Commit Graph

47 Commits

Author SHA1 Message Date
Adrian Prantl
460dd60c1a [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288683 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-05 18:04:47 +00:00
Mandeep Singh Grang
21e956f318 [MemorySSA] Fix unit tests broken by D26704
Summary:
D26704 fixed the non-determinism in codegen by sorting basic blocks before
iteration so as to have a defined iteration order. As a result we need to fix
the names (numbers) of the temporaries in the following unit tests:
  test/Transforms/Util/MemorySSA/multi-edges.ll
  test/Transforms/Util/MemorySSA/multiple-backedges-hal.ll

Reviewers: dberlin, david2050, mgrang

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26926

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287575 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-21 20:39:08 +00:00
Mandeep Singh Grang
d8c5ecbd82 [MemorySSA] Fix for non-determinism in codegen
This patch fixes the non-determinism caused due to iterating SmallPtrSet's
which was uncovered due to the experimental "reverse iteration order " patch:
https://reviews.llvm.org/D26718

The following unit tests failed because of the undefined order of iteration.
LLVM :: Transforms/Util/MemorySSA/cyclicphi.ll
LLVM :: Transforms/Util/MemorySSA/many-dom-backedge.ll
LLVM :: Transforms/Util/MemorySSA/many-doms.ll
LLVM :: Transforms/Util/MemorySSA/phi-translation.ll

Reviewers: dberlin, mgrang

Subscribers: dberlin, llvm-commits, david2050

Differential Revision: https://reviews.llvm.org/D26704

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287563 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-21 19:33:02 +00:00
Michael Ilseman
5bd98bf7d6 Add -strip-nonlinetable-debuginfo capability
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.

The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches.  For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.

The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.

Thanks to Adrian Prantl for stewarding this patch!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285094 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-25 18:44:13 +00:00
Anna Thomas
79f85df65a [StripGCRelocates] New pass to remove gc.relocates added by RS4GC
Summary:
Utility pass to remove gc.relocates created by rewrite statepoints for GC.
With respect to safepoint verification, the IR generated would be incorrect, and cannot run
as such.

This would be a single transformation on the final optimized IR.
The benefit of the pass is for easy analysis when the IRs are 'polluted' by too
many gc.relocates.
Added tests.

test run: All RS4GC tests with -verify option. Local downstream tests on large
IR files. This also works when the pointer being gc.relocated is another
gc.relocate.

Reviewers: sanjoy, reames

Subscribers: beanz, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D25096

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284855 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-21 18:43:16 +00:00
Rong Xu
fe89a6bcf0 Conditionally eliminate library calls where the result value is not used
Summary:
This pass shrink-wraps a condition to some library calls where the call
result is not used. For example:
   sqrt(val);
 is transformed to
   if (val < 0)
     sqrt(val);
Even if the result of library call is not being used, the compiler cannot
safely delete the call because the function can set errno on error
conditions.
Note in many functions, the error condition solely depends on the incoming
parameter. In this optimization, we can generate the condition can lead to
the errno to shrink-wrap the call. Since the chances of hitting the error
condition is low, the runtime call is effectively eliminated.

These partially dead calls are usually results of C++ abstraction penalty
exposed by inlining. This optimization hits 108 times in 19 C/C++ programs
in SPEC2006.

Reviewers: hfinkel, mehdi_amini, davidxl

Subscribers: modocache, mgorny, mehdi_amini, xur, llvm-commits, beanz

Differential Revision: https://reviews.llvm.org/D24414

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284542 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-18 21:36:27 +00:00
Michael Ilseman
33fe838cad Revert "Add -strip-nonlinetable-debuginfo capability"
This reverts commit r283473.

Reverted until review is completed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283478 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-06 18:30:26 +00:00
Michael Ilseman
bda4e020b8 Add -strip-nonlinetable-debuginfo capability
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.

The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches.  For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.

