Commit Graph

1413 Commits

Author SHA1 Message Date
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
David Majnemer 726901b638 [InstCombine] Optimize subtract of selects into a select of a sub
This came up when examining some code generated by clang's IRGen for
certain member pointers.

llvm-svn: 240369
2015-06-23 02:49:24 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
David Majnemer 7fddeccb8b Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Philip Reames c25df11614 Reapply 239795 - [InstCombine] Propagate non-null facts to call parameters
The original change broke clang side tests.  I will be submitting those momentarily.  This change includes post commit feedback on the original change from from Pete Cooper.

Original Submission comments:
If a parameter to a function is known non-null, use the existing parameter attributes to record that fact at the call site. This has no optimization benefit by itself - that I know of - but is an enabling change for http://reviews.llvm.org/D9129.

Differential Revision: http://reviews.llvm.org/D9132

llvm-svn: 239849
2015-06-16 20:24:25 +00:00
Philip Reames 1a6305f313 Revert 239795
I forgot to update some clang test cases.  I'll fix and resubmit tomorrow.

llvm-svn: 239800
2015-06-16 01:20:53 +00:00
Philip Reames dfc29fba60 [InstCombine] Propagate non-null facts to call parameters
If a parameter to a function is known non-null, use the existing parameter attributes to record that fact at the call site. This has no optimization benefit by itself - that I know of - but is an enabling change for http://reviews.llvm.org/D9129.

Differential Revision: http://reviews.llvm.org/D9132

llvm-svn: 239795
2015-06-16 00:43:54 +00:00
David Majnemer 3f0fb98d01 [InstCombine, InstSimplify] Move xforms from Combine to Simplify
There were several SelectInst combines that always returned an existing
instruction instead of modifying an old one or creating a new one.
These are prime candidates for moving to InstSimplify.

llvm-svn: 239229
2015-06-06 22:40:21 +00:00
David Majnemer 468f670021 [InstCombine] Don't miscompile select to poison
If we have (select a, b, c), it is sometimes valid to simplify this to a
single select operand.  However, doing so is only valid if the
computation doesn't inject poison into the computation.

It might be helpful to consider the following example:
  (select (icmp ne %i, INT_MAX), (add nsw %i, 1), INT_MIN)

The select is equivalent to (add %i, 1) but not (add nsw %i, 1).

Self hosting on x86_64 revealed that this occurs very, very rarely so
bailing out is hopefully pretty reasonable.

llvm-svn: 239215
2015-06-06 02:30:43 +00:00
Renato Golin 3dabb23384 Revert "[InstCombine] Rephrase fix to SimplifyWithOpReplaced"
This reverts commit r239141. This commit was an attempt to reintroduce
a previous patch that broke many self-hosting bots with clang timeouts,
but it still has slowdown issues, at least  on ARM, increasing the
compilation time (stage 2, clang's) by 5x.

llvm-svn: 239175
2015-06-05 18:24:12 +00:00
Sanjoy Das c80dad6f18 [InstCombine][NFC] Add a ``break;`` statement.
This change is NFC because both the ``break;`` and the fall through end
up returning immediately. However, this helps clarify intent and also
ensures correctness in case more ``case`` blocks are added later.

llvm-svn: 239172
2015-06-05 18:04:46 +00:00
Sanjoy Das 72cb5e1087 [InstCombine] Fix PR23751.
PR23751 was caused by a missing ``break;`` in r234388.

llvm-svn: 239171
2015-06-05 18:04:42 +00:00
David Majnemer 6d8081835d [InstCombine] Rephrase fix to SimplifyWithOpReplaced
I don't have the IR which is causing the build bot breakage but I can
postulate as to why they are timing out:
1. SimplifyWithOpReplaced was stripping flags from the simplified value.
2. visitSelectInstWithICmp was overriding SimplifyWithOpReplaced because
   it's simplification wasn't correct.
3. InstCombine would revisit the add instruction and note that it can
   rederive the flags.
4. By modifying the value, we chose to revisit instructions which reuse
   the value.  One of the instructions is the original select, causing
   LLVM to never reach fixpoint.

