There was an alias between 'simplifycfg' and 'simplify-cfg' in the
PassRegistry. That was the original reason for this patch, which
effectively removes the alias.
This patch also replaces all occurrances of 'simplify-cfg'
by 'simplifycfg'. Reason for choosing that form for the name is
that it matches the DEBUG_TYPE for the pass, and the legacy PM name
and also how it is spelled out in other passes such as
'loop-simplifycfg', and in other options such as
'simplifycfg-merge-cond-stores'.
I for some reason the name should be changed to 'simplify-cfg' in
the future, then I think such a renaming should be more widely done
and not only impacting the PassRegistry.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D105627
This change yields an additional 2% size reduction on an internal search
binary, and an additional 0.5% size reduction on fuchsia.
Differential Revision: https://reviews.llvm.org/D104751
It seems incorrect to use TTI data in some places,
and override it in others. In this case, TTI says
that `extractvalue` are free, yet we bill them.
While this doesn't address https://bugs.llvm.org/show_bug.cgi?id=50099 yet,
it reduces the cost from 55 to 50 while the threshold is 45.
Differential Revision: https://reviews.llvm.org/D101228
The simplifyInstruction() in visitUnaryInstruction() does not trigger
for all of check-llvm. Looking at all delegates to UnaryInstruction in
InstVisitor, the only instructions that either don't have a visitor in
CallAnalyzer, or redirect to UnaryInstruction, are VAArgInst and Alloca.
VAArgInst will never get simplified, and visitUnaryInstruction(Alloca)
would always return false anyway.
Reviewed By: mtrofin, lebedev.ri
Differential Revision: https://reviews.llvm.org/D101577
SROA can handle invariant group intrinsics, let the inliner know that
for better heuristics when the intrinsics are present.
This fixes size issues in a couple files when turning on
-fstrict-vtable-pointers in Chrome.
Reviewed By: rnk, mtrofin
Differential Revision: https://reviews.llvm.org/D100249
Attempts to compute savings more accurately cannot impact the set of critically important call sites.
Reviewed By: kazu
Differential Revision: https://reviews.llvm.org/D98577
This patch enables the cost-benefit-analysis-based inliner by default
if we have instrumentation profile.
- SPEC CPU 2017 shows a 0.4% improvement.
- An internal large benchmark shows a 0.9% reduction in the cycle
count along with 14.6% reduction in the number of call instructions
executed.
Differential Revision: https://reviews.llvm.org/D98213
With cost-benefit analysis for inlining, we bypass the cost-threshold by returning inline result from call analyzer early.
However the cost and threshold are still available from call analyzer, and when cost is actually higher than threshold, we incorrect set the reason.
The change makes the decision from cost-benefit analysis explicit. It's mostly NFC, except that it allows the priority-based sample loader inliner used by CSSPGO to use cost-benefit heuristic.
Differential Revision: https://reviews.llvm.org/D99302
This patch enables the cost-benefit-analysis-based inliner by default
if we have instrumentation profile.
- SPEC CPU 2017 shows a 0.4% improvement.
- An internal large benchmark shows a 0.9% reduction in the cycle
count along with 14.6% reduction in the number of call instructions
executed.
Differential Revision: https://reviews.llvm.org/D98213
Before D94153 this threshold was in a pre-scaled units.
After D94153 inlining threshold multiplier is not applied
to this portion of the threshold anymore. Restore the
threshold by applying the multiplier.
Differential Revision: https://reviews.llvm.org/D98362
Having a custom inliner doesn't really fit in with the new PM's
pipeline. It's also extra technical debt.
amdgpu-inline only does a couple of custom things compared to the normal
inliner:
1) It disables inlining if the number of BBs in a function would exceed
some limit
2) It increases the threshold if there are pointers to private arrays(?)
These can all be handled as TTI inliner hooks.
There already exists a hook for backends to multiply the inlining
threshold.
This way we can remove the custom amdgpu-inline pass.
