5 Commits

Author SHA1 Message Date
Andrea Di Biagio
6b6a90fb85 [MC][X86] Correctly model additional operand latency caused by transfer delays from the integer to the floating point unit.
This patch adds a new ReadAdvance definition named ReadInt2Fpu.
ReadInt2Fpu allows x86 scheduling models to accurately describe delays caused by
data transfers from the integer unit to the floating point unit.
ReadInt2Fpu currently defaults to a delay of zero cycles (i.e. no delay) for all
x86 models excluding BtVer2. That means, this patch is only a functional change
for the Jaguar cpu model only.

Tablegen definitions for instructions (V)PINSR* have been updated to account for
the new ReadInt2Fpu. That read is mapped to the the GPR input operand.
On Jaguar, int-to-fpu transfers are modeled as a +6cy delay. Before this patch,
that extra delay was added to the opcode latency. In practice, the insert opcode
only executes for 1cy. Most of the actual latency is actually contributed by the
so-called operand-latency. According to the AMD SOG for family 16h, (V)PINSR*
latency is defined by expression f+1, where f is defined as a forwarding delay
from the integer unit to the fpu.

When printing instruction latency from MCA (see InstructionInfoView.cpp) and LLC
(only when flag -print-schedule is speified), we now need to account for any
extra forwarding delays. We do this by checking if scheduling classes declare
any negative ReadAdvance entries. Quoting a code comment in TargetSchedule.td:
"A negative advance effectively increases latency, which may be used for
cross-domain stalls". When computing the instruction latency for the purpose of
our scheduling tests, we now add any extra delay to the formula. This avoids
regressing existing codegen and mca schedule tests. It comes with the cost of an
extra (but very simple) hook in MCSchedModel.

Differential Revision: https://reviews.llvm.org/D57056


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351965 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-23 16:35:07 +00:00
Chandler Carruth
6b547686c5 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Fangrui Song
467c30721b [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345612 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-30 15:56:08 +00:00
Andrea Di Biagio
a9c48593d9 [llvm-mca] Refactor class SourceMgr. NFCI
Added begin()/end() methods to allow the usage of SourceMgr in foreach loops.
With this change, method getMCInstFromIndex() (as well as a couple of other
methods) are now redundant, and can be removed from the public interface.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345147 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-24 15:06:27 +00:00
Matt Davis
444bd8165f [llvm-mca] Move views and stats into a Views subdir. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340645 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-24 20:24:53 +00:00