The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283473 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-06 17:58:38 +00:00
Daniel Berlin
a50e80efdf Remove pruning of phi nodes in MemorySSA - it makes updating harder
Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24923

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282419 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-26 17:22:54 +00:00
Hans Wennborg
a613eb13a3 Revert r281895 "Add @llvm.dbg.value entries for the phi node created by -mem2reg"
(And follow-up r281964.)

It caused PR30468.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282077 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-21 15:55:53 +00:00
Keith Walker
383922dd5b Add @llvm.dbg.value entries for the phi node created by -mem2reg
When phi nodes are created in the -mem2reg phase, the @llvm.dbg.declare
entries are converted to @llvm.dbg.value entries at the place where the
store instructions existed. However no entry is created to describe
the resulting value of the phi node.

The effect of this is especially noticeable in for loops which have a
constant for the intial value; the loop control variable's location
would be described as the intial constant value in the loop body once
the -mem2reg optimization phase was run.

This change adds the creation of the @llvm.dbg.value entries to describe
variables whose location is the result of a phi node created in -mem2reg.

Also when the phi node is finally lowered to a machine instruction it
is important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.

Differential Revision: https://reviews.llvm.org/D23715


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281895 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 09:49:30 +00:00
Daniel Berlin
cd3dcaa09e [MSSA] Fix PR28880 by fixing use optimizer's lower bound tracking behavior.
Summary:
In the use optimizer, we need to keep of whether the lower bound still
dominates us or else we may decide a lower bound is still valid when it
is not due to intervening pushes/pops.  Fixes PR28880 (and probably a
bunch of other things).

Reviewers: george.burgess.iv

Subscribers: MatzeB, llvm-commits, sebpop

Differential Revision: https://reviews.llvm.org/D23237

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277978 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-08 04:44:53 +00:00
George Burgess IV
cd112f0139 [MSSA] Add special handling for invariant/constant loads.
This is a follow-up to r277637. It teaches MemorySSA that invariant
loads (and loads of provably constant memory) are always liveOnEntry.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277640 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 19:57:02 +00:00
George Burgess IV
94c82b281d [MSSA] Add logic for special handling of atomics/volatiles.
This patch makes MemorySSA recognize atomic/volatile loads, and makes
MSSA treat said loads specially. This allows us to be a bit more
aggressive in some cases.

Administrative note: Revision was LGTM'ed by reames in person.
Additionally, this doesn't include the `invariant.load` recognition in
the differential revision, because I feel it's better to commit that
separately. Will commit soon.

Differential Revision: https://reviews.llvm.org/D16875


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277637 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 19:39:54 +00:00
Daniel Berlin
9d6e4f22e7 Support for lifetime begin/end markers in the MemorySSA use optimizer
Summary: Depends on D23072

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277553 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 00:01:46 +00:00
George Burgess IV
9906b88abc [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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275940 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-19 01:29:15 +00:00
Chad Rosier
705101d800 [MemorySSA] Reinstate the legacy printer and verifier.
Differential Revision: http://reviews.llvm.org/D22058

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274679 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-06 21:20:47 +00:00
Daniel Berlin
dad636ee26 Fix handling of forward unreachable but reverse-reachable blocks in MemorySSA construction
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274606 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-06 05:32:05 +00:00
Geoff Berry
783607f8e8 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271432 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-01 21:30:40 +00:00
Peter Collingbourne
5c78f7db18 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270823 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-26 04:58:46 +00:00
Geoff Berry
4c9f41e56f [BasicAA] Treat llvm.assume as not accessing memory in getModRefBehavior(Function)
Reviewers: dberlin, chandlerc, hfinkel, reames, sanjoy

