As discussed on PR42025, with more complex boolean math we can end up with many truncations/extensions of the comparison results through each bitop.
This patch handles the cases introduced in combineBitcastvxi1 by pushing the sign extension through the AND/OR/XOR ops so its just the original SETCC ops that gets extended.
Differential Revision: https://reviews.llvm.org/D68226
llvm-svn: 373834
I don't see an ideal solution to these 2 related, potentially large, perf regressions:
https://bugs.llvm.org/show_bug.cgi?id=42708https://bugs.llvm.org/show_bug.cgi?id=43146
We decided that load combining was unsuitable for IR because it could obscure other
optimizations in IR. So we removed the LoadCombiner pass and deferred to the backend.
Therefore, preventing SLP from destroying load combine opportunities requires that it
recognizes patterns that could be combined later, but not do the optimization itself (
it's not a vector combine anyway, so it's probably out-of-scope for SLP).
Here, we add a scalar cost model adjustment with a conservative pattern match and cost
summation for a multi-instruction sequence that can probably be reduced later.
This should prevent SLP from creating a vector reduction unless that sequence is
extremely cheap.
In the x86 tests shown (and discussed in more detail in the bug reports), SDAG combining
will produce a single instruction on these tests like:
movbe rax, qword ptr [rdi]
or:
mov rax, qword ptr [rdi]
Not some (half) vector monstrosity as we currently do using SLP:
vpmovzxbq ymm0, dword ptr [rdi + 1] # ymm0 = mem[0],zero,zero,..
vpsllvq ymm0, ymm0, ymmword ptr [rip + .LCPI0_0]
movzx eax, byte ptr [rdi]
movzx ecx, byte ptr [rdi + 5]
shl rcx, 40
movzx edx, byte ptr [rdi + 6]
shl rdx, 48
or rdx, rcx
movzx ecx, byte ptr [rdi + 7]
shl rcx, 56
or rcx, rdx
or rcx, rax
vextracti128 xmm1, ymm0, 1
vpor xmm0, xmm0, xmm1
vpshufd xmm1, xmm0, 78 # xmm1 = xmm0[2,3,0,1]
vpor xmm0, xmm0, xmm1
vmovq rax, xmm0
or rax, rcx
vzeroupper
ret
Differential Revision: https://reviews.llvm.org/D67841
llvm-svn: 373833
Rename some variables to match lowerShuffleAsRepeatedMaskAndLanePermute - prep work toward adding some equivalent sublane functionality.
llvm-svn: 373832
The motivation is to reuse the key value parsing logic here to
parse instance specific pass options within the context of MLIR.
The primary functionality exposed is the "," splitting for
arrays and the logic for properly handling duplicate definitions
of a single flag.
Patch by: Parker Schuh <parkers@google.com>
Differential Revision: https://reviews.llvm.org/D68294
llvm-svn: 373815
This is an omission in rL371441. Loads which happened to be unordered weren't being added to the PendingLoad set, and thus weren't be ordered w/respect to side effects which followed before the end of the block.
Included test case is how I spotted this. We had an atomic load being folded into a using instruction after a fence that load was supposed to be ordered with. I'm sure it showed up a bunch of other ways as well.
Spotted via manual inspecting of assembly differences in a corpus w/and w/o the new experimental mode. Finding this with testing would have been "unpleasant".
llvm-svn: 373814
This reverts r371177 (git commit f879c6875563c0a8cd838f1e13b14dd33558f1f8)
It caused PR43566 by removing empty, address-taken MachineBasicBlocks.
Such blocks may have references from blockaddress or other operands, and
need more consideration to be removed.
See the PR for a test case to use when relanding.
llvm-svn: 373805
We do indeed already get it right in some cases, but only transitively,
with one-use restrictions. Since we only need to produce a single
comparison, it makes sense to match the pattern directly:
https://rise4fun.com/Alive/kPg
llvm-svn: 373802
Initially (D65380) i believed that if we have rightshift-trunc-rightshift,
we can't do any folding. But as it usually happens, i was wrong.
https://rise4fun.com/Alive/GEwhttps://rise4fun.com/Alive/gN2O
In https://bugs.llvm.org/show_bug.cgi?id=43564 we happen to have
this very sequence, of two right shifts separated by trunc.
And "just" so that happens, we apparently can fold the pattern
if the total shift amount is either 0, or it's equal to the bitwidth
of the innermost widest shift - i.e. if we are left with only the
original sign bit. Which is exactly what is wanted there.
llvm-svn: 373801
Outlining from noreturn functions doesn't do the correct thing right now. The
outliner should respect that the caller is marked noreturn. In the event that
we have a noreturn function, and the outlined code is in tail position, the
outliner will not see that the outlined function should be tail called. As a
result, you end up with a regular call containing a return.
Fixing this requires that we check that all candidates live inside noreturn
functions. So, for the sake of correctness, don't outline from noreturn
functions right now.
Add machine-outliner-noreturn.mir to test this.
llvm-svn: 373791
InstrEmitter's virtual register handling assumes that clones are emitted
after the cloned node. Make sure this assumption actually holds.
Fixes a "Node emitted out of order - early" assertion on the testcase.
This is probably a very rare case to actually hit in practice; even
without the explicit edge, the scheduler will usually end up scheduling
the nodes in the expected order due to other constraints.
