Summary:
This patch eliminates many places where we originally needed to pass index
values to represent an instruction. The index is still used as a key, in various parts of
MCA. I'm not comfortable eliminating the index just yet. By burying the index in
the instruction, we can avoid exposing that value in many places.
Eventually, we should consider removing the Instructions list in the Backend
all together, it's only used to hold and reclaim the memory for the allocated
Instruction instances. Instead we could pass around a smart pointer. But that's
a separate discussion/patch.
Reviewers: andreadb, courbet, RKSimon
Reviewed By: andreadb
Subscribers: javed.absar, tschuett, gbedwell, llvm-commits
Differential Revision: https://reviews.llvm.org/D46367
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331660 91177308-0d34-0410-b5e6-96231b3b80d8
This change removes method Backend::getProcResourceMasks() and simplifies some
logic in the Views. This effectively removes yet another dependency between the
views and the Backend.
No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327214 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-mca is an LLVM based performance analysis tool that can be used to
statically measure the performance of code, and to help triage potential
problems with target scheduling models.
llvm-mca uses information which is already available in LLVM (e.g. scheduling
models) to statically measure the performance of machine code in a specific cpu.
Performance is measured in terms of throughput as well as processor resource
consumption. The tool currently works for processors with an out-of-order
backend, for which there is a scheduling model available in LLVM.
The main goal of this tool is not just to predict the performance of the code
when run on the target, but also help with diagnosing potential performance
issues.
Given an assembly code sequence, llvm-mca estimates the IPC (instructions per
cycle), as well as hardware resources pressure. The analysis and reporting style
were mostly inspired by the IACA tool from Intel.
This patch is related to the RFC on llvm-dev visible at this link:
http://lists.llvm.org/pipermail/llvm-dev/2018-March/121490.html
Differential Revision: https://reviews.llvm.org/D43951
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326998 91177308-0d34-0410-b5e6-96231b3b80d8
