Summary:
Add an option to prevent diagnostics that do not meet a minimum hotness
threshold from being output. When generating optimization remarks for
large codebases with a ton of cold code paths, this option can be used
to limit the optimization remark output at a reasonable size. Discussion of
this change can be read here:
http://lists.llvm.org/pipermail/llvm-dev/2017-June/114377.html
Reviewers: anemet, davidxl, hfinkel
Reviewed By: anemet
Subscribers: qcolombet, javed.absar, fhahn, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D34867
llvm-svn: 306912
Summary:
To enable profile hotness information in diagnostics output, Clang takes
the option `-fdiagnostics-show-hotness` -- that's "diagnostics", with an
"s" at the end. Clang also defines `CodeGenOptions::DiagnosticsWithHotness`.
LLVM, on the other hand, defines
`LLVMContext::getDiagnosticHotnessRequested` -- that's "diagnostic", not
"diagnostics". It's a small difference, but it's confusing, typo-inducing, and
frustrating.
Add a new method with the spelling "diagnostics", and "deprecate" the
old spelling.
Reviewers: anemet, davidxl
Reviewed By: anemet
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D34864
llvm-svn: 306848
Since LoopInfo is not available in machine passes as universally as in IR
passes, using the same approach for OptimizationRemarkEmitter as we did for IR
will run LoopInfo and DominatorTree unnecessarily. (LoopInfo is not used
lazily by ORE.)
To fix this, I am modifying the approach I took in D29836. LazyMachineBFI now
uses its client passes including MachineBFI itself that are available or
otherwise compute them on the fly.
So for example GreedyRegAlloc, since it's already using MBFI, will reuse that
instance. On the other hand, AsmPrinter in Justin's patch will generate DT,
LI and finally BFI on the fly.
(I am of course wondering now if the simplicity of this approach is even
preferable in IR. I will do some experiments.)
Testing is provided by an updated version of D29837 which requires Justin's
patch to bring ORE to the AsmPrinter.
Differential Revision: https://reviews.llvm.org/D30128
llvm-svn: 295996
And use it in MachineOptimizationRemarkEmitter. A test will follow on top of
Justin's changes to enable MachineORE in AsmPrinter.
The approach is similar to the IR-level pass. It's a bit simpler because BPI
is immutable at the Machine level so we don't need to make that lazy.
Because of this, a new function mapping is introduced (BPIPassTrait::getBPI).
This function extracts BPI from the pass. In case of the lazy pass, this is
when the calculation of the BFI occurs. For Machine-level, this is the
identity function.
Differential Revision: https://reviews.llvm.org/D29836
llvm-svn: 295072
This allows MIR passes to emit optimization remarks with the same level
of functionality that is available to IR passes.
It also hooks up the greedy register allocator to report spills. This
allows for interesting use cases like increasing interleaving on a loop
until spilling of registers is observed.
I still need to experiment whether reporting every spill scales but this
demonstrates for now that the functionality works from llc
using -pass-remarks*=<pass>.
Differential Revision: https://reviews.llvm.org/D29004
llvm-svn: 293110
Brian Gesiak