This patch corresponds to review:
https://reviews.llvm.org/D23155
This patch removes the VSHRC register class (based on D20310) and adds
exploitation of the Power9 sub-word integer loads into VSX registers as well
as vector sign extensions.
The new instructions are useful for a few purposes:
Int to Fp conversions of 1 or 2-byte values loaded from memory
Building vectors of 1 or 2-byte integers with values loaded from memory
Storing individual 1 or 2-byte elements from integer vectors
This patch implements all of those uses.
llvm-svn: 283190
This adds a target hook getInstSizeInBytes to TargetInstrInfo that a lot of
subclasses already implement.
Differential Revision: https://reviews.llvm.org/D22885
llvm-svn: 277126
This is mostly a mechanical change to make TargetInstrInfo API take
MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator)
when the argument is expected to be a valid MachineInstr. This is a
general API improvement.
Although it would be possible to do this one function at a time, that
would demand a quadratic amount of churn since many of these functions
call each other. Instead I've done everything as a block and just
updated what was necessary.
This is mostly mechanical fixes: adding and removing `*` and `&`
operators. The only non-mechanical change is to split
ARMBaseInstrInfo::getOperandLatencyImpl out from
ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a
`MachineInstr*` which it updated to the instruction bundle leader; now,
the latter calls the former either with the same `MachineInstr&` or the
bundle leader.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
Note: I updated WebAssembly, Lanai, and AVR (despite being
off-by-default) since it turned out to be easy. I couldn't run tests
for AVR since llc doesn't link with it turned on.
llvm-svn: 274189
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
llvm-svn: 272512
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest). All of these
functions require non-null parameters already, so references are more
clear. As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.
No functionality change intended.
llvm-svn: 261605
Also, remove an enum hack where enum values were used as indexes into an array.
We may want to make this a real class to allow pattern-based queries/customization (D13417).
llvm-svn: 252196
Add support for MIR serialization of PowerPC-specific operand target flags
(based on the generic infrastructure added in r244185 and r245383).
I won't even pretend that this is good test coverage, but this includes the
regression test associated with r246372. Adding an MIR test for that fix is far
superior to adding an IR-level test because particular instruction-scheduling
decisions are necessary in order to expose the bug, and using an MIR test we
can start the pipeline post-scheduling.
llvm-svn: 246373
This is a direct port of the code from the X86 backend (r239486/r240361), which
uses the MachineCombiner to reassociate (floating-point) adds/muls to increase
ILP, to the PowerPC backend. The rationale is the same.
There is a lot of copy-and-paste here between the X86 code and the PowerPC
code, and we should extract at least some of this into CodeGen somewhere.
However, I don't want to do that until this code is enhanced to handle FMAs as
well. After that, we'll be in a better position to extract the common parts.
llvm-svn: 242279
PowerPC uses itineraries to describe processor pipelines (and dispatch-group
restrictions for P7/P8 cores). Unfortunately, the target-independent
implementation of TII.getInstrLatency calls ItinData->getStageLatency, and that
looks for the largest cycle count in the pipeline for any given instruction.
This, however, yields the wrong answer for the PPC itineraries, because we
don't encode the full pipeline. Because the functional units are fully
pipelined, we only model the initial stages (there are no relevant hazards in
the later stages to model), and so the technique employed by getStageLatency
does not really work. Instead, we should take the maximum output operand
latency, and that's what PPCInstrInfo::getInstrLatency now does.
This caused some test-case churn, including two unfortunate side effects.
First, the new arrangement of copies we get from function parameters now
sometimes blocks VSX FMA mutation (a FIXME has been added to the code and the
test cases), and we have one significant test-suite regression:
SingleSource/Benchmarks/BenchmarkGame/spectral-norm
56.4185% +/- 18.9398%
In this benchmark we have a loop with a vectorized FP divide, and it with the
new scheduling both divides end up in the same dispatch group (which in this
case seems to cause a problem, although why is not exactly clear). The grouping
structure is hard to predict from the bottom of the loop, and there may not be
much we can do to fix this.
