Rename the pass to be able to extend it to function properties other than inliner features.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D82044
This reverts commit 9908a3b9f5.
The fix was to exclude the content of TFUtils.h (automatically
included in the LLVM_Analysis module, when LLVM_ENABLE_MODULES is enabled).
Differential Revision: https://reviews.llvm.org/D82817
Summary:
This is an experimental ML-based native size estimator, necessary for
computing partial rewards during -Oz inliner policy training. Data
extraction for model training will be provided in a separate patch.
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html
Reviewers: davidxl, jdoerfert
Subscribers: mgorny, hiraditya, mgrang, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82817
The legacy pass name is "loop-fusion".
Fixes most tests under Transforms/LoopFusion under NPM.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D83066
The legacy pass was called "loop-reduce".
This lowers the number of check-llvm failures under NPM by 83.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D82925
The legacy pass is called "loop-unroll", but in the new PM it's called "unroll".
Also applied to unroll-and-jam and unroll-full.
Fixes various check-llvm tests when NPM is turned on.
Reviewed By: Whitney, dmgreen
Differential Revision: https://reviews.llvm.org/D82590
The dependency was introduced in
5134020ea6. The only functional change
from this removal would be the new PM interface for the two codegen
passes. This is not necessary since we don't have codegen pipeline using
new PM yet. This removal is to break the potential circular dependency between
Passes and CodeGen once the codegen begins to gain new PM support.
This class allows to see the inliner's decisions for better
optimization verifications and tests. To use, use flag
"-passes="print<inline-cost>"".
This is the second attempt to integrate the patch.
The problem from the first try has been discussed and
fixed in D82205.
Reviewers: apilipenko, mtrofin, davidxl, fedor.sergeev
Reviewed By: mtrofin
Differential revision: https://reviews.llvm.org/D81743
Summary:
Seems to just be missing from PassRegistry.def.
Makes the number of check-llvm failures under new PM go from 2619 to 2581.
Reviewers: hans, ychen, asbirlea, leonardchan
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82422
Summary:
-simplifycfg is the legacy pass name for SimplifyCFGPass.
There is already -simplify-cfg in FUNCTION_PASS_WITH_PARAMS which
handles options for SimplifyCFGPass. Maybe that should be renamed to
-simplifycfg as well?
This reduces the number of check-llvm failures under NewPM from 2619 to 2392.
Reviewers: hans, leonardchan, asbirlea, ychen
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82421
Summary:
Extend StackLifetime with option to calculate liveliness
where alloca is only considered alive on basic block entry
if all non-dead predecessors had it alive at terminators.
Depends on D82043.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82124
This class allows to see the inliner's decisions for better
optimization verifications and tests. To use, use flag
"-passes="print<inline-cost>"".
Reviewers: apilipenko, mtrofin, davidxl, fedor.sergeev
Reviewed By: mtrofin
Differential revision: https://reviews.llvm.org/D81743
This lets us to remove !stack-safe metadata and
better controll when to perform StackSafety
analysis.
Reviewers: eugenis
Subscribers: hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D80771
Summary:
If an induction variable is frozen and used, SCEV yields imprecise result
because it doesn't say anything about frozen variables.
Due to this reason, performance degradation happened after
https://reviews.llvm.org/D76483 is merged, causing
SCEV yield imprecise result and preventing LSR to optimize a loop.
The suggested solution here is to add a pass which canonicalizes frozen variables
inside a loop. To be specific, it pushes freezes out of the loop by freezing
the initial value and step values instead & dropping nsw/nuw flags from instructions used by freeze.
This solution was also mentioned at https://reviews.llvm.org/D70623 .
Reviewers: spatel, efriedma, lebedev.ri, fhahn, jdoerfert
Reviewed By: fhahn
Subscribers: nikic, mgorny, hiraditya, javed.absar, llvm-commits, sanwou01, nlopes
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77523
Summary:
This change introduces InliningAdvisor (and related APIs), the interface
that abstracts decision making away from the inlining pass. We will use
this interface to delegate decision making to a trained ML model,
subsequently (see referenced RFC).
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html
Reviewers: davidxl, eraman, dblaikie
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79042
don't span their entire scope.
The previous commit (6d1c40c171) is an older version of the test.
Reviewed By: aprantl, vsk
Differential Revision: https://reviews.llvm.org/D79573
Summary:
This simplifies testing in scenarios where we want to set up module-wide
analyses for inlining. The patch enables treating inlining and its
function cleanups, as a module pass. The alternative would be for tests
to describe the pipeline, which is tedious and adds maintenance
overhead.
Reviewers: davidxl, dblaikie, jdoerfert, sstefan1
Subscribers: hiraditya, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78512
Summary:
Run StackSafetyAnalysis at the end of the IR pipeline and annotate
proven safe allocas with !stack-safe metadata. Do not instrument such
allocas in the AArch64StackTagging pass.
Reviewers: pcc, vitalybuka, ostannard
Reviewed By: vitalybuka
Subscribers: merge_guards_bot, kristof.beyls, hiraditya, cfe-commits, gilang, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73513
Summary: This patch adds an analysis pass to collect loop nests and
summarize properties of the nest (e.g the nest depth, whether the nest
is perfect, what's the innermost loop, etc...).
The motivation for this patch was discussed at the latest meeting of the
LLVM loop group (https://ibm.box.com/v/llvm-loop-nest-analysis) where we
discussed
the unimodular loop transformation framework ( “A Loop Transformation
Theory and an Algorithm to Maximize Parallelism”, Michael E. Wolf and
Monica S. Lam, IEEE TPDS, October 1991). The unimodular framework
provides a convenient way to unify legality checking and code generation
for several loop nest transformations (e.g. loop reversal, loop
interchange, loop skewing) and their compositions. Given that the
unimodular framework is applicable to perfect loop nests this is one
property of interest we expose in this analysis. Several other utility
functions are also provided. In the future other properties of interest
can be added in a centralized place.
Authored By: etiotto
Reviewer: Meinersbur, bmahjour, kbarton, Whitney, dmgreen, fhahn,
reames, hfinkel, jdoerfert, ppc-slack
Reviewed By: Meinersbur
Subscribers: bryanpkc, ppc-slack, mgorny, hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D68789
Summary: This patch adds an analysis pass to collect loop nests and
summarize properties of the nest (e.g the nest depth, whether the nest
is perfect, what's the innermost loop, etc...).
The motivation for this patch was discussed at the latest meeting of the
LLVM loop group (https://ibm.box.com/v/llvm-loop-nest-analysis) where we
discussed
the unimodular loop transformation framework ( “A Loop Transformation
Theory and an Algorithm to Maximize Parallelism”, Michael E. Wolf and
Monica S. Lam, IEEE TPDS, October 1991). The unimodular framework
provides a convenient way to unify legality checking and code generation
for several loop nest transformations (e.g. loop reversal, loop
interchange, loop skewing) and their compositions. Given that the
unimodular framework is applicable to perfect loop nests this is one
property of interest we expose in this analysis. Several other utility
functions are also provided. In the future other properties of interest
can be added in a centralized place.
Authored By: etiotto
Reviewer: Meinersbur, bmahjour, kbarton, Whitney, dmgreen, fhahn,
reames, hfinkel, jdoerfert, ppc-slack
Reviewed By: Meinersbur
Subscribers: bryanpkc, ppc-slack, mgorny, hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D68789
Summary:
Depends on https://reviews.llvm.org/D71900.
The fourth in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements
'coro-cleanup'.
