181 Commits

Author SHA1 Message Date
Eli Friedman
35ff6f0857 [DSE] Don't remove stores made live by a call which unwinds.
Issue exposed by noalias or more aggressive alias analysis.

Fixes http://llvm.org/PR25422.

Differential revision: https://reviews.llvm.org/D21007



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278451 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-12 01:09:53 +00:00
Anna Thomas
9cd4907159 [AliasAnalysis] Treat invariant.start as read-memory
Summary:
We teach alias analysis that invariant.start is readonly.
This helps with GVN and memcopy optimizations that currently treat.
invariant.start as a clobber.
We need to treat this as readonly, so that DSE does not incorrectly
remove stores prior to the invariant.start

Reviewers: sanjoy, reames, majnemer, dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23214

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278138 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-09 17:18:05 +00:00
Jun Bum Lim
0618303382 Recommit - [DSE]Enhance shorthening MemIntrinsic based on OverlapIntervals
Recommiting r275571 after fixing crash reported in PR28270.
Now we erase elements of IOL in deleteDeadInstruction().

Original Summary:
This change use the overlap interval map built from partial overwrite tracking to perform shortening MemIntrinsics.
Add test cases which was missing opportunities before.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276452 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-22 18:27:24 +00:00
Alexander Kornienko
71c0ef585b Revert "r275571 [DSE]Enhance shorthening MemIntrinsic based on OverlapIntervals"
Causes https://llvm.org/bugs/show_bug.cgi?id=28588


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275801 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 15:51:31 +00:00
Jun Bum Lim
2ca934ea31 [DSE]Enhance shorthening MemIntrinsic based on OverlapIntervals
Summary:
This change use the overlap interval map built from partial overwrite tracking to perform shortening MemIntrinsics.
Add test cases which was missing opportunities before.

Reviewers: hfinkel, eeckstein, mcrosier

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D21909

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275571 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-15 16:14:34 +00:00
Anna Thomas
6a6fa34ee1 [DSE] Remove dead stores in end blocks containing fence
We can remove dead stores in the presence of fence instructions. Fence
does not change an otherwise thread local store to visible.

reviewers: reames, dexonsmith, jfb
Differential Revision: http://reviews.llvm.org/D22001

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274795 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-07 20:51:42 +00:00
Chad Rosier
9b917c506a [DSE] Avoid iterator invalidation bugs.
The dse_with_dbg_value.ll test committed with r273141 is removed because this
we no longer performs any type of back tracking, which is what was causing the
codegen differences with and without debug information.

Differential Revision: http://reviews.llvm.org/D21613

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274660 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-06 19:48:52 +00:00
Jun Bum Lim
fe4360eba5 [DSE] Fix bug in partial overwrite tracking
Summary:
Found cases where DSE incorrectly add partially-overwritten intervals.
Please see the test case for details.

Reviewers: mcrosier, eeckstein, hfinkel

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D21859

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274237 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-30 15:32:20 +00:00
Hal Finkel
3ae5db8d60 Allow DeadStoreElimination to track combinations of partial later wrties
DeadStoreElimination can currently remove a small store rendered unnecessary by
a later larger one, but could not remove a larger store rendered unnecessary by
a series of later smaller ones. This adds that capability.

It works by keeping a map, which is used as an effective interval map, for each
store later overwritten only partially, and filling in that interval map as
more such stores are discovered. No additional walking or aliasing queries are
used. In the map forms an interval covering the the entire earlier store, then
it is dead and can be removed. The map is used as an interval map by storing a
mapping between the ending offset and the beginning offset of each interval.

I discovered this problem when investigating a performance issue with code like
this on PowerPC:

  #include <complex>
  using namespace std;

  complex<float> bar(complex<float> C);
  complex<float> foo(complex<float> C) {
    return bar(C)*C;
  }

which produces this:

  define void @_Z4testSt7complexIfE(%"struct.std::complex"* noalias nocapture sret %agg.result, i64 %c.coerce) {
  entry:
    %ref.tmp = alloca i64, align 8
    %tmpcast = bitcast i64* %ref.tmp to %"struct.std::complex"*
    %c.sroa.0.0.extract.shift = lshr i64 %c.coerce, 32
    %c.sroa.0.0.extract.trunc = trunc i64 %c.sroa.0.0.extract.shift to i32
    %0 = bitcast i32 %c.sroa.0.0.extract.trunc to float
    %c.sroa.2.0.extract.trunc = trunc i64 %c.coerce to i32
    %1 = bitcast i32 %c.sroa.2.0.extract.trunc to float
    call void @_Z3barSt7complexIfE(%"struct.std::complex"* nonnull sret %tmpcast, i64 %c.coerce)
    %2 = bitcast %"struct.std::complex"* %agg.result to i64*
    %3 = load i64, i64* %ref.tmp, align 8
    store i64 %3, i64* %2, align 4 ; <--- ***** THIS SHOULD NOT BE HERE ****
    %_M_value.realp.i.i = getelementptr inbounds %"struct.std::complex", %"struct.std::complex"* %agg.result, i64 0, i32 0, i32 0
    %4 = lshr i64 %3, 32
    %5 = trunc i64 %4 to i32
    %6 = bitcast i32 %5 to float
    %_M_value.imagp.i.i = getelementptr inbounds %"struct.std::complex", %"struct.std::complex"* %agg.result, i64 0, i32 0, i32 1
    %7 = trunc i64 %3 to i32
    %8 = bitcast i32 %7 to float
    %mul_ad.i.i = fmul fast float %6, %1
    %mul_bc.i.i = fmul fast float %8, %0
    %mul_i.i.i = fadd fast float %mul_ad.i.i, %mul_bc.i.i
    %mul_ac.i.i = fmul fast float %6, %0
    %mul_bd.i.i = fmul fast float %8, %1
    %mul_r.i.i = fsub fast float %mul_ac.i.i, %mul_bd.i.i
    store float %mul_r.i.i, float* %_M_value.realp.i.i, align 4
    store float %mul_i.i.i, float* %_M_value.imagp.i.i, align 4
    ret void
  }

the problem here is not just that the i64 store is unnecessary, but also that
it blocks further backend optimizations of the other uses of that i64 value in
the backend.

In the future, we might want to add a special case for handling smaller
accesses (e.g. using a bit vector) if the map mechanism turns out to be
noticeably inefficient. A sorted vector is also a possible replacement for the
map for small numbers of tracked intervals.

Differential Revision: http://reviews.llvm.org/D18586

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273559 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-23 13:46:39 +00:00
Patrik Hagglund
76e55eedd6 Fix for PR27940
After a store has been eliminated, when making sure that the
instruction iterator points to a valid instruction, dbg intrinsics are
now ignored as a new instruction.

Patch by Henric Karlsson.

Reviewed by Daniel Berlin.

Differential Revision: http://reviews.llvm.org/D21076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273141 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-20 09:10:10 +00:00
Sanjoy Das
60271907e7 Move previously added test case to the right location
In rL272580 I accidentally added a test case to test/CodeGen when
test/Transforms/DeadStoreElimination/ is a better place for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272581 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-13 20:12:07 +00:00
Justin Bogner
9c81a3f598 [PM] Port DSE to the new pass manager
Patch by JakeVanAdrighem. Thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269847 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-17 21:38:13 +00:00
Jun Bum Lim
950aa30304 [DeadStoreElimination] Shorten beginning of memset overwritten by later stores
Summary: This change will shorten memset if the beginning of memset is overwritten by later stores.

Reviewers: hfinkel, eeckstein, dberlin, mcrosier

Subscribers: mgrang, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18906

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267197 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-22 19:51:29 +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
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
Adrian Prantl
39bb84a097 Move the DebugEmissionKind enum from DIBuilder into DICompileUnit.
This mostly cosmetic patch moves the DebugEmissionKind enum from DIBuilder
into DICompileUnit. DIBuilder is not the right place for this enum to live
in — a metadata consumer should not have to include DIBuilder.h.
I also added a Verifier check that checks that the emission kind of a
DICompileUnit is actually legal.

http://reviews.llvm.org/D18612
<rdar://problem/25427165>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265077 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 23:56:58 +00:00
Philip Reames
779f485d35 Allow value forwarding past release fences in GVN
A release fence acts as a publication barrier for stores within the current thread to become visible to other threads which might observe the release fence. It does not require the current thread to observe stores performed on other threads. As a result, we can allow store-load and load-load forwarding across a release fence.  

We choose to be much more conservative about stores.  In theory, nothing prevents us from shifting a store from after a release fence to before it, and then eliminating the preceeding (previously fenced) store.  Doing this without actually moving the second store is likely also legal, but we chose to be conservative at this time.

The LangRef indicates only atomic loads and stores are effected by fences. This patch chooses to be far more conservative then that. 

This is the GVN companion to http://reviews.llvm.org/D11434 which applied the same logic in EarlyCSE and has been baking in tree for a while now.