Very few other test-suite performance effects were really significant, but
almost all weakly favor this change. However, in light of the issues
highlighted above, I've left the old behavior available via a
command-line flag.
llvm-svn: 242188
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
This will use Itinieraries if available, but will also work if just a
MCSchedModel is available.
Differential Revision: http://reviews.llvm.org/D10428
llvm-svn: 239658
MachineLICM uses a callback named hasLowDefLatency to determine if an
instruction def operand has a 'low' latency. If all relevant operands have a
'low' latency, the instruction is considered too cheap to hoist out of loops
even in low-register-pressure situations. On PowerPC cores, both the embedded
cores and the others, there is no reason to believe that this is a good choice:
all instructions have a cost inside a loop, and hoisting them when not limited
by register pressure is a reasonable default.
llvm-svn: 225471
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
Although the first two operands are the ones that can be swapped, the tied
input operand is listed before them, so we need to adjust for that.
I have a test case for this, but it goes along with an upcoming commit (so it
will come soon).
llvm-svn: 204748
Aside from a few minor latency corrections, the major change here is a new
hazard recognizer which focuses on better dispatch-group formation on the
POWER7. As with the PPC970's hazard recognizer, the most important thing it
does is avoid load-after-store hazards within the same dispatch group. It uses
the POWER7's special dispatch-group-terminating nop instruction (instead of
inserting multiple regular nop instructions). This new hazard recognizer makes
use of the scheduling dependency graph itself, built using AA information, to
robustly detect the possibility of load-after-store hazards.
significant test-suite performance changes (the error bars are 99.5% confidence
intervals based on 5 test-suite runs both with and without the change --
speedups are negative):
speedups:
MultiSource/Benchmarks/FreeBench/pcompress2/pcompress2
-0.55171% +/- 0.333168%
MultiSource/Benchmarks/TSVC/CrossingThresholds-dbl/CrossingThresholds-dbl
-17.5576% +/- 14.598%
MultiSource/Benchmarks/TSVC/Reductions-dbl/Reductions-dbl
-29.5708% +/- 7.09058%
MultiSource/Benchmarks/TSVC/Reductions-flt/Reductions-flt
-34.9471% +/- 11.4391%
SingleSource/Benchmarks/BenchmarkGame/puzzle
-25.1347% +/- 11.0104%
SingleSource/Benchmarks/Misc/flops-8
-17.7297% +/- 9.79061%
SingleSource/Benchmarks/Shootout-C++/ary3
-35.5018% +/- 23.9458%
SingleSource/Regression/C/uint64_to_float
-56.3165% +/- 25.4234%
SingleSource/UnitTests/Vectorizer/gcc-loops
-18.5309% +/- 6.8496%
regressions:
MultiSource/Benchmarks/ASCI_Purple/SMG2000/smg2000
18.351% +/- 12.156%
SingleSource/Benchmarks/Shootout-C++/methcall
27.3086% +/- 14.4733%
llvm-svn: 197099
This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file. The memory leaks in this version have been fixed. Thanks
Alexey for pointing them out.
Differential Revision: http://llvm-reviews.chandlerc.com/D2068
Reviewed by Andy
llvm-svn: 195064
This change is incorrect. If you delete virtual destructor of both a base class
and a subclass, then the following code:
Base *foo = new Child();
delete foo;
will not cause the destructor for members of Child class. As a result, I observe
plently of memory leaks. Notable examples I investigated are:
ObjectBuffer and ObjectBufferStream, AttributeImpl and StringSAttributeImpl.
llvm-svn: 194997
This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file.