No existing regression tests check the behavior of coro-cleanup on its
own, so this patch adds one. (A test named 'coro-cleanup.ll' exists, but
it relies on the entire coroutines pipeline being run. It's updated to
test the new pass manager in the 5th patch of this series.)
Reviewers: GorNishanov, lewissbaker, chandlerc, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71901
Summary:
Depends on https://reviews.llvm.org/D71899.
The third in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements 'coro-elide'.
The new pass manager infrastructure does not implicitly repeat CGSCC
pass pipelines when a function is devirtualized, and so the tests
for the new pass manager that rely on that behavior now explicitly
specify `repeat<2>`.
Reviewers: GorNishanov, lewissbaker, chandlerc, jdoerfert, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, EricWF, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71900
Summary:
This patch has four dependencies:
1. The first in this series of patches that implement coroutine passes in the
new pass manager: https://reviews.llvm.org/D71898.
2. A patch that introduces an API for CGSCC passes to add new reference
edges to a `LazyCallGraph`, `updateCGAndAnalysisManagerForCGSCCPass`:
https://reviews.llvm.org/D72025.
3. A patch that introduces a `CallGraphUpdater` helper class that is
capable of mutating internal `LazyCallGraph` state in order to insert
new function nodes into a specific SCC: https://reviews.llvm.org/D70927.
4. And finally, a small edge case fix for updating `LazyCallGraph` that
patch 3 above happens to run into: https://reviews.llvm.org/D72226.
This is the second in a series of patches that ports the LLVM coroutines
passes to the new pass manager infrastructure. This patch implements
'coro-split'.
Some notes:
* Using the new CGSCC pass manager resulted in IR being printed in the
reverse order in some tests. To prevent FileCheck checks from failing due
to these reversed orders, this patch splits up test files that test
multiple different coroutine functions: specifically
coro-alloc-with-param.ll, coro-split-eh.ll, and coro-eh-aware-edge-split.ll.
* CoroSplit.cpp contained 2 overloads of `splitCoroutine`, one of which
dispatched to the other based on the coroutine ABI being used (C++20
switch-based versus Swift returned-continuation-based). I found this
confusing, especially with the additional branching based on `CallGraph`
vs. `LazyCallGraph`, so I removed the ABI-checking overload of
`splitCoroutine`.
Reviewers: GorNishanov, lewissbaker, chandlerc, jdoerfert, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, qcolombet, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71899
Summary:
The first in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements
'coro-early'.
NB: All coroutines passes begin by checking that coroutine intrinsics are
declared within the LLVM IR module they're operating on. To do so, they call
`coro::declaresIntrinsics`. The next 3 patches in this series, which add new
pass manager implementations of the 'coro-split', 'coro-elide', and
'coro-cleanup' passes, use a similar pattern as the one used here: a static
function is shared across both old and new passes to detect if relevant
coroutine intrinsics are delcared. To make this pattern easier to read, this
patch adds `const` keywords to the parameters of `coro::declaresIntrinsics`.
Reviewers: GorNishanov, lewissbaker, junparser, chandlerc, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: ychen, wenlei, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71898
We have several bug reports that could be characterized as "reducing scalarization",
and this topic was also raised on llvm-dev recently:
http://lists.llvm.org/pipermail/llvm-dev/2020-January/138157.html
...so I'm proposing that we deal with these patterns in a new, lightweight IR vector
pass that runs before/after other vectorization passes.
There are 4 alternate options that I can think of to deal with this kind of problem
(and we've seen various attempts at all of these), but they all have flaws:
InstCombine - can't happen without TTI, but we don't want target-specific
folds there.
SDAG - too late to assist other vectorization passes; TLI is not equipped
for these kind of cost queries; limited to a single basic block.
CGP - too late to assist other vectorization passes; would need to re-implement
basic cleanups like CSE/instcombine.
SLP - doesn't fit with existing transforms; limited to a single basic block.
This initial patch/transform is based on existing code in AggressiveInstCombine:
we walk backwards through the function looking for a pattern match. But we diverge
from that cost-independent IR canonicalization pass by using TTI to decide if the
vector alternative is profitable.
We probably have at least 10 similar bug reports/patterns (binops, constants,
inserts, cheap shuffles, etc) that would fit in this pass as follow-up enhancements.
It's possible that we could iterate on a worklist to fix-point like InstCombine does,
but it's safer to start with a most basic case and evolve from there, so I didn't
try to do anything fancy with this initial implementation.
Differential Revision: https://reviews.llvm.org/D73480
In addition to the module pass, this patch introduces a CGSCC pass that
runs the Attributor on a strongly connected component of the call graph
(both old and new PM). The Attributor was always design to be used on a
subset of functions which makes this patch mostly mechanical.
The one change is that we give up `norecurse` deduction in the module
pass in favor of doing it during the CGSCC pass. This makes the
interfaces simpler but can be revisited if needed.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D70767
The OpenMPOpt pass is a CGSCC pass in which OpenMP specific
optimizations can reside.
The OpenMPOpt pass uses the OpenMPKinds.def file to identify runtime
calls and their uses. This allows targeted transformations and eases
their implementation.
This initial patch deduplicates `__kmpc_global_thread_num` and
`omp_get_thread_num` calls. We can also identify arguments that are
equivalent to such a call result and use it instead. Later we can
determine "gtid" arguments based on the use in kernel functions etc.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D69930
Fix attempt
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Introduce parsing, add a few instances of parameter use into GVN-PRE tests.
Reviewers: skatkov, asbirlea
Reviewed By: skatkov
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72752
This ports the MergeFunctions pass to the NewPM. This was rather
straightforward, as no analyses are used.
Additionally MergeFunctions needs to be conditionally enabled in
the PassBuilder, but I left that part out of this patch.
Differential Revision: https://reviews.llvm.org/D72537
pass.
Summary: This patch changes LoopUnrollAndJamPass to a function pass, and
keeps the loops traversal order same as defined in
FunctionToLoopPassAdaptor LoopPassManager.h.
The next patch will change the loop traversal to outer to inner order,
so more loops can be transform.
Discussion in llvm-dev mailing list:
https://groups.google.com/forum/#!topic/llvm-dev/LF4rUjkVI2g
Reviewer: dmgreen, jdoerfert, Meinersbur, kbarton, bmahjour, etiotto
Reviewed By: dmgreen
Subscribers: hiraditya, zzheng, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D72230
This is the first patch adding an initial set of matrix intrinsics and a
corresponding lowering pass. This has been discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2019-October/136240.html
The first patch introduces four new intrinsics (transpose, multiply,
columnwise load and store) and a LowerMatrixIntrinsics pass, that
lowers those intrinsics to vector operations.
Matrixes are embedded in a 'flat' vector (e.g. a 4 x 4 float matrix
embedded in a <16 x float> vector) and the intrinsics take the dimension
information as parameters. Those parameters need to be ConstantInt.
For the memory layout, we initially assume column-major, but in the RFC
we also described how to extend the intrinsics to support row-major as
well.
For the initial lowering, we split the input of the intrinsics into a
set of column vectors, transform those column vectors and concatenate
the result columns to a flat result vector.
This allows us to lower the intrinsics without any shape propagation, as
mentioned in the RFC. In follow-up patches, we plan to submit the
following improvements:
* Shape propagation to eliminate the embedding/splitting for each
intrinsic.
* Fused & tiled lowering of multiply and other operations.
* Optimization remarks highlighting matrix expressions and costs.
