Commit Graph

7 Commits

Author SHA1 Message Date
Andrea Di Biagio be8616f5f2 [MCSchedule] Add the ability to compute the latency and throughput information for MCInst.
This patch extends the MCSchedModel API with new methods that can be used to
obtain the latency and reciprocal througput information for an MCInst.

Scheduling models have recently gained the ability to resolve variant scheduling
classes associated with MCInst objects. Before, models were only able to resolve
a variant scheduling class from a MachineInstr object.

This patch is mainly required by D47374 to avoid regressing a pair of x86
specific -print-schedule tests for btver2. Patch D47374 introduces a new variant
class to teach the btver scheduling model (x86 target) how to correctly compute
the latency profile for some zero-idioms using the new scheduling predicates.

The new methods added by this patch would be mainly used by llc when flag
-print-schedule is specified. In particular, tests that contain inline assembly
require that code is parsed at code emission stage into a sequence of MCInst.
That forces the print-schedule functionality to query the latency/rthroughput
information for MCInst instructions too. If we don't expose this new API, then
we lose "-print-schedule" test coverage as soon as variant scheduling classes
are added to the x86 models.

The tablegen SubtargetEmitter changes teaches how to query latency profile
information using a object that derives from TargetSubtargetInfo. Note that this
should really have been part of r333286. To avoid code duplication, the logic
that "resolves" variant scheduling classes for MCInst, has been moved to a
common place in MC. That logic is used by the "resolveVariantSchedClass" methods
redefined in override by the tablegen'd GenSubtargetInfo classes.

Differential Revision: https://reviews.llvm.org/D47536

llvm-svn: 333650
2018-05-31 13:30:42 +00:00
Andrea Di Biagio b9acf13907 [MC] Moved all the remaining logic that computed instruction latency and reciprocal throughput from TargetSchedModel to MCSchedModel.
TargetSchedModel now always delegates to MCSchedModel the computation of
instruction latency and reciprocal throughput.
No functional change intended.

llvm-svn: 330099
2018-04-15 17:32:17 +00:00
Andrea Di Biagio 823e5f90db [MC] Fix -Wmissing-field-initializer warning after r329067.
This should fix the problem reported by the lld buildbots:
 - Builder lld-x86_64-darwin13, Build #19782
 - Builder lld-perf-testsuite, Build #1419

llvm-svn: 329068
2018-04-03 13:52:26 +00:00
Andrea Di Biagio 7faea7cb53 [MC] Move the reciprocal throughput computation from TargetSchedModel to MCSchedModel.
The goal is to make the reciprocal throughput computation accessible through the
MCSchedModel interface. This is particularly important for llvm-mca because it
can only query the MCSchedModel interface.

No functional change intended.

Differential Revision: https://reviews.llvm.org/D44392

llvm-svn: 327420
2018-03-13 16:28:55 +00:00
Andrea Di Biagio 30c1ba4834 [MC] Move the instruction latency computation from TargetSchedModel to MCSchedModel.
The goal is to make the latency information accessible through the MCSchedModel
interface. This is particularly important for tools like llvm-mca that only have
access to the MCSchedModel API.

This partially fixes PR36676.
No functional change intended.

Differential Revision: https://reviews.llvm.org/D44383

llvm-svn: 327406
2018-03-13 15:22:13 +00:00
Duncan P. N. Exon Smith f787ed0b35 Add <type_traits> for is_pod, fixing r241947
llvm-svn: 241949
2015-07-10 22:17:49 +00:00
Duncan P. N. Exon Smith f862f87ff2 MC: Remove the copy of MCSchedModel in MCSubtargetInfo
`MCSchedModel` is large.  Make `MCSchedModel::GetDefaultSchedModel()`
return by-reference instead of by-value, so we can store a pointer in
`MCSubtargetInfo::CPUSchedModel` instead of a copy.

Note: since `MCSchedModel` is POD, this doesn't create a static
constructor.

llvm-svn: 241947
2015-07-10 22:13:43 +00:00