Commit Graph

3443 Commits

Author SHA1 Message Date
Adam Nemet 12937c361f [LoopUnroll] Include hotness of region in opt remark
LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter
is added to the common function analysis passes that loop passes
depend on.

The BFI and indirectly BPI used in this pass is computed lazily so no
overhead should be observed unless -pass-remarks-with-hotness is used.

This is how the patch affects the O3 pipeline:

         Dominator Tree Construction
         Natural Loop Information
         Canonicalize natural loops
         Loop-Closed SSA Form Pass
         Basic Alias Analysis (stateless AA impl)
         Function Alias Analysis Results
         Scalar Evolution Analysis
+        Lazy Branch Probability Analysis
+        Lazy Block Frequency Analysis
+        Optimization Remark Emitter
         Loop Pass Manager
           Rotate Loops
           Loop Invariant Code Motion
           Unswitch loops
         Simplify the CFG
         Dominator Tree Construction
         Basic Alias Analysis (stateless AA impl)
         Function Alias Analysis Results
         Combine redundant instructions
         Natural Loop Information
         Canonicalize natural loops
         Loop-Closed SSA Form Pass
         Scalar Evolution Analysis
+        Lazy Branch Probability Analysis
+        Lazy Block Frequency Analysis
+        Optimization Remark Emitter
         Loop Pass Manager
           Induction Variable Simplification
           Recognize loop idioms
           Delete dead loops
           Unroll loops
...

llvm-svn: 277203
2016-07-29 19:29:47 +00:00
Andrew Kaylor b99d1cc7ed Recommitting r275284: add support to inline __builtin_mempcpy
Patch by Sunita Marathe

Third try, now following fixes to MSan to handle mempcy in such a way that this commit won't break the MSan buildbots. (Thanks, Evegenii!)

llvm-svn: 277189
2016-07-29 18:23:18 +00:00
David Majnemer d536f2328e [ConstnatFolding] Teach the folder how to fold ConstantVector
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.

Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.

llvm-svn: 277099
2016-07-29 03:27:26 +00:00
Piotr Padlewski 84abc74f2c Added ThinLTO inlining statistics
Summary:
copypasta doc of ImportedFunctionsInliningStatistics class
 \brief Calculate and dump ThinLTO specific inliner stats.
 The main statistics are:
 (1) Number of inlined imported functions,
 (2) Number of imported functions inlined into importing module (indirect),
 (3) Number of non imported functions inlined into importing module
 (indirect).
 The difference between first and the second is that first stat counts
 all performed inlines on imported functions, but the second one only the
 functions that have been eventually inlined to a function in the importing
 module (by a chain of inlines). Because llvm uses bottom-up inliner, it is
 possible to e.g. import function `A`, `B` and then inline `B` to `A`,
 and after this `A` might be too big to be inlined into some other function
 that calls it. It calculates this statistic by building graph, where
 the nodes are functions, and edges are performed inlines and then by marking
 the edges starting from not imported function.

 If `Verbose` is set to true, then it also dumps statistics
 per each inlined function, sorted by the greatest inlines count like
 - number of performed inlines
 - number of performed inlines to importing module

Reviewers: eraman, tejohnson, mehdi_amini

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D22491

llvm-svn: 277089
2016-07-29 00:27:16 +00:00
Evgeniy Stepanov d240a889ad [sanitizer] Simplify and future-proof maybeMarkSanitizerLibraryCallNoBuiltin().
Sanitizers set nobuiltin attribute on certain library functions to
avoid a situation where such function is neither instrumented nor
intercepted.

At the moment the list of interesting functions is hardcoded. This
change replaces it with logic based on
TargetLibraryInfo::hasOptimizedCodegen and the presense of readnone
function attribute (sanitizers are generally interested in memory
behavior of library functions).

This is expected to be a no-op change: the new logic matches exactly
the same set of functions.

r276771 (currently reverted) added mempcpy() to the list, breaking
MSan tests. With this change, r276771 can be safely re-landed.

llvm-svn: 277086
2016-07-28 23:45:15 +00:00
Michael Zolotukhin ff5ce639de Add verifyAnalysis for LCSSA.
Summary:
LCSSAWrapperPass currently doesn't override verifyAnalysis method, so pass
manager doesn't verify LCSSA. This patch adds the method so that we start
verifying LCSSA between loop passes.

Reviewers: chandlerc, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22888

llvm-svn: 276941
2016-07-27 23:35:53 +00:00
Sean Silva 285e0974f0 Refactor - CodeExtractor : Move check for valid block to static utility
This lets you actually check to see if a block is valid before trying to
extract.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22699

llvm-svn: 276846
2016-07-27 08:02:46 +00:00
Andrew Kaylor f990fa5f7b Reverting r276771 due to MSan failures.
llvm-svn: 276824
2016-07-27 01:19:24 +00:00
Adam Nemet 2f2bd8caf4 [LoopUtils] Sort headers
llvm-svn: 276776
2016-07-26 17:52:02 +00:00
Andrew Kaylor 3104a6bad0 Re-committing r275284: add support to inline __builtin_mempcpy
Patch by Sunita Marathe

Differential Revision: http://reviews.llvm.org/D21920

llvm-svn: 276771
2016-07-26 17:23:13 +00:00
Michael Kuperstein 39feb6290c [PM] Port SymbolRewriter to the new PM
Differential Revision: https://reviews.llvm.org/D22703

llvm-svn: 276687
2016-07-25 20:52:00 +00:00
Michael Kuperstein 9a89b15aa2 Attempt to pacify windows bots.
llvm-svn: 276672
2016-07-25 18:39:08 +00:00
Michael Kuperstein 8f8e1d1bf6 Don't use iplist in SymbolRewriter. NFC.
There didn't appear to be a good reason to use iplist in this case, a regular
list of unique_ptr works just as well.
Change made in preparation to a new PM port (since iplist is not moveable).

llvm-svn: 276668
2016-07-25 18:10:54 +00:00
David Majnemer 6f014d37d5 [Utils] Simplify combineMetadata
Use a range-based for loop, no functional change is intended.

llvm-svn: 276600
2016-07-25 02:21:19 +00:00
Elena Demikhovsky 376a18bd92 [Loop Vectorizer] Handling loops FP induction variables.
Allowed loop vectorization with secondary FP IVs. Like this:
float *A;
float x = init;
for (int i=0; i < N; ++i) {
  A[i] = x;
  x -= fp_inc;
}

The auto-vectorization is possible when the induction binary operator is "fast" or the function has "unsafe" attribute.

Differential Revision: https://reviews.llvm.org/D21330

llvm-svn: 276554
2016-07-24 07:24:54 +00:00
George Burgess IV 93ea19b9a6 [MSSA] Make EXPENSIVE_CHECKS check more.
checkClobberSanity will now be run for all results of `ClobberWalk`,
instead of just the crazy phi-optimized ones. This can help us catch
cases where our cache is being wonky.

llvm-svn: 276553
2016-07-24 07:03:49 +00:00
George Burgess IV f23eb70e03 [MSSA] Remove useless assert. NFC.
liveOnEntry is always a MemoryDef; asserting that a MemoryPhi isn't
liveOnEntry, while correct, isn't very helpful. :)

llvm-svn: 276542
2016-07-24 01:50:07 +00:00
Sean Silva ab6a683765 Avoid using a raw AssumptionCacheTracker in various inliner functions.
This unblocks the new PM part of River's patch in
https://reviews.llvm.org/D22706

Conveniently, this same change was needed for D21921 and so these
changes are just spun out from there.

llvm-svn: 276515
2016-07-23 04:22:50 +00:00
Wei Mi e04d0eff29 [PM] Port BreakCriticalEdges to the new PM.
Differential Revision: https://reviews.llvm.org/D22688

llvm-svn: 276449
2016-07-22 18:04:25 +00:00
George Burgess IV 400ae40348 [MSSA] Add an overload for getClobberingMemoryAccess.
A seemingly common use for the walker's getClobberingMemoryAccess
function is:

```
MemoryAccess *getClobber(MemorySSAWalker *W, MemoryUseOrDef *MUD) {
  const Instruction *I = MUD->getMemoryInst();
  return W->getClobberingMemoryAccess(I);
}
```

Which is kind of redundant, since walkers will ultimately query MSSA to
find out which MemoryAccess `I` maps to (...which is always `MUD`).

So, this patch adds an overload of getClobberingMemoryAccess that
accepts MemoryAccesses directly. As a result, the Instruction overload
of getClobberingMemoryAccess becomes a lightweight wrapper around our
new overload.

Additionally, this patch un`virtual`izes the Instruction overload of
getClobberingMemoryAccess, since there doesn't seem to be a walker that
benefits from that being virtual, and I can't think of how else one
would implement it. Happy to make it virtual again if we would benefit
from doing so.

llvm-svn: 276169
2016-07-20 19:51:34 +00:00
Sanjay Patel 683170bf56 move decomposeBitTestICmp() to Transforms/Utils; NFC
As noted in https://reviews.llvm.org/D22537 , we can use this functionality in 
visitSelectInstWithICmp() and InstSimplify, but currently we have duplicated
code.

llvm-svn: 276140
2016-07-20 17:18:45 +00:00
Sanjay Patel be53c65fab fix documentation comments; NFC
llvm-svn: 276135
2016-07-20 16:30:55 +00:00
Michael Zolotukhin 6bc56d552a Revert "Revert r275883 and r275891. They seem to cause PR28608."
This reverts commit r276064, and thus reapplies r275891 and r275883 with
a fix for PR28608.

llvm-svn: 276077
2016-07-20 01:55:27 +00:00
Sean Silva 554efb28d2 Revert r275883 and r275891. They seem to cause PR28608.
Revert "[LoopSimplify] Update LCSSA after separating nested loops."