Differential Revision: http://llvm-reviews.chandlerc.com/D2068
Reviewed by Andy
llvm-svn: 194865
Frame index handling is now target-agnostic, so delete the target hooks
for creation & asm printing of target-specific addressing in DBG_VALUEs
and any related functions.
llvm-svn: 184067
Many PPC instructions have a so-called 'record form' which stores to a specific
condition register the result of comparing the result of the instruction with
zero (always as a signed comparison). For integer operations on PPC64, this is
always a 64-bit comparison.
This implementation is derived from the implementation in the ARM backend;
there are some differences because PPC condition registers are allocatable
virtual registers (although the record forms always use a specific one), and we
look for a matching subtraction instruction after the compare (but before the
first use) in addition to before it.
llvm-svn: 179802
I've not seen this happen in practice, and probably can't until we start
allowing decrement-counter-based conditional branches to be double predicated,
but just in case, don't allow predication of a diamond in which both sides have
ctr-defining branches. Even though the branching behavior of these can be
predicated, the counter-decrementing behavior cannot be.
llvm-svn: 179199
This enables us to form predicated branches (which are the same conditional
branches we had before) and also a larger set of predicated returns (including
instructions like bdnzlr which is a conditional return and loop-counter
decrement all in one).
At the moment, if conversion does not capture all possible opportunities. A
simple example is provided in early-ret2.ll, where if conversion forms one
predicated return, and then the PPCEarlyReturn pass picks up the other one. So,
at least for now, we'll keep both mechanisms.
llvm-svn: 179134
There are certain PPC instructions into which we can fold a zero immediate
operand. We can detect such cases by looking at the register class required
by the using operand (so long as it is not otherwise constrained).
llvm-svn: 178961
On cores for which we know the misprediction penalty, and we have
the isel instruction, we can profitably perform early if conversion.
This enables us to replace some small branch sequences with selects
and avoid the potential stalls from mispredicting the branches.
Enabling this feature required implementing canInsertSelect and
insertSelect in PPCInstrInfo; isel code in PPCISelLowering was
refactored to use these functions as well.
llvm-svn: 178926
In preparation for using the new register scavenger capability for providing
more than one register simultaneously, specifically note functions that have
spilled VRSAVE (currently, this can happen only in functions that use the
setjmp intrinsic). As with CR spilling, such functions will need to provide two
emergency spill slots to the scavenger.
No functionality change intended.
llvm-svn: 177832
This change cleans up two issues with Altivec register spilling:
1. The spilling code was inefficient (using two instructions, and add and a
load, when just one would do)
2. The code assumed that r0 would always be available (true for now, but this
will change)
The new code handles VR spilling just like GPR spills but forced into r+r mode.
As a result, when any VR spills are present, we must now always allocate the
register-scavenger spill slot.
llvm-svn: 177231
The PPC::EXTSW instruction preserves the low 32 bits of its input, just
like some of the x86 instructions. Use it to reduce register pressure
when the low 32 bits have multiple uses.
This requires a small change to PeepholeOptimizer since EXTSW takes a
64-bit input register.
This is related to PR5997.
llvm-svn: 158743
DAG scheduling during isel. Most new functionality is currently
guarded by -enable-sched-cycles and -enable-sched-hazard.
Added InstrItineraryData::IssueWidth field, currently derived from
ARM itineraries, but could be initialized differently on other targets.
Added ScheduleHazardRecognizer::MaxLookAhead to indicate whether it is
active, and if so how many cycles of state it holds.
Added SchedulingPriorityQueue::HasReadyFilter to allowing gating entry
into the scheduler's available queue.
ScoreboardHazardRecognizer now accesses the ScheduleDAG in order to
get information about it's SUnits, provides RecedeCycle for bottom-up
scheduling, correctly computes scoreboard depth, tracks IssueCount, and
considers potential stall cycles when checking for hazards.
ScheduleDAGRRList now models machine cycles and hazards (under
flags). It tracks MinAvailableCycle, drives the hazard recognizer and
priority queue's ready filter, manages a new PendingQueue, properly
accounts for stall cycles, etc.
llvm-svn: 122541
Nemanja Ivanovic