Differential Revision: http://reviews.llvm.org/D11436




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264472 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-25 22:40:35 +00:00
Igor Laevsky
a08c9225d2 [BasicAliasAnalysis] Take into account operand bundles in the getModRefInfo function
Differential Revision: http://reviews.llvm.org/D16225



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257991 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-16 12:15:53 +00:00
Keno Fischer
621b821be3 Reapply r257105 "[Verifier] Check that debug values have proper size"
I originally reapplied this in 257550, but had to revert again due to bot
breakage. The only change in this version is to allow either the TypeSize
or the TypeAllocSize of the variable to be the one represented in debug info
(hopefully in the future we can figure out how to encode the difference).
Additionally, several bot failures following r257550, were due to
optimizer bugs now fixed in r257787 and r257795.

r257550 commit message was:

```
The follow extra changes were made to test cases:

Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:

    LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
    LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
    LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
    LLVM :: DebugInfo/Generic/varargs.ll

Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):

    LLVM :: DebugInfo/Generic/restrict.ll
    LLVM :: DebugInfo/Generic/tu-composite.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/type-unique-simple2.ll

Fixing an incorrect DW_OP_deref

    LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll

Fixing a missing DW_OP_deref

    LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll

Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.

The original commit message was:
``
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.

One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.

Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
  it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
  variable as that would depend on the target, even though this test is
  supposed to be generic
- I had to manually declared size/align for reference type. See also the
  discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
``

```

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257850 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-15 00:46:17 +00:00
Keno Fischer
6c1dec62d2 Re-Revert r257105 (Verifier debug info changes)
While I investigate some new buildbot failures. This was originally reapplied
as r257550 and r257558.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257563 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-13 02:31:14 +00:00
Keno Fischer
99220ce3fc Reapply r257105 "[Verifier] Check that debug values have proper size"
The follow extra changes were made to test cases:

Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:

    LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
    LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
    LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
    LLVM :: DebugInfo/Generic/varargs.ll

Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):

    LLVM :: DebugInfo/Generic/restrict.ll
    LLVM :: DebugInfo/Generic/tu-composite.ll
    LLVM :: Linker/type-unique-type-array-a.ll
    LLVM :: Linker/type-unique-simple2.ll

Fixing an incorrect DW_OP_deref

    LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll

Fixing a missing DW_OP_deref

    LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll

Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.

The original commit message was:
```
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.

One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.

Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
  it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
  variable as that would depend on the target, even though this test is
  supposed to be generic
- I had to manually declared size/align for reference type. See also the
  discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
```

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257550 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-13 00:31:44 +00:00
Keno Fischer
c950114021 Temporarily revert r257105 "[Verifier] Check that debug values have proper size"
Looks like there's a case where clang generates debug info that triggers
the new verifier check. Reverting while investigating.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257107 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-07 22:39:11 +00:00
Keno Fischer
97515eb97b [Verifier] Check that debug values have proper size
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.

One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.

Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
  it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
  variable as that would depend on the target, even though this test is
  supposed to be generic
- I had to manually declared size/align for reference type. See also the
  discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref

Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D14276

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257105 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-07 22:18:37 +00:00
Chad Rosier
23c0f3b5a2 Revert r255247, r255265, and r255286 due to serious compile-time regressions.
Revert "[DSE] Disable non-local DSE to see if the bots go green."
Revert "[DeadStoreElimination] Use range-based loops. NFC."
Revert "[DeadStoreElimination] Add support for non-local DSE."

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255354 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-11 18:39:41 +00:00
Chad Rosier
7d33195bda [DSE] Disable non-local DSE to see if the bots go green.
I see a few bots timing out, so I'm speculatively disabling r255247.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255286 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-10 19:23:02 +00:00
Chad Rosier
d4526d51db [DeadStoreElimination] Add support for non-local DSE.
We extend the search for redundant stores to predecessor blocks that
unconditionally lead to the block BB with the current store instruction.  That
also includes single-block loops that unconditionally lead to BB, and
if-then-else blocks where then- and else-blocks unconditionally lead to BB.

http://reviews.llvm.org/D13363
Patch by Ivan Baev <ibaev@codeaurora.org>!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255247 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-10 13:51:43 +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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253543 91177308-0d34-0410-b5e6-96231b3b80d8
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
Peter Collingbourne
5f220beefc DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252219 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 22:03:56 +00:00
Igor Laevsky
ebe9301ae1 [DeadStoreElimination] Remove dead zero store to calloc initialized memory
This change allows dead store elimination to remove zero and null stores into memory freshly allocated with calloc-like function.