Instead, strip the flags only when we are sure we are going to perform
the simplification.

llvm-svn: 239141
2015-06-05 09:57:57 +00:00
Daniel Jasper 917fa5ee66 Revert "[InstCombine] Don't miscompile safe increment idiom"
This is breaking a lot of build bots and is causing very long-running
compiles (infinite loops)?

Likely, we shouldn't return nullptr?

llvm-svn: 239139
2015-06-05 09:31:20 +00:00
David Majnemer 00f7d9ecc8 [InstCombine] Don't miscompile safe increment idiom
We cleverly handle cases where computation done in one argument of a select
instruction is suitable for the other operand, thus obviating the need
of the select and the comparison.  However, the other operand cannot
have flags.

This fixes PR23757.

llvm-svn: 239115
2015-06-04 23:11:30 +00:00
Benjamin Kramer f5e2fc474d Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

llvm-svn: 238602
2015-05-29 19:43:39 +00:00
David Majnemer dd04352558 [InstCombine] Fold IntToPtr and PtrToInt into preceding loads.
Currently we only fold a BitCast into a Load when the BitCast is its
only user.

Do the same for any no-op cast.

Differential Revision: http://reviews.llvm.org/D9152

llvm-svn: 238452
2015-05-28 18:39:17 +00:00
David Majnemer 4c3753c4d4 [InstCombine] Don't eagerly propagate nsw for A*B+A*C => A*(B+C)
InstCombine transforms A *nsw B +nsw A *nsw C to A *nsw (B + C).
This is incorrect -- e.g. if A = -1, B = 1, C = INT_SMAX. Then
nothing in the LHS overflows, but the multiplication in RHS overflows.

We need to first make sure that we won't multiple by INT_SMAX + 1.

Test case `add_of_mul` contributed by Sanjoy Das.

This fixes PR23635.

Differential Revision: http://reviews.llvm.org/D9629

llvm-svn: 238066
2015-05-22 23:02:11 +00:00
David Majnemer 1503258157 [InstSimplify] Handle some overflow intrinsics in InstSimplify
This change does a few things:
- Move some InstCombine transforms to InstSimplify
- Run SimplifyCall from within InstCombine::visitCallInst
- Teach InstSimplify to fold [us]mul_with_overflow(X, undef) to 0.

llvm-svn: 237995
2015-05-22 03:56:46 +00:00
David Majnemer 27e89ba24c [InstCombine] X - 0 is equal to X, not undef
A refactoring made @llvm.ssub.with.overflow.i32(i32 %X, i32 0) transform
into undef instead of %X.

This fixes PR23624.

llvm-svn: 237968
2015-05-21 23:04:21 +00:00
James Molloy 2b21a7cf36 Reapply r237539 with a fix for the Chromium build.
Make sure if we're truncating a constant that would then be sign extended
that the sign extension of the truncated constant is the same as the
original constant.

> Canonicalize min/max expressions correctly.
>
> This patch introduces a canonical form for min/max idioms where one operand
> is extended or truncated. This often happens when the other operand is a
> constant. For example:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = sext i32 %a to i64
> %3 = select i1 %1, i64 %2, i64 0
>
> Would now be canonicalized into:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = select i1 %1, i32 %a, i32 0
> %3 = sext i32 %2 to i64
>
> This builds upon a patch posted by David Majenemer
> (https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
> passively stopped instcombine from ruining canonical patterns. This
> patch additionally actively makes instcombine canonicalize too.
>
> Canonicalization of expressions involving a change in type from int->fp
> or fp->int are not yet implemented.

llvm-svn: 237821
2015-05-20 18:41:25 +00:00
Hans Wennborg 2f21b8760e Revert r237539: "Reapply r237520 with another fix for infinite looping"
This caused PR23583.

llvm-svn: 237739
2015-05-19 23:06:30 +00:00
David Blaikie ff6409d096 Simplify IRBuilder::CreateCall* by using ArrayRef+initializer_list/braced init only
llvm-svn: 237624
2015-05-18 22:13:54 +00:00
James Molloy 53958e187a Reapply r237520 with another fix for infinite looping
SimplifyDemandedBits was "simplifying" a constant by removing just sign bits.
This caused a canonicalization race between different parts of instcombine.