* Generate loops for operations on large matrixes.
* More general block processing for operation on large vectors,
exploiting shape information.
We would like to add dedicated transpose, columnwise load and store
intrinsics, even though they are not strictly necessary. For example, we
could instead emit a large shufflevector instruction instead of the
transpose. But we expect that to
(1) become unwieldy for larger matrixes (even for 16x16 matrixes,
the resulting shufflevector masks would be huge),
(2) risk instcombine making small changes, causing us to fail to
detect the transpose, preventing better lowerings
For the load/store, we are additionally planning on exploiting the
intrinsics for better alias analysis.
Reviewers: anemet, Gerolf, reames, hfinkel, andrew.w.kaylor, efriedma, rengolin
Reviewed By: anemet
Differential Revision: https://reviews.llvm.org/D70456
New pass manager doesn't use verifyAnalysis, so currently there is no
way to call SCEV verification from command line when new PM is used.
This patch adds a pass that allows you to do that.
Reviewers: reames, fhahn, sanjoy.google, nikic
Reviewed By: fhahn
Subscribers: hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70423
This patch introduces a function pass to inject the scalar-to-vector
mappings stored in the TargetLIbraryInfo (TLI) into the Vector
Function ABI (VFABI) variants attribute.
The test is testing the injection for three vector libraries supported
by the TLI (Accelerate, SVML, MASSV).
The pass does not change any of the analysis associated to the
function.
Differential Revision: https://reviews.llvm.org/D70107
Add a pass to lower is.constant and objectsize intrinsics
This pass lowers is.constant and objectsize intrinsics not simplified by
earlier constant folding, i.e. if the object given is not constant or if
not using the optimized pass chain. The result is recursively simplified
and constant conditionals are pruned, so that dead blocks are removed
even for -O0. This allows inline asm blocks with operand constraints to
work all the time.
The new pass replaces the existing lowering in the codegen-prepare pass
and fallbacks in SDAG/GlobalISEL and FastISel. The latter now assert
on the intrinsics.
Differential Revision: https://reviews.llvm.org/D65280
llvm-svn: 374784
This pass lowers is.constant and objectsize intrinsics not simplified by
earlier constant folding, i.e. if the object given is not constant or if
not using the optimized pass chain. The result is recursively simplified
and constant conditionals are pruned, so that dead blocks are removed
even for -O0. This allows inline asm blocks with operand constraints to
work all the time.
The new pass replaces the existing lowering in the codegen-prepare pass
and fallbacks in SDAG/GlobalISEL and FastISel. The latter now assert
on the intrinsics.
Differential Revision: https://reviews.llvm.org/D65280
llvm-svn: 374743
Summary:
If we insert them from function pass some analysis may be missing or invalid.
Fixes PR42877.
Reviewers: eugenis, leonardchan
Reviewed By: leonardchan
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68832
> llvm-svn: 374481
Signed-off-by: Vitaly Buka <vitalybuka@google.com>
llvm-svn: 374527
Summary:
If we insert them from function pass some analysis may be missing or invalid.
Fixes PR42877.
Reviewers: eugenis, leonardchan
Reviewed By: leonardchan
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68832
llvm-svn: 374481
Summary:
This is the first patch in a series of patches that will implement data dependence graph in LLVM. Many of the ideas used in this implementation are based on the following paper:
D. J. Kuck, R. H. Kuhn, D. A. Padua, B. Leasure, and M. Wolfe (1981). DEPENDENCE GRAPHS AND COMPILER OPTIMIZATIONS.
This patch contains support for a basic DDGs containing only atomic nodes (one node for each instruction). The edges are two fold: def-use edges and memory-dependence edges.
The implementation takes a list of basic-blocks and only considers dependencies among instructions in those basic blocks. Any dependencies coming into or going out of instructions that do not belong to those basic blocks are ignored.
The algorithm for building the graph involves the following steps in order:
1. For each instruction in the range of basic blocks to consider, create an atomic node in the resulting graph.
2. For each node in the graph establish def-use edges to/from other nodes in the graph.
3. For each pair of nodes containing memory instruction(s) create memory edges between them. This part of the algorithm goes through the instructions in lexicographical order and creates edges in reverse order if the sink of the dependence occurs before the source of it.
Authored By: bmahjour
Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert
Reviewed By: Meinersbur, fhahn, myhsu
Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto
Tag: #llvm
Differential Revision: https://reviews.llvm.org/D65350
llvm-svn: 372238
Summary:
This is the first patch in a series of patches that will implement data dependence graph in LLVM. Many of the ideas used in this implementation are based on the following paper:
D. J. Kuck, R. H. Kuhn, D. A. Padua, B. Leasure, and M. Wolfe (1981). DEPENDENCE GRAPHS AND COMPILER OPTIMIZATIONS.
This patch contains support for a basic DDGs containing only atomic nodes (one node for each instruction). The edges are two fold: def-use edges and memory-dependence edges.
The implementation takes a list of basic-blocks and only considers dependencies among instructions in those basic blocks. Any dependencies coming into or going out of instructions that do not belong to those basic blocks are ignored.
The algorithm for building the graph involves the following steps in order:
1. For each instruction in the range of basic blocks to consider, create an atomic node in the resulting graph.
2. For each node in the graph establish def-use edges to/from other nodes in the graph.
3. For each pair of nodes containing memory instruction(s) create memory edges between them. This part of the algorithm goes through the instructions in lexicographical order and creates edges in reverse order if the sink of the dependence occurs before the source of it.
Authored By: bmahjour
Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert
Reviewed By: Meinersbur, fhahn, myhsu
Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto
Tag: #llvm
Differential Revision: https://reviews.llvm.org/D65350
llvm-svn: 372162
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.
This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.
Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.
There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.
Reviewers: chandlerc, hfinkel
Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66428
llvm-svn: 371284
If we have:
bb5:
br i1 %arg3, label %bb6, label %bb7
bb6:
%tmp = getelementptr inbounds i32, i32* %arg1, i64 2
store i32 3, i32* %tmp, align 4
br label %bb9
bb7:
%tmp8 = getelementptr inbounds i32, i32* %arg1, i64 2
store i32 3, i32* %tmp8, align 4
br label %bb9
bb9: ; preds = %bb4, %bb6, %bb7
...
We can't sink stores directly into bb9.
This patch creates new BB that is successor of %bb6 and %bb7
and sinks stores into that block.
SplitFooterBB is the parameter to the pass that controls
that behavior.
Change-Id: I7fdf50a772b84633e4b1b860e905bf7e3e29940f
Differential: https://reviews.llvm.org/D66234
llvm-svn: 371089
This patch merges the sancov module and funciton passes into one module pass.
The reason for this is because we ran into an out of memory error when
attempting to run asan fuzzer on some protobufs (pc.cc files). I traced the OOM
error to the destructor of SanitizerCoverage where we only call
appendTo[Compiler]Used which calls appendToUsedList. I'm not sure where precisely
in appendToUsedList causes the OOM, but I am able to confirm that it's calling
this function *repeatedly* that causes the OOM. (I hacked sancov a bit such that
I can still create and destroy a new sancov on every function run, but only call
appendToUsedList after all functions in the module have finished. This passes, but
when I make it such that appendToUsedList is called on every sancov destruction,
we hit OOM.)
I don't think the OOM is from just adding to the SmallSet and SmallVector inside
appendToUsedList since in either case for a given module, they'll have the same
max size. I suspect that when the existing llvm.compiler.used global is erased,
the memory behind it isn't freed. I could be wrong on this though.
