As a fix for https://bugs.llvm.org/show_bug.cgi?id=40986 ("excessive compile
time building opencollada"), this patch makes sure that no phys reg is hinted
more than once from getRegAllocationHints().
This handles the case were many virtual registers are assigned to the same
physreg. The previous compile time fix (r343686) in weightCalcHelper() only
made sure that physical/virtual registers are passed no more than once to
addRegAllocationHint().
Review: Dimitry Andric, Quentin Colombet
https://reviews.llvm.org/D59201
llvm-svn: 355854
Summary:
Extract the functionality of eliminating unreachable basic blocks
within a function, previously encapsulated within the
-unreachableblockelim pass, and make it available as a function within
BlockUtils.h. No functional change intended other than making the logic
reusable.
Exposing this logic makes it easier to implement
https://reviews.llvm.org/D59068, which fixes coroutines bug
https://bugs.llvm.org/show_bug.cgi?id=40979.
Reviewers: mkazantsev, wmi, davidxl, silvas, davide
Reviewed By: davide
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59069
llvm-svn: 355846
Inserting an overflowing arithmetic intrinsic can increase register
pressure by producing two values at a point where only one is needed,
while the second use maybe several blocks away. This increase in
pressure is likely to be more detrimental on performance than
rematerialising one of the original instructions.
So, check that the arithmetic and compare instructions are no further
apart than their immediate successor/predecessor.
Differential Revision: https://reviews.llvm.org/D59024
llvm-svn: 355823
The control flow here cannot ever use the uninitialized value, but it's
too hard for the compiler to figure that out. Clang warns:
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: error: variable 'CarrySum' is used uninitialized whenever 'for' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized]
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2604:26: note: uninitialized use occurs here
CarrySumPrevDstIdx = CarrySum;
^~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: note: remove the condition if it is always true
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2583:22: note: initialize the variable 'CarrySum' to silence this warning
unsigned CarrySum;
^
= 0
llvm-svn: 355818
Narrow Scalar G_MUL for MIPS32.
Revisit NarrowScalar implementation in LegalizerHelper.
Introduce new helper function multiplyRegisters.
It performs generic multiplication of values held in multiple registers.
Generated instructions use only types NarrowTy and i1.
Destination can be same or two times size of the source.
Differential Revision: https://reviews.llvm.org/D58824
llvm-svn: 355814
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.
Original commit message:
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355784
This saves needing to call getInt32 ourselves. Making the code a little shorter.
The test changes are because insert/extract use getInt64 internally. Shouldn't be a functional issue.
This cleanup because I plan to write similar code for expandload/compressstore.
llvm-svn: 355767
There are special cases in the scalarization for constant masks. If we hit one of the special cases we don't need to reset the iteration.
Noticed while starting work on adding expandload/compressstore to this pass.
llvm-svn: 355754
r44412 fixed a huge compile time regression but it needed ModifiedDT flag to be
maintained correctly in optimizations in optimizeBlock() and optimizeInst().
Function optimizeSelectInst() does not update the flag.
This patch propagates the flag in optimizeSelectInst() back to
optimizeBlock().
This patch also removes ModifiedDT in CodeGenPrepare class (which is not used).
The property of ModifiedDT is now recorded in a ref parameter.
Differential Revision: https://reviews.llvm.org/D59139
llvm-svn: 355751
This avoids breaking possible value dependencies when sorting loads by
offset.
AMDGPU has some load instructions that write into the high or low bits
of the destination register, and have a tied input for the other input
bits. These can easily have the same base pointer, but be a swizzle so
the high address load needs to come first. This was inserting glue
forcing the opposite ordering, producing a cycle the InstrEmitter
would assert on. It may be potentially expensive to look for the
dependency between the other loads, so just skip any where this could
happen.
Fixes bug 40936 by reverting r351379, which added a hacky attempt to
fix this by adding chains in this case, which I think was just working
around broken glue before the InstrEmitter. The core of the patch is
re-implementing the fix for that problem.
llvm-svn: 355728
many valnos.
Recently we found compile time out problem in several cases when
SpeculativeLoadHardening was enabled. The significant compile time was spent
in register coalescing pass, where register coalescer tried to join many other
live intervals with some very large live intervals with many valnos.
Specifically, every time JoinVals::mapValues is called, computeAssignment will
be called by getNumValNums() times of the target live interval. If the large
live interval has N valnos and has N copies associated with it, trying to
coalescing those copies will at least cost N^2 complexity.
The patch adds some limit to the effort trying to join those very large live
intervals with others. By default, for live interval with > 100 valnos, and
when it has been coalesced with other live interval by more than 100 times,
we will stop coalescing for the live interval anymore. That put a compile
time cap for the N^2 algorithm and effectively solves the compile time
problem we saw.