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19730

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268068 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-29 17:18:28 +00:00
Duncan P. N. Exon Smith
de7484036b DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267296 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-23 21:08:00 +00:00
Adrian Prantl
4eeaa0da04 [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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266446 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-15 15:57:41 +00:00
Adrian Prantl
5362126448 Fix missing DICompileUnits in testcases
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265974 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-11 18:15:44 +00:00
Adrian Prantl
7876f64bc3 testcase gardening: update the emissionKind enum to the new syntax. (NFC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265081 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-01 00:16:49 +00:00
Davide Italiano
a528f3f7b7 [DebugInfo] Subprograms should belong to a CU.
Start fixing tests accordingly. There are still
about 35 failures before we can enable this check
in the IR verifier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264990 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 03:40:07 +00:00
George Burgess IV
ff01852cd7 [MemorySSA] Make the visitor more careful with calls.
Prior to this patch, the MemorySSA caching visitor would cache all
calls that it visited. When paired with phi optimization, this can be
problematic. Consider:

define void @foo() {
  ; 1 = MemoryDef(liveOnEntry)
  call void @clobberFunction()
  br i1 undef, label %if.end, label %if.then

if.then:
  ; MemoryUse(??)
  call void @readOnlyFunction()
  ; 2 = MemoryDef(1)
  call void @clobberFunction()
  br label %if.end

if.end:
  ; 3 = MemoryPhi(...)
  ; MemoryUse(?)
  call void @readOnlyFunction()
  ret void
}

When optimizing MemoryUse(?), we visit defs 1 and 2, so we note to
cache them later. We ultimately end up not being able to optimize
passed the Phi, so we set MemoryUse(?) to point to the Phi. We then
cache the clobbering call for def 1 to be the Phi.

This commit changes this behavior so that we wipe out any calls
added to VisistedCalls while visiting the defs of a phi we couldn't
optimize.

Aside: With this patch, we now can bootstrap clang/LLVM without a
single MemorySSA verifier failure. Woohoo. :)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264820 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-30 03:12:08 +00:00
George Burgess IV
2e682ed868 [MemorySSA] Change how the walker views/walks visited phis.
This patch teaches the caching MemorySSA walker a few things:

1. Not to walk Phis we've walked before. It seems that we tried to do
   this before, but it didn't work so well in cases like:

define void @foo() {
  %1 = alloca i8
  %2 = alloca i8
  br label %begin

begin:
  ; 3 = MemoryPhi({%0,liveOnEntry},{%end,2})
  ; 1 = MemoryDef(3)
  store i8 0, i8* %2
  br label %end

end:
  ; MemoryUse(?)
  load i8, i8* %1
  ; 2 = MemoryDef(1)
  store i8 0, i8* %2
  br label %begin
}

Because we wouldn't put Phis in Q.Visited until we tried to visit them.
So, when trying to optimize MemoryUse(?):
  - We would visit 3 above
    - ...Which would make us put {%0,liveOnEntry} in Q.Visited
    - ...Which would make us visit {%0,liveOnEntry}
    - ...Which would make us put {%end,2} in Q.Visited
    - ...Which would make us visit {%end,2}
      - ...Which would make us visit 3
        - ...Which would realize we've already visited everything in 3
        - ...Which would make us conservatively return 3.

In the added test-case, (@looped_visitedonlyonce) this behavior would
cause us to give incorrect results. Specifically, we'd visit 4 twice
in the same query, but on the second visit, we'd skip while.cond because
it had been visited, visit if.then/if.then2, and cache "1" as the
clobbering def on the way back.

2. If we try to walk the defs of a {Phi,MemLoc} and see it has been
   visited before, just hand back the Phi we're trying to optimize.

I promise this isn't as terrible as it seems. :)

We now insert {Phi,MemLoc} pairs just before walking the Phi's upward
defs. So, we check the cache for the {Phi,MemLoc} pair before checking
if we've already walked the Phi.

The {Phi,MemLoc} pair is (almost?) always guaranteed to have a cache
entry if we've already fully walked it, because we cache as we go.