This caused inline-hint.ll to fail, and after some investigation, it
looks like getInliningThresholdMultiplier() was previously getting
applied twice in amdgpu-inline (https://reviews.llvm.org/D62707 fixed it
not applying at all, so some later inliner change must have fixed
something), so I had to change the threshold in the test.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D94153
This patch teaches the inliner to compute the full cost for a call
site where the newly introduced cost benefit analysis is enabled.
Note that the cost benefit analysis requires the full cost to be
computed. However, without this patch or the -inline-cost-full
option, the early termination logic would kick in when the cost
exceeds the threshold, so we don't get to perform the cost benefit
analysis. For this reason, we would need to specify four clang
options:
-mllvm -inline-cost-full
-mllvm -inline-enable-cost-benefit-analysis
This patch eliminates the need to specify -inline-cost-full.
Differential Revision: https://reviews.llvm.org/D93658
This patch adds an alternative cost metric for the inliner to take
into account both the cost (i.e. size) and cycle count savings into
account.
Without this patch, we decide to inline a given call site if the size
of inlining the call site is below the threshold that is computed
according to the hotness of the call site.
This patch adds a new cost metric, turned off by default, to take over
the handling of hot call sites. Specifically, with the new cost
metric, we decide to inline a given call site if the ratio of cycle
savings to size exceeds a threshold. The cycle savings are computed
from call site costs, parameter propagation, folded conditional
branches, etc, all weighted by their respective profile counts. The
size is primarily the callee size, but we subtract call site costs and
the size of basic blocks that are never executed.
The new cost metric implicitly takes advantage of the machine function
splitter recently introduced by Snehasish Kumar, which dramatically
reduces the cost of duplicating (e.g. inlining) cold basic blocks by
placing cold basic blocks of hot functions in the .text.split
section.
We evaluated the new cost metric on clang bootstrap and SPECInt 2017.
For clang bootstrap, we observe 0.69% runtime improvement.
For SPECInt we report the change in IntRate the C/C++ benchmarks. All
benchmarks apart from perlbench and omnetpp improve, on average by
0.21% with the max for mcf at 1.96%.
Benchmark % Change
500.perlbench_r -0.45
502.gcc_r 0.13
505.mcf_r 1.96
520.omnetpp_r -0.28
523.xalancbmk_r 0.49
525.x264_r 0.00
531.deepsjeng_r 0.00
541.leela_r 0.35
557.xz_r 0.21
Differential Revision: https://reviews.llvm.org/D92780
This is a rework of D85812, which didn't land.
When callee coroutine function is inlined into caller coroutine function before coro-split pass, llvm will emits "coroutine should have exactly one defining @llvm.coro.begin". It seems that coro-early pass can not handle this quiet well.
So we believe that unsplited coroutine function should not be inlined.
This patch fix such issue by not inlining function if it has attribute "coroutine.presplit" (it means the function has not been splited) to fix this issue
test plan: check-llvm, check-clang
In D85812, there was suggestions on moving the macros to Attributes.td to avoid circular header dependency issue.
I believe it's not worth doing just to be able to use one constant string in one place.
Today, there are already 3 possible attribute values for "coroutine.presplit": c6543cc6b8/llvm/lib/Transforms/Coroutines/CoroInternal.h (L40-L42)
If we move them into Attributes.td, we would be adding 3 new attributes to EnumAttr, just to support this, which I think is an overkill.
Instead, I think the best way to do this is to add an API in Function class that checks whether this function is a coroutine, by checking the attribute by name directly.
Differential Revision: https://reviews.llvm.org/D92706
It's common for code that manipulates the stack via inline assembly or
that has to set up its own stack canary (such as the Linux kernel) would
like to avoid stack protectors in certain functions. In this case, we've
been bitten by numerous bugs where a callee with a stack protector is
inlined into an attribute((no_stack_protector)) caller, which
generally breaks the caller's assumptions about not having a stack
protector. LTO exacerbates the issue.
