Summary:
Subtargets can define the libpfm counter names that can be used to
measure cycles and uops issued on ProcResUnits.
This allows making llvm-exegesis available on more targets.
Fixes PR36984.
Reviewers: gchatelet, RKSimon, andreadb, craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45360
llvm-svn: 329675
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: stoklund, kparzysz, dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45144
llvm-svn: 329451
This patch adds the ability to describe properties of the hardware retire
control unit.
Tablegen class RetireControlUnit has been added for this purpose (see
TargetSchedule.td).
A RetireControlUnit specifies the size of the reorder buffer, as well as the
maximum number of opcodes that can be retired every cycle.
A zero (or negative) value for the reorder buffer size means: "the size is
unknown". If the size is unknown, then llvm-mca defaults it to the value of
field SchedMachineModel::MicroOpBufferSize. A zero or negative number of
opcodes retired per cycle means: "there is no restriction on the number of
instructions that can be retired every cycle".
Models can optionally specify an instance of RetireControlUnit. There can only
be up-to one RetireControlUnit definition per scheduling model.
Information related to the RCU (RetireControlUnit) is stored in (two new fields
of) MCExtraProcessorInfo. llvm-mca loads that information when it initializes
the DispatchUnit / RetireControlUnit (see Dispatch.h/Dispatch.cpp).
This patch fixes PR36661.
Differential Revision: https://reviews.llvm.org/D45259
llvm-svn: 329304
For schedule models that don't use itineraries, checkCompleteness still checks that an instruction has a matching itinerary instead of skipping and going straight to matching the InstRWs. That doesn't seem to match what happens in TargetSchedule.cpp
This patch causes problems for a number of models that had been incorrectly flagged as complete.
Differential Revision: https://reviews.llvm.org/D43235
llvm-svn: 329280
This patch allows the description of register files in processor scheduling
models. This addresses PR36662.
A new tablegen class named 'RegisterFile' has been added to TargetSchedule.td.
Targets can optionally describe register files for their processors using that
class. In particular, class RegisterFile allows to specify:
- The total number of physical registers.
- Which target registers are accessible through the register file.
- The cost of allocating a register at register renaming stage.
Example (from this patch - see file X86/X86ScheduleBtVer2.td)
def FpuPRF : RegisterFile<72, [VR64, VR128, VR256], [1, 1, 2]>
Here, FpuPRF describes a register file for MMX/XMM/YMM registers. On Jaguar
(btver2), a YMM register definition consumes 2 physical registers, while MMX/XMM
register definitions only cost 1 physical register.
The syntax allows to specify an empty set of register classes. An empty set of
register classes means: this register file models all the registers specified by
the Target. For each register class, users can specify an optional register
cost. By default, register costs default to 1. A value of 0 for the number of
physical registers means: "this register file has an unbounded number of
physical registers".
This patch is structured in two parts.
* Part 1 - MC/Tablegen *
A first part adds the tablegen definition of RegisterFile, and teaches the
SubtargetEmitter how to emit information related to register files.
Information about register files is accessible through an instance of
MCExtraProcessorInfo.
The idea behind this design is to logically partition the processor description
which is only used by external tools (like llvm-mca) from the processor
information used by the llvm machine schedulers.
I think that this design would make easier for targets to get rid of the extra
processor information if they don't want it.
* Part 2 - llvm-mca related *
The second part of this patch is related to changes to llvm-mca.
The main differences are:
1) class RegisterFile now needs to take into account the "cost of a register"
when allocating physical registers at register renaming stage.
2) Point 1. triggered a minor refactoring which lef to the removal of the
"maximum 32 register files" restriction.
3) The BackendStatistics view has been updated so that we can print out extra
details related to each register file implemented by the processor.
The effect of point 3. is also visible in tests register-files-[1..5].s.
Differential Revision: https://reviews.llvm.org/D44980
llvm-svn: 329067
This patch throws a fatal error if an instregex entry doesn't actually match any instructions. This is part of the work to reduce the compile time impact of increased instregex usage (PR35955), although the x86 models seem to be relatively clean.
All the cases I encountered have now been fixed in trunk and this will ensure they don't get reintroduced.
