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
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Many of these uses can get by with forward declarations. Hopefully this
speeds up compilation after adding a single intrinsic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312759 91177308-0d34-0410-b5e6-96231b3b80d8
This patch provides such debug information for integer
variables whose type is shrinked to bool by providing
dwarf expression which returns either constant initial
value or other value.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D35994
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Summary:
When jumptable encoding does not match target code encoding (arm vs
thumb), a veneer is inserted by the linker. We can not avoid this
in all cases, because entries within one jumptable must have the same
encoding, but we can make it less common by selecting the jumptable
encoding to match the majority of its targets.
This change only covers FullLTO, and not ThinLTO.
Reviewers: pcc
Subscribers: aemerson, mehdi_amini, javed.absar, kristof.beyls, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37171
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312054 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Cross-DSO CFI needs all __cfi_check exports to use the same encoding
(ARM vs Thumb).
Reviewers: pcc
Subscribers: aemerson, srhines, kristof.beyls, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D37243
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Summary:
Remove some code that was no longer needed. The first FIXME is
stale since we long ago started using the index to drive importing,
rather than doing force importing based on linkage type. And
now with r309278, we no longer import any aliases.
Reviewers: dblaikie
Subscribers: inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D37266
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Prior to this change (and after r311371), we computed it
unconditionally, causin gsevere compile time regressions (in some
cases, 5 to 10x).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311804 91177308-0d34-0410-b5e6-96231b3b80d8
Currently, the inline cost model will bail once the inline cost exceeds the
inline threshold in order to avoid unnecessary compile-time. However, when
debugging it is useful to compute the full cost, so this command line option
is added to override the default behavior.
I took over this work from Chad Rosier (mcrosier@codeaurora.org).
Differential Revision: https://reviews.llvm.org/D35850
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Summary:
Follow up to fix in r311023, which fixed the case where the combined
index is written to disk. The same samplePGO logic exists for the
in-memory index when computing imports, so we need to filter out
GlobalVariable summaries there too.
Reviewers: davidxl
Subscribers: inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D36919
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Updating remark API to newer OptimizationDiagnosticInfo API. This
allows remarks to show up in diagnostic yaml file, and enables use
of opt-viewer tool.
Hotness information for remarks (L505 and L751) do not display hotness
information, most likely due to profile information not being
propagated yet. Unsure if this is the desired outcome.
Patch by Tarun Rajendran.
Differential Revision: https://reviews.llvm.org/D36127
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The frontend may have requested a higher alignment for any reason, and
downstream optimizations may already have taken advantage of it. We
should keep the same alignment when moving the allocation from the
parameter area to the local variable area.
Fixes PR34038
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This is similar to what we are doing in "regular" SROA and creates
DW_OP_LLVM_fragment operations to describe the resulting variables.
rdar://problem/33654891
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infinite-inlining across multiple runs of the inliner by keeping a tiny
history of internal-to-SCC inlining decisions.
This is still a bit gross, but I don't yet have any fundamentally better
ideas and numerous people are blocked on this to use new PM and ThinLTO
together.
The core of the idea is to detect when we are about to do an inline that
has a chance of re-splitting an SCC which we have split before with
a similar inlining step. That is a critical component in the inlining
forming a cycle and so far detects all of the various cyclic patterns
I can come up with as well as the original real-world test case (which
comes from a ThinLTO build of libunwind).
I've added some tests that I think really demonstrate what is going on
here. They are essentially state machines that march the inliner through
various steps of a cycle and check that we stop when the cycle is closed
and that we actually did do inlining to form that cycle.
A lot of thanks go to Eric Christopher and Sanjoy Das for the help
understanding this issue and improving the test cases.
The biggest "yuck" here is the layering issue -- the CGSCC pass manager
is providing somewhat magical state to the inliner for it to use to make
itself converge. This isn't great, but I don't honestly have a lot of
better ideas yet and at least seems nicely isolated.
I have tested this patch, and it doesn't block *any* inlining on the
entire LLVM test suite and SPEC, so it seems sufficiently narrowly
targeted to the issue at hand.
We have come up with hypothetical issues that this patch doesn't cover,
but so far none of them are practical and we don't have a viable
solution yet that covers the hypothetical stuff, so proceeding here in
the interim. Definitely an area that we will be back and revisiting in
the future.
Differential Revision: https://reviews.llvm.org/D36188
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D33925 added a control flow simplification for -O2 --lto-O0 builds that
manually splits blocks and reassigns conditional branches but does not
correctly update phi nodes. If the else case being branched to had
incoming phi nodes the control-flow simplification would leave phi nodes
in that BB with an unhandled predecessor.
Patch by Vlad Tsyrklevich!
Differential Revision: https://reviews.llvm.org/D36012
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Summary:
Since r293359, most dump() function are only defined when
`!defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` holds. print() functions
only used by dump() functions are now unused in release builds,
generating lots of warnings. This patch only defines some print()
functions if they are used.
Reviewers: MatzeB
Reviewed By: MatzeB
Subscribers: arsenm, mzolotukhin, nhaehnle, llvm-commits
Differential Revision: https://reviews.llvm.org/D35949
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309553 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The original 3.0 hot mupltiplier is too small, and would prevent hot callsites from being inline. This patch increases the hot multilier to 10.0
Reviewers: davidxl, tejohnson
Reviewed By: tejohnson
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D35969
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The alias support was dead code since 2011. It was last touched
in r124182, where it was reintroduced after being removed
in r110434, and since then it was gated behind a HasGlobalAliases
flag that was permanently stuck as `false`.