While developers can avoid this by putting all no_stack_protector
functions in one translation unit together and compiling those with
-fno-stack-protector, it's generally not very ergonomic or as
ergonomic as a function attribute, and still doesn't work for LTO. See also:
https://lore.kernel.org/linux-pm/20200915172658.1432732-1-rkir@google.com/https://lore.kernel.org/lkml/20200918201436.2932360-30-samitolvanen@google.com/T/#u
SSP attributes can be ordered by strength. Weakest to strongest, they
are: ssp, sspstrong, sspreq. Callees with differing SSP attributes may be
inlined into each other, and the strongest attribute will be applied to the
caller. (No change)
After this change:
* A callee with no SSP attributes will no longer be inlined into a
caller with SSP attributes.
* The reverse is also true: a callee with an SSP attribute will not be
inlined into a caller with no SSP attributes.
* The alwaysinline attribute overrides these rules.
Functions that get synthesized by the compiler may not get inlined as a
result if they are not created with the same stack protector function
attribute as their callers.
Alternative approach to https://reviews.llvm.org/D87956.
Fixes pr/47479.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed By: rnk, MaskRay
Differential Revision: https://reviews.llvm.org/D91816
ConstantOffsetPtrs contains mappings from a Value to a base pointer and
an offset. The offset is typed and has a size, and at least when dealing
with ptrtoint, it could happen that we had a mapping from a ptrtoint
with type i32 to an offset with type i16. This could later cause
problems, showing up in PR 47969 and PR 38500.
In PR 47969 we ended up in an assert complaining that trunc i16 to i16
is invalid and in Pr 38500 that a cmp on an i32 and i16 value isn't
valid.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D90610
This change introduces a new IR intrinsic named `llvm.pseudoprobe` for pseudo-probe block instrumentation. Please refer to https://reviews.llvm.org/D86193 for the whole story.
A pseudo probe is used to collect the execution count of the block where the probe is instrumented. This requires a pseudo probe to be persisting. The LLVM PGO instrumentation also instruments in similar places by placing a counter in the form of atomic read/write operations or runtime helper calls. While these operations are very persisting or optimization-resilient, in theory we can borrow the atomic read/write implementation from PGO counters and cut it off at the end of compilation with all the atomics converted into binary data. This was our initial design and we’ve seen promising sample correlation quality with it. However, the atomics approach has a couple issues:
1. IR Optimizations are blocked unexpectedly. Those atomic instructions are not going to be physically present in the binary code, but since they are on the IR till very end of compilation, they can still prevent certain IR optimizations and result in lower code quality.
2. The counter atomics may not be fully cleaned up from the code stream eventually.
3. Extra work is needed for re-targeting.
We choose to implement pseudo probes based on a special LLVM intrinsic, which is expected to have most of the semantics that comes with an atomic operation but does not block desired optimizations as much as possible. More specifically the semantics associated with the new intrinsic enforces a pseudo probe to be virtually executed exactly the same number of times before and after an IR optimization. The intrinsic also comes with certain flags that are carefully chosen so that the places they are probing are not going to be messed up by the optimizer while most of the IR optimizations still work. The core flags given to the special intrinsic is `IntrInaccessibleMemOnly`, which means the intrinsic accesses memory and does have a side effect so that it is not removable, but is does not access memory locations that are accessible by any original instructions. This way the intrinsic does not alias with any original instruction and thus it does not block optimizations as much as an atomic operation does. We also assign a function GUID and a block index to an intrinsic so that they are uniquely identified and not merged in order to achieve good correlation quality.
Let's now look at an example. Given the following LLVM IR:
```
define internal void @foo2(i32 %x, void (i32)* %f) !dbg !4 {
bb0:
%cmp = icmp eq i32 %x, 0
br i1 %cmp, label %bb1, label %bb2
bb1:
br label %bb3
bb2:
br label %bb3
bb3:
ret void
}
```
The instrumented IR will look like below. Note that each `llvm.pseudoprobe` intrinsic call represents a pseudo probe at a block, of which the first parameter is the GUID of the probe’s owner function and the second parameter is the probe’s ID.