This reverts commit r275891.

Revert "[LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form."

This reverts commit r275883.

llvm-svn: 276064
2016-07-19 23:54:29 +00:00
Daniel Berlin 1986030b62 Fix unused variable
llvm-svn: 276050
2016-07-19 23:08:08 +00:00
Daniel Berlin 5c46b943db Make MemorySSA::dominates/locallydominates constant time
Summary: Make MemorySSA::dominates/locallydominates constant time

Reviewers: george.burgess.iv, gberry

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22527

llvm-svn: 276046
2016-07-19 22:49:43 +00:00
George Burgess IV 5f30897b7b [MemorySSA] Update to the new shiny walker.
This patch updates MemorySSA's use-optimizing walker to be more
accurate and, in some cases, faster.

Essentially, this changed our core walking algorithm from a
cache-as-you-go DFS to an iteratively expanded DFS, with all of the
caching happening at the end. Said expansion happens when we hit a Phi,
P; we'll try to do the smallest amount of work possible to see if
optimizing above that Phi is legal in the first place. If so, we'll
expand the search to see if we can optimize to the next phi, etc.

An iteratively expanded DFS lets us potentially quit earlier (because we
don't assume that we can optimize above all phis) than our old walker.
Additionally, because we don't cache as we go, we can now optimize above
loops.

As an added bonus, this patch adds a ton of verification (if
EXPENSIVE_CHECKS are enabled), so finding bugs is easier.

Differential Revision: https://reviews.llvm.org/D21777

llvm-svn: 275940
2016-07-19 01:29:15 +00:00
Michael Zolotukhin ea5b72825b [LoopSimplify] Update LCSSA after separating nested loops.
Summary:
Usually LCSSA survives this transformation, but in some cases (see
attached test) it doesn't: values from the original loop after
separating might be used from the outer loop. Before the transformation
it was the same loop, so LCSSA phis were not required.

This fixes PR28272.

Reviewers: sanjoy, hfinkel, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21665

llvm-svn: 275891
2016-07-18 19:44:19 +00:00
Michael Zolotukhin 7a3040dc83 [LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form.
Summary:
SSAUpdate might insert PHI-nodes inside loops, which can break LCSSA
form unless we fix it up.

This fixes PR28424.

Reviewers: sanjoy, chandlerc, hfinkel

Subscribers: uabelho, llvm-commits

Differential Revision: http://reviews.llvm.org/D21997

llvm-svn: 275883
2016-07-18 19:05:08 +00:00
Michael Zolotukhin a78937afb2 Make processInstruction from LCSSA.cpp externally available.
Summary:
When a pass tries to keep LCSSA form it's often convenient to be able to update
LCSSA for a set of instructions rather than for the entire loop. This patch makes the
processInstruction from LCSSA externally available under a name
formLCSSAForInstruction.

Reviewers: chandlerc, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22378

llvm-svn: 275613
2016-07-15 21:08:41 +00:00
David Majnemer a940f360cb [AliasAnalysis] Give back AA results for fence instructions
Calling getModRefInfo with a fence resulted in crashes because fences
don't have a memory location.  Add a new predicate to Instruction
called isFenceLike which indicates that the instruction mutates memory
but not any single memory location in particular. In practice, it is a
proxy for the set of instructions which "mayWriteToMemory" but cannot be
used with MemoryLocation::get.

This fixes PR28570.

llvm-svn: 275581
2016-07-15 17:19:24 +00:00
Andrew Kaylor 346dd7f1bd Reverting r275284 due to platform-specific test failures
llvm-svn: 275304
2016-07-13 19:09:16 +00:00
Andrew Kaylor 12cccdd731 Fix for Bug 26903, adds support to inline __builtin_mempcpy
Patch by Sunita Marathe

Differential Revision: http://reviews.llvm.org/D21920

llvm-svn: 275284
2016-07-13 17:25:11 +00:00
Davide Italiano 081fd139b3 [LoopSimplify] Remove a comment which is unlikely to age well.
Chandler pointed out in his review but I forgot to remove before
committing, my bad.

llvm-svn: 274963
2016-07-09 03:27:24 +00:00
Davide Italiano cd96cfd8df [PM] Port LoopSimplify to the new pass manager.
While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.

Differential Revision:  http://reviews.llvm.org/D21404

llvm-svn: 274959
2016-07-09 03:03:01 +00:00
Xinliang David Li 7853c1dd73 Rename LoopAccessAnalysis to LoopAccessLegacyAnalysis /NFC
llvm-svn: 274927
2016-07-08 20:55:26 +00:00
Davide Italiano 16284df8ec [PM] Port InstSimplify to the new pass manager.
llvm-svn: 274796
2016-07-07 21:14:36 +00:00
Sjoerd Meijer 7435a910b5 Addressing post-commit comments for not rewriting fputs:
moved the optimise for size check inside function optimizeFPuts.

llvm-svn: 274758
2016-07-07 14:31:19 +00:00
Sjoerd Meijer 17c08dc701 Code size optimisation: don't rewrite fputs to fwrite when optimising for size
because fwrite requires more arguments and thus extra MOVs are required.

llvm-svn: 274753
2016-07-07 13:56:23 +00:00
Chad Rosier 232e29ebea [MemorySSA] Reinstate the legacy printer and verifier.
Differential Revision: http://reviews.llvm.org/D22058

llvm-svn: 274679
2016-07-06 21:20:47 +00:00
Daniel Berlin fc7e651bfd Fix handling of forward unreachable but reverse-reachable blocks in MemorySSA construction
llvm-svn: 274606
2016-07-06 05:32:05 +00:00
George Burgess IV a362b09a81 [MSSA] Fix typo. NFC.
llvm-svn: 274590
2016-07-06 00:28:43 +00:00
Xinliang David Li 94734eef33 [PM] refactor LoopAccessInfo code part-2
Differential Revision: http://reviews.llvm.org/D21636

llvm-svn: 274334
2016-07-01 05:59:55 +00:00
Michael Kuperstein 835facd863 [PM] Normalize FIXMEs for missing PreserveCFG to have the same wording.
llvm-svn: 273974
2016-06-28 00:54:12 +00:00
Daniel Berlin 16ed57c86b Factor out buildMemorySSA from getWalker.
NFC.

llvm-svn: 273901
2016-06-27 18:22:27 +00:00
Benjamin Kramer 706e48839d [CodeExtractor] Merge DEBUG statements in an attempt to fix the msvc
build.

There's a known bug in msvc 2013 that fails to compile do-while loops
inside of ranged for loops.

llvm-svn: 273811
2016-06-26 13:39:33 +00:00
Benjamin Kramer 135f735af1 Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
2016-06-26 12:28:59 +00:00
David Majnemer 9f506259c8 Just a small cleanup
No functional change is intended

llvm-svn: 273780
2016-06-25 08:34:38 +00:00
David Majnemer e14e7bc4b8 Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"
This reverts commit r273778, it seems to break UBSan :/

llvm-svn: 273779
2016-06-25 08:19:55 +00:00
David Majnemer d346a37737 [SimplifyCFG] Stop inserting calls to llvm.trap for UB
SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.

While InstCombine canonicalizes certain undefined behavior IR patterns
to stores of undef, phase ordering means that this cannot be relied upon
in general.

There are much better tools than llvm.trap: UBSan and ASan.

N.B. I could be argued into reverting this change if a clear argument as
to why it is important that we synthesize llvm.trap for stores, I'd be
hard pressed to see why it'd be useful for invokes...

llvm-svn: 273778
2016-06-25 08:04:19 +00:00
David Majnemer 1fea77c6fc [SimplifyCFG] Replace calls to null/undef with unreachable
Calling null is undefined behavior, a call to undef can be trivially
treated as a call to null.

llvm-svn: 273776
2016-06-25 07:37:27 +00:00
Michael Kuperstein f4c56e97df It isn't meaningful for a transform to preserve another transform. NFC.
llvm-svn: 273761
2016-06-25 00:47:21 +00:00
David Majnemer b8da3a2bb2 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
2016-06-25 00:04:10 +00:00
David Majnemer 580e754348 Silence a -Wsign-compare warning
llvm-svn: 273752
2016-06-25 00:04:06 +00:00
Nico Weber ae2ef4ccd4 Revert r273711, it caused PR28298.
llvm-svn: 273743
2016-06-24 22:52:39 +00:00
George Burgess IV fd1f2f8561 [MemorySSA] Move code around a bit. NFC.
This patch moves MSSA's caching walker into MemorySSA, and moves the
actual definition of MSSA's caching walker out of MemorySSA.h. This is
done in preparation for the new walker, which should be out for review
soonish.

Also, this patch removes a field from UpwardsMemoryQuery and has a few
lines of diff from clang-format'ing MemorySSA.cpp.

llvm-svn: 273723
2016-06-24 21:02:12 +00:00
David Majnemer 3b3e954ea2 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
2016-06-24 19:34:46 +00:00
David Majnemer d770877328 Switch more loops to be range-based
This makes the code a little more concise, no functional change is
intended.

llvm-svn: 273644
2016-06-24 04:05:21 +00:00
Chuang-Yu Cheng 68f7f1cf00 Teaching SimplifyCFG to recognize the Or-Mask trick that InstCombine uses to
reduce the number of comparisons.