So, if the {Phi,MemLoc} pair isn't in cache, either:
 (a) we must be in the process of visiting it (in which case, we can't
     give a better answer in a cache-as-we-go DFS walker)

 (b) we visited it, but didn't cache it on the way back (...which seems
     to require `ModifyingAccess` to not dominate `StartingAccess`,
     so I'm 99% sure that would be an error. If it's not an error, I
     haven't been able to get it to happen locally, so I suspect it's
     rare.)

- - - - -

As a consequence of this change, we no longer skip upward defs of phis,
so we can kill the `VisitedOnlyOne` check. This gives us better accuracy
than we had before, at the cost of potentially doing a bit more work
when we have a loop.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264814 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-30 00:26:26 +00:00
George Burgess IV
0a451a3606 Fix bugs in the MemorySSA walker.
There are a few bugs in the walker that this patch addresses.
Primarily:
- Caching can break when we have multiple BBs without phis
- We weren't optimizing some phis properly
- Because of how the DFS iterator works, there were times where we
  wouldn't cache any results of our DFS

I left the test cases with FIXMEs in, because I'm not sure how much
effort it will take to get those to work (read: We'll probably
ultimately have to end up redoing the walker, or we'll have to come up
with some creative caching tricks), and more test coverage = better.

Differential Revision: http://reviews.llvm.org/D18065


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264180 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-23 18:31:55 +00:00
George Burgess IV
127a8ddf85 [MemorySSA] Consider def-only BBs for live-in calculations.
If we have a BB with only MemoryDefs, live-in calculations will ignore
it. This means we get results like this:

define void @foo(i8* %p) {
  ; 1 = MemoryDef(liveOnEntry)
  store i8 0, i8* %p
  br i1 undef, label %if.then, label %if.end

if.then:
  ; 2 = MemoryDef(1)
  store i8 1, i8* %p
  br label %if.end

if.end:
  ; 3 = MemoryDef(1)
  store i8 2, i8* %p
  ret void
}

...When there should be a MemoryPhi in the `if.end` BB.

This patch fixes that behavior.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263991 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-21 21:25:39 +00:00
Daniel Berlin
d4797742f9 Make check line consistent
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260055 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-07 20:57:46 +00:00
George Burgess IV
8114867d8b Add a test for MemorySSA. NFC.
We don't currently have many tests that deal with operations on multiple
local MemoryLocations. This new test helps out a bit in that regard.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259854 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-05 00:42:02 +00:00
Benjamin Kramer
67256b88e5 The canonical way to XFAIL a test for all targets is XFAIL: *, not XFAIL:
Fix the lit bug that enabled this "feature" (empty triple is substring
of all possible target triples) and change the two outliers to use the
documented * syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259799 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-04 16:21:38 +00:00
George Burgess IV
02e0bb6dc6 This patch adds MemorySSA to LLVM.
Please see include/llvm/Transforms/Utils/MemorySSA.h for a description
of MemorySSA, and what it does.

Differential Revision: http://reviews.llvm.org/D7864


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2016-02-02 22:46:49 +00:00
Keno Fischer
4d6ccf4c99 [Utils] Fix incorrect dbg.declare store conversion
Summary: The dbg.declare -> dbg.value conversion did not check which operand of
the store instruction the alloca was passed to. As a result code that stored the
address of an alloca, rather than storing to the alloca, would still trigger
the conversion routine, leading to the insertion of an incorrect dbg.value
intrinsic.

Reviewers: aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16169

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2016-01-14 19:12:27 +00:00
Keno Fischer
58b254770a [Utils] Insert DW_OP_bit_piece when only describing part of the variable
Summary: The dbg.declare -> dbg.value conversion looks through any zext/sext
to find a value to describe the variable (in the expectation that those
zext/sext instruction will go away later). However, those values do not
cover the entire variable and thus need a DW_OP_bit_piece.

