Summary:
This is a follow-up to r353988 where tryEvict was extended to take last
chance recoloring into account. Now we do the same thing for trySplit and
tryAssign.
Now we always pass a "FixedRegisters" argument to canEvictInterference and
tryEvict so it doesn't need to have a default value anymore.
The need for this was found long ago in an out-of-tree target.
Unfortunately I don't have a reproducer for an in-tree target.
Reviewers: qcolombet, rudkx
Reviewed By: qcolombet, rudkx
Subscribers: rudkx, MatzeB, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58376
llvm-svn: 354439
Last chance recoloring inserts into FixedRegisters those virtual
registers it is attempting to assign a physical register to.
We must consider these when we consider candidates for eviction so that
we do not end up evicting something while we are attempting to recolor
to assign it.
This is hitting in an out-of-tree target and no longer reproduces on
trunk. That does not appear to be a result of it having been fixed, but
rather, it appears that optimization changes and/or other changes to
register allocation mask the problem.
I haven't found a way to come up with a reasonable test case for this
(i.e. one that I can actually commit to open source, is reasonable
in size, and actually reproduces the issue).
rdar://problem/45708741
llvm-svn: 353988
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
It costs nothing to spill an IMPLICIT_DEF value (the only spill code that's
generated is a KILL of the value), so when creating split constraints if the
live-out value is IMPLICIT_DEF the exit constraint should be DontCare instead
of PrefReg.
Differential Revision: https://reviews.llvm.org/D55652
llvm-svn: 349151
For the AMDGPU target if a MBB contains exec mask restore preamble, SplitEditor may get state when it cannot insert a spill instruction.
E.g. for a MIR
bb.100:
%1 = S_OR_SAVEEXEC_B64 %2, implicit-def $exec, implicit-def $scc, implicit $exec
and if the regalloc will try to allocate a virtreg to the physreg already assigned to virtreg %1, it should insert spill instruction before the S_OR_SAVEEXEC_B64 instruction.
But it is not possible since can generate incorrect code in terms of exec mask.
The change makes regalloc to ignore such physreg candidates.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D52052
llvm-svn: 343004
tryLocalSplit only handles a single use block, but an interval may
have multiple use blocks. So don't crash in that case. This fixes
PR38795.
Differential revision: https://reviews.llvm.org/D52277
llvm-svn: 342682
This removes the FrameAccess struct that was added to the interface
in D51537, since the PseudoValue from the MachineMemoryOperand
can be safely casted to a FixedStackPseudoSourceValue.
Reviewers: MatzeB, thegameg, javed.absar
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D51617
llvm-svn: 341454
For instructions that spill/fill to and from multiple frame-indices
in a single instruction, hasStoreToStackSlot and hasLoadFromStackSlot
should return an array of accesses, rather than just the first encounter
of such an access.
This better describes FI accesses for AArch64 (paired) LDP/STP
instructions.
Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D51537
llvm-svn: 341301
trivially rematerializable.
We run into a case where machineLICM hoists a large number of live ranges
outside of a big loop because it thinks those live ranges are trivially
rematerializable. In regalloc, global splitting is tried out first for those
live ranges before they are spilled and rematerialized. Because the global
splitting algorithm is quadratic, increasing a lot of global splitting
candidates causes huge compile time increase (50s to 1400s on my local
machine when compiling a module).
However, we think for live ranges which are very large and are trivially
rematerialiable, it is better to just skip global splitting so as to save
compile time with little chance of sacrificing performance. We uses the
segment size of live range to indirectly evaluate whether the global
splitting of the live range can introduce high cost, and use an option
as a knob to adjust the size limit threshold.
Differential Revision: https://reviews.llvm.org/D49353
llvm-svn: 337186
RegAlloc keeps a insertion-time ordered map of evictee information,
but we only use membership. Replace MapVector with contextually
equivalent DenseMap which is smaller and faster.
llvm-svn: 333981
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
When selecting a split candidate for region splitting, the register allocator tries to predict which candidate will have the cheapest spill cost.
Global splitting may cause the creation of local intervals, and they might spill.
This patch makes RA take into account the spill cost of local split intervals in use blocks (we already take into account the spill cost in through blocks).
A flag ("-condsider-local-interval-cost") controls weather we do this advanced cost calculation (it's on by default for X86 target, off for the rest).
Differential Revision: https://reviews.llvm.org/D41585
Change-Id: Icccb8ad2dbf13124f5d97a18c67d95aa6be0d14d
llvm-svn: 323870
Headers/Implementation files should be named after the class they
declare/define.
Also eliminated an `#include "llvm/CodeGen/LiveIntervalAnalysis.h"` in
favor of `class LiveIntarvals;`
llvm-svn: 320546
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.
The MIR printer prints the IR name of a MBB only for block definitions.
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix
Differential Revision: https://reviews.llvm.org/D40422
llvm-svn: 319665
These command line options are not intended for public use, and often
don't even make sense in the context of a particular tool anyway. About
90% of them are already hidden, but when people add new options they
forget to hide them, so if you were to make a brand new tool today, link
against one of LLVM's libraries, and run tool -help you would get a
bunch of junk that doesn't make sense for the tool you're writing.
This patch hides these options. The real solution is to not have
libraries defining command line options, but that's a much larger effort
and not something I'm prepared to take on.
Differential Revision: https://reviews.llvm.org/D40674
llvm-svn: 319505
As part of the unification of the debug format and the MIR format, avoid
printing "vreg" for virtual registers (which is one of the current MIR
possibilities).
