3b80d8
Bit-shifts by a whole number of bytes can be represented as a shuffle mask suitable for combining.
Added a 'getFauxShuffleMask' function to allow us to create shuffle masks from other suitable operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288040 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The one tricky thing about this is that the sign/zero_extend_inreg uses v64i8 as an input type which isn't legal without BWI support. Though the vpmovsxbq and vpmovzxbq instructions themselves don't require BWI. To support this we need to add custom lowering for ZERO_EXTEND_VECTOR_INREG with v64i8 input. This can mostly reuse the existing sign extend code with a couple checks for sign extend vs zero extend added.
Reviewers: delena, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25594
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285053 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we were extending to copying the whole ZMM register. The register allocator shouldn't use XMM16-31 or YMM16-31 in this configuration as the instructions to spill them aren't available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280648 91177308-0d34-0410-b5e6-96231b3b80d8
Split extensions to large vectors into 256-bit chunks - the equivalent of what we do with pre-AVX2 into 128-bit chunks
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277939 91177308-0d34-0410-b5e6-96231b3b80d8
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274952 91177308-0d34-0410-b5e6-96231b3b80d8
The script now replace '.LCPI888_8' style asm symbols with the {{\.LCPI.*}} re pattern - this helps stop hardcoded symbols in 32-bit x86 tests changing with every edit of the file
Refreshed some tests to demonstrate the new check
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272488 91177308-0d34-0410-b5e6-96231b3b80d8
If all a BUILD_VECTOR's source elements are the same bit (AND/XOR/OR) operation type and each has one constant operand, lower to a pair of BUILD_VECTOR and just apply the bit operation to the vectors.
The constant operands will form a constant vector meaning that we still only have a single BUILD_VECTOR to lower and we will have replaced all the scalarized operations with a single SSE equivalent.
Its not in our interest to start make a general purpose vectorizer from this, but I'm seeing enough of these scalar bit operations from the later legalization/scalarization stages to support them at least.
Differential Revision: http://reviews.llvm.org/D18492
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264666 91177308-0d34-0410-b5e6-96231b3b80d8
On AVX2 target we are poorly legalizing SIGN_EXTEND ops for which the input's legalized type doesn't have the same number of elements as the destination, resulting in an ANY_EXTEND followed by a SIGN_EXTEND_INREG.
This patch uses the existing SIGN_EXTEND -> SIGN_EXTEND_VECTOR_INREG combine to extend the input to the size of the result and using SIGN_EXTEND_VECTOR_INREG instead.
Differential Revision: http://reviews.llvm.org/D16994
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260210 91177308-0d34-0410-b5e6-96231b3b80d8
The combineX86ShufflesRecursively only supports unary shuffles, but was missing the opportunity to combine binary shuffles with a zero / undef second input.
This patch resolves target shuffle inputs, converting the shuffle mask elements to SM_SentinelUndef/SM_SentinelZero where possible. It then resolves the updated mask to check if we have created a faux unary shuffle.
Additionally, we now attempt to recursively call combineX86ShufflesRecursively for all input operands (we used to just recurse for unary integer shuffles and unary unpacks) - it safely returns early if its not a target shuffle.
Differential Revision: http://reviews.llvm.org/D16683
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260063 91177308-0d34-0410-b5e6-96231b3b80d8
This folds (ashr (shl a, [56,48,32,24,16]), SarConst)
into (shl, (sext (a), [56,48,32,24,16] - SarConst))
or into (lshr, (sext (a), SarConst - [56,48,32,24,16]))
depending on sign of (SarConst - [56,48,32,24,16])
sexts in X86 are MOVs.
The MOVs have the same code size as above SHIFTs (only SHIFT by 1 has lower code size).
However the MOVs have 2 advantages to SHIFTs on x86:
1. MOVs can write to a register that differs from source.
2. MOVs accept memory operands.
This fixes PR24373.
Patch by: evgeny.v.stupachenko@intel.com
Differential Revision: http://reviews.llvm.org/D13161
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255761 91177308-0d34-0410-b5e6-96231b3b80d8
Caller saved regs differ between SysV and Win64. Use the tail call available set to scavenge from.
Refactor register info to create new helper to get at tail call GPRs. Added a new test case for windows. Fixed up a number of X64 tests since now RCX is preferred over RDX on SysV.
Differential Revision: http://reviews.llvm.org/D14878
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253927 91177308-0d34-0410-b5e6-96231b3b80d8
autogenerated.
Also update existing test cases which appear to be generated by it and
weren't modified (other than addition of the header) by rerunning it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253917 91177308-0d34-0410-b5e6-96231b3b80d8
This patch is enabling combining UNPCKL with vector_shuffle that moves the upper
half of a vector into the lower half, into a UNPCKH instruction. For example:
t2: v16i8 = vector_shuffle<8,9,10,11,12,13,14,15,u,u,u,u,u,u,u,u> t1, undef:v16i8
t3: v16i8 = X86ISD::UNPCKL undef:v16i8, t2
will be combined to:
t3: v16i8 = X86ISD::UNPCKH undef:v16i8, t1
Differential revision: http://reviews.llvm.org/D14399
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253067 91177308-0d34-0410-b5e6-96231b3b80d8
Most 128-bit and 256-bit shuffles were manually matching UNPCK patterns - use lowerVectorShuffleWithUNPCK to be more thorough.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251211 91177308-0d34-0410-b5e6-96231b3b80d8
This patch generalizes the lowering of shuffles as zero extensions to allow extensions that don't start from the first element. It now recognises extensions starting anywhere in the lower 128-bits or at the start of any higher 128-bit lane.
The motivation was to reduce the number of high cost pshufb calls, but it also improves the SSE2 case as well.
Differential Revision: http://reviews.llvm.org/D12561
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248250 91177308-0d34-0410-b5e6-96231b3b80d8