This patch works around the OOM issue by just calling appendToUsedList at the
end of every module run instead of function run. The same amount of constants
still get added to llvm.compiler.used, abd we make the pass usage and logic
simpler by not having any inter-pass dependencies.
Differential Revision: https://reviews.llvm.org/D66988
llvm-svn: 370971
Summary: Implement a new analysis to estimate the number of cache lines
required by a loop nest.
The analysis is largely based on the following paper:
Compiler Optimizations for Improving Data Locality
By: Steve Carr, Katherine S. McKinley, Chau-Wen Tseng
http://www.cs.utexas.edu/users/mckinley/papers/asplos-1994.pdf
The analysis considers temporal reuse (accesses to the same memory
location) and spatial reuse (accesses to memory locations within a cache
line). For simplicity the analysis considers memory accesses in the
innermost loop in a loop nest, and thus determines the number of cache
lines used when the loop L in loop nest LN is placed in the innermost
position.
The result of the analysis can be used to drive several transformations.
As an example, loop interchange could use it determine which loops in a
perfect loop nest should be interchanged to maximize cache reuse.
Similarly, loop distribution could be enhanced to take into
consideration cache reuse between arrays when distributing a loop to
eliminate vectorization inhibiting dependencies.
The general approach taken to estimate the number of cache lines used by
the memory references in the inner loop of a loop nest is:
Partition memory references that exhibit temporal or spatial reuse into
reference groups.
For each loop L in the a loop nest LN: a. Compute the cost of the
reference group b. Compute the 'cache cost' of the loop nest by summing
up the reference groups costs
For further details of the algorithm please refer to the paper.
Authored By: etiotto
Reviewers: hfinkel, Meinersbur, jdoerfert, kbarton, bmahjour, anemet,
fhahn
Reviewed By: Meinersbur
Subscribers: reames, nemanjai, MaskRay, wuzish, Hahnfeld, xusx595,
venkataramanan.kumar.llvm, greened, dmgreen, steleman, fhahn, xblvaOO,
Whitney, mgorny, hiraditya, mgrang, jsji, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63459
llvm-svn: 368439
changes were made to the patch since then.
--------
[NewPM] Port Sancov
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.
Changes:
- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.
llvm-svn: 367053
This will let us instrument globals during initialization. This required
making the new PM pass a module pass, which should still provide access to
analyses via the ModuleAnalysisManager.
Differential Revision: https://reviews.llvm.org/D64843
llvm-svn: 366379
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.
Changes:
- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.
Differential Revision: https://reviews.llvm.org/D62888
llvm-svn: 365838
Implements a transform pass which instruments IR such that poison semantics are made explicit. That is, it provides a (possibly partial) executable semantics for every instruction w.r.t. poison as specified in the LLVM LangRef. There are obvious parallels to the sanitizer tools, but this pass is focused purely on the semantics of LLVM IR, not any particular source language.
The target audience for this tool is developers working on or targetting LLVM from a frontend. The idea is to be able to take arbitrary IR (with the assumption of known inputs), and evaluate it concretely after having made poison semantics explicit to detect cases where either a) the original code executes UB, or b) a transform pass introduces UB which didn't exist in the original program.
At the moment, this is mostly the framework and still needs to be fleshed out. By reusing existing code we have decent coverage, but there's a lot of cases not yet handled. What's here is good enough to handle interesting cases though; for instance, one of the recent LFTR bugs involved UB being triggered by integer induction variables with nsw/nuw flags would be reported by the current code.
(See comment in PoisonChecking.cpp for full explanation and context)
Differential Revision: https://reviews.llvm.org/D64215
llvm-svn: 365536
NOTE: Note that no attributes are derived yet. This patch will not go in
alone but only with others that derive attributes. The framework is
split for review purposes.
This commit introduces the Attributor pass infrastructure and fixpoint
iteration framework. Further patches will introduce abstract attributes
into this framework.
In a nutshell, the Attributor will update instances of abstract
arguments until a fixpoint, or a "timeout", is reached. Communication
between the Attributor and the abstract attributes that are derived is
restricted to the AbstractState and AbstractAttribute interfaces.
Please see the file comment in Attributor.h for detailed information
including design decisions and typical use case. Also consider the class
documentation for Attributor, AbstractState, and AbstractAttribute.
Reviewers: chandlerc, homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes, nicholas, reames
Subscribers: mehdi_amini, mgorny, hiraditya, bollu, steven_wu, dexonsmith, dang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59918
llvm-svn: 362578
Port hardware assisted address sanitizer to new PM following the same guidelines as msan and tsan.
Changes:
- Separate HWAddressSanitizer into a pass class and a sanitizer class.
- Create new PM wrapper pass for the sanitizer class.
- Use the getOrINsert pattern for some module level initialization declarations.
- Also enable kernel-kwasan in new PM
- Update llvm tests and add clang test.
Differential Revision: https://reviews.llvm.org/D61709
llvm-svn: 360707
While ASan and MSan passes were already ported to new PM, the kernel
variants weren't setup in the pipeline which makes the KASan and KMSan
tests in Clang fail.
Differential Revision: https://reviews.llvm.org/D61664
llvm-svn: 360313
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
1. Adjacent (no code between them)
2. Control flow equivalent (if one loop executes, the other loop executes)
3. Identical bounds (both loops iterate the same number of iterations)
4. No negative distance dependencies between the loop bodies.
The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.
The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.
Differential Revision: https://reviews.llvm.org/D55851
llvm-svn: 358607
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
1. Adjacent (no code between them)
2. Control flow equivalent (if one loop executes, the other loop executes)
3. Identical bounds (both loops iterate the same number of iterations)
4. No negative distance dependencies between the loop bodies.
The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.
The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.
Phabricator: https://reviews.llvm.org/D55851
llvm-svn: 358543
Straightforward port of StatepointIRVerifier pass to new Pass Manager framework.
Fix By: skatkov
Reviewed By: fedor.sergeev
Differential Revision: https://reviews.llvm.org/D59825
This is a re-land of r357147/r357148 with LLVM_ENABLE_MODULES build fixed.
Adding IR/SafepointIRVerifier.h into its own module.
llvm-svn: 357361
to unbreak the modular bots and its follow-up commit.
This reverts commit https://reviews.llvm.org/D59825
because it introduced a
fatal error: cyclic dependency in module 'LLVM_intrinsic_gen': LLVM_intrinsic_gen -> LLVM_IR -> LLVM_intrinsic_gen
llvm-svn: 357201
The basic idea of the pass is to use a circular buffer to log the execution ordering of the functions. We only log the function when it is first executed. We use a 8-byte hash to log the function symbol name.
In this pass, we add three global variables:
(1) an order file buffer: a circular buffer at its own llvm section.
(2) a bitmap for each module: one byte for each function to say if the function is already executed.
(3) a global index to the order file buffer.
At the function prologue, if the function has not been executed (by checking the bitmap), log the function hash, then atomically increase the index.
Differential Revision: https://reviews.llvm.org/D57463
llvm-svn: 355133
This is the second attempt to port ASan to new PM after D52739. This takes the
initialization requried by ASan from the Module by moving it into a separate
class with it's own analysis that the new PM ASan can use.
Changes:
- Split AddressSanitizer into 2 passes: 1 for the instrumentation on the
function, and 1 for the pass itself which creates an instance of the first
during it's run. The same is done for AddressSanitizerModule.
- Add new PM AddressSanitizer and AddressSanitizerModule.
