History log of /llvm-project/llvm/lib/Transforms/Scalar/JumpThreading.cpp (Results 276 – 300 of 567)
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# 4f80c93a 15-Nov-2016 Pablo Barrio <pablo.barrio@arm.com>

Revert "[JumpThreading] Unfold selects that depend on the same condition"

This reverts commit ac54d0066c478a09c7cd28d15d0f9ff8af984afc.

llvm-svn: 286976


# 5f782bb0 15-Nov-2016 Pablo Barrio <pablo.barrio@arm.com>

Revert "[JumpThreading] Prevent non-deterministic use lists"

This reverts commit f2c2f5354070469dac253373c66527ca971ddc66.

llvm-svn: 286975


# 7ce2c5ec 14-Nov-2016 Pablo Barrio <pablo.barrio@arm.com>

[JumpThreading] Prevent non-deterministic use lists

Summary:
Unfolding selects was previously done with the help of a vector
of pointers that was then sorted to be able to remove duplicates.
As this

[JumpThreading] Prevent non-deterministic use lists

Summary:
Unfolding selects was previously done with the help of a vector
of pointers that was then sorted to be able to remove duplicates.
As this sorting depends on the memory addresses, it was
non-deterministic. A SetVector is used now so that duplicates are
removed without the need of sorting first.

Reviewers: mgrang, efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26450

llvm-svn: 286807

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# 9f452541 08-Nov-2016 Pablo Barrio <pablo.barrio@arm.com>

[JumpThreading] Unfold selects that depend on the same condition

Summary:
These are good candidates for jump threading. This enables later opts
(such as InstCombine) to combine instructions from the

[JumpThreading] Unfold selects that depend on the same condition

Summary:
These are good candidates for jump threading. This enables later opts
(such as InstCombine) to combine instructions from the selects with
instructions out of the selects. SimplifyCFG will fold the select
again if unfolding wasn't worth it.

Patch by James Molloy and Pablo Barrio.

Reviewers: rengolin, haicheng, sebpop

Subscribers: jojo, jmolloy, llvm-commits

Differential Revision: https://reviews.llvm.org/D26391

llvm-svn: 286236

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# b38d3411 24-Oct-2016 Nico Weber <nicolasweber@gmx.de>

Revert 284971.

It seems to break selfhost on some bots, see e.g.
http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/21
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-multista

Revert 284971.

It seems to break selfhost on some bots, see e.g.
http://lab.llvm.org:8011/builders/clang-x86-windows-msvc2015/builds/21
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-multistage/builds/20
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/22

llvm-svn: 284979

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# f9e0d0b7 24-Oct-2016 Pablo Barrio <pablo.barrio@arm.com>

[JumpThreading] Unfold selects that depend on the same condition

Summary:
These are good candidates for jump threading. This enables later opts
(such as InstCombine) to combine instructions from the

[JumpThreading] Unfold selects that depend on the same condition

Summary:
These are good candidates for jump threading. This enables later opts
(such as InstCombine) to combine instructions from the selects with
instructions out of the selects. SimplifyCFG will fold the select
again if unfolding wasn't worth it.

Patch by James Molloy and Pablo Barrio.

Reviewers: reames, bkramer, mcrosier, gberry, haicheng, jmolloy, sebpop

Subscribers: jojo, rengolin, llvm-commits

Differential Revision: https://reviews.llvm.org/D25477

llvm-svn: 284971

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# b4d2678c 03-Oct-2016 Hans Wennborg <hans@hanshq.net>

Jump threading: avoid trying to split edge into landingpad block (PR27840)

Splitting the edge is nontrivial because of the landing pad, and we would
currently assert trying to do it.

Differential R

Jump threading: avoid trying to split edge into landingpad block (PR27840)

Splitting the edge is nontrivial because of the landing pad, and we would
currently assert trying to do it.

Differential Revision: https://reviews.llvm.org/D24680

llvm-svn: 283129

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# c520822d 06-Sep-2016 Adam Nemet <anemet@apple.com>

[JumpThreading] Only write back branch-weight MDs for blocks that originally had PGO info

Currently the pass updates branch weights in the IR if the function has
any PGO info (entry frequency is set

[JumpThreading] Only write back branch-weight MDs for blocks that originally had PGO info

Currently the pass updates branch weights in the IR if the function has
any PGO info (entry frequency is set). However we could still have
regions of the CFG that does not have branch weights collected (e.g. a
cold region). In this case we'd use static estimates. Since static
estimates for branches are determined independently, they are
inconsistent. Updating them can "randomly" inflate block frequencies.