Fix and regression test added - third time lucky?

llvm-svn: 237539
2015-05-17 08:27:27 +00:00
James Molloy e8698ae3e1 Revert commits r237521 and r237520.
The AArch64 LNT bot is unhappy - I've found that the problem is in
SimpliftDemandedBits, but that's going to require another code review
so reverting in the meantime.

llvm-svn: 237528
2015-05-16 21:27:14 +00:00
James Molloy b5aa200a33 Reapply r237453 with a fix for the test timeouts.
The test timeouts were due to instcombine fighting itself. Regression test added.
Original log message:

Canonicalize min/max expressions correctly.

This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
    %2 = sext i32 %a to i64
      %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
    %2 = select i1 %1, i32 %a, i32 0
      %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237520
2015-05-16 13:10:45 +00:00
James Molloy 1675b4a57f Revert "Canonicalize min/max expressions correctly."
This reverts r237453 - it was causing timeouts on some bots. Reverting
while I investigate (it's probably InstCombine fighting itself...)

llvm-svn: 237458
2015-05-15 17:45:09 +00:00
James Molloy 6edf0b4cd4 Canonicalize min/max expressions correctly.
This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
  %2 = sext i32 %a to i64
  %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
  %2 = select i1 %1, i32 %a, i32 0
  %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237453
2015-05-15 16:10:59 +00:00
Jingyue Wu ca32190379 [ValueTracking] refactor: extract method haveNoCommonBitsSet
Summary:
Extract method haveNoCommonBitsSet so that we don't have to duplicate this logic in
InstCombine and SeparateConstOffsetFromGEP.

This patch also makes SeparateConstOffsetFromGEP more precise by passing
DominatorTree to computeKnownBits.

Test Plan: value-tracking-domtree.ll that tests ValueTracking indeed leverages dominating conditions

Reviewers: broune, meheff, majnemer

Reviewed By: majnemer

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9734

llvm-svn: 237407
2015-05-14 23:53:19 +00:00
Pete Cooper 833f34d837 Convert PHI getIncomingValue() to foreach over incoming_values(). NFC.
We already had a method to iterate over all the incoming values of a PHI.  This just changes all eligible code to use it.

Ineligible code included anything which cared about the index, or was also trying to get the i'th incoming BB.

llvm-svn: 237169
2015-05-12 20:05:31 +00:00
Sanjoy Das 89c5491a72 [RewriteStatepointsForGC] Fix a bug on creating gc_relocate for pointer to vector of pointers
Summary:
In RewriteStatepointsForGC pass, we create a gc_relocate intrinsic for
each relocated pointer, and the gc_relocate has the same type with the
pointer. During the creation of gc_relocate intrinsic, llvm requires to
mangle its type. However, llvm does not support mangling of all possible
types. RewriteStatepointsForGC will hit an assertion failure when it
tries to create a gc_relocate for pointer to vector of pointers because
mangling for vector of pointers is not supported.

This patch changes the way RewriteStatepointsForGC pass creates
gc_relocate. For each relocated pointer, we erase the type of pointers
and create an unified gc_relocate of type i8 addrspace(1)*. Then a
bitcast is inserted to convert the gc_relocate to the correct type. In
this way, gc_relocate does not need to deal with different types of
pointers and the unsupported type mangling is no longer a problem. This
change would also ease further merge when LLVM erases types of pointers
and introduces an unified pointer type.