Differential Revision: https://reviews.llvm.org/D44687
llvm-svn: 328459
We already know all the of instructions we're processing in the instruction loop belong to no class or all to the same class. So we only have to worry about remapping one class. So hoist it all out and remove the SmallPtrSet that tracked which class we'd already remapped.
I had to introduce new instruction loop inside this code to print an error message, but that only occurs on the error path.
llvm-svn: 328142
We already have an OldSCIdx variable in the outer loop here. And we already did the map lookup in the loop that populated ClassInstrs. And the outer OldSCIdx got it from ClassInstrs.
llvm-svn: 328139
Summary:
This code previously had a SmallVector of std::pairs containing an unsigned and another SmallVector. The outer vector was using the unsigned effectively as a key to decide which SmallVector to add into. So each time something new needed to be added the out vector needed to be scanned. If it wasn't found a new entry needed to be added to be added. This sounds very much like a map, but the next loop iterates over the outer vector to get a deterministic order.
We can simplify this code greatly if use SmallMapVector instead. This uses more stack space since we now have a vector and a map, but the searching and creating new entries all happens behind the scenes. It should also make the search more efficient though usually there are only a few entries so that doesn't matter much.
We could probably get determinism by just using std::map which would iterate over the unsigned key, but that would generate different output from what we get with the current implementation.
Reviewers: RKSimon, dblaikie
Reviewed By: dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44711
llvm-svn: 328070
Both vectors contain unsigned so we can just use append to do the copying. Not only is this shorter, but it should be able to predict the final size and only grow the vector once if needed.
llvm-svn: 328033
This is similar to the check later when we remap some of the instructions from one class to a new one. But if we reuse the class we don't get to do that check.
So many CPUs have violations of this check that I had to add a flag to the SchedMachineModel to allow it to be disabled. Hopefully we can get those cleaned up quickly and remove this flag.
A lot of the violations are due to overlapping regular expressions, but that's not the only kind of issue it found.
llvm-svn: 327808
Summary:
Right now only the ProcResourceUnits that are directly referenced by
instructions are emitted. This change emits all of them, so that
analysis passes can use the information.
This has no functional impact. It typically adds a few entries (e.g. 4
for X86/haswell) to the generated ProcRes table.
Reviewers: gchatelet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42903
llvm-svn: 324228
This is a bit of a hack, but removes a cycle that broke modular builds
of LLVM. Of course the cycle is still there in form of a dependency
on the .def file.
llvm-svn: 323383
llvm::Regex is still the slowest regex engine on earth, running it over
all instructions on X86 takes a while. Extract a prefix and use a binary
search to reduce the search space before we resort to regex matching.
There are a couple of caveats here:
- The generic opcodes are outside of the sorted enum. They're handled in an extra loop.
- If there's a top-level bar we can't use the prefix trick.
- We bail on top-level ?. This could be handled, but it's rare.
This brings the time to generate X86GenInstrInfo.inc from 21s to 4.7s on
my machine.
llvm-svn: 323277
When searching for a resource unit, use the reference location instead of
the definition location in case of an error.
Differential revision: https://reviews.llvm.org/D40263
llvm-svn: 318803
Add headers for each section of output, with white space and "+++" to
improve readability.
Differential Revision: https://reviews.llvm.org/D34713
llvm-svn: 306492
The CodeGenSchedModels::checkCompleteness routine in TableGen/
CodeGenSchedule.cpp is supposed to verify for each processor
model that is marked as "complete" that it actually defines a
scheduling class for each instruction.
However, this did not work correctly due to an incorrect
check whether a scheduling class has an itinerary.
Reviewer: atrick
Differential revision: https://reviews.llvm.org/D26156
llvm-svn: 285622
-debug-only=subtarget-emitter prints a lot of machine model diagnostics.
This prunes the output so that the "No machine model for XXX on processor YYY"
only appears when there is definitely no machine model for that opcode.
Previously it was printing that error even if the opcode was covered by
a more general scheduling class.
<rdar://problem/15919845> [TableGen][CodeGenSchedule] Debug output does not help spotting the missing scheduling classes
llvm-svn: 284452