I've run into this in a completely cold loop of h264ref from
SPEC. -Rpass-with-hotness showed the loop to be completely cold during
inlining (before JT) but completely hot during vectorization (after JT).

The new testcase demonstrate the problem. We check array elements
against 1, 2 and 3 in a loop. The check against 3 is the loop-exiting
check. The block names should be self-explanatory.

In this example, jump threading incorrectly updates the weight of the
loop-exiting branch to 0, drastically inflating the frequency of the
loop (in the range of billions).

There is no run-time profile info for edges inside the loop, so branch
probabilities are estimated. These are the resulting branch and block
frequencies for the loop body:

check_1 (16)
(8) / |
eq_1 | (8)
\ |
check_2 (16)
(8) / |
eq_2 | (8)
\ |
check_3 (16)
(1) / |
(loop exit) | (15)
|
(back edge)

First we thread eq_1 -> check_2 to check_3. Frequencies are updated to
remove the frequency of eq_1 from check_2 and then from the false edge
leaving check_2. Changed frequencies are highlighted with * *:

check_1 (16)
(8) / |
eq_1~ | (8)
/ |
/ check_2 (*8*)
/ (8) / |
\ eq_2 | (*0*)
\ \ |
` --- check_3 (16)
(1) / |
(loop exit) | (15)
|
(back edge)

Next we thread eq_1 -> check_3 and eq_2 -> check_3 to check_1 as new
back edges. Frequencies are updated to remove the frequency of eq_1 and
eq_3 from check_3 and then the false edge leaving check_3 (changed
frequencies are highlighted with * *):

check_1 (16)
(8) / |
eq_1~ | (8)
/ |
/ check_2 (*8*)
/ (8) / |
/-- eq_2~ | (*0*)
(back edge) |
check_3 (*0*)
(*0*) / |
(loop exit) | (*0*)
|
(back edge)

As a result, the loop exit edge ends up with 0 frequency which in turn makes
the loop header to have maximum frequency.

There are a few potential problems here:

1. The profile data seems odd. There is a single profile sample of the
loop being entered. On the other hand, there are no weights inside the
loop.

2. Based on static estimation we shouldn't set edges to "extreme"
values, i.e. extremely likely or unlikely.

3. We shouldn't create profile metadata that is calculated from static
estimation. I am not sure what policy is but it seems to make sense to
treat profile metadata as something that is known to originate from
profiling. Estimated probabilities should only be reflected in BPI/BFI.

Any one of these would probably fix the immediate problem. I went for 3
because I think it's a good policy to have and added a FIXME about 2.

Differential Revision: https://reviews.llvm.org/D24118

llvm-svn: 280713

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Revision tags: llvmorg-3.9.0, llvmorg-3.9.0-rc3, llvmorg-3.9.0-rc2
# 0d955d0b 11-Aug-2016 David Majnemer <david.majnemer@gmail.com>

Use the range variant of find instead of unpacking begin/end

If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

ll

Use the range variant of find instead of unpacking begin/end

If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

llvm-svn: 278433

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# 36e0d01e 09-Aug-2016 Sean Silva <chisophugis@gmail.com>

Consistently use FunctionAnalysisManager

Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching e

Consistently use FunctionAnalysisManager

Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278077

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# 02419a98 08-Aug-2016 Eli Friedman <eli.friedman@gmail.com>

[JumpThreading] Fix handling of aliasing metadata.

Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the

[JumpThreading] Fix handling of aliasing metadata.

Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the
behavior of other passes, like instcombine and GVN.

There's also a minor optimization improvement here: for load PRE, the
aliasing metadata on the inserted load should be the same as the
metadata on the original load. Not sure why the old code was throwing
it away.

Issue found by inspection.

Differential Revision: http://reviews.llvm.org/D21460

llvm-svn: 277977

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Revision tags: llvmorg-3.9.0-rc1
# 522a9118 22-Jul-2016 David Majnemer <david.majnemer@gmail.com>

Don't remove side effecting instructions due to ConstantFoldInstruction

Just because we can constant fold the result of an instruction does not
imply that we can delete the instruction. It may have

Don't remove side effecting instructions due to ConstantFoldInstruction

Just because we can constant fold the result of an instruction does not
imply that we can delete the instruction. It may have side effects.

This fixes PR28655.

llvm-svn: 276389

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# 13623ad0 14-Jul-2016 Sanjoy Das <sanjoy@playingwithpointers.com>

[JumpThreading] PRE unordered loads

Summary: Extend JumpThreading's PRE to unordered atomic loads.

Reviewers: hfinkel, reames

Subscribers: mcrosier, llvm-commits

Differential Revision: http://rev

[JumpThreading] PRE unordered loads

Summary: Extend JumpThreading's PRE to unordered atomic loads.