```
define internal void @foo2(i32 %x, void (i32)* %f) !dbg !4 {
bb0:
%cmp = icmp eq i32 %x, 0
call void @llvm.pseudoprobe(i64 837061429793323041, i64 1)
br i1 %cmp, label %bb1, label %bb2
bb1:
call void @llvm.pseudoprobe(i64 837061429793323041, i64 2)
br label %bb3
bb2:
call void @llvm.pseudoprobe(i64 837061429793323041, i64 3)
br label %bb3
bb3:
call void @llvm.pseudoprobe(i64 837061429793323041, i64 4)
ret void
}
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D86490
If the GEP instruction contanins only constants as its arguments,
then it should be recognized as a constant. For now, there was
also added a flag to turn off this simplification if it causes
any regressions ("disable-gep-const-evaluation") which is off
by default. Once I gather needed data of the effectiveness of
this simplification, the flag will be deleted.
Reviewers: apilipenko, davidxl, mtrofin
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D81026
Some sequences of optimizations can generate call sites which may never be
executed during runtime, and through constant propagation result in dynamic
allocas being converted to static allocas with very large allocation amounts.
The inliner tries to move these to the caller's entry block, resulting in the
stack limits being reached/bypassed. Avoid inlining functions if this would
result.
The threshold of 64k currently doesn't get triggered on the test suite with an
-Os LTO build on arm64, care should be taken in changing this in future to avoid
needlessly pessimising inlining behaviour.
Differential Revision: https://reviews.llvm.org/D81765
This patch enables printing of constants to see which instructions were
constant-folded. Needed for tests and better visiual analysis of
inliner's work.
Reviewers: apilipenko, mtrofin, davidxl, fedor.sergeev
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D81024
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
For the upcoming changes, we need to have an ability to dump
InlineCostCallAnalyzer info in non-debug builds as well.
Reviewed-By: mtrofin
Differential Revision: https://reviews.llvm.org/D82205
If the GEP instruction contanins only constants as its arguments,
then it should be recognized as a constant. For now, there was
also added a flag to turn off this simplification if it causes
any regressions ("disable-gep-const-evaluation") which is off
by default. Once I gather needed data of the effectiveness of
this simplification, the flag will be deleted.
Reviewers: apilipenko, davidxl, mtrofin
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D81026
This patch enables printing of constants to see which instructions were
constant-folded. Needed for tests and better visiual analysis of
inliner's work.
Reviewers: apilipenko, mtrofin, davidxl, fedor.sergeev
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D81024
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
- Renaming the printer class, flag
- Refactoring
- Changing some tests
This patch is a preparational stage for introducing a new printing pass and new
functionality to the existing Annotation Writer. I plan to extend
this functionality for this tool to be more useful when looking at the inline
process.
Summary:
Experiments show that inline deferral past pre-inlining slightly
pessimizes the performance.
This patch introduces an option to control inline deferral during PGO.
The option defaults to true for now (that is, NFC).
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80776
This reverts commit 454de99a6f.
The problem was that one of the ctor arguments of CallAnalyzer was left
to be const std::function<>&. A function_ref was passed for it, and then
the ctor stored the value in a function_ref field. So a std::function<>
would be created as a temporary, and not survive past the ctor
invocation, while the field would.
Tested locally by following https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild
Original Differential Revision: https://reviews.llvm.org/D79917
Summary:
Replacing uses of std::function pointers or refs, or Optional, to
function_ref, since the usage pattern allows that. If the function is
optional, using a default parameter value (nullptr). This led to a few
parameter reshufles, to push all optionals to the end of the parameter
list.
Reviewers: davidxl, dblaikie
Subscribers: arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79917
The assert checks that every instruction must be annotated by this point while it is not
necessary. If the inlining process was interrupted because the threshold was reached, the rest
of the instructions would not be annotated which triggers the assert.
The added test shows the situation in which it can happen.
This is a recommit as the original commit fail due to the absence of REQUIRES: assert in the test.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D79107
The assert checks that every instruction must be annotated by this point while it is not
necessary. If the inlining process was interrupted because the threshold was reached, the rest
of the instructions would not be annotated which triggers the assert.
The added test shows the situation in which it can happen.
Reviewed-By: mtrofin
Diff: https://reviews.llvm.org/D79107
There are several different types of cost that TTI tries to provide
explicit information for: throughput, latency, code size along with
a vague 'intersection of code-size cost and execution cost'.