Specifically, InstCombine can turn:
  (i == 5334 || i == 5335)
into:
  ((i | 1) == 5335)

SimplifyCFG was already able to detect the pattern:
  (i == 5334 || i == 5335)
to:
  ((i & -2) == 5334)

This patch supersedes D21315 and resolves PR27555
(https://llvm.org/bugs/show_bug.cgi?id=27555).

Thanks to David and Chandler for the suggestions!

Author: Thomas Jablin (tjablin)
Reviewers: majnemer chandlerc halfdan cycheng

http://reviews.llvm.org/D21397

llvm-svn: 273639
2016-06-24 01:59:00 +00:00
Rafael Espindola 2b7fef681f Delete more dead code.
Found by gcc 6.

llvm-svn: 273402
2016-06-22 12:44:16 +00:00
Daniel Berlin 1430026142 Add MemoryAccess creation and PHI creation APIs to MemorySSA
Reviewers: george.burgess.iv, gberry, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21463

llvm-svn: 273295
2016-06-21 18:39:20 +00:00
Daniel Berlin ada263dcd0 Rename to be consistent with other type names. NFC
llvm-svn: 273194
2016-06-20 20:21:33 +00:00
Marcin Koscielnicki 3feda222c6 [sanitizers] Disable target-specific lowering of string functions.
CodeGen has hooks that allow targets to emit specialized code instead
of calls to memcmp, memchr, strcpy, stpcpy, strcmp, strlen, strnlen.
When ASan/MSan/TSan/ESan is in use, this sidesteps its interceptors, resulting
in uninstrumented memory accesses.  To avoid that, make these sanitizers
mark the calls as nobuiltin.

Differential Revision: http://reviews.llvm.org/D19781

llvm-svn: 273083
2016-06-18 10:10:37 +00:00
Chuang-Yu Cheng 5078f94690 Use m_APInt in SimplifyCFG
Switch from m_Constant to m_APInt per David's request. NFC.

Author: Thomas Jablin (tjablin)
Reviewers: majnemer cycheng

http://reviews.llvm.org/D21440

llvm-svn: 272977
2016-06-17 00:04:39 +00:00
Evgeniy Stepanov 72d961a1da [safestack] Fixup llvm.dbg.value when rewriting unsafe allocas.
When moving unsafe allocas to the unsafe stack, dbg.declare intrinsics are
updated to refer to the new location.

This change does the same to dbg.value intrinsics.

llvm-svn: 272968
2016-06-16 22:34:00 +00:00
Igor Laevsky 87f0d0e185 Revert r272891 "[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo"
It was causing failures in Profile-i386 and Profile-x86_64 tests.

llvm-svn: 272912
2016-06-16 16:25:53 +00:00
Igor Laevsky c9179fd2c2 [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
2016-06-16 13:28:25 +00:00
Adam Nemet bdbc5227ce [LAA] Default getInfo to not speculate symbolic strides. NFC
Soon we won't be passing Strides to getInfo and then we'll have fewer
call sites to update.

llvm-svn: 272878
2016-06-16 08:26:56 +00:00
Chuang-Yu Cheng dbe00d51b4 SimplifyCFG is able to detect the pattern:
(i == 5334 || i == 5335)
to:
    ((i & -2) == 5334)

This transformation has some incorrect side conditions. Specifically, the
transformation is only applied when the right-hand side constant (5334 in
the example) is a power of two not equal and not equal to the negated mask.
These side conditions were added in r258904 to fix PR26323. The correct side
condition is that: ((Constant & Mask) == Constant)[(5334 & -2) == 5334].

It's a little bit hard to see why these transformations are correct and what
the side conditions ought to be. Here is a CVC3 program to verify them for
64-bit values:
    ONE  : BITVECTOR(64) = BVZEROEXTEND(0bin1, 63);
    x    : BITVECTOR(64);
    y    : BITVECTOR(64);
    z    : BITVECTOR(64);
    mask : BITVECTOR(64) = BVSHL(ONE, z);
    QUERY( (y & ~mask = y) =>
           ((x & ~mask = y) <=> (x = y OR x = (y |  mask)))
    );

Please note that each pattern must be a dual implication (<--> or iff). One
directional implication can create spurious matches. If the implication is
only one-way, an unsatisfiable condition on the left side can imply a
satisfiable condition on the right side. Dual implication ensures that
satisfiable conditions are transformed to other satisfiable conditions and
unsatisfiable conditions are transformed to other unsatisfiable conditions.

Here is a concrete example of a unsatisfiable condition on the left
implying a satisfiable condition on the right:
    mask = (1 << z)
    (x & ~mask) == y --> (x == y || x == (y | mask))

Substituting y = 3, z = 0 yields:
    (x & -2) == 3 --> (x == 3 || x == 2)

The version of this code before r258904 had no side-conditions and
incorrectly justified itself in comments through one-directional
implication.

Thanks to Chandler for the suggestion!

Author: Thomas Jablin (tjablin)
Reviewers: chandlerc majnemer hfinkel cycheng

http://reviews.llvm.org/D21417

llvm-svn: 272873
2016-06-16 04:44:25 +00:00
Xinliang David Li 1e16d61f1f Address review feedbacks of AddDiscriminator change
llvm-svn: 272850
2016-06-15 22:20:56 +00:00
Xinliang David Li 1eaecefaf9 [PM] Port Add discriminator pass to new PM
llvm-svn: 272847
2016-06-15 21:51:30 +00:00
Davide Italiano 9d305d707e [LoopSimplify] Analyses do not need to be member variables.
In preparation for porting this pass to the new PM.

llvm-svn: 272818
2016-06-15 18:51:25 +00:00
Geoff Berry efb0dd176a [MemorySSA] Set CFGOnly correctly for MemorySSAWrapperPass
Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D21344

llvm-svn: 272712
2016-06-14 21:19:40 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Adam Nemet 57fb8989a5 [LoopVer] Remove an assert that's redundant now. NFC
Ensuring that the PHI are all single-operand is not performed in the
second pass added by the previous pass.  This removes the assert from
the first pass.

llvm-svn: 272650
2016-06-14 09:39:01 +00:00
Adam Nemet 73a26957fc [LoopVer] Update all existing PHIs in the exit block
We only used to add the edge from the cloned loop to PHIs that
corresponded to values defined by the loop.  We need to do this for all
PHIs obviously since we need a PHI operand for each incoming edge.

This includes things like PHIs with a constant value or with values
defined before the original loop (see the testcases).

After the patch the PHIs are added to the exit block in two passes.

In the first pass we ensure there is a single-operand (LCSSA) PHI for
each value defined by the loop.

In the second pass we loop through each (single-operand) PHI and add the
value for the edge from the cloned loop.  If the value is defined in the
loop we'll use the cloned instruction from the cloned loop.

Fixes PR28037

llvm-svn: 272649
2016-06-14 09:38:54 +00:00
Davide Italiano cccf4f01ad [PM] Port Mem2Reg to the new pass manager.
llvm-svn: 272630
2016-06-14 03:22:22 +00:00
Vikram TV 299abc10e7 Fix a typo in loop versioning.
Reviewers: ashutosh.nema

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21281

llvm-svn: 272545
2016-06-13 10:49:28 +00:00
Benjamin Kramer 4ca41fd09e Run clang-tidy's performance-unnecessary-copy-initialization over LLVM.
No functionality change intended.

llvm-svn: 272516
2016-06-12 17:30:47 +00:00
Benjamin Kramer d3f4c05aea Move instances of std::function.
Or replace with llvm::function_ref if it's never stored. NFC intended.

llvm-svn: 272513
2016-06-12 16:13:55 +00:00
Benjamin Kramer bdc4956bac Pass DebugLoc and SDLoc by const ref.
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
2016-06-12 15:39:02 +00:00
Eli Friedman f1da33e4d3 [LICM] Make isGuaranteedToExecute more accurate.
Summary:
Make isGuaranteedToExecute use the
isGuaranteedToTransferExecutionToSuccessor helper, and make that helper
a bit more accurate.

There's a potential performance impact here from assuming that arbitrary
calls might not return. This probably has little impact on loads and
stores to a pointer because most things alias analysis can reason about
are dereferenceable anyway. The other impacts, like less aggressive
hoisting of sdiv by a variable and less aggressive hoisting around
volatile memory operations, are unlikely to matter for real code.

This also impacts SCEV, which uses the same helper.  It's a minor
improvement there because we can tell that, for example, memcpy always
returns normally. Strictly speaking, it's also introducing
a bug, but it's not any worse than everywhere else we assume readonly
functions terminate.

Fixes http://llvm.org/PR27857.

Reviewers: hfinkel, reames, chandlerc, sanjoy

Subscribers: broune, llvm-commits

Differential Revision: http://reviews.llvm.org/D21167

llvm-svn: 272489
2016-06-11 21:48:25 +00:00
Vikram TV c702b8b3d7 Delay dominator updation while cloning loop.
Summary:
Dominator updation fails for a loop inserted with a new basicblock.

A block required by DT to set the IDom might not have been cloned yet. This is because there is no predefined ordering of loop blocks (except for the header block which should be the first block in the list).

The patch first creates DT nodes for the cloned blocks and then separately updates the DT in a follow-on loop.