Reviewers: hfinkel, reames

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D22326

llvm-svn: 275456

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# 931df67a 13-Jul-2016 Sanjoy Das <sanjoy@playingwithpointers.com>

[JumpThreading] Delete commented out debug code; NFC

llvm-svn: 275346


# f50d4b6c 06-Jul-2016 Sean Silva <chisophugis@gmail.com>

Work around PR28400 a bit harder.

We were still crashing in the "no change" case because LVI was not
getting invalidated.

See the thread "Should analyses be able to hold AssertingVH to IR?
(related

Work around PR28400 a bit harder.

We were still crashing in the "no change" case because LVI was not
getting invalidated.

See the thread "Should analyses be able to hold AssertingVH to IR?
(related to PR28400)" for more discussion.

llvm-svn: 274656

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# fa6db901 03-Jul-2016 Sean Silva <chisophugis@gmail.com>

PR28400: Partly undo r274440 to bring test-suite back to life with the new PM

PR28400 seems to be not an isolated issue, but a general problem related
to caching analyses. We will need to discuss on

PR28400: Partly undo r274440 to bring test-suite back to life with the new PM

PR28400 seems to be not an isolated issue, but a general problem related
to caching analyses. We will need to discuss on llvm-dev.

A test case is in the PR.

llvm-svn: 274457

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# f2db01c6 02-Jul-2016 Sean Silva <chisophugis@gmail.com>

[PM] Fix a small typo from when I ported JumpThreading

llvm-svn: 274440


# b8da3a2b 25-Jun-2016 David Majnemer <david.majnemer@gmail.com>

Reinstate r273711

r273711 was reverted by r273743. The inliner needs to know about any
call sites in the inlined function. These were obscured if we replaced
a call to undef with an undef but kept

Reinstate r273711

r273711 was reverted by r273743. The inliner needs to know about any
call sites in the inlined function. These were obscured if we replaced
a call to undef with an undef but kept the call around.

This fixes PR28298.

llvm-svn: 273753

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# ae2ef4cc 24-Jun-2016 Nico Weber <nicolasweber@gmx.de>

Revert r273711, it caused PR28298.

llvm-svn: 273743


# 3b3e954e 24-Jun-2016 David Majnemer <david.majnemer@gmail.com>

SimplifyInstruction does not imply DCE

We cannot remove an instruction with no uses just because
SimplifyInstruction succeeds. It may have side effects.

llvm-svn: 273711


# 87f0d0e1 16-Jun-2016 Igor Laevsky <igmyrj@gmail.com>

Revert r272891 "[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo"

It was causing failures in Profile-i386 and Profile-x86_64 tests.

llvm-svn: 272912


# c9179fd2 16-Jun-2016 Igor Laevsky <igmyrj@gmail.com>

[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo

We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise
we will get danglin

[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo

We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise
we will get dangling pointer inside BranchProbabilityInfo cache.

Differential Revision: http://reviews.llvm.org/D20957

llvm-svn: 272891

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# 46590d55 14-Jun-2016 Sean Silva <chisophugis@gmail.com>

Bring back "[PM] Port JumpThreading to the new PM" with a fix

This reverts commit r272603 and adds a fix.

Big thanks to Davide for pointing me at r216244 which gives some insight
into how to fix th

Bring back "[PM] Port JumpThreading to the new PM" with a fix

This reverts commit r272603 and adds a fix.

Big thanks to Davide for pointing me at r216244 which gives some insight
into how to fix this VS2013 issue. VS2013 can't synthesize a move
constructor. So the fix here is to add one explicitly to the
JumpThreadingPass class.

llvm-svn: 272607

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# 7d5a57cb 14-Jun-2016 Sean Silva <chisophugis@gmail.com>

Revert "[PM] Port JumpThreading to the new PM"

This reverts commit r272597.

Will investigate issue with VS2013 compilation and then recommit.

llvm-svn: 272603


# f81328d0 13-Jun-2016 Sean Silva <chisophugis@gmail.com>

[PM] Port JumpThreading to the new PM

This follows the approach in r263208 (for GVN) pretty closely:
- move the bulk of the body of the function to the new PM class.
- expose a runImpl method on the

[PM] Port JumpThreading to the new PM

This follows the approach in r263208 (for GVN) pretty closely:
- move the bulk of the body of the function to the new PM class.
- expose a runImpl method on the new-PM class that takes the IRUnitT and
pointers/references to any analyses and use that to implement the
old-PM class.
- use a private namespace in the header for stuff that used to be file
scope

llvm-svn: 272597

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