Commit Graph

8 Commits

Author SHA1 Message Date
Andrea Di Biagio f6a60f1f80 [llvm-mca][scheduler-stats] Print issued micro opcodes per cycle. NFCI
It makes more sense to print out the number of micro opcodes that are issued
every cycle rather than the number of instructions issued per cycle.
This behavior is also consistent with the dispatch-stats: numbers from the two
views can now be easily compared.

llvm-svn: 357919
2019-04-08 16:05:54 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Andrea Di Biagio 373a4ccf6c [llvm-mca][MC] Add the ability to declare which processor resources model load/store queues (PR36666).
This patch adds the ability to specify via tablegen which processor resources
are load/store queue resources.

A new tablegen class named MemoryQueue can be optionally used to mark resources
that model load/store queues.  Information about the load/store queue is
collected at 'CodeGenSchedule' stage, and analyzed by the 'SubtargetEmitter' to
initialize two new fields in struct MCExtraProcessorInfo named `LoadQueueID` and
`StoreQueueID`.  Those two fields are identifiers for buffered resources used to
describe the load queue and the store queue.
Field `BufferSize` is interpreted as the number of entries in the queue, while
the number of units is a throughput indicator (i.e. number of available pickers
for loads/stores).

At construction time, LSUnit in llvm-mca checks for the presence of extra
processor information (i.e. MCExtraProcessorInfo) in the scheduling model.  If
that information is available, and fields LoadQueueID and StoreQueueID are set
to a value different than zero (i.e. the invalid processor resource index), then
LSUnit initializes its LoadQueue/StoreQueue based on the BufferSize value
declared by the two processor resources.

With this patch, we more accurately track dynamic dispatch stalls caused by the
lack of LS tokens (i.e. load/store queue full). This is also shown by the
differences in two BdVer2 tests. Stalls that were previously classified as
generic SCHEDULER FULL stalls, are not correctly classified either as "load
queue full" or "store queue full".

About the differences in the -scheduler-stats view: those differences are
expected, because entries in the load/store queue are not released at
instruction issue stage. Instead, those are released at instruction executed
stage.  This is the main reason why for the modified tests, the load/store
queues gets full before PdEx is full.

Differential Revision: https://reviews.llvm.org/D54957

llvm-svn: 347857
2018-11-29 12:15:56 +00:00
Fangrui Song 5a8fd65700 [llvm-mca] Move namespace mca inside llvm::
Summary: This allows to remove `using namespace llvm;` in those *.cpp files

When we want to revisit the decision (everything resides in llvm::mca::*) in the future, we can move things to a nested namespace of llvm::mca::, to conceptually make them separate from the rest of llvm::mca::*

Reviewers: andreadb, mattd

Reviewed By: andreadb

Subscribers: javed.absar, tschuett, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D53407

llvm-svn: 345612
2018-10-30 15:56:08 +00:00
Andrea Di Biagio 77c26aebda [llvm-mca] Removed a couple of redundant method declarations, and simplified code in ResourcePressureView. NFC
llvm-svn: 345259
2018-10-25 11:51:34 +00:00
Andrea Di Biagio 29c5d5aa36 [llvm-mca] Pass an instruction reference when notifying event listeners about reserved/released buffer resources. NFC
llvm-svn: 340821
2018-08-28 13:14:42 +00:00
Andrea Di Biagio b89b96c1b2 [llvm-mca] Improved report generated by the SchedulerStatistics view.
Before this patch, the SchedulerStatistics only printed the maximum number of
buffer entries consumed in each scheduler's queue at a given point of the
simulation.

This patch restructures the reported table, and adds an extra field named
"Average number of used buffer entries" to it.
This patch also uses different colors to help identifying bottlenecks caused by
high scheduler's buffer pressure.

llvm-svn: 340746
2018-08-27 14:52:52 +00:00
Matt Davis 10aa09f008 [llvm-mca] Move views and stats into a Views subdir. NFC.
llvm-svn: 340645
2018-08-24 20:24:53 +00:00