Differential Revision: https://reviews.llvm.org/D68068
llvm-svn: 373782
The immediate form of VPCMP can represent these completely. The
vpcmpgt/eq are just shorter encodings.
This patch removes the isel patterns and just swaps the opcodes
and removes the immediate in MCInstLower. This matches where we do
some other encodings tricks.
Removes over 10K bytes from the isel table.
Differential Revision: https://reviews.llvm.org/D68446
llvm-svn: 373766
We already do this for ISD::TRUNCATE, but we can do the same for X86ISD::VTRUNC
Differential Revision: https://reviews.llvm.org/D68432
llvm-svn: 373765
This is a trivial point fix. Terminator instructions aren't scheduled, so
we shouldn't expect to be able to remap them.
This doesn't affect Hexagon and PPC because their terminators are always
hardware loop backbranches that have no register operands.
llvm-svn: 373762
Darwin platforms need the frame register to always point at a valid record even
if it's not updated in a leaf function. Backtraces are more important than one
extra GPR.
llvm-svn: 373738
Rather than having a mixture of location-state shared between DBG_VALUEs
and VarLoc objects in LiveDebugValues, this patch makes VarLoc the
master record of variable locations. The refactoring means that the
transfer of locations from one place to another is always a performed by
an operation on an existing VarLoc, that produces another transferred
VarLoc. DBG_VALUEs are only created at the end of LiveDebugValues, once
all locations are known. As a plus, there is now only one method where
DBG_VALUEs can be created.
The test case added covers a circumstance that is now impossible to
express in LiveDebugValues: if an already-indirect DBG_VALUE is spilt,
previously it would have been restored-from-spill as a direct DBG_VALUE.
We now don't lose this information along the way, as VarLocs always
refer back to the "original" non-transfer DBG_VALUE, and we can always
work out whether a location was "originally" indirect.
Differential Revision: https://reviews.llvm.org/D67398
llvm-svn: 373727
When transfering variable locations from one place to another,
LiveDebugValues immediately creates a DBG_VALUE representing that
transfer. This causes trouble if the variable location should
subsequently be invalidated by a loop back-edge, such as in the added
test case: the transfer DBG_VALUE from a now-invalid location is used
as proof that the variable location is correct. This is effectively a
self-fulfilling prophesy.
To avoid this, defer the insertion of transfer DBG_VALUEs until after
analysis has completed. Some of those transfers are still sketchy, but
we don't propagate them into other blocks now.
Differential Revision: https://reviews.llvm.org/D67393
llvm-svn: 373720
Summary:
This patch fixes a potential aliasing problem in InstClassEnum,
where local values were mixed with machine opcodes.
Introducing InstSubclass will keep them separate and help extending
InstClassEnum with other instruction types (e.g. MIMG) in the future.
This patch also makes getSubRegIdxs() more concise.
Reviewers: nhaehnle, arsenm, tstellar
Reviewed By: arsenm
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68384
llvm-svn: 373699
In the Atom model the symbols, content and relocations of a relocatable object
file are represented as a graph of atoms, where each Atom represents a
contiguous block of content with a single name (or no name at all if the
content is anonymous), and where edges between Atoms represent relocations.
If more than one symbol is associated with a contiguous block of content then
the content is broken into multiple atoms and layout constraints (represented by
edges) are introduced to ensure that the content remains effectively contiguous.
These layout constraints must be kept in mind when examining the content
associated with a symbol (it may be spread over multiple atoms) or when applying
certain relocation types (e.g. MachO subtractors).
This patch replaces the Atom model in JITLink with a blocks-and-symbols model.
The blocks-and-symbols model represents relocatable object files as bipartite
graphs, with one set of nodes representing contiguous content (Blocks) and
another representing named or anonymous locations (Symbols) within a Block.
Relocations are represented as edges from Blocks to Symbols. This scheme
removes layout constraints (simplifying handling of MachO alt-entry symbols,
and hopefully ELF sections at some point in the future) and simplifies some
relocation logic.
llvm-svn: 373689
We would like to split the SP adjustment to reduce the instructions in
prologue and epilogue as the following case. In this way, the offset of
the callee saved register could fit in a single store.
add sp,sp,-2032
sw ra,2028(sp)
sw s0,2024(sp)
sw s1,2020(sp)
sw s3,2012(sp)
sw s4,2008(sp)
add sp,sp,-64
Differential Revision: https://reviews.llvm.org/D68011
llvm-svn: 373688
Without this we can encounter link errors or incorrect behaviour
at runtime as a result of the wrong function being referenced.
Differential Revision: https://reviews.llvm.org/D67945
llvm-svn: 373678
As discussed on llvm-dev and:
https://bugs.llvm.org/show_bug.cgi?id=43542
...we have transforms that assume shift operations are legal and transforms to
use them are profitable, but that may not hold for simple targets.
In this case, the MSP430 target custom lowers shifts by repeating (many)
simpler/fixed ops. That can be avoided by keeping this code as setcc/select.
Differential Revision: https://reviews.llvm.org/D68397
llvm-svn: 373666
Move the write-if-changed logic behind a flag and don't pass it
with the MSVC generator. msbuild doesn't have a restat optimization,
so not doing write-if-change there doesn't have a cost, and it
should fix whatever causes PR43385.
llvm-svn: 373664