The vectorizer is a keen user of RecipThroughput and there's at least
'getInstructionThroughput' and 'getArithmeticInstrCost' designed to
help with this cost. The latency cost has a single use and a single
implementation. The intersection cost appears to cover most of the
rest of the API.
getUserCost is explicitly called from within TTI when the user has
been explicit in wanting the code size (also only one use) as well
as a few passes which are concerned with a mixture of size and/or
a relative cost. In many cases these costs are closely related, such
as when multiple instructions are required, but one evident diverging
cost in this function is for div/rem.
This patch adds an argument so that the cost required is explicit,
so that we can make the important distinction when necessary.
Differential Revision: https://reviews.llvm.org/D78635
Summary:
llvm::getInlineCost starts off by determining whether inlining should
happen or not because of user directives or easily determinable
unviability. This CL refactors this functionality as a reusable API.
Reviewers: davidxl, eraman
Reviewed By: davidxl, eraman
Subscribers: hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73825
This reverts commit 60c642e74b.
This patch is making the TLI "closed" for a predefined set of VecLib
while at the moment it is extensible for anyone to customize when using
LLVM as a library.
Reverting while we figure out a way to re-land it without losing the
generality of the current API.
Differential Revision: https://reviews.llvm.org/D77925
Summary:
Encode `-fveclib` setting as per-function attribute so it can threaded through to LTO backends. Accordingly per-function TLI now reads
the attributes and select available vector function list based on that. Now we also populate function list for all supported vector
libraries for the shared per-module `TargetLibraryInfoImpl`, so each function can select its available vector list independently but without
duplicating the vector function lists. Inlining between incompatbile vectlib attributed is also prohibited now.
Subscribers: hiraditya, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77632
Ensured initialized fields; encapsulad delta calulations and evaluation
of threshold having had changed; assertion for CostThresholdMap
dereference, to indicate design intent.
Differential Revision: https://reviews.llvm.org/D77762
Summary:
Final patch in series to fix inlining between functions with different
nobuiltin attributes/options, which was specifically an issue in LTO.
See discussion on D61634 for background.
The prior patch in this series (D67923) enabled per-Function TLI
construction that identified the nobuiltin attributes.
Here I have allowed inlining to proceed if the callee's nobuiltins are a
subset of the caller's nobuiltins, but not in the reverse case, which
should be conservatively correct. This is controlled by a new option,
-inline-caller-superset-nobuiltin, which is enabled by default.
Reviewers: hfinkel, gchatelet, chandlerc, davidxl
Subscribers: arsenm, jvesely, nhaehnle, mehdi_amini, eraman, hiraditya, haicheng, dexonsmith, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74162
Add extra diagnostics for the inline cost analysis under
-print-instruction-deltas cl option. When enabled along with
-debug-only=inline-cost it prints the IR of inline candidate
annotated with cost and threshold change per every instruction.
Reviewed By: apilipenko, davidxl, mtrofin
Differential Revision: https://reviews.llvm.org/D71501
Summary:
It can be useful to tune the default inline threshold without overriding other inlining thresholds (e.g. in code compiled for size).
The existing `-inline-threshold` flag overrides other thresholds, so it is insufficient in codebases where there is a mix of code compiled for size and speed.
Patch by Michael Holman <michael.holman@microsoft.com>
Reviewers: eraman, tejohnson
Reviewed By: tejohnson
Subscribers: tejohnson, mtrofin, davidxl, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73217
Summary:
It is called when instructions aren't simplified, and the implementation
is expected to account for a penalty. Renamed to
onCommonInstructionMissedSimplification.
Reviewers: davidxl, eraman
Reviewed By: davidxl
Subscribers: hiraditya, baloghadamsoftware, haicheng, a.sidorin, Szelethus, donat.nagy, dkrupp, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73662
Summary:
Follow-up from https://reviews.llvm.org/D71733. Also moved an
initialization to the base class, where it belonged in the first place.