- Add legacy and new PM analyses for reading data needed to initialize ASan with.
- Removed DominatorTree dependency from ASan since it was unused.
- Move GlobalsMetadata and ShadowMapping out of anonymous namespace since the
new PM analysis holds these 2 classes and will need to expose them.
Differential Revision: https://reviews.llvm.org/D56470
llvm-svn: 353985
Introduces a pass that provides default lowering strategy for the
`experimental.widenable.condition` intrinsic, replacing all its uses with
`i1 true`.
Differential Revision: https://reviews.llvm.org/D56096
Reviewed By: reames
llvm-svn: 352739
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
Summary:
Second iteration of D56433 which got reverted in rL350719. The problem
in the previous version was that we dropped the thunk calling the tsan init
function. The new version keeps the thunk which should appease dyld, but is not
actually OK wrt. the current semantics of function passes. Hence, add a
helper to insert the functions only on the first time. The helper
allows hooking into the insertion to be able to append them to the
global ctors list.
Reviewers: chandlerc, vitalybuka, fedor.sergeev, leonardchan
Subscribers: hiraditya, bollu, llvm-commits
Differential Revision: https://reviews.llvm.org/D56538
llvm-svn: 351314
Allow to specify loop-unrolling with optional parameters explicitly
spelled out in -passes pipeline specification.
Introducing somewhat generic way of specifying parameters parsing via
FUNCTION_PASS_PARAMETRIZED pass registration.
Syntax of parametrized unroll pass name is as follows:
'unroll<' parameter-list '>'
Where parameter-list is ';'-separate list of parameter names and optlevel
optlevel: 'O[0-3]'
parameter: { 'partial' | 'peeling' | 'runtime' | 'upperbound' }
negated: 'no-' parameter
Example:
-passes=loop(unroll<O3;runtime;no-upperbound>)
this invokes LoopUnrollPass configured with OptLevel=3,
Runtime, no UpperBound, everything else by default.
llvm-svn: 350808
A straightforward port of tsan to the new PM, following the same path
as D55647.
Differential Revision: https://reviews.llvm.org/D56433
llvm-svn: 350647
The new-pm version of DA is untested. Testing requires a printer, so
add that and use it in the existing DA tests.
Differential Revision: https://reviews.llvm.org/D56386
llvm-svn: 350624
At -O0, globalopt is not run during the compile step, and we can have a
chain of an alias having an immediate aliasee of another alias. The
summaries are constructed assuming aliases in a canonical form
(flattened chains), and as a result only the base object but no
intermediate aliases were preserved.
Fix by adding a pass that canonicalize aliases, which ensures each
alias is a direct alias of the base object.
Reviewers: pcc, davidxl
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits
Differential Revision: https://reviews.llvm.org/D54507
llvm-svn: 350423
Summary:
Keeping msan a function pass requires replacing the module level initialization:
That means, don't define a ctor function which calls __msan_init, instead just
declare the init function at the first access, and add that to the global ctors
list.
Changes:
- Pull the actual sanitizer and the wrapper pass apart.
- Add a newpm msan pass. The function pass inserts calls to runtime
library functions, for which it inserts declarations as necessary.
- Update tests.
Caveats:
- There is one test that I dropped, because it specifically tested the
definition of the ctor.
Reviewers: chandlerc, fedor.sergeev, leonardchan, vitalybuka
Subscribers: sdardis, nemanjai, javed.absar, hiraditya, kbarton, bollu, atanasyan, jsji
Differential Revision: https://reviews.llvm.org/D55647
llvm-svn: 350305
When multiple loop transformation are defined in a loop's metadata, their order of execution is defined by the order of their respective passes in the pass pipeline. For instance, e.g.
#pragma clang loop unroll_and_jam(enable)
#pragma clang loop distribute(enable)
is the same as
#pragma clang loop distribute(enable)
#pragma clang loop unroll_and_jam(enable)
and will try to loop-distribute before Unroll-And-Jam because the LoopDistribute pass is scheduled after UnrollAndJam pass. UnrollAndJamPass only supports one inner loop, i.e. it will necessarily fail after loop distribution. It is not possible to specify another execution order. Also,t the order of passes in the pipeline is subject to change between versions of LLVM, optimization options and which pass manager is used.
This patch adds 'followup' attributes to various loop transformation passes. These attributes define which attributes the resulting loop of a transformation should have. For instance,
!0 = !{!0, !1, !2}
!1 = !{!"llvm.loop.unroll_and_jam.enable"}
!2 = !{!"llvm.loop.unroll_and_jam.followup_inner", !3}
!3 = !{!"llvm.loop.distribute.enable"}
defines a loop ID (!0) to be unrolled-and-jammed (!1) and then the attribute !3 to be added to the jammed inner loop, which contains the instruction to distribute the inner loop.
Currently, in both pass managers, pass execution is in a fixed order and UnrollAndJamPass will not execute again after LoopDistribute. We hope to fix this in the future by allowing pass managers to run passes until a fixpoint is reached, use Polly to perform these transformations, or add a loop transformation pass which takes the order issue into account.
For mandatory/forced transformations (e.g. by having been declared by #pragma omp simd), the user must be notified when a transformation could not be performed. It is not possible that the responsible pass emits such a warning because the transformation might be 'hidden' in a followup attribute when it is executed, or it is not present in the pipeline at all. For this reason, this patche introduces a WarnMissedTransformations pass, to warn about orphaned transformations.
Since this changes the user-visible diagnostic message when a transformation is applied, two test cases in the clang repository need to be updated.
To ensure that no other transformation is executed before the intended one, the attribute `llvm.loop.disable_nonforced` can be added which should disable transformation heuristics before the intended transformation is applied. E.g. it would be surprising if a loop is distributed before a #pragma unroll_and_jam is applied.
With more supported code transformations (loop fusion, interchange, stripmining, offloading, etc.), transformations can be used as building blocks for more complex transformations (e.g. stripmining+stripmining+interchange -> tiling).
Reviewed By: hfinkel, dmgreen
Differential Revision: https://reviews.llvm.org/D49281
Differential Revision: https://reviews.llvm.org/D55288
llvm-svn: 348944
This patch introduces a new instinsic `@llvm.experimental.widenable_condition`
that allows explicit representation for guards. It is an alternative to using
`@llvm.experimental.guard` intrinsic that does not contain implicit control flow.
We keep finding places where `@llvm.experimental.guard` is not supported or
treated too conservatively, and there are 2 reasons to that:
- `@llvm.experimental.guard` has memory write side effect to model implicit control flow,
and this sometimes confuses passes and analyzes that work with memory;
- Not all passes and analysis are aware of the semantics of guards. These passes treat them
as regular throwing call and have no idea that the condition of guard may be used to prove
something. One well-known place which had caused us troubles in the past is explicit loop
iteration count calculation in SCEV. Another example is new loop unswitching which is not
aware of guards. Whenever a new pass appears, we potentially have this problem there.
Rather than go and fix all these places (and commit to keep track of them and add support
in future), it seems more reasonable to leverage the existing optimizer's logic as much as possible.
The only significant difference between guards and regular explicit branches is that guard's condition
can be widened. It means that a guard contains (explicitly or implicitly) a `deopt` block successor,
and it is always legal to go there no matter what the guard condition is. The other successor is
a guarded block, and it is only legal to go there if the condition is true.