It is also broken. I'm not sure if it bitrotted or was just broken
in the first place because it appears to have never been tested,
but the following IR results in a crash:
define internal i32 @a(i32 %a, i32 %b) unnamed_addr {
%c = add i32 %a, %b
%d = xor i32 %a, %c
ret i32 %c
}
define internal i32 @b(i32 %a, i32 %b) unnamed_addr {
%c = add i32 %a, %b
%d = xor i32 %a, %c
ret i32 %c
}
It seems safe to remove buggy untested code that no one cared about
for seven years.
Differential Revision: https://reviews.llvm.org/D34802
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Summary:
Until a more advanced version of importing can be implemented for
aliases (one that imports an alias as an available_externally definition
of the aliasee), skip the narrow subset of cases that was possible but
came at a cost: aliases of linkonce_odr functions could be imported
because the linkonce_odr function could be safely duplicated from the
source module. This came/comes at the cost of not being able to 'home'
imported linkonce functions (they had to be emitted linkonce_odr in all
the destination modules (even if they weren't used by an alias) rather
than as available_externally - causing extra object size).
Tangentially, this also was the only reason ThinLTO would emit multiple
CUs in to the resulting DWARF - which happens to be a problem for
Fission (there's a fix for this in GDB but not released yet, etc).
(actually it's not the only reason - but I'm sending a patch to fix the
other reason shortly)
There's no reason to believe this particularly narrow alias importing
was especially/meaningfully important, only that it was /possible/ to
implement in this way. When a more general solution is done, it should
still satisfy the DWARF concerns above, since the import will still be
available_externally, and thus not create extra CUs.
Since now all aliases are treated the same, I removed/simplified some
test cases since they were testing corner cases where there are no
longer any corners.
Reviewers: tejohnson, mehdi_amini
Differential Revision: https://reviews.llvm.org/D35875
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Summary: Currently the ThinLTO minimized bitcode file only strip the debug info, but there is still a lot of information in the minimized bit code file that will be not used for thin linker. In this patch, most of the extra information is striped to reduce the minimized bitcode file. Now only ModuleVersion, ModuleInfo, ModuleGlobalValueSummary, ModuleHash, Symtab and Strtab are left. Now the minimized bitcode file size is reduced to 15%-30% of the debug info stripped bitcode file size.
Reviewers: danielcdh, tejohnson, pcc
Reviewed By: pcc
Subscribers: mehdi_amini, aprantl, inglorion, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D35334
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Previously we were (mis)handling jump table members with a prevailing
definition in a full LTO module and a non-prevailing definition in a
ThinLTO module by dropping type metadata on those functions entirely,
which would cause type tests involving such functions to fail.
This patch causes us to drop metadata only if we are about to replace
it with metadata from cfi.functions.
We also want to replace metadata for available_externally functions,
which can arise in the opposite scenario (prevailing ThinLTO
definition, non-prevailing full LTO definition). The simplest way
to handle that is to remove the definition; there's little value in
keeping it around at this point (i.e. after most optimization passes
have already run) and later code will try to use the function's linkage
to create an alias, which would result in invalid IR if the function
is available_externally.
Fixes PR33832.
Differential Revision: https://reviews.llvm.org/D35604
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functions.
In the prior commit, we provide ordering to the LCG between functions
and library function definitions that they might begin to call through
transformations. But we still would delete these library functions from
the call graph if they became dead during inlining.
While this immediately crashed, it also exposed a loss of information.
We shouldn't remove definitions of library functions that can still
usefully participate in the LCG-powered CGSCC optimization process. If
new call edges are formed, we want to have definitions to be called.
We can still remove these functions if truly dead using global-dce, etc,
but removing them during the CGSCC walk is premature.
This fixes a crash in the new PM when optimizing some unusual libraries
that end up with "internal" lib functions such as the code in the "R"
language's libraries.
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This restores r308078/r308079 with a fix for bot non-determinisim (make
sure we run llvm-lto in single threaded mode so the debug output doesn't get
interleaved).
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that appears to exhibit non-determinism and is flaking on the bots
pretty consistently.
r308078: [ThinLTO] Ensure we always select the same function copy to import
r308079: Require asserts in new test that uses debug flag
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308095 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Check if the first eligible callee is under the instruction threshold.
Checking this on the first eligible callee ensures that we don't end
up selecting different callees to import when we invoke this routine
with different thresholds due to reaching the callee via paths that
are shallower or hotter (when there are multiple copies, i.e. with
weak or linkonce linkage). We don't want to leave the decision of which
copy to import up to the backend.
Reviewers: mehdi_amini
Subscribers: inglorion, fhahn, llvm-commits
Differential Revision: https://reviews.llvm.org/D35436
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308078 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
DominatorTreeBase used to have IsPostDominators (bool) member to indicate if the tree is a dominator or a postdominator tree. This made it possible to switch between the two 'modes' at runtime, but it isn't used in practice anywhere.
This patch makes IsPostDominator a template argument. This way, it is easier to switch between different algorithms at compile-time based on this argument and design external utilities around it. It also makes it impossible to incidentally assign a postdominator tree to a dominator tree (and vice versa), and to further simplify template code in GenericDominatorTreeConstruction.
Reviewers: dberlin, sanjoy, davide, grosser
Reviewed By: dberlin
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D35315
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This commit reapplies r307215 now that we found out and fixed
the cause of the cfi test failure (in r307871).
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This normally indicates mixed CFI + non-CFI compilation, and will
result in us treating the function in the same way as a function
defined outside of the LTO unit.
Part of PR33752.
Differential Revision: https://reviews.llvm.org/D35281
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[GlobalOpt] Remove unreachable blocks before optimizing a function.
While the change is presumably correct, it exposes a latent bug
in DI which breaks on of the CFI checks. I'll analyze it further
and try to understand what's going on.
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