Commit Graph

6507 Commits

Author SHA1 Message Date
James