Some minor changes are also introduced to gc_relocate related part in
InstCombineCalls, CodeGenPrepare, and Verifier accordingly.

Patch by Chen Li!

Reviewers: reames, AndyAyers, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9592

llvm-svn: 237009
2015-05-11 18:49:34 +00:00
James Molloy 71b91c2dba Rip min/max pattern matching out of InstCombine and into
ValueTracking.

This matching functionality is useful in more than just InstCombine, so
make it available in ValueTracking.

NFC.

llvm-svn: 236998
2015-05-11 14:42:20 +00:00
Hal Finkel f0d68d788b [InstCombine/PowerPC] Fix single-precision QPX load/store replacement
The QPX single-precision load/store intrinsics have implied
truncation/extension from/to the declared value type of <4 x double> to the
memory type of <4 x float>. When we can prove the alignment of the pointer
argument, and thus replace the intrinsic with a regular load or store, we need
to load or store the correct data type (<4 x float>) instead of (<4 x double>).

llvm-svn: 236973
2015-05-11 06:37:03 +00:00
David Majnemer 7536460c0f [InstCombine] Canonicalize single element array store
Use the element type instead of the aggregate type.

Differential Revision: http://reviews.llvm.org/D9591

llvm-svn: 236969
2015-05-11 05:04:27 +00:00
David Majnemer 58fb038b1b [InstCombine] Canonicalize single element array load
Use the element type instead of the aggregate type.

Differential Revision: http://reviews.llvm.org/D9596

llvm-svn: 236968
2015-05-11 05:04:22 +00:00
Mehdi Amini 2668a487a7 Update InstCombine to transform aggregate loads into scalar loads.
Summary:
One step further getting aggregate loads and store being optimized
properly. This will only handle struct with one element at this point.

Test Plan: Added unit tests for the new supported cases.

Reviewers: chandlerc, joker-eph, joker.eph, majnemer

Reviewed By: majnemer

Subscribers: pete, llvm-commits

Differential Revision: http://reviews.llvm.org/D8339

Patch by Amaury Sechet.

From: Amaury Sechet <amaury@fb.com>
llvm-svn: 236695
2015-05-07 05:52:40 +00:00
Pete Cooper 2777d88745 Change typeIncompatible to return an AttrBuilder instead of new-ing an AttributeSet.
This makes use of the new API which can remove attributes from a set given a builder.

This is much faster than creating a temporary set and reduces llc time by about 0.3% which was all spent creating temporary attributes sets on the context.

llvm-svn: 236668
2015-05-06 23:19:56 +00:00
Sanjoy Das 499d703f52 [Statepoint] Clean up Statepoint.h: accessor names.
Use getFoo() as accessors consistently and some other naming changes.

llvm-svn: 236564
2015-05-06 02:36:26 +00:00
David Blaikie 73cf872adb [opaque pointer type] Track explicit GEP pointee type through in-memory IR
llvm-svn: 236510
2015-05-05 18:03:48 +00:00
Matthias Braun e48484c64f InstCombineSimplifyDemanded: Remove nsw/nuw flags when optimizing demanded bits
When optimizing demanded bits of the operands of an Add we have to
remove the nsw/nuw flags as we have no guarantee anymore that we don't
wrap.  This is legal here because the top bit is not demanded.  In fact
this operaion was already performed but missed in the case of an Add
with a constant on the right side.  To fix this this patch refactors the
code to unify the code paths in SimplifyDemandedUseBits() handling of
Add/Sub:

- The transformation of Add->Or is removed from the simplify demand
  code because the equivalent transformation exists in
  InstCombiner::visitAdd()
- KnownOnes/KnownZero are not adjusted for Add x, C anymore as
  computeKnownBits() already performs these computations.
- The simplification of the operands is unified. In this new version
  constant on the right side of a Sub are shrunk now as I could not find
  a reason why not to do so.
- The special case for clearing nsw/nuw in ShrinkDemandedConstant() is
  not necessary anymore as the caller does that already.