This patch introduces a new explicit form of guards alternative to `@llvm.experimental.guard`
intrinsic. Now a widenable guard can be represented in the CFG explicitly like this:
%widenable_condition = call i1 @llvm.experimental.widenable.condition()
%new_condition = and i1 %cond, %widenable_condition
br i1 %new_condition, label %guarded, label %deopt
guarded:
; Guarded instructions
deopt:
call type @llvm.experimental.deoptimize(<args...>) [ "deopt"(<deopt_args...>) ]
The new intrinsic `@llvm.experimental.widenable.condition` has semantics of an
`undef`, but the intrinsic prevents the optimizer from folding it early. This form
should exploit all optimization boons provided to `br` instuction, and it still can be
widened by replacing the result of `@llvm.experimental.widenable.condition()`
with `and` with any arbitrary boolean value (as long as the branch that is taken when
it is `false` has a deopt and has no side-effects).
For more motivation, please check llvm-dev discussion "[llvm-dev] Giving up using
implicit control flow in guards".
This patch introduces this new intrinsic with respective LangRef changes and a pass
that converts old-style guards (expressed as intrinsics) into the new form.
The naming discussion is still ungoing. Merging this to unblock further items. We can
later change the name of this intrinsic.
Reviewed By: reames, fedor.sergeev, sanjoy
Differential Revision: https://reviews.llvm.org/D51207
llvm-svn: 348593
Unlike its legacy counterpart new pass manager's LoopUnrollPass does
not provide any means to select which flavors of unroll to run
(runtime, peeling, partial), relying on global defaults.
In some cases having ability to run a restricted LoopUnroll that
does more than LoopFullUnroll is needed.
Introduced LoopUnrollOptions to select optional unroll behaviors.
Added 'unroll<peeling>' to PassRegistry mainly for the sake of testing.
Reviewers: chandlerc, tejohnson
Differential Revision: https://reviews.llvm.org/D53440
llvm-svn: 345723
This reverts commit 8d6af840396f2da2e4ed6aab669214ae25443204 and commit
b78d19c287b6e4a9abc9fb0545de9a3106d38d3d which causes slower build times
by initializing the AddressSanitizer on every function run.
The corresponding revisions are https://reviews.llvm.org/D52814 and
https://reviews.llvm.org/D52739.
llvm-svn: 345433
This patch ports the legacy pass manager to the new one to take advantage of
the benefits of the new PM. This involved moving a lot of the declarations for
`AddressSantizer` to a header so that it can be publicly used via
PassRegistry.def which I believe contains all the passes managed by the new PM.
This patch essentially decouples the instrumentation from the legacy PM such
hat it can be used by both legacy and new PM infrastructure.
Differential Revision: https://reviews.llvm.org/D52739
llvm-svn: 344274
Modified the testcases to use both pass managers
Use single commandline flag for both pass managers.
Differential Revision: https://reviews.llvm.org/D52708
Reviewers: sebpop, tejohnson, brzycki, SirishP
Reviewed By: tejohnson, brzycki
llvm-svn: 343662
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Made getName helper to return std::string (instead of StringRef initially) to fix
asan builtbot failures on CGSCC tests.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342664
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342597
Summary:
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342544
Summary:
Control height reduction merges conditional blocks of code and reduces the
number of conditional branches in the hot path based on profiles.
if (hot_cond1) { // Likely true.
do_stg_hot1();
}
if (hot_cond2) { // Likely true.
do_stg_hot2();
}
->
if (hot_cond1 && hot_cond2) { // Hot path.
do_stg_hot1();
do_stg_hot2();
} else { // Cold path.
if (hot_cond1) {
do_stg_hot1();
}
if (hot_cond2) {
do_stg_hot2();
}
}
This speeds up some internal benchmarks up to ~30%.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: xbolva00, dmgreen, mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D50591
llvm-svn: 341386
Summary:
Enable these passes for CFI and WPD in ThinLTO and LTO with the new pass
manager. Add a couple of tests for both PMs based on the clang tests
tools/clang/test/CodeGen/thinlto-distributed-cfi*.ll, but just test
through llvm-lto2 and not with distributed ThinLTO.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49429
llvm-svn: 337461
This is a simple implementation of the unroll-and-jam classical loop
optimisation.
The basic idea is that we take an outer loop of the form:
for i..
ForeBlocks(i)
for j..
SubLoopBlocks(i, j)
AftBlocks(i)
Instead of doing normal inner or outer unrolling, we unroll as follows:
for i... i+=2
ForeBlocks(i)
ForeBlocks(i+1)
for j..
SubLoopBlocks(i, j)
SubLoopBlocks(i+1, j)
AftBlocks(i)
AftBlocks(i+1)
Remainder Loop
So we have unrolled the outer loop, then jammed the two inner loops into
one. This can lead to a simpler inner loop if memory accesses can be shared
between the now jammed loops.
To do this we have to prove that this is all safe, both for the memory
accesses (using dependence analysis) and that ForeBlocks(i+1) can move before
AftBlocks(i) and SubLoopBlocks(i, j).
Differential Revision: https://reviews.llvm.org/D41953
llvm-svn: 336062
and diretory.
Also cleans up all the associated naming to be consistent and removes
the public access to the pass ID which was unused in LLVM.
Also runs clang-format over parts that changed, which generally cleans
up a bunch of formatting.
This is in preparation for doing some internal cleanups to the pass.
Differential Revision: https://reviews.llvm.org/D47352
llvm-svn: 336028
Extends the CFGPrinter and CallPrinter with heat colors based on heuristics or
profiling information. The colors are enabled by default and can be toggled
on/off for CFGPrinter by using the option -cfg-heat-colors for both
-dot-cfg[-only] and -view-cfg[-only]. Similarly, the colors can be toggled
on/off for CallPrinter by using the option -callgraph-heat-colors for both
-dot-callgraph and -view-callgraph.
Patch by Rodrigo Caetano Rocha!
Differential Revision: https://reviews.llvm.org/D40425
llvm-svn: 335996
This pass is being added in order to make the information available to BasicAA,
which can't do caching of this information itself, but possibly this information
may be useful for other passes.
Incorporates code based on Daniel Berlin's implementation of Tarjan's algorithm.
Differential Revision: https://reviews.llvm.org/D47893
llvm-svn: 335857
=== Generating the CG Profile ===
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
```
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
```
Differential Revision: https://reviews.llvm.org/D48105
llvm-svn: 335794
This is a simple implementation of the unroll-and-jam classical loop
optimisation.
The basic idea is that we take an outer loop of the form:
for i..
ForeBlocks(i)
for j..
SubLoopBlocks(i, j)
AftBlocks(i)
Instead of doing normal inner or outer unrolling, we unroll as follows:
for i... i+=2
ForeBlocks(i)
ForeBlocks(i+1)
for j..
SubLoopBlocks(i, j)
SubLoopBlocks(i+1, j)
AftBlocks(i)
AftBlocks(i+1)
Remainder
So we have unrolled the outer loop, then jammed the two inner loops into
one. This can lead to a simpler inner loop if memory accesses can be shared
between the now-jammed loops.
To do this we have to prove that this is all safe, both for the memory
accesses (using dependence analysis) and that ForeBlocks(i+1) can move before
AftBlocks(i) and SubLoopBlocks(i, j).
Differential Revision: https://reviews.llvm.org/D41953
llvm-svn: 333358
The plan had always been to move towards using this rather than so much
in-pass simplification within the loop pipeline, but we never got around
to it.... until only a couple months after it was removed due to disuse.
=/
This commit is just a pure revert of the removal. I will add tests and
do some basic cleanup in follow-up commits. Then I'll wire it into the
loop pass pipeline.