Differential revision: https://reviews.llvm.org/D59143
llvm-svn: 355714
Summary:
The logic in the -unreachableblockelim pass does the following:
1. It traverses the function it's given in depth-first order and
creates a set of basic blocks that are unreachable from the
function's entry node.
2. It iterates over each of those unreachable blocks and (1) removes any
successors' references to the dead block, and (2) replaces any uses of
instructions from the dead block with null.
The logic in (2) above is identical to what the `llvm::DeleteDeadBlocks`
function from `BasicBlockUtils.h` does. The only difference is that
`llvm::DeleteDeadBlocks` replaces uses of instructions from dead blocks
not with null, but with undef.
Replace the duplicate logic in the -unreachableblockelim pass with a
call to `llvm::DeleteDeadBlocks`. This results in less code but no
functional change (NFC).
Reviewers: mkazantsev, wmi, davidxl, silvas, davide
Reviewed By: davide
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59064
llvm-svn: 355634
Restore a reverted commit, with the silly mistake fixed. Sorry for the previous breakage.
Be consistent about how we treat atomics in non-zero address spaces. If we get to the backend, we tend to lower them as if in address space 0. Do the same if we need to insert a libcall instead.
Differential Revision: https://reviews.llvm.org/D58760
llvm-svn: 355540
Move the x86 combine from D58974 into the DAGCombine VSELECT code and update the SELECT version to use the isBooleanFlip helper as well.
Requested by @spatel on D59006
llvm-svn: 355533
Summary:
In r354298 a DominatorTree construction was added via new function
combineToUSubWithOverflow, which was subsequently restructured into
replaceMathCmpWithIntrinsic in r354689. We are hitting a very long
compile time due to this repeated construction, once per math cmp in
the function.
We shouldn't need to build the DominatorTree more than once per
function, except when a transformation invalidates it. There is already
a boolean flag that is returned from these methods indicating whether
the DT has been modified. We can simply build the DT once per
Function walk in CodeGenPrepare::runOnFunction, since any time a change
is made we break out of the Function walk and restart it.
I modified the code so that both replaceMathCmpWithIntrinsic as well as
mergeSExts (which was also building a DT) use the DT constructed by the
run method.
From -mllvm -time-passes:
Before this patch: CodeGen Prepare user time is 328s
With this patch: CodeGen Prepare user time is 21s
Reviewers: spatel
Subscribers: jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58995
llvm-svn: 355512
This allows us to store more info about where we're emitting the remarks
without cluttering LLVMContext. This is needed for future support for
the remark section.
Differential Revision: https://reviews.llvm.org/D58996
llvm-svn: 355507
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.
Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
llvm-svn: 355490
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.
Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
llvm-svn: 355483
Be consistent about how we treat atomics in non-zero address spaces. If we get to the backend, we tend to lower them as if in address space 0. Do the same if we need to insert a libcall instead.
Differential Revision: https://reviews.llvm.org/D58760
llvm-svn: 355453
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.
llvm-svn: 355433
These arrays are both keyed by CPU name and go into the same tablegenerated file. Merge them so we only need to store keys once.
This also removes a weird space saving quirk where we used the ProcDesc.size() to create to build an ArrayRef for ProcSched.
Differential Revision: https://reviews.llvm.org/D58939
llvm-svn: 355431
The description for CPUs was just the CPU name wrapped with "Select the " and " processor". We can just do that directly in the help printer instead of making a separate version in the binary for each CPU.
Also remove the Value field that isn't needed and was always 0.
Differential Revision: https://reviews.llvm.org/D58938
llvm-svn: 355429
The test is reduced from an example in the post-commit thread for:
rL354746
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190304/632396.html
While we must avoid dying here, the real question should be:
Why is non-canonical and/or degenerate code making it to CGP when
using the new pass manager?
llvm-svn: 355345
This patch enables combining integer bitcasts of integer build vectors when the new scalar type is legal. I've avoided floating point because the implementation bitcasts float to int along the way and we would need to check the intermediate types for legality
Differential Revision: https://reviews.llvm.org/D58884
llvm-svn: 355324
Summary:
Before when we implemented the first EH proposal, 'catch <tag>'
instruction may not catch an exception so there were multiple EH pads an
exception can unwind to. That means a BB could have multiple EH pad
successors.
Now after we switched to the new proposal, every 'catch' instruction
catches an exception, and there is only one catchpad per catchswitch, so
we at most have one EH pad successor, making `ThrowUnwindDest` map in
`WasmEHInfo` unnecessary.
Keeping `ThrowUnwindDest` map in `WasmEHInfo` has its own problems,
because other optimization passes can split a BB that contains possibly
throwing calls (previously invokes), and we have to update the map every
time that happens, which is not easy for common CodeGen passes.
This also correctly updates successor info in LateEHPrepare when we add
a rethrow instruction.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58486
llvm-svn: 355296