Differential Revision: http://reviews.llvm.org/D9415

llvm-svn: 236269
2015-04-30 22:05:30 +00:00
Matthias Braun ec6833420f InstCombine: Move Sub->Xor rule from SimplifyDemanded to InstCombine
The rule that turns a sub to xor if the LHS is 2^n-1 and the remaining bits
are known zero, does not use the demanded bits at all: Move it to the
normal InstCombine code path.

Differential Revision: http://reviews.llvm.org/D9417

llvm-svn: 236268
2015-04-30 22:04:26 +00:00
Sanjoy Das 08e95b4703 [InstCombine] Add new rule for MIN(MAX(~A, ~B), ~C) et. al.
Summary:
Optimizing these well are especially interesting for IRCE since it
"clamps" values by generating this sort of pattern through SCEV
expressions.

Depends on D9352.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9353

llvm-svn: 236203
2015-04-30 04:56:04 +00:00
Sanjoy Das a8c178f280 [InstCombine] Add a new formula for SMIN.
Summary:
After this change `MatchSelectPattern` recognizes the following form
of SMIN:

  Y >s C ? ~Y : ~C == ~Y <s ~C ? ~Y : ~C = SMIN(~Y, ~C)

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9352

llvm-svn: 236202
2015-04-30 04:56:00 +00:00
Sanjay Patel c1d20a36fb [x86] instcombine more cases of insertps into a shufflevector
This is a follow-on to D8833 (insertps optimization when the zero mask is not used).

In this patch, we check for the case where the zmask is used, but both input vectors
to the insertps intrinsic are the same operand or the zmask overrides the destination
lane. This lets us replace the 2nd shuffle input operand with the zero vector.

Differential Revision: http://reviews.llvm.org/D9257

llvm-svn: 235810
2015-04-25 20:55:25 +00:00
Philip Reames 5461d45abf Move Value.isDereferenceablePointer to ValueTracking [NFC]
Move isDereferenceablePointer function to Analysis. This function recursively tracks dereferencability over a chain of values like other functions in ValueTracking.

This refactoring is motivated by further changes to support dereferenceable_or_null attribute (http://reviews.llvm.org/D8650). isDereferenceablePointer will be extended to perform context-sensitive analysis and IR is not a good place to have such functionality.

Patch by: Artur Pilipenko <apilipenko@azulsystems.com>
Differential Revision: reviews.llvm.org/D9075

llvm-svn: 235611
2015-04-23 17:36:48 +00:00
David Majnemer 7d0e99c601 [InstCombine] Use a more targeted fix instead of r235544
Only clear out the NSW/NUW flags if we are optimizing 'add'/'sub' while
taking advantage that the sign bit is not set.  We do this optimization
to further shrink the mask but shrinking the mask isn't NSW/NUW
preserving in this case.

llvm-svn: 235558
2015-04-22 22:42:05 +00:00
David Majnemer fe58d13a17 [InstCombine] Clear out nsw/nuw if we modify computation in the chain
An nsw/nuw operation relies on the values feeding into it to not
overflow if 'poison' is not to be produced.  This means that
optimizations which make modifications to the bottom of a chain (like
SimplifyDemandedBits) must strip out nsw/nuw if they cannot ensure that
they will be preserved.

This fixes PR23309.

llvm-svn: 235544
2015-04-22 20:59:28 +00:00
Wei Mi a0adf9fd41 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimization,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D8911

llvm-svn: 235455
2015-04-21 23:02:15 +00:00
Wei Mi 2940bc82ac Revert r235451 since it is attached to a wrong Differential Revision. Sorry.
llvm-svn: 235453
2015-04-21 22:56:09 +00:00
Wei Mi 6e3344ed98 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimizations,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D9007

llvm-svn: 235451
2015-04-21 22:37:09 +00:00