Reviewers: anemet, dberlin

Subscribers: dberlin, llvm-commits

Differential Revision: http://reviews.llvm.org/D20899

llvm-svn: 272479
2016-06-11 16:41:10 +00:00
Sebastian Pop e1f60b1fb3 MemorySSA: fix memory access local dominance function for live on entry
A memory access defined on function entry cannot be locally dominated by another memory access.
The patch was split from http://reviews.llvm.org/D19338 which exposes the problem.

Differential Revision: http://reviews.llvm.org/D21039

llvm-svn: 272436
2016-06-10 21:36:41 +00:00
Evgeniy Stepanov 122f984a33 Move isGuaranteedToExecute out of LICM.
Also rename LICMSafetyInfo to LoopSafetyInfo.
Both will be used in LoopUnswitch in a separate change.

llvm-svn: 272420
2016-06-10 20:03:17 +00:00
Easwaran Raman e12c487b8c [PM] Port LCSSA to the new PM.
Differential Revision: http://reviews.llvm.org/D21090

llvm-svn: 272294
2016-06-09 19:44:46 +00:00
Xinliang David Li ecde1c7f3d Revert r272194 No need for it if loop Analysis Manager is used
llvm-svn: 272243
2016-06-09 03:22:39 +00:00
Michael Zolotukhin 8e7e76729d [LoopSimplify] Preserve LCSSA when merging exit blocks.
Summary:
This fixes PR26682. Also add LCSSA as a preserved pass to LoopSimplify,
that looks correct to me and allows to write a test for the issue.

Reviewers: chandlerc, bogner, sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21112

llvm-svn: 272224
2016-06-08 23:13:21 +00:00
Michael Zolotukhin aa547616d2 [LoopUnroll] Check that DT is available before trying to verify it.
llvm-svn: 272221
2016-06-08 22:49:59 +00:00
Xinliang David Li 572135f717 [PM] Refector LoopAccessInfo analysis code
This is the preparation patch to port the analysis to new PM

Differential Revision: http://reviews.llvm.org/D20560

llvm-svn: 272194
2016-06-08 20:15:37 +00:00
Davide Italiano 2d5ab0a56a [PM] LoopSimplify. Remove unneeded pass dependencies. NFCI.
llvm-svn: 272140
2016-06-08 13:56:59 +00:00
Sanjoy Das f90e28d6fd [IndVars] Remove -liv-reduce
It is an off-by-default option that no one seems to use[0], and given
that SCEV directly understands the overflow instrinsics there is no real
need for it anymore.

[0]: http://lists.llvm.org/pipermail/llvm-dev/2016-April/098181.html

llvm-svn: 271845
2016-06-05 18:01:12 +00:00
David Majnemer 2482e1c017 [SimplifyCFG] Don't kill empty cleanuppads with multiple uses
A basic block could contain:
  %cp = cleanuppad []
  cleanupret from %cp unwind to caller

This basic block is empty and is thus a candidate for removal.  However,
there can be other uses of %cp outside of this basic block.  This is
only possible in unreachable blocks.

Make our transform more correct by checking that the pad has a single
user before removing the BB.

This fixes PR28005.

llvm-svn: 271816
2016-06-04 23:50:03 +00:00
Geoff Berry b96d3b2dd8 [MemorySSA] Port to new pass manager
Add support for the new pass manager to MemorySSA pass.

Change MemorySSA to be computed eagerly upon construction.

Change MemorySSAWalker to be owned by the MemorySSA object that creates
it.

Reviewers: dberlin, george.burgess.iv

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19664

llvm-svn: 271432
2016-06-01 21:30:40 +00:00
Peter Collingbourne 382d81cacf IR: Allow multiple global metadata attachments with the same type.
This will be necessary to allow the global merge pass to attach
multiple debug info metadata nodes to global variables once we reverse
the edge from DIGlobalVariable to GlobalVariable.

Differential Revision: http://reviews.llvm.org/D20414

llvm-svn: 271358
2016-06-01 01:17:57 +00:00
Benjamin Kramer 728f4448a9 Remove some 'const' specifiers that do nothing but prevent moving the argument.
Found by clang-tidy's misc-move-const-arg. While there drop some
obsolete c_str() calls.

llvm-svn: 271181
2016-05-29 10:46:35 +00:00
Sanjoy Das ae09b3cd4c [IndVars] Eliminate op.with.overflow when possible (re-apply)
Summary:
If we can prove that an op.with.overflow intrinsic does not overflow, we
can get rid of the intrinsic, and replace it with non-wrapping
arithmetic.

This was first checked in at r265913 but reverted in r265950 because it
exposed some issues around how SCEV handled post-inc add recurrences.
Those issues have now been fixed.

Reviewers: atrick, regehr

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18685

llvm-svn: 271153
2016-05-29 00:36:25 +00:00
Mehdi Amini bcc47419d9 ValueMapper: fix assertion when null-mapping a constant for linking metadata
Summary:
When RF_NullMapMissingGlobalValues is set, mapValue can return null
for GlobalValue. When mapping the operands of a constant that is
referenced from metadata, we need to handle this case and actually
return null instead of mapping this constant.

Reviewers: dexonsmith, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D20713

llvm-svn: 271129
2016-05-28 17:26:03 +00:00
Evgeny Stupachenko ea2aef4a1d The patch refactors unroll pass.
Summary:
Unroll factor (Count) calculations moved to a new function.
Early exits on pragma and "-unroll-count" defined factor added.
New type of unrolling "Force" introduced (previously used implicitly).
New unroll preference "AllowRemainder" introduced and set "true" by default.
(should be set to false for architectures that suffers from it).

Reviewers: hfinkel, mzolotukhin, zzheng

Differential Revision: http://reviews.llvm.org/D19553

From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 271071
2016-05-27 23:15:06 +00:00
Davide Italiano 88a7892a07 [LCSSA] Simplify. Suggested by Sanjoy.
llvm-svn: 271041
2016-05-27 20:25:31 +00:00
Tim Northover 10a1e8b1fe Vectorizer: track non-fast FP instructions through phis when finding reductions.
When we traced through a phi node looking for floating-point reductions, we
forgot whether we'd ever seen an instruction without fast-math flags (that
would block vectorization). This propagates it through to the end.

llvm-svn: 271015
2016-05-27 16:40:27 +00:00
Benjamin Kramer 4fed928f53 Avoid some copies by using const references.
clang-tidy's performance-unnecessary-copy-initialization with some manual
fixes. No functional changes intended.

llvm-svn: 270988
2016-05-27 12:30:51 +00:00
Mehdi Amini 9ee054aea8 ValueMapper: fix typo in minor optimization on constant mapping (NFC)
If every operands of a constant are mapping to themselves, and the
type does not change, we have an early exit as acknowledged in the
comment:

  // Otherwise, we have some other constant to remap.  Start by checking to see
  // if all operands have an identity remapping.

However instead of checking for identity the code was checking if the
operands were mapped to the constant itself, which is rarely true.

As a consequence, the coverage report showed that the early exit was
never taken.

llvm-svn: 270944
2016-05-27 00:32:12 +00:00
Chad Rosier e5819e2732 [InstCombine] Catch more bswap cases missed due to zext and truncs.
Fixes PR27824.
Differential Revision: http://reviews.llvm.org/D20591.

llvm-svn: 270853
2016-05-26 14:58:51 +00:00
Peter Collingbourne b9aa1f4a03 MemorySSA: Revert r269678 and r268068; replace with special casing in MemorySSA.
It turns out that too many passes are relying on alias analysis results
for control dependencies. Until we fix that by introducing a more accurate
modelling of control dependencies, special case assume in MemorySSA instead.

Also introduce tests to ensure we don't regress the FunctionAttrs or LICM
passes.

Differential Revision: http://reviews.llvm.org/D20658

llvm-svn: 270823
2016-05-26 04:58:46 +00:00
Peter Collingbourne ffecb1441b MemorySSA: Remove argument to createNewAccess function.
There is only one caller of MemorySSA::createNewAccess, and it passes true
as the IgnoreNonMemory argument. Remove that argument and fold its behavior
into createNewAccess.

llvm-svn: 270812
2016-05-26 01:19:17 +00:00
Mehdi Amini cc8c107e6a ValueMaterializer: rename materializeDeclFor() to materialize()
It may materialize a declaration, or a definition. The name could
be misleading. This is following a merge of materializeInitFor()
into materializeDeclFor().

Differential Revision: http://reviews.llvm.org/D20593

llvm-svn: 270759
2016-05-25 21:03:21 +00:00
Mehdi Amini 53a6672e21 ValueMaterializer: fuse materializeDeclFor and materializeInitFor (NFC)
They were originally separated to handle the co-recursion between
the ValueMapper and the ValueMaterializer. This recursion does not
exist anymore: the ValueMapper now uses a Worklist and the
ValueMaterializer is scheduling job on the Worklist.

Differential Revision: http://reviews.llvm.org/D20593

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 270758
2016-05-25 21:01:51 +00:00
Chad Rosier a00df49dc5 Clarify that we match BSwap in InstCombine and BitReverse in CGP. NFC.
Also, rename recognizeBitReverseOrBSwapIdiom to recognizeBSwapOrBitReverseIdiom,
so the ordering of the MatchBSwaps and MatchBitReversals arguments are
consistent with the function name.

llvm-svn: 270715
2016-05-25 16:22:14 +00:00
Chad Rosier 56def258e3 Fix 80-column violation.
llvm-svn: 270329
2016-05-21 21:12:06 +00:00
David Majnemer 9f92f4c497 [SimplifyCFG] Remove cleanuppads which are empty except for calls to lifetime.end
A cleanuppad is not cheap, they turn into many instructions and result
in additional spills and fills.  It is not worth keeping a cleanuppad
around if all it does is hold a lifetime.end instruction.