Basically:
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/%vreg([0-9]+)/%\1/g"
* grep -nr '%vreg' . and fix if needed
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/ vreg([0-9]+)/ %\1/g"
* grep -nr 'vreg[0-9]\+' . and fix if needed
Differential Revision: https://reviews.llvm.org/D40420
llvm-svn: 319427
LLVM Coding Standards:
Function names should be verb phrases (as they represent actions), and
command-like function should be imperative. The name should be camel
case, and start with a lower case letter (e.g. openFile() or isFoo()).
Differential Revision: https://reviews.llvm.org/D40416
llvm-svn: 319168
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.
llvm-svn: 317647
This fixes bugzilla 26810
https://bugs.llvm.org/show_bug.cgi?id=26810
This is intended to prevent sequences like:
movl %ebp, 8(%esp) # 4-byte Spill
movl %ecx, %ebp
movl %ebx, %ecx
movl %edi, %ebx
movl %edx, %edi
cltd
idivl %esi
movl %edi, %edx
movl %ebx, %edi
movl %ecx, %ebx
movl %ebp, %ecx
movl 16(%esp), %ebp # 4 - byte Reload
Such sequences are created in 2 scenarios:
Scenario #1:
vreg0 is evicted from physreg0 by vreg1
Evictee vreg0 is intended for region splitting with split candidate physreg0 (the reg vreg0 was evicted from)
Region splitting creates a local interval because of interference with the evictor vreg1 (normally region spliiting creates 2 interval, the "by reg" and "by stack" intervals. Local interval created when interference occurs.)
one of the split intervals ends up evicting vreg2 from physreg1
Evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills
Scenario #2
vreg0 is evicted from physreg0 by vreg1
vreg2 is evicted from physreg2 by vreg3 etc
Evictee vreg0 is intended for region splitting with split candidate physreg1
Region splitting creates a local interval because of interference with the evictor vreg1
one of the split intervals ends up evicting back original evictor vreg1 from physreg0 (the reg vreg0 was evicted from)
Another evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills
As compile time was a concern, I've added a flag to control weather we do cost calculations for local intervals we expect to be created (it's on by default for X86 target, off for the rest).
Differential Revision: https://reviews.llvm.org/D35816
Change-Id: Id9411ff7bbb845463d289ba2ae97737a1ee7cc39
llvm-svn: 316295
parameterized emit() calls
Summary: This is not functional change to adopt new emit() API added in r313691.
Reviewed By: anemet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38285
llvm-svn: 315476
Summary:
If we have a non-allocated register, we allow us to try recoloring of an
already allocated and "Done" register, even if they are of the same
register class, if the non-allocated register has at least one tied def
and the allocated one has none.
It should be easier to recolor the non-tied register than the tied one, so
it might be an improvement even if they use the same regclasses.
Reviewers: qcolombet
Reviewed By: qcolombet
Subscribers: llvm-commits, MatzeB
Differential Revision: https://reviews.llvm.org/D38309
llvm-svn: 314388
removing them"
This was temporarily reverted, but now that the fix has been commited (r313197)
it should be put back in place.
https://bugs.llvm.org/show_bug.cgi?id=34502
This reverts commit 9ef93d9dc4c51568e858cf8203cd2c5ce8dca796.
llvm-svn: 313349
When removing a live-range we used to not touch them making debug
prints harder to read because the IR was not matching what the
live-ranges information was saying.
This only affects debug printing and allows to put stronger asserts in
the code (see r308906 for instance).
llvm-svn: 311401
We can now end up in situations where we initiate LiveIntervalUnion
queries with different SubRanges against the same register unit, so the
assert() no longer holds in all cases. Just recalculate now when we know
the cache is out of date.
llvm-svn: 296928
- We only need the information from the base class, not the additional
details in the LiveInterval class.
- Spread more `const`
- Some code cleanup
llvm-svn: 296684
This allows MIR passes to emit optimization remarks with the same level
of functionality that is available to IR passes.
It also hooks up the greedy register allocator to report spills. This
allows for interesting use cases like increasing interleaving on a loop
until spilling of registers is observed.
I still need to experiment whether reporting every spill scales but this
demonstrates for now that the functionality works from llc
using -pass-remarks*=<pass>.
Differential Revision: https://reviews.llvm.org/D29004
llvm-svn: 293110
The previously used "names" are rather descriptions (they use multiple
words and contain spaces), use short programming language identifier
like strings for the "names" which should be used when exporting to
machine parseable formats.
Also removed a unused TimerGroup from Hexxagon.
Differential Revision: https://reviews.llvm.org/D25583
llvm-svn: 287369
In https://reviews.llvm.org/D25347, Geoff noticed that we still have
useless copy that we can eliminate after register allocation. At the
time the allocation is chosen for those copies, they are not useless
but, because of changes in the surrounding code, later on they might
become useless.
The Greedy allocator already has a mechanism to deal with such cases
with a late recoloring. However, we missed to record the some of the
missed hints.
This commit fixes that.
llvm-svn: 287070
About when we should move a vreg from CurrentNewVRegs to NewVRegs,
if the vreg in CurrentNewVRegs was added into RecoloringCandidate and was
evicted, it shouldn't be added to NewVRegs because its physical register
will be restored at the end of tryLastChanceRecoloring after the recoloring
failed. If the vreg in CurrentNewVRegs was not in RecoloringCandidate, i.e.
it was evicted in selectOrSplitImpl inside tryRecoloringCandidates, its
physical register will not be restored even if the recoloring failed. In
that case, we need to add the vreg to NewVRegs.
Same as r281783, the problem was seen on out-of-tree target and we didn't
have a test case that reproduce the problem with in-tree targets.
llvm-svn: 286259
Relax the constraint for empty live-ranges while doing last chance
recoloring. Indeed, those live-ranges do not need an actual color to be
fond for the recoloring to work.
Empty live-range may happen as a result of splitting/spilling.
Unfortunately no test case for in-tree targets.
llvm-svn: 284152
Fangrui Song