Reviewers: eraman, davidxl
Reviewed By: davidxl
Subscribers: hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72949
Summary:
InlineResult is used both in APIs assessing whether a call site is
inlinable (e.g. llvm::isInlineViable) as well as in the function
inlining utility (llvm::InlineFunction). It means slightly different
things (can/should inlining happen, vs did it happen), and the
implicit casting may introduce ambiguity (casting from 'false' in
InlineFunction will default a message about hight costs,
which is incorrect here).
The change renames the type to a more generic name, and disables
implicit constructors.
Reviewers: eraman, davidxl
Reviewed By: davidxl
Subscribers: kerbowa, arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72744
Summary:
The goal is to simplify experimentation on the cost model. Today,
CallAnalyzer decides 2 things: legality, and benefit. The refactoring
keeps legality assessment in CallAnalyzer, and factors benefit
evaluation out, as an extension.
Reviewers: davidxl, eraman
Reviewed By: davidxl
Subscribers: kamleshbhalui, fedor.sergeev, hiraditya, baloghadamsoftware, haicheng, a.sidorin, Szelethus, donat.nagy, dkrupp, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71733
Summary:
The goal is to simplify experimentation on the cost model. Today,
CallAnalyzer decides 2 things: legality, and benefit. The refactoring
keeps legality assessment in CallAnalyzer, and factors benefit
evaluation out, as an extension.
Reviewers: davidxl, eraman
Subscribers: kamleshbhalui, fedor.sergeev, hiraditya, baloghadamsoftware, haicheng, a.sidorin, Szelethus, donat.nagy, dkrupp, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71733
Summary:
All the use cases of CallAnalyzer use the same call site parameter to
both construct the CallAnalyzer, and then pass to the analysis member.
This change removes this duplication.
Reviewers: davidxl, eraman, Jim
Reviewed By: davidxl
Subscribers: Jim, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71645
GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.
This fixes the buildbot failures.
Differential Revision: https://reviews.llvm.org/D68328
Patch by Joseph Faulls!
GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.
Differential Revision: https://reviews.llvm.org/D68328
Patch by Joseph Faulls!
Currently every time we encounter an indirect call of a known function,
we try to evaluate the inline cost of that function. In case of a
recursion, that evaluation never stops.
The solution I propose is to evaluate only the indirect call of the
function, while any further indirect calls (of a known function) will be
treated just as direct function calls, which, actually, never tries to
evaluate the call.
Fixes PR35469.
Differential Revision: https://reviews.llvm.org/D69349
Currently every time we encounter an indirect call of a known function,
we try to evaluate the inline cost of that function. In case of a
recursion, that evaluation never stops.
The solution presented is to evaluate only the indirect call of the
function, while any further indirect calls (of a known function) will be
treated just as direct function calls, which, actually, never tries to
evaluate the call.
Fixes PR35469.
Differential Revision: https://reviews.llvm.org/D69349
* Adds a TypeSize struct to represent the known minimum size of a type
along with a flag to indicate that the runtime size is a integer multiple
of that size
* Converts existing size query functions from Type.h and DataLayout.h to
return a TypeSize result
* Adds convenience methods (including a transparent conversion operator
to uint64_t) so that most existing code 'just works' as if the return
values were still scalars.
* Uses the new size queries along with ElementCount to ensure that all
supported instructions used with scalable vectors can be constructed
in IR.
Reviewers: hfinkel, lattner, rkruppe, greened, rovka, rengolin, sdesmalen
Reviewed By: rovka, sdesmalen
Differential Revision: https://reviews.llvm.org/D53137
llvm-svn: 374042
Summary:
The CallAnalyzer::visitSwitchInst has an early exit when the estimated
lower bound of the switch cost will put the overall cost of the inline
above the threshold. However, this code is not correctly estimating the
lower bound for switches that can be transformed into bit tests, leading
to unnecessary lost inlines, and also differing behavior with
optimization remarks enabled.
First, the early exit is controlled by whether ComputeFullInlineCost is
enabled or not, and that in turn is disabled by default but enabled when
enabling -pass-remarks=missed. This by itself wouldn't lead to a
problem, except that as described below, the lower bound can be above
the real lower bound, so we can sometimes get different inline decisions
with inline remarks enabled, which is problematic.