N.B.  We first try to merge the cleanuppad with another cleanuppad to
avoid dropping the lifetime and debug info markers.

llvm-svn: 270314
2016-05-21 05:12:32 +00:00
Sanjay Patel 75892a1543 [SimplifyCFG] eliminate switch cases based on known range of switch condition
This was noted in PR24766:
https://llvm.org/bugs/show_bug.cgi?id=24766#c2

We may not know whether the sign bit(s) are zero or one, but we can still
optimize based on knowing that the sign bit is repeated.

Differential Revision: http://reviews.llvm.org/D20275

llvm-svn: 270222
2016-05-20 14:53:09 +00:00
Dehao Chen f16376b505 Follow-up patch of http://reviews.llvm.org/D19948 to handle missing profiles when simplifying CFG.
Summary: Set default branch weight to 1:1 if one of the branch has profile missing when simplifying CFG.

Reviewers: spatel, davidxl

Subscribers: danielcdh, llvm-commits

Differential Revision: http://reviews.llvm.org/D20307

llvm-svn: 269995
2016-05-18 22:41:03 +00:00
Dehao Chen f6c0083b55 clang-format SimplifyCFG.cpp.
llvm-svn: 269974
2016-05-18 19:44:21 +00:00
Davide Italiano bfe3801d16 [LCSSA] Use llvm::any_of instead of std::size_of.
The API is simpler. Suggested by David Blaikie!

llvm-svn: 269800
2016-05-17 19:01:02 +00:00
Davide Italiano a0e0feea1d [PM/LCSSA] Fix dependency list. Some passes are preserved, not required.
llvm-svn: 269768
2016-05-17 14:32:12 +00:00
Davide Italiano b75b16e2ff [LCSSA] Use any_of() to simplify the code. NFCI.
llvm-svn: 269767
2016-05-17 14:24:41 +00:00
Sanjay Patel 5d5134f676 use range-loops; NFCI
llvm-svn: 269471
2016-05-13 20:24:53 +00:00
Chandler Carruth 49c22190d0 [PM] Port of the DepndenceAnalysis to the new PM.
Ported DA to the new PM by splitting the former DependenceAnalysis Pass
into a DependenceInfo result type and DependenceAnalysisWrapperPass type
and adding a new PM-style DependenceAnalysis analysis pass returning the
DependenceInfo.

Patch by Philip Pfaffe, most of the review by Justin.

Differential Revision: http://reviews.llvm.org/D18834

llvm-svn: 269370
2016-05-12 22:19:39 +00:00
Sanjoy Das e0aa414acf All llvm.deoptimize declarations must use the same calling convention
This new verifier rule lets us unambigously pick a calling convention
when creating a new declaration for
`@llvm.experimental.deoptimize.<ty>`.  It is also congruent with our
lowering strategy -- since all calls to `@llvm.experimental.deoptimize`
are lowered to calls to `__llvm_deoptimize`, it is reasonable to enforce
a unique calling convention.

Some of the tests that were breaking this verifier rule have had to be
split up into different .ll files.

The inliner was violating this rule as well, and has been fixed to avoid
producing invalid IR.

llvm-svn: 269261
2016-05-12 01:17:38 +00:00
Dehao Chen b76e5d948a Propagate branch metadata when some branch probability is missing.
Summary: In sample profile, some branches may have profile missing due to profile inaccuracy. We want existing branch probability still valid after propagation.

Reviewers: hfinkel, davidxl, spatel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19948

llvm-svn: 269137
2016-05-10 23:07:19 +00:00
Peter Collingbourne dba995601b Cloning: Clean up the interface to the CloneFunction function.
Remove the ModuleLevelChanges argument, and the ability to create new
subprograms for cloned functions. The latter was added without review in
r203662, but it has no in-tree clients (all non-test callers pass false
for ModuleLevelChanges [1], so it isn't reachable outside of tests). It
also isn't clear that adding a duplicate subprogram to the compile unit is
always the right thing to do when cloning a function within a module. If
this functionality comes back it should be accompanied with a more concrete
use case.

Furthermore, all in-tree clients add the returned function to the module.
Since that's pretty much the only sensible thing you can do with the function,
just do that in CloneFunction.

[1] http://llvm-cs.pcc.me.uk/lib/Transforms/Utils/CloneFunction.cpp/rCloneFunction

Differential Revision: http://reviews.llvm.org/D18628

llvm-svn: 269110
2016-05-10 20:23:24 +00:00
Elena Demikhovsky c434d091c5 [LoopVectorize] Handling induction variable with non-constant step.
Allow vectorization when the step is a loop-invariant variable.
This is the loop example that is getting vectorized after the patch:

 int int_inc;
 int bar(int init, int *restrict A, int N) {

  int x = init;
  for (int i=0;i<N;i++){
    A[i] = x;
    x += int_inc;
  }
  return x;
 }

"x" is an induction variable with *loop-invariant* step.
But it is not a primary induction. Primary induction variable with non-constant step is not handled yet.

Differential Revision: http://reviews.llvm.org/D19258

llvm-svn: 269023
2016-05-10 07:33:35 +00:00
Justin Lebar 50deb6d028 Minor formatting fixes in LoopUnroll.cpp.
llvm-svn: 268995
2016-05-10 00:31:23 +00:00
Joerg Sonnenberger 8ffe7ab7c2 Optimize a printf with a double procent to putchar.
llvm-svn: 268922
2016-05-09 14:36:16 +00:00
Junmo Park 955298746d Minor code cleanups. NFC.
llvm-svn: 268888
2016-05-08 23:22:58 +00:00
Sanjay Patel 1cb6241a89 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 / r268751 with possible fix)
Retrying r268550/r268751 which were reverted at r268577/r268765 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken another guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268767
2016-05-06 18:07:46 +00:00
Sanjay Patel 84a0bf64a8 revert r268751 - caused same failures on msan bot
llvm-svn: 268765
2016-05-06 17:51:37 +00:00
Sanjay Patel 6609510c32 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 with possible fix)
Retrying r268550 which was reverted at r268577 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken a guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268751
2016-05-06 17:07:47 +00:00
Chad Rosier 4ab37c0037 [SimplifyCFG] Prefer a simplification based on a dominating condition.
Rather than merge two branches with a common destination.
Differential Revision: http://reviews.llvm.org/D19743

llvm-svn: 268735
2016-05-06 14:25:14 +00:00
Mehdi Amini 3b132e34b0 ThinLTO: fix assertion and refactor check for hidden use from inline ASM in a helper function
This test was crashing, and currently it breaks bootstrapping clang with debuginfo

Differential Revision: http://reviews.llvm.org/D20008

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268715
2016-05-06 08:25:33 +00:00
Dehao Chen f50c67ce7c Revert http://reviews.llvm.org/D19926 as it breaks tests.
llvm-svn: 268681
2016-05-05 20:47:53 +00:00
Dehao Chen e48b4ee98c Simplify CFG before assigning discriminator.
Summary: We need to clean up CFG before assigning discriminator to minimize the impact of optimization on debug info.

Reviewers: davidxl, dblaikie, dnovillo

Subscribers: dnovillo, danielcdh, llvm-commits

Differential Revision: http://reviews.llvm.org/D19926

llvm-svn: 268675
2016-05-05 20:18:49 +00:00
Silviu Baranga c05bab8a9c [LV] Identify more induction PHIs by coercing expressions to AddRecExprs
Summary:
Some PHIs can have expressions that are not AddRecExprs due to the presence
of sext/zext instructions. In order to prevent the Loop Vectorizer from
bailing out when encountering these PHIs, we now coerce the SCEV
expressions to AddRecExprs using SCEV predicates (when possible).

We only do this when the alternative would be to not vectorize.

Reviewers: mzolotukhin, anemet

Subscribers: mssimpso, sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17153

llvm-svn: 268633
2016-05-05 15:20:39 +00:00
Vitaly Buka fdcea9d78a Revert "[SimplifyCFG] propagate branch metadata when creating select"
MemorySanitizer: use-of-uninitialized-value
0x4910e47 in count /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:159:12
0x4910e47 in countLeadingZeros<unsigned long> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:183
0x4910e47 in FitWeights /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:855
0x4910e47 in SimplifyCondBranchToCondBranch /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2895

This reverts commit 609f4dd4bf3bc735c8c047a4d4b0a8e9e4d202e2.

llvm-svn: 268577
2016-05-04 23:59:33 +00:00
Sanjay Patel 7e8c285814 [SimplifyCFG] propagate branch metadata when creating select
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268550
2016-05-04 20:48:24 +00:00
Hans Wennborg 0c3518e84b [SimplifyCFG] isSafeToSpeculateStore now ignores debug info
This patch fixes PR27615.

@llvm.dbg.value instructions no longer count towards the maximum number of
instructions to look back at in the instruction list when searching for a
store instruction. This should make the output consistent between debug and
non-debug build.

Patch by Henric Karlsson <henric.karlsson@ericsson.com>!