Differential Revision: http://reviews.llvm.org/D13021



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248374 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-23 11:38:44 +00:00
Duncan P. N. Exon Smith
a5ae7c1c9f DI: Require subprogram definitions to be distinct
As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'.  Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.

While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore.  Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node.  The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.

I updated almost all the IR with the following script:

    git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'

Likely some variant of would work for out-of-tree testcases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246327 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-28 20:26:49 +00:00
Bjorn Steinbrink
0299ff2d55 Revert "[DSE] Enable removal of lifetime intrinsics in terminating blocks"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245543 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-20 08:58:47 +00:00
Bjorn Steinbrink
1ca4f6f1ca [DSE] Enable removal of lifetime intrinsics in terminating blocks
Usually DSE is not supposed to remove lifetime intrinsics, but it's
actually ok to remove them for dead objects in terminating blocks,
because they convey no extra information there. Until we hit a lifetime
start that cannot be removed, that is. Because from that point on the
lifetime intrinsics become interesting again, e.g. for stack coloring.

Reviewers: reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11710

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245542 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-20 08:25:28 +00:00
Eric Christopher
d5369c945d Revert "Fix PR24469 resulting from r245025 and re-enable dead store elimination across basicblocks."
This is causing bootstrap problems, e.g.: http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/2960

This reverts r245195.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245402 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-19 02:15:13 +00:00
Karthik Bhat
75f2d37686 Fix PR24469 resulting from r245025 and re-enable dead store elimination across basicblocks.
PR24469 resulted because DeleteDeadInstruction in handleNonLocalStoreDeletion was
deleting the next basic block iterator. Fixed the same by resetting the basic block iterator
post call to DeleteDeadInstruction.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245195 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-17 05:51:39 +00:00
David Majnemer
a0a7755665 Revert "Add support for cross block dse. This patch enables dead stroe elimination across basicblocks."
This reverts commit r245025, it caused PR24469.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245172 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-16 07:11:59 +00:00
Karthik Bhat
20c7897930 Add support for cross block dse.
This patch enables dead stroe elimination across basicblocks.

Example:
define void @test_02(i32 %N) {
  %1 = alloca i32
  store i32 %N, i32* %1
  store i32 10, i32* @x
  %2 = load i32, i32* %1
  %3 = icmp ne i32 %2, 0
  br i1 %3, label %4, label %5

; <label>:4
  store i32 5, i32* @x
  br label %7

; <label>:5
  %6 = load i32, i32* @x
  store i32 %6, i32* @y
  br label %7

; <label>:7
  store i32 15, i32* @x
  ret void
}
In the above example dead store "store i32 5, i32* @x" is now eliminated.

Differential Revision: http://reviews.llvm.org/D11143



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245025 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-14 04:17:23 +00:00
Erik Eckstein
22af77d94f [DeadStoreElimination] remove a redundant store even if the load is in a different block.
DeadStoreElimination does eliminate a store if it stores a value which was loaded from the same memory location.
So far this worked only if the store is in the same block as the load.
Now we can also handle stores which are in a different block than the load.
Example:

define i32 @test(i1, i32*) {
entry:
  %l2 = load i32, i32* %1, align 4
  br i1 %0, label %bb1, label %bb2
bb1:
  br label %bb3
bb2:
  ; This store is redundant
  store i32 %l2, i32* %1, align 4
  br label %bb3
bb3:
  ret i32 0
}

Differential Revision: http://reviews.llvm.org/D11854



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244901 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-13 15:36:11 +00:00
Duncan P. N. Exon Smith
c61bc48acb DI: Disallow uniquable DICompileUnits
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243885 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-03 17:26:41 +00:00
Duncan P. N. Exon Smith
bf2040f00c DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243774 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-31 18:58:39 +00:00
Duncan P. N. Exon Smith
e56023a059 IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:38:44 +00:00
Duncan P. N. Exon Smith
666ef776b3 DebugInfo: Add missing !dbg attachments to intrinsics
Add missing `!dbg` attachments to `@llvm.dbg.*` intrinsics.  I updated
these using a script (add-dbg-to-intrinsics.sh) that I'll attach to
PR22778 for posterity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235040 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 21:04:10 +00:00
Duncan P. N. Exon Smith
de89228dfb Verifier: Call verifyModule() from llc and opt
Change `llc` and `opt` to run `verifyModule()`.  This ensures that we
check the full module before `FunctionPass::doInitialization()` ever
gets called (I was getting crashes in `DwarfDebug` instead of verifier
failures when testing a WIP patch that checks operands of compile
units).  In `opt`, also move up debug-info-stripping so that it still
runs before verification.