The early exit was added in along with a new switch cost model in D31085.
The reason why this early exit was added is due to a concern one reviewer
raised about compile time for large switches:
https://reviews.llvm.org/D31085?id=94559#inline-276200
However, the code just below there calls
getEstimatedNumberOfCaseClusters, which in turn immediately calls
BasicTTIImpl getEstimatedNumberOfCaseClusters, which in the worst case
does a linear scan of the cases to get the high and low values. The
bit test handling in particular is guarded by whether the number of
cases fits into the max bit width. There is no suggestion that anyone
measured a compile time issue, it appears to be theoretical.
The problem is that the reviewer's comment about the lower bound
calculation is incorrect, specifically in the case of a switch that can
be lowered to a bit test. This isn't followed up on the comment
thread, but the author does add a FIXME to that effect above the early
exit added when they subsequently revised the patch.
As a result, we were incorrectly early exiting and not inlining
functions with switch statements that would be lowered to bit tests in
cases where we were nearing the threshold. Combined with the fact that
this early exit was skipped with opt remarks enabled, this caused
different inlining decisions to be made when -pass-remarks=missed is
enabled to debug the missing inline.
Remove the early exit for the above reasons.
I also copied over an existing AArch64 inlining test to X86, and
adjusted the threshold so that the bit test inline only occurs with the
fix in this patch.
Reviewers: davidxl
Subscribers: eraman, kristof.beyls, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67716
llvm-svn: 372440
Summary:
SimplifyFPBinOp is a variant of SimplifyBinOp that lets you specify
fast math flags, but the name is misleading because both functions
can simplify both FP and non-FP ops. Instead, overload SimplifyBinOp
so that you can optionally specify fast math flags.
Likewise for SimplifyFPUnOp.
Reviewers: spatel
Reviewed By: spatel
Subscribers: xbolva00, cameron.mcinally, eraman, hiraditya, haicheng, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64902
llvm-svn: 366902
Summary:
Since the target has no significant advantage of vectorization,
vector instructions bous threshold bonus should be optional.
amdgpu-inline-arg-alloca-cost parameter default value and the target
InliningThresholdMultiplier value tuned then respectively.
Reviewers: arsenm, rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64642
llvm-svn: 366348
This reverts r364422 (git commit 1a3dc76186)
The inlining cost calculation is incorrect, leading to stack overflow due to large stack frames from heavy inlining.
llvm-svn: 365000
Summary:
Doing better separation of Cost and Threshold.
Cost counts the abstract complexity of live instructions, while Threshold is an upper bound of complexity that inlining is comfortable to pay.
There are two parts:
- huge 15K last-call-to-static bonus is no longer subtracted from Cost
but rather is now added to Threshold.
That makes much more sense, as the cost of inlining (Cost) is not changed by the fact
that internal function is called once. It only changes the likelyhood of this inlining
being profitable (Threshold).
- bonus for calls proved-to-be-inlinable into callee is no longer subtracted from Cost
but added to Threshold instead.
While calculations are somewhat different, overall InlineResult should stay the same since Cost >= Threshold compares the same.
Reviewers: eraman, greened, chandlerc, yrouban, apilipenko
Reviewed By: apilipenko
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60740
llvm-svn: 364422
This adds support for unary fneg based on the implementation of BinaryOperator without the soft float FP cost.
Previously we would just delegate to visitUnaryInstruction. I think the only real change is that we will pass the FastMath flags to SimplifyFNeg now.
Differential Revision: https://reviews.llvm.org/D62699
llvm-svn: 362732
Summary: Fneg can be implemented with an xor rather than a function call so we don't need to add the function call overhead. This was pointed out in D62699
Reviewers: efriedma, cameron.mcinally
Reviewed By: efriedma
Subscribers: javed.absar, eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62747
llvm-svn: 362304
Replace "unary operator" with "unary instruction" in visitUnaryInstruction since
we now have a UnaryOperator class which might needs its own visit function.