Differential Revision: http://reviews.llvm.org/D19912

llvm-svn: 268512
2016-05-04 15:40:57 +00:00
David Majnemer 95549497ec [GlobalDCE, Misc] Don't remove functions referenced by ifuncs
We forgot to consider the target of ifuncs when considering if a
function was alive or dead.

N.B. Also update a few auxiliary tools like bugpoint and
verify-uselistorder.

This fixes PR27593.

llvm-svn: 268468
2016-05-04 00:20:48 +00:00
Andrew Kaylor 50271f787e Add opt-bisect support to additional passes that can be skipped
Differential Revision: http://reviews.llvm.org/D19882

llvm-svn: 268457
2016-05-03 22:32:30 +00:00
Reid Kleckner bca59d2a43 Revert "[SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics"
This reverts commit r268254.

This change causes assertion failures while building Chromium. Reduced
test case coming soon.

llvm-svn: 268288
2016-05-02 19:43:22 +00:00
Hans Wennborg b7599329fc [SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics
Make it possible that TryToSimplifyUncondBranchFromEmptyBlock merges empty
basic block including lifetime intrinsics as well as phi nodes and
unconditional branch into its successor or predecessor(s).

If successor of empty block has single predecessor, all contents including
lifetime intrinsics are sinked into the successor. Otherwise, they are
hoisted into its predecessor(s) and then merged into the predecessor(s).

Patch by Josh Yoon <josh.yoon@samsung.com>!

Differential Revision: http://reviews.llvm.org/D19257

llvm-svn: 268254
2016-05-02 17:22:54 +00:00
Sanjoy Das 107aefc2fc Mark guards on true as "trivially dead"
This moves some logic added to EarlyCSE in rL268120 into
`llvm::isInstructionTriviallyDead`.  Adds a test case for DCE to
demonstrate that passes other than EarlyCSE can now pick up on the new
information.

llvm-svn: 268126
2016-04-29 22:23:16 +00:00
George Burgess IV 1b1fef30d0 [MemorySSA] Fix bugs in walker; refactor unittests a bit.
This patch fixes two somewhat related bugs in MemorySSA's caching
walker. These bugs were found because D19695 brought up the problem
that we'd have defs cached to themselves, which is incorrect.

The bugs this fixes are:

- We would sometimes skip the nearest clobber of a MemoryAccess, because
  we would query our cache for a given potential clobber before
  checking if the potential clobber is the clobber we're looking for.
  The cache entry for the potential clobber would point to the nearest
  clobber *of the potential clobber*, so if that was a cache hit, we'd
  ignore the potential clobber entirely.

- There are times (sometimes in DFS, sometimes in the getClobbering...
  functions) where we would insert cache entries that say a def
  clobbers itself.

There's a bit of common code between the fixes for the bugs, so they
aren't split out into multiple commits.

This patch also adds a few unit tests, and refactors existing tests a
bit to reduce the duplication of setup code.

llvm-svn: 268087
2016-04-29 18:42:55 +00:00
Filipe Cabecinhas 0da9937517 Unify XDEBUG and EXPENSIVE_CHECKS (into the latter), and add an option to the cmake build to enable them.
Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.

This will also make it easier to turn it on in buildbots.

Reviewers: chandlerc

Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits

Differential Revision: http://reviews.llvm.org/D19723

llvm-svn: 268050
2016-04-29 15:22:48 +00:00
Hal Finkel 50316d95a9 [Inliner] Preserve llvm.mem.parallel_loop_access metadata
When inlining a call site with llvm.mem.parallel_loop_access metadata, this
metadata needs to be propagated to all cloned memory-accessing instructions.
Otherwise, inlining parts of the loop body will invalidate the annotation.

With this functionality, we now vectorize the following as expected:

  void Body(int *res, int *c, int *d, int *p, int i) {
    res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
  }

  void Test(int *res, int *c, int *d, int *p, int n) {
    int i;

  #pragma clang loop vectorize(assume_safety)
    for (i = 0; i < 1600; i++) {
      Body(res, c, d, p, i);
    }
  }

llvm-svn: 267949
2016-04-28 23:00:04 +00:00
Sanjay Patel facf45a82f [SimplifyCFG] propagate branch metadata when creating select
There's no existing test for this path, and I don't know how to expose
it in a regression test, but I'm assuming there's some reason this
path exists. 

llvm-svn: 267813
2016-04-27 23:14:12 +00:00
Ahmed Bougacha 44c19876c7 [InferAttrs] Mark memset_pattern16 params nocapture.
Differential Revision: http://reviews.llvm.org/D19471

llvm-svn: 267760
2016-04-27 19:04:43 +00:00
Ahmed Bougacha b0624a2cb4 [TLI] Unify LibFunc attribute inference. NFCI.
Now the pass is just a tiny wrapper around the util. This lets us reuse
the logic elsewhere (done here for BuildLibCalls) instead of duplicating
it.

The next step is to have something like getOrInsertLibFunc that also
sets the attributes.

Differential Revision: http://reviews.llvm.org/D19470

llvm-svn: 267759
2016-04-27 19:04:40 +00:00
Ahmed Bougacha d765a82b54 [TLI] Unify LibFunc signature checking. NFCI.
I tried to be as close as possible to the strongest check that
existed before; cleaning these up properly is left for future work.

Differential Revision: http://reviews.llvm.org/D19469

llvm-svn: 267758
2016-04-27 19:04:35 +00:00
Teresa Johnson df5ef8711f [ThinLTO] Refine fix to avoid renaming of uses in inline assembly.
Summary:
Refine the workaround from r266877 that attempts to prevent
renaming of locals in inline assembly, so that in addition to looking
for a llvm.used local value, that there is at least one inline assembly
call in the module. Otherwise, debug functions added to the llvm.used
can block importing/exporting unnecessarily.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19573

llvm-svn: 267717
2016-04-27 14:19:38 +00:00
Vaivaswatha Nagaraj 08efb0efcd [Cloning] cloneLoopWithPreheader(): add assert to ensure no sub-loops
Summary:
cloneLoopWithPreheader() does not update LoopInfo for sub-loop of
the original loop being cloned. Add assert to ensure no sub-loops for loop being cloned.

Reviewers: anemet, ashutosh.nema, hfinkel

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D15922

llvm-svn: 267671
2016-04-27 05:25:09 +00:00
Evgeny Stupachenko 23ce61b663 The patch fixes PR27392.
Summary:
 It is incorrect to compare TripCount (which is BECount + 1)
  with extraiters (or Count) to check if we should enter unrolled
  loop or not, because TripCount can potentially overflow
  (when BECount is max unsigned integer).
 While comparing BECount with (Count - 1) is overflow safe and
  therefore correct.

Reviewer: hfinkel

Differential Revision: http://reviews.llvm.org/D19256

From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 267662
2016-04-27 03:04:54 +00:00
Mehdi Amini b4e1e8297b ThinLTO: do not promote GlobalVariable that have a specific section.
Differential Revision: http://reviews.llvm.org/D18298

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267646
2016-04-27 00:32:13 +00:00
Sanjay Patel 29dea0d230 [SimplifyCFG] propagate branch metadata when creating select
llvm-svn: 267624
2016-04-26 23:15:48 +00:00
David Majnemer abb9f55c80 Revert "[SimplifyLibCalls] sprintf doesn't copy null bytes"
The destination buffer that sprintf uses is restrict qualified, we do
not need to worry about derived pointers referenced via format
specifiers.

This reverts commit r267580.

llvm-svn: 267605
2016-04-26 21:04:47 +00:00
David Majnemer 8cd77baebc [SimplifyLibCalls] sprintf doesn't copy null bytes
sprintf doesn't read or copy the terminating null byte from it's string
operands.  sprintf will append it's own after processing all of the
format specifiers.

This fixes PR27526.

llvm-svn: 267580
2016-04-26 18:16:49 +00:00
Hal Finkel e4c0c1679b [SimplifyCFG] Preserve !llvm.mem.parallel_loop_access when merging
When SimplifyCFG merges identical instructions from both sides of a diamond, it
can preserve !llvm.mem.parallel_loop_access (as it does with most of the other
metadata). There's no real data or control dependency change in this case.

llvm-svn: 267515
2016-04-26 02:06:06 +00:00
Chad Rosier e2cbd13e56 [ValueTracking] Improve isImpliedCondition when the dominating cond is false.
llvm-svn: 267430
2016-04-25 17:23:36 +00:00
Sanjay Patel dc88bd6e1f replace duplicated static functions for profile metadata access with BranchInst member function; NFCI
llvm-svn: 267295
2016-04-23 20:01:22 +00:00
Sanjay Patel 85ce0f1f1f improve documentation comments; NFC
llvm-svn: 267292
2016-04-23 16:31:48 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Adam Nemet fe3def7c2a [LoopUtils] Extend findStringMetadataForLoop to return the value for metadata
E.g. for:

  !1 = {"llvm.distribute", i32 1}

it now returns the MDOperand for 1.

I will use this in LoopDistribution to check the value of the metadata.

Note that the change is backward-compatible with its current use in
LoopVersioningLICM.  An Optional implicitly converts to a bool depending
whether it contains a value or not.

llvm-svn: 267190
2016-04-22 19:10:05 +00:00
Geoff Berry 9fe26e6dc9 [MemorySSA] Fix bug in CachingMemorySSAWalker::invalidateInfo
Summary:
CachingMemorySSAWalker::invalidateInfo was using IsCall to determine
which cache map needed to be cleared of entries referring to the invalidated
MemoryAccess, but there could also be entries referring to it in the
other cache map (value entries, not key entries).  This change just
clears both tables to be conservatively correct.