Differential Revision: https://reviews.llvm.org/D47353
llvm-svn: 333250
There are two nontrivial details here:
* Loop structure update interface is quite different with new pass manager,
so the code to add new loops was factored out
* BranchProbabilityInfo is not a loop analysis, so it can not be just getResult'ed from
within the loop pass. It cant even be queried through getCachedResult as LoopCanonicalization
sequence (e.g. LoopSimplify) might invalidate BPI results.
Complete solution for BPI will likely take some time to discuss and figure out,
so for now this was partially solved by making BPI optional in IRCE
(skipping a couple of profitability checks if it is absent).
Most of the IRCE tests got their corresponding new-pass-manager variant enabled.
Only two of them depend on BPI, both marked with TODO, to be turned on when BPI
starts being available for loop passes.
Reviewers: chandlerc, mkazantsev, sanjoy, asbirlea
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D43795
llvm-svn: 327619
LoopInstSimplify is unused and untested. Reading through the commit
history the pass also seems to have a high maintenance burden.
It would be best to retire the pass for now. It should be easy to
recover if we need something similar in the future.
Differential Revision: https://reviews.llvm.org/D44053
llvm-svn: 327329
Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.
For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.
It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.
Differential Revision: https://reviews.llvm.org/D38313
llvm-svn: 323321
Summary:
This pass synthesizes function entry counts by traversing the callgraph
and using the relative block frequencies of the callsites. The intended
use of these counts is in inlining to determine hot/cold callsites in
the absence of profile information.
The pass is split into two files with the code that propagates the
counts in a callgraph in a Utils file. I plan to add support for
propagation in the thinlto link phase and the propagation code will be
shared and hence this split. I did not add support to the old PM since
hot callsite determination in inlining is not possible in old PM
(although we could use hot callee heuristic with synthetic counts in the
old PM it is not worth the effort tuning it)
Reviewers: davidxl, silvas
Subscribers: mgorny, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D41604
llvm-svn: 322110
Summary:
The port is nearly straightforward.
The only complication is related to the analyses handling,
since one of the analyses used in this module pass is domtree,
which is a function analysis. That requires asking for the results
of each function and disallows a single interface for run-on-module
pass action.
Decided to copy-paste the main body of this pass.
Most of its code is requesting analyses anyway, so not that much
of a copy-paste.
The rest of the code movement is to transform all the implementation
helper functions like stripNonValidData into non-member statics.
Extended all the related LLVM tests with new-pass-manager use.
No failures.
Reviewers: sanjoy, anna, reames
Reviewed By: anna
Subscribers: skatkov, llvm-commits
Differential Revision: https://reviews.llvm.org/D41162
llvm-svn: 320796
The core idea is to (re-)introduce some redundancies where their cost is
hidden by the cost of materializing immediates for constant operands of
PHI nodes. When the cost of the redundancies is covered by this,
avoiding materializing the immediate has numerous benefits:
1) Less register pressure
2) Potential for further folding / combining
3) Potential for more efficient instructions due to immediate operand
As a motivating example, consider the remarkably different cost on x86
of a SHL instruction with an immediate operand versus a register
operand.
This pattern turns up surprisingly frequently, but is somewhat rarely
obvious as a significant performance problem.
The pass is entirely target independent, but it does rely on the target
cost model in TTI to decide when to speculate things around the PHI
node. I've included x86-focused tests, but any target that sets up its
immediate cost model should benefit from this pass.
There is probably more that can be done in this space, but the pass
as-is is enough to get some important performance on our internal
benchmarks, and should be generally performance neutral, but help with
more extensive benchmarking is always welcome.
One awkward part is that this pass has to be scheduled after
*everything* that can eliminate these kinds of redundancies. This
includes SimplifyCFG, GVN, etc. I'm open to suggestions about better
places to put this. We could in theory make it part of the codegen pass
pipeline, but there doesn't really seem to be a good reason for that --
it isn't "lowering" in any sense and only relies on pretty standard cost
model based TTI queries, so it seems to fit well with the "optimization"
pipeline model. Still, further thoughts on the pipeline position are
welcome.
I've also only implemented this in the new pass manager. If folks are
very interested, I can try to add it to the old PM as well, but I didn't
really see much point (my use case is already switched over to the new
PM).
I've tested this pretty heavily without issue. A wide range of
benchmarks internally show no change outside the noise, and I don't see
any significant changes in SPEC either. However, the size class
computation in tcmalloc is substantially improved by this, which turns
into a 2% to 4% win on the hottest path through tcmalloc for us, so
there are definitely important cases where this is going to make
a substantial difference.
Differential revision: https://reviews.llvm.org/D37467
llvm-svn: 319164
Clang implements the -finstrument-functions flag inherited from GCC, which
inserts calls to __cyg_profile_func_{enter,exit} on function entry and exit.
This is useful for getting a trace of how the functions in a program are
executed. Normally, the calls remain even if a function is inlined into another
function, but it is useful to be able to turn this off for users who are
interested in a lower-level trace, i.e. one that reflects what functions are
called post-inlining. (We use this to generate link order files for Chromium.)
LLVM already has a pass for inserting similar instrumentation calls to
mcount(), which it does after inlining. This patch renames and extends that
pass to handle calls both to mcount and the cygprofile functions, before and/or
after inlining as controlled by function attributes.
Differential Revision: https://reviews.llvm.org/D39287
llvm-svn: 318195
Registers it and everything, updates all the references, etc.
Next patch will add support to Clang's `-fexperimental-new-pass-manager`
path to actually enable BoundsChecking correctly.
Differential Revision: https://reviews.llvm.org/D39084
llvm-svn: 318128
This recommit r317351 after fixing a buildbot failure.
Original commit message:
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
llvm-svn: 317362
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
Reviewers: davidxl, huntergr, chandlerc, mcrosier, eraman, davide
Reviewed By: davidxl
Subscribers: sdesmalen, ashutosh.nema, fhahn, mssimpso, aemerson, mgorny, mehdi_amini, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D39137
llvm-svn: 317351
This patch adds a new pass for attaching !callees metadata to indirect call
sites. The pass propagates values to call sites by performing an IPSCCP-like
analysis using the generic sparse propagation solver. For indirect call sites
having a small set of possible callees, the attached metadata indicates what
those callees are. The metadata can be used to facilitate optimizations like
intersecting the function attributes of the possible callees, refining the call
graph, performing indirect call promotion, etc.
Differential Revision: https://reviews.llvm.org/D37355
llvm-svn: 316576
This is intended to be a superset of the functionality from D31037 (EarlyCSE) but implemented
as an independent pass, so there's no stretching of scope and feature creep for an existing pass.
I also proposed a weaker version of this for SimplifyCFG in D30910. And I initially had almost
this same functionality as an addition to CGP in the motivating example of PR31028:
https://bugs.llvm.org/show_bug.cgi?id=31028
The advantage of positioning this ahead of SimplifyCFG in the pass pipeline is that it can allow
more flattening. But it needs to be after passes (InstCombine) that could sink a div/rem and
undo the hoisting that is done here.
Decomposing remainder may allow removing some code from the backend (PPC and possibly others).
Differential Revision: https://reviews.llvm.org/D37121
llvm-svn: 312862
Summary:
This is largely NFC*, in preparation for utilizing ProfileSummaryInfo
and BranchFrequencyInfo analyses. In this patch I am only doing the
splitting for the New PM, but I can do the same for the legacy PM as
a follow-on if this looks good.