Fix a copy/paste in visitCastInst that appears to have been copied from
visitPtrToInt.
llvm-svn: 361794
Summary:
It was supposed that Ref LazyCallGraph::Edge's were being inserted by
inlining, but that doesn't seem to be the case. Instead, it seems that
there was no test for a blockaddress Constant in an instruction that
referenced the function that contained the instruction. Ex:
```
define void @f() {
%1 = alloca i8*, align 8
2:
store i8* blockaddress(@f, %2), i8** %1, align 8
ret void
}
```
When iterating blockaddresses, do not add the function they refer to
back to the worklist if the blockaddress is referring to the contained
function (as opposed to an external function).
Because blockaddress has sligtly different semantics than GNU C's
address of labels, there are 3 cases that can occur with blockaddress,
where only 1 can happen in GNU C due to C's scoping rules:
* blockaddress is within the function it refers to (possible in GNU C).
* blockaddress is within a different function than the one it refers to
(not possible in GNU C).
* blockaddress is used in to declare a global (not possible in GNU C).
The second case is tested in:
```
$ ./llvm/build/unittests/Analysis/AnalysisTests \
--gtest_filter=LazyCallGraphTest.HandleBlockAddress
```
This patch adjusts the iteration of blockaddresses in
LazyCallGraph::visitReferences to not revisit the blockaddresses
function in the first case.
The Linux kernel contains code that's not semantically valid at -O0;
specifically code passed to asm goto. It requires that asm goto be
inline-able. This patch conservatively does not attempt to handle the
more general case of inlining blockaddresses that have non-callbr users
(pr/39560).
https://bugs.llvm.org/show_bug.cgi?id=39560https://bugs.llvm.org/show_bug.cgi?id=40722https://github.com/ClangBuiltLinux/linux/issues/6https://reviews.llvm.org/rL212077
Reviewers: jyknight, eli.friedman, chandlerc
Reviewed By: chandlerc
Subscribers: george.burgess.iv, nathanchance, mgorny, craig.topper, mengxu.gatech, void, mehdi_amini, E5ten, chandlerc, efriedma, eraman, hiraditya, haicheng, pirama, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58260
llvm-svn: 361173
Converting InlineCost interface and its internals into CallBase usage.
Inliners themselves are still not converted.
Reviewed By: reames
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60636
llvm-svn: 358982
Create method `optForNone()` testing for the function level equivalent of
`-O0` and refactor appropriately.
Differential revision: https://reviews.llvm.org/D59852
llvm-svn: 357638
as long as their uses does not contain calls to functions that capture
the argument (potentially allowing the blockaddress to "escape" the
lifetime of the caller).
TODO:
- add more tests
- fix crash in llvm::updateCGAndAnalysisManagerForFunctionPass when
invoking Transforms/Inline/blockaddress.ll
llvm-svn: 354079
Summary:
While compiling openJDK11 (also other workloads), some make files would pass both CFLAGS and LDFLAGS at link step ; resulting in duplicate options on the command line when one is using LTO and trying to influence the inliner. Most of the internal flags are ZeroOrMore, this diff changes the remaining ones.
Reviewers: david2050, twoh, modocache
Reviewed By: twoh
Subscribers: mehdi_amini, dexonsmith, eraman, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57537
Patch by: Abdoul-Kader Keita
llvm-svn: 353071
InlineCost's isInlineViable() is changed to return InlineResult
instead of bool. This provides messages for failure reasons and
allows to get more specific messages for cases where callsites
are not viable for inlining.
Reviewed By: xbolva00, anemet
Differential Revision: https://reviews.llvm.org/D57089
llvm-svn: 352849
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
We currently seem to underestimate the size of functions with loops in them,
both in terms of absolute code size and in the difficulties of dealing with
such code. (Calls, for example, can be tail merged to further reduce
codesize). At -Oz, we can then increase code size by inlining small loops
multiple times.
This attempts to penalise functions with loops at -Oz by adding a CallPenalty
for each top level loop in the function. It uses LI (and hence DT) to calculate
the number of loops. As we are dealing with minsize, the inline threshold is
small and functions at this point should be relatively small, making the
construction of these cheap.
Differential Revision: https://reviews.llvm.org/D52716
llvm-svn: 346134
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
Liqiang Tao