Also add a verifyRemoved() function, called when expensive
checks (i.e. XDEBUG) are enabled to verify that the invalidated
MemoryAccess object is not referenced in any of the caches.

Reviewers: dberlin, george.burgess.iv

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19388

llvm-svn: 267157
2016-04-22 14:44:10 +00:00
Vedant Kumar 6013f45f92 Revert "Initial implementation of optimization bisect support."
This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
2016-04-22 06:51:37 +00:00
Duncan P. N. Exon Smith 71480bd0c7 ValueMapper/Enumerator: Clean up code in post-order traversals, NFC
Re-layer the functions in the new (i.e., newly correct) post-order
traversals in ValueEnumerator (r266947) and ValueMapper (r266949).
Instead of adding a node to the worklist in a helper function and
returning a flag to say what happened, return the node itself.  This
makes the code way cleaner: the worklist is local to the main function,
there is no flag for an early loop exit (since we can cleanly bury the
loop), and it's perfectly clear when pointers into the worklist might be
invalidated.

I'm fixing both algorithms in the same commit to avoid repeating the
commit message; if you take the time to understand one the other should
be easy.  The diff itself isn't entirely obvious since the traversals
have some noise (i.e., things to do), but here's the high-level change:

    auto helper = [&WL](T *Op) {     auto helper = [](T **&I, T **E) {
                                 =>    while (I != E) {
      if (shouldVisit(Op)) {             T *Op = *I++;
        WL.push(Op, Op->begin());        if (shouldVisit(Op)) {
        return true;                       return Op;
      }                                }
      return false;                    return nullptr;
    };                               };
                                 =>
    WL.push(S, S->begin());          WL.push(S, S->begin());
    while (!empty()) {               while (!empty()) {
      auto *N = WL.top().N;            auto *N = WL.top().N;
      auto *&I = WL.top().I;           auto *&I = WL.top().I;
      bool DidChange = false;
      while (I != N->end())
        if (helper(*I++)) {      =>    if (T *Op = helper(I, N->end()) {
          DidChange = true;              WL.push(Op, Op->begin());
          break;                         continue;
        }                              }
      if (DidChange)
        continue;

      POT.push(WL.pop());        =>    POT.push(WL.pop());
    }                                }

Thanks to Mehdi for helping me find a better way to layer this.

llvm-svn: 267099
2016-04-22 02:33:06 +00:00
Andrew Kaylor f0f279291c Initial implementation of optimization bisect support.
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit).  Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit.  A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check.  Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute.  A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022
2016-04-21 17:58:54 +00:00
Adam Nemet 6dcf0788fc [LoopUtils] Fix typo in comment
llvm-svn: 267016
2016-04-21 17:33:22 +00:00
Adam Nemet 293be666eb [LoopUtils] Add asserts to findStringMetadataForLoop. NFC
These ensure that operand array has at least one element and it is the
self-reference.

llvm-svn: 267015
2016-04-21 17:33:20 +00:00
Adam Nemet 963341c872 [LoopUtils] Move def of findStringMetadataForLoop to LoopUtils.cpp. NFC
The decl is in LoopUtils.h.  I think that this was added to
LoopVersioningLICM.cpp by mistake.

llvm-svn: 267014
2016-04-21 17:33:17 +00:00
Sanjoy Das 54a3a006ca [SimplifyCFG] Fold `llvm.guard(false)` to unreachable
Summary:
`llvm.guard(false)` always bails out of the current compilation unit, so
we can prune any control flow following it.

Reviewers: hfinkel, pcc, reames

Subscribers: majnemer, reames, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19245

llvm-svn: 266955
2016-04-21 05:09:12 +00:00
Duncan P. N. Exon Smith 0ab44dbf8f ValueMapper: Map uniqued nodes in post-order
The iteratitive algorithm from r265456 claimed but failed to create a
post-order traversal.  It had the same error that was fixed in the
ValueEnumerator in r266947: now, instead of pushing all operands on the
worklist at once, we pause whenever an operand gets pushed in order to
go depth-first (I know, it sounds obvious).

Sadly, I have no idea how to observe this from outside the algorithm and
so I haven't written a test.  The output should be the same; it should
just use fewer temporary nodes now.  I've added some comments that I
hope make the current logic clear enough it's unlikely to regress.

llvm-svn: 266949
2016-04-21 02:34:36 +00:00
Chad Rosier 41dd31f0b0 [ValueTracking] Make isImpliedCondition return an Optional<bool>. NFC.
Phabricator Revision: http://reviews.llvm.org/D19277

llvm-svn: 266904
2016-04-20 19:15:26 +00:00
Teresa Johnson b35cc691ea [ThinLTO] Prevent importing of "llvm.used" values
Summary:
This patch prevents importing from (and therefore exporting from) any
module with a "llvm.used" local value. Local values need to be promoted
and renamed when importing, and their presense on the llvm.used variable
indicates that there are opaque uses that won't see the rename. One such
example is a use in inline assembly.

See also the discussion at:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098047.html

As part of this, move collectUsedGlobalVariables out of Transforms/Utils
and into IR/Module so that it can be used more widely. There are several
other places in LLVM that used copies of this code that can be cleaned
up as a follow on NFC patch.

Reviewers: joker.eph

Subscribers: pcc, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18986

llvm-svn: 266877
2016-04-20 14:39:45 +00:00
Mehdi Amini bb3a1d92f3 ThinLTO: never promote as external weak
This linkage is *not* intended to express that a declaration refers
to a weak symbol, but that the symbol might not be present at link
time. I don't believe it was the intent.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266856
2016-04-20 04:18:11 +00:00
Chad Rosier b7dfbb40a3 [ValueTracking] Improve isImpliedCondition for conditions with matching operands.
This patch improves SimplifyCFG to catch cases like:

  if (a < b) {
    if (a > b) <- known to be false
      unreachable;
  }

Phabricator Revision: http://reviews.llvm.org/D18905

llvm-svn: 266767
2016-04-19 17:19:14 +00:00
Daniel Berlin 77fa84eadd Correct IDF calculator for ReverseIDF
Summary:
Need to use predecessors for reverse graph, successors for forward graph.
succ_iterator/pred_iterator are not compatible, this patch is all the work necessary to work around that (which is what everywhere else does).  Not sure if there is a better way, so cc'ing some random folks to take a gander :)

Reviewers: dblaikie, qcolombet, echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18796

llvm-svn: 266718
2016-04-19 06:13:28 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Duncan P. N. Exon Smith 724c503499 Transforms: Try harder to fix bootstrap after r266565
This catches two nullptr insertions into the ValueMap I missed in
r266567.  I missed CloneFunction becuase it never calls RemapInstruction
directly.  Here's one of the still-failing bots:
  http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/11496

llvm-svn: 266570
2016-04-17 20:11:09 +00:00
Duncan P. N. Exon Smith 0fdaf8c9c2 Linker: Don't double-schedule appending variables
Add an assertion to ValueMapper that prevents double-scheduling of
GlobalValues to remap, and fix the one place it happened.  There are
tons of tests that fail with this assertion in place and without the
code change, so I'm not adding another.

Although it looks related, r266563 was, indeed, removing dead code.
AFAICT, this cross-file double-scheduling started in r266510 when the
cross-file recursion was removed.

llvm-svn: 266569
2016-04-17 19:40:20 +00:00
Duncan P. N. Exon Smith a71301befa Transforms: Fix bootstrap after r266565
Apparently there isn't test coverage for all of these.  I'd appreciate
if someone with could reproduce and send me something to reduce, but for
now I've just looked for users of RemapInstruction and MapValue and
ensured they don't accidentally insert nullptr.  Here is one of the
bootstraps that caught:

  http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/11494

llvm-svn: 266567
2016-04-17 19:26:49 +00:00
Duncan P. N. Exon Smith 3d555ac96d ValueMapper: Don't allow explicit null mappings of Values, NFC
As a follow-up to r123058, assert that there are no null mappings in the
ValueMap instead of just ignoring them when they are there.  There were
a couple of accidental insertions in CloneFunction so I cleaned those up
(caught by testcases).

llvm-svn: 266565
2016-04-17 18:53:24 +00:00
Duncan P. N. Exon Smith 5ab2be094e IR: Use an explicit map for debug info type uniquing
Rather than relying on the structural equivalence of DICompositeType to
merge type definitions, use an explicit map on the LLVMContext that
LLParser and BitcodeReader consult when constructing new nodes.
Each non-forward-declaration DICompositeType with a non-empty
'identifier:' field is stored/loaded from the type map, and the first
definiton will "win".

This map is opt-in: clients that expect ODR types from different modules
to be merged must call LLVMContext::ensureDITypeMap.

  - Clients that just happen to load more than one Module in the same
    LLVMContext won't magically merge types.

  - Clients (like LTO) that want to continue to merge types based on ODR
    identifiers should opt-in immediately.

I have updated LTOCodeGenerator.cpp, the two "linking" spots in
gold-plugin.cpp, and llvm-link (unless -disable-debug-info-type-map) to
set this.