Reviewers: aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16061

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2016-01-12 22:46:09 +00:00
Keno Fischer
bae9026417 Clean up the processing of dbg.value in various places
Summary:
First up is instcombine, where in the dbg.declare -> dbg.value conversion,
the llvm.dbg.value needs to be called on the actual loaded value, rather
than the address (since the whole point of this transformation is to be
able to get rid of the alloca). Further, now that that's cleaned up, we
can remove a hack in the backend, that would add an implicit OP_deref if
the argument to dbg.value was an alloca. This stems from before the
existence of DIExpression and is no longer necessary since the deref can
be expressed explicitly.

Now, in order to make sure that the tests pass with this change, we need to
correct the printing of DEBUG_VALUE comments to take into account the
expression, which wasn't taken into account before.

Unfortunately, for both these changes, there were a number of incorrect
test cases (mostly the wrong number of DW_OP_derefs, but also a couple
where the test itself was broken more badly). aprantl and I have gone
through and adjusted these test case in order to make them pass with
these fixes and in some cases to make sure they're actually testing
what they are meant to test.

Reviewers: aprantl

Subscribers: dsanders

Differential Revision: http://reviews.llvm.org/D14186

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2015-12-19 02:02:44 +00:00
Rafael Espindola
a2197f8f51 Have a single way for creating unique value names.
We had two code paths. One would create names like "foo.1" and the other
names like "foo1".

For globals it is important to use "foo.1" to help C++ name demangling.
For locals there is no strong reason to go one way or the other so I
kept the most common mangling (foo1).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253804 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-22 00:16:24 +00:00
Pete Cooper
6d024c616a Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

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2015-11-19 05:56:52 +00:00
Pete Cooper
8b170f7f29 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253511 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-18 22:17:24 +00:00
Sunil Srivastava
561c44fc33 Changed renaming of local symbols by inserting a dot vefore the numeric suffix.
One code change and several test changes to match that
details in http://reviews.llvm.org/D9481


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2015-05-12 16:47:30 +00:00
Michael Liao
de3983775e [SwitchLowering] Remove incoming values in the reverse order
- To prevent invalidating *successive* indices.
 


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2015-03-17 18:03:10 +00:00
Bjorn Steinbrink
61a16d2a16 Correctly combine alias.scope metadata by a union instead of intersecting
Summary:
The alias.scope metadata represents sets of things an instruction might
alias with. When generically combining the metadata from two
instructions the result must be the union of the original sets, because
the new instruction might alias with anything any of the original
instructions aliased with.

Reviewers: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7490

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2015-02-08 17:07:14 +00:00
Bruno Cardoso Lopes
495e547ef9 [SwitchLowering] Handle destinations on multiple phi instructions
Follow up from r222926. Also handle multiple destinations from merged
cases on multiple and subsequent phi instructions.

rdar://problem/19106978

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223135 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 18:31:53 +00:00
Bruno Cardoso Lopes
04122090c2 [SwitchLowering] Handle multiple destinations on condensed case stmts
Switch cases statements with sequential values that branch to the same
destination BB may often be handled together in a single new source BB.
In this scenario we need to remove remaining incoming values from PHI
instructions in the destination BB, as to match the number of source
branches.

Differential Revision: http://reviews.llvm.org/D6415

rdar://problem/19040894

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2014-11-28 19:47:33 +00:00
Juergen Ributzka
d0995fb982 [SwitchLowering] Fix the "fixPhis" function.
Switch statements may have more than one incoming edge into the same BB if they
all have the same value. When the switch statement is converted these incoming
edges are now coming from multiple BBs. Updating all incoming values to be from
a single BB is incorrect and would generate invalid LLVM IR.

The fix is to only update the first occurrence of an incoming value. Switch
lowering will perform subsequent calls to this helper function for each incoming
edge with a new basic block - updating all edges in the process.

This fixes rdar://problem/18916275.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221627 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-10 21:05:27 +00:00
Jan Vesely
d3fa093dc9 utils: Fix segfault in flattencfg
v2: continue iterating through the rest of the bb
    use for loop

v3: initialize FlattenCFG pass in ScalarOps
    add test

v4: split off initializing flattencfg to a separate patch
    add comment

Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-13 20:31:53 +00:00