*Not NFC since for partial unrolling we lose the updates done to the
loop traversal (adding new sibling and child loops) - according to
Chandler this is not very useful for partial unrolling, but it also
means that the debugging flag -unroll-revisit-child-loops no longer
works for partial unrolling.
Reviewers: chandlerc
Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D36157
llvm-svn: 309886
Currently, this pass only focuses on *trivial* loop unswitching. At that
reduced problem it remains significantly better than the current loop
unswitch:
- Old pass is worse than cubic complexity. New pass is (I think) linear.
- New pass is much simpler in its design by focusing on full unswitching. (See
below for details on this).
- New pass doesn't carry state for thresholds between pass iterations.
- New pass doesn't carry state for correctness (both miscompile and
infloop) between pass iterations.
- New pass produces substantially better code after unswitching.
- New pass can handle more trivial unswitch cases.
- New pass doesn't recompute the dominator tree for the entire function
and instead incrementally updates it.
I've ported all of the trivial unswitching test cases from the old pass
to the new one to make sure that major functionality isn't lost in the
process. For several of the test cases I've worked to improve the
precision and rigor of the CHECKs, but for many I've just updated them
to handle the new IR produced.
My initial motivation was the fact that the old pass carried state in
very unreliable ways between pass iterations, and these mechansims were
incompatible with the new pass manager. However, I discovered many more
improvements to make along the way.
This pass makes two very significant assumptions that enable most of these
improvements:
1) Focus on *full* unswitching -- that is, completely removing whatever
control flow construct is being unswitched from the loop. In the case
of trivial unswitching, this means removing the trivial (exiting)
edge. In non-trivial unswitching, this means removing the branch or
switch itself. This is in opposition to *partial* unswitching where
some part of the unswitched control flow remains in the loop. Partial
unswitching only really applies to switches and to folded branches.
These are very similar to full unrolling and partial unrolling. The
full form is an effective canonicalization, the partial form needs
a complex cost model, cannot be iterated, isn't canonicalizing, and
should be a separate pass that runs very late (much like unrolling).
2) Leverage LLVM's Loop machinery to the fullest. The original unswitch
dates from a time when a great deal of LLVM's loop infrastructure was
missing, ineffective, and/or unreliable. As a consequence, a lot of
complexity was added which we no longer need.
With these two overarching principles, I think we can build a fast and
effective unswitcher that fits in well in the new PM and in the
canonicalization pipeline. Some of the remaining functionality around
partial unswitching may not be relevant today (not many test cases or
benchmarks I can find) but if they are I'd like to add support for them
as a separate layer that runs very late in the pipeline.
Purely to make reviewing and introducing this code more manageable, I've
split this into first a trivial-unswitch-only pass and in the next patch
I'll add support for full non-trivial unswitching against a *fixed*
threshold, exactly like full unrolling. I even plan to re-use the
unrolling thresholds, as these are incredibly similar cost tradeoffs:
we're cloning a loop body in order to end up with simplified control
flow. We should only do that when the total growth is reasonably small.
One of the biggest changes with this pass compared to the previous one
is that previously, each individual trivial exiting edge from a switch
was unswitched separately as a branch. Now, we unswitch the entire
switch at once, with cases going to the various destinations. This lets
us unswitch multiple exiting edges in a single operation and also avoids
numerous extremely bad behaviors, where we would introduce 1000s of
branches to test for thousands of possible values, all of which would
take the exact same exit path bypassing the loop. Now we will use
a switch with 1000s of cases that can be efficiently lowered into
a jumptable. This avoids relying on somehow forming a switch out of the
branches or getting horrible code if that fails for any reason.
Another significant change is that this pass actively updates the CFG
based on unswitching. For trivial unswitching, this is actually very
easy because of the definition of loop simplified form. Doing this makes
the code coming out of loop unswitch dramatically more friendly. We
still should run loop-simplifycfg (at the least) after this to clean up,
but it will have to do a lot less work.
Finally, this pass makes much fewer attempts to simplify instructions
based on the unswitch. Something like loop-instsimplify, instcombine, or
GVN can be used to do increasingly powerful simplifications based on the
now dominating predicate. The old simplifications are things that
something like loop-instsimplify should get today or a very, very basic
loop-instcombine could get. Keeping that logic separate is a big
simplifying technique.
Most of the code in this pass that isn't in the old one has to do with
achieving specific goals:
- Updating the dominator tree as we go
- Unswitching all cases in a switch in a single step.
I think it is still shorter than just the trivial unswitching code in
the old pass despite having this functionality.
Differential Revision: https://reviews.llvm.org/D32409
llvm-svn: 301576
This patch optimizes two memory intrinsic operations: memset and memcpy based
on the profiled size of the operation. The high level transformation is like:
mem_op(..., size)
==>
switch (size) {
case s1:
mem_op(..., s1);
goto merge_bb;
case s2:
mem_op(..., s2);
goto merge_bb;
...
default:
mem_op(..., size);
goto merge_bb;
}
merge_bb:
Differential Revision: http://reviews.llvm.org/D28966
llvm-svn: 299446
Now that the call graph supports efficient replacement of a function and
spurious reference edges, we can port ArgumentPromotion to the new pass
manager very easily.
The old PM-specific bits are sunk into callbacks that the new PM simply
doesn't use. Unlike the old PM, the new PM simply does argument
promotion and afterward does the update to LCG reflecting the promoted
function.
Differential Revision: https://reviews.llvm.org/D29580
llvm-svn: 294667
the main pipeline.
This is a very straight forward port. Nothing weird or surprising.
This brings the number of missing passes from the new PM's pipeline down
to three.
llvm-svn: 293249
factory functions for the two modes the loop unroller is actually used
in in-tree: simplified full-unrolling and the entire thing including
partial unrolling.
I've also wired these up to nice names so you can express both of these
being in a pipeline easily. This is a precursor to actually enabling
these parts of the O2 pipeline.
Differential Revision: https://reviews.llvm.org/D28897
llvm-svn: 293136
This patch introduces guard based loop predication optimization. The new LoopPredication pass tries to convert loop variant range checks to loop invariant by widening checks across loop iterations. For example, it will convert
for (i = 0; i < n; i++) {
guard(i < len);
...
}
to
for (i = 0; i < n; i++) {
guard(n - 1 < len);
...
}
After this transformation the condition of the guard is loop invariant, so loop-unswitch can later unswitch the loop by this condition which basically predicates the loop by the widened condition:
if (n - 1 < len)
for (i = 0; i < n; i++) {
...
}
else
deoptimize
This patch relies on an NFC change to make ScalarEvolution::isMonotonicPredicate public (revision 293062).
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D29034
llvm-svn: 293064
Like several other loop passes (the vectorizer, etc) this pass doesn't
really fit the model of a loop pass. The critical distinction is that it
isn't intended to be pipelined together with other loop passes. I plan
to add some documentation to the loop pass manager to make this more
clear on that side.
LoopSink is also different because it doesn't really need a lot of the
infrastructure of our loop passes. For example, if there aren't loop
invariant instructions causing a preheader to exist, there is no need to
form a preheader. It also doesn't need LCSSA because this pass is
only involved in sinking invariant instructions from a preheader into
the loop, not reasoning about live-outs.
This allows some nice simplifications to the pass in the new PM where we
can directly walk the loops once without restructuring them.
Differential Revision: https://reviews.llvm.org/D28921
llvm-svn: 292589
Mircea Trofin