With this in place, it will be straightforward to remove the DITypeRef
concept (i.e., referencing types by their 'identifier:' string rather
than pointing at them directly).

llvm-svn: 266549
2016-04-17 03:58:21 +00:00
Duncan P. N. Exon Smith 694ab4e966 ValueMapper: Separate mapping of distinct and uniqued nodes (again)
Since the result of a mapped distinct node is known up front, it's more
efficient to map them separately from uniqued nodes.  This commit pulls
them out of the post-order traversal and stores them in a worklist to be
remapped at the top-level.

This is essentially reapplying r244181 ("ValueMapper: Rotate distinct
node remapping algorithm") to the new iterative algorithm from r265456
("ValueMapper: Rewrite Mapper::mapMetadata without recursion").

Now that the traversal logic only handles uniqued MDNodes, it's much
simpler to inline it all into MDNodeMapper::createPOT (I've killed the
MDNodeMapper::push and MDNodeMapper::tryToPop helpers and localized the
traversal worklist).

The resulting high-level algorithm for MDNodeMapper::map now looks like
this:

  - Distinct nodes are immediately mapped and added to
    MDNodeMapper::DistinctWorklist using MDNodeMapper::mapDistinctNode.

  - Uniqued nodes are mapped via MDNodeMapper::mapTopLevelUniquedNode,
    which traverses the transitive uniqued subgraph of a node to
    calculate uniqued node mappings in bulk.

      - This is a simplified version of MDNodeMapper::map from before
        this commit (originally r265456) that doesn't traverse through
        any distinct nodes.

      - Distinct nodes are added to MDNodeMapper::DistinctWorklist via
        MDNodeMapper::mapDistinctNode.

      - This uses MDNodeMapper::createPOT to fill a
        MDNodeMapper::UniquedGraph (a post-order traversal and side
        table), UniquedGraph::propagateChanges to track which uniqued
        nodes need to change, and MDNodeMapper::mapNodesInPOT to create
        the uniqued nodes.

      - Placeholders for forward references are now only needed when
        there's a uniquing cycle (a cycle of uniqued nodes unbroken by
        distinct nodes).  This is the key functionality change that
        we're reintroducing (from r244181).  As of r265456, a temporary
        forward reference might be needed for any cycle that involved
        uniqued nodes.

  - After mapping the first node appropriately, MDNodeMapper::map works
    through MDNodeMapper::DistinctWorklist.  For each distinct node, its
    operands are remapped with MDNodeMapper::mapDistinctNode and
    MDNodeMapper::mapTopLevelUniquedNode until all nodes have been
    mapped.

Sadly there's nothing observable I can test here; no real functionality
change, just a compile-time speedup from reduced malloc traffic.

llvm-svn: 266537
2016-04-16 21:44:08 +00:00
Duncan P. N. Exon Smith 0cb5c344b4 ValueMapper: Only put cyclic nodes into CyclicNodes, NFCI
As a minor fixup to r266258, only track nodes that needed a placeholder
in CyclicNodes in MDNodeMapper::mapUniquedNodes.  There should be no
observable functionality change, just some local memory savings because
CyclicNodes only needs to grow to accommodate nodes that are actually
involved in cycles.  (This was the original intent of r266258, or else
the vector would have been called "ChangedNodes".)

llvm-svn: 266536
2016-04-16 21:09:53 +00:00
Simon Atanasyan e12bef7ea7 ValueMapper: Fix unused var warning. NFC
llvm-svn: 266529
2016-04-16 11:49:40 +00:00
Duncan P. N. Exon Smith a77d073305 ValueMapper: Stop memoizing ConstantAsMetadata
Stop memoizing ConstantAsMetadata in ValueMapper::mapMetadata.  Now we
have to recompute it, but these metadata aren't particularly common, and
it restricts the lifetime of the Metadata map unnecessarily.

(The motivation is that I have a patch which uses a single Metadata map
for the lifetime of IRMover.  Mehdi profiled r266446 with the patch
applied and we saw a pretty big speedup in lib/Linker.)

llvm-svn: 266513
2016-04-16 03:39:44 +00:00
Duncan P. N. Exon Smith 39423b0294 Reapply "ValueMapper: Eliminate cross-file co-recursion, NFC"
This reverts commit r266507, reapplying r266503 (and r266505
"ValueMapper: Use API from r266503 in unit tests, NFC") completely
unchanged.

I reverted because of a bot failure here:
  http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/16810/

However, looking more closely, the failure was from a host-compiler
crash (clang 3.7.1) when building:
  lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/DwarfAccelTable.cpp.o

I didn't modify that file, or anything it includes, with that commit.

The next build (which hadn't picked up my revert) got past it:
  http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/16811/

I think this was just unfortunate timing.  I suppose the bot must be
flakey.

llvm-svn: 266510
2016-04-16 02:29:55 +00:00
Duncan P. N. Exon Smith 6fe1ff260b Revert "ValueMapper: Eliminate cross-file co-recursion, NFC"
This reverts commit r266503, in case it's the root cause of this bot
failure:

  http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/16810

I'm also reverting r266505 -- "ValueMapper: Use API from r266503 in unit
tests, NFC" -- since it's in the way.

llvm-svn: 266507
2016-04-16 02:05:33 +00:00
Duncan P. N. Exon Smith f0d73f95c1 ValueMapper: Eliminate cross-file co-recursion, NFC
Eliminate co-recursion of Mapper::mapValue through
ValueMaterializer::materializeInitFor, through a major redesign of the
ValueMapper.cpp interface.

  - Expose a ValueMapper class that controls the entry points to the
    mapping algorithms.
  - Change IRLinker to use ValueMapper directly, rather than
    llvm::RemapInstruction, llvm::MapValue, etc.
  - Use (e.g.) ValueMapper::scheduleMapGlobalInit to add mapping work to
    a worklist in ValueMapper instead of recursing.

There were two fairly major complications.

Firstly, IRLinker::linkAppendingVarProto incorporates an on-the-fly IR
ugprade that I had to split apart.  Long-term, this upgrade should be
done in the bitcode reader (and we should only accept the "new" form),
but for now I've just made it work and added a FIXME.  The hold-op is
that we need to deprecate C API that relies on this.

Secondly, IRLinker has special logic to correctly implement aliases with
comdats, and uses two ValueToValueMapTy instances and two
ValueMaterializers.  I supported this by allowing clients to register an
alternate mapping context, whose MCID can be passed in when scheduling
new work.

While out of scope for this commit, it should now be straightforward to
remove recursion from Mapper::mapValue.

llvm-svn: 266503
2016-04-16 01:29:08 +00:00
Duncan P. N. Exon Smith db6861e7dd ValueMapper: Hide Mapper::VM behind an accessor, NFC
Change Mapper::VM to a pointer and add a `getVM()` accessor for it.
While this has no functionality change, it minimizes the diff on an
upcoming patch that allows switching between instances of
ValueToValueMapTy on a single Mapper instance.

llvm-svn: 266490
2016-04-15 23:18:43 +00:00
Adrian Prantl 75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Sanjay Patel f11ab05bdb [SimplifyCFG] propagate branch metadata when creating select (PR27344)
This is almost identical to:
http://reviews.llvm.org/rL264527

This doesn't solve PR27344; it just allows the profile weights to survive. 
To solve the bug, we need to use the profile weights in the backend.

llvm-svn: 266442
2016-04-15 15:32:12 +00:00
Dehao Chen 34cc676732 Fix null pointer access for discriminator assignment.
Summary: This fixes the buildbot failure.

Reviewers: dnovillo, davidxl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19129

llvm-svn: 266360
2016-04-14 19:46:38 +00:00
Dehao Chen 46f8fbbb1b Update discriminator assignment algorithm to handle nested call correctly.
Summary: Add discriminator for nested call correctly.

Reviewers: davidxl, dnovillo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19127

llvm-svn: 266354
2016-04-14 18:37:18 +00:00
Davide Italiano 96d2a1c603 [ValueMapper] Range-loopify to improve readability. NFC.
llvm-svn: 266350
2016-04-14 18:07:32 +00:00
Duncan P. N. Exon Smith 11f60fd65a ValueMapper: Resolve cycles on the new nodes
Fix a major bug from r265456.  Although it's now much rarer, ValueMapper
sometimes has to duplicate cycles.  The
might-transitively-reference-a-temporary counts don't decrement on their
own when there are cycles, and you need to call MDNode::resolveCycles to
fix it.

r265456 was checking the input nodes to see if they were unresolved.
This is useless; they should never be unresolved.  Instead we should
check the output nodes and resolve cycles on them.

llvm-svn: 266258
2016-04-13 22:54:01 +00:00
David L Kreitzer 752c1448fe Simplify strlen to a subtraction for certain cases.
Patch by Li Huang (li1.huang@intel.com)

Differential Revision: http://reviews.llvm.org/D18230

llvm-svn: 266200
2016-04-13 14:31:06 +00:00
Mehdi Amini 818f67add5 Fix mismatch on returned type between header and implementation for createNameAnonFunctionPass()
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266151
2016-04-12 23:25:11 +00:00
Mehdi Amini d5faa267c4 Add a pass to name anonymous/nameless function
Summary:
For correct handling of alias to nameless
function, we need to be able to refer them through a GUID in the summary.
Here we name them using a hash of the non-private global names in the module.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18883

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266132
2016-04-12 21:35:28 +00:00
Mehdi Amini ae280e54a9 ThinLTO renaming: use module hash instead of position in the summary
This is more robust to changes in the link ordering.

Differential Revision: http://reviews.llvm.org/D18946

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266018
2016-04-11 23:26:46 +00:00