There was a fair bit of broken code that was sitting in tree.
Interestingly, some were cases of a `select` that referred to itself in
`-instcombine` tests (apparently an intermediate result).  I split them
off to `*-noverify.ll` tests with RUN lines like this:

    opt < %s -S -disable-verify -instcombine | opt -S | FileCheck %s

This avoids verifying the input file (so we can get the broken code into
`-instcombine), but still verifies the output with a second call to
`opt` (to verify that `-instcombine` will clean it up like it should).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233432 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 22:04:28 +00:00
David Majnemer
ac5b42cad8 MemoryDependenceAnalysis: Don't miscompile atomics
r216771 introduced a change to MemoryDependenceAnalysis that allowed it
to reason about acquire/release operations.  However, this change does
not ensure that the acquire/release operations pair.  Unfortunately,
this leads to miscompiles as we won't see an acquire load as properly
memory effecting.  This largely reverts r216771.

This fixes PR22708.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232889 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 06:19:17 +00:00
Duncan P. N. Exon Smith
763e18696f DebugInfo: Fix testcases that fail -verify-debug-info=true
As part of PR22777, fix testcases that fail the debug info verifier.
The changes fall into the following categories:

  - Empty `filename:` fields in `MDFile`s.  Compile units and some types
    require non-empty filenames.  A number of testcases have empty
    filenames, probably due to hand-reduction of testcases.
  - Not-quite empty arrays: `!{i32 0}`.  This used to be equivalent in
    the debug info schema to `!{}`.  They cause problems for
    `!MDSubroutineType`'s `types:` array, since it requires all operands
    to be valid types.  (Note that `!{null}` is the correct type array
    for functions that take no arguments and return `void`.)
  - Significantly bitrotted testcases.  Nodes got left behind a few
    upgrades ago because of missing or invalid tags.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-16 21:10:12 +00:00
Duncan P. N. Exon Smith
08e687e684 Verifier: Check debug info intrinsic arguments
Verify that debug info intrinsic arguments are valid.  (These checks
will not recurse through the full debug info graph, so they don't need
to be cordoned of in `DebugInfoVerifier`.)

With those checks in place, changing the `DbgIntrinsicInst` accessors to
downcast to `MDLocalVariable` and `MDExpression` is natural (added isa
specializations in `Metadata.h` to support this).

Added tests to `test/Verifier` for the new -verify checks, and fixed the
debug info in all the in-tree tests.

If you have out-of-tree testcases that have started to fail to -verify,
hopefully the verify checks are helpful.  The most likely problem is
that the expression argument is `!{}` (instead of `!MDExpression()`).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232296 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-15 01:21:30 +00:00
Duncan P. N. Exon Smith
b056aa798d DebugInfo: Move new hierarchy into place
Move the specialized metadata nodes for the new debug info hierarchy
into place, finishing off PR22464.  I've done bootstraps (and all that)
and I'm confident this commit is NFC as far as DWARF output is
concerned.  Let me know if I'm wrong :).

The code changes are fairly mechanical:

  - Bumped the "Debug Info Version".
  - `DIBuilder` now creates the appropriate subclass of `MDNode`.
  - Subclasses of DIDescriptor now expect to hold their "MD"
    counterparts (e.g., `DIBasicType` expects `MDBasicType`).
  - Deleted a ton of dead code in `AsmWriter.cpp` and `DebugInfo.cpp`
    for printing comments.
  - Big update to LangRef to describe the nodes in the new hierarchy.
    Feel free to make it better.

Testcase changes are enormous.  There's an accompanying clang commit on
its way.

If you have out-of-tree debug info testcases, I just broke your build.

  - `upgrade-specialized-nodes.sh` is attached to PR22564.  I used it to
    update all the IR testcases.
  - Unfortunately I failed to find way to script the updates to CHECK
    lines, so I updated all of these by hand.  This was fairly painful,
    since the old CHECKs are difficult to reason about.  That's one of
    the benefits of the new hierarchy.

This work isn't quite finished, BTW.  The `DIDescriptor` subclasses are
almost empty wrappers, but not quite: they still have loose casting
checks (see the `RETURN_FROM_RAW()` macro).  Once they're completely
gutted, I'll rename the "MD" classes to "DI" and kill the wrappers.  I
also expect to make a few schema changes now that it's easier to reason
about everything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231082 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 17:24:31 +00:00
David Blaikie
7c9c6ed761 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
David Blaikie
198d8baafb [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230786 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 19:29:02 +00:00
Duncan P. N. Exon Smith
1ef70ff39b IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 19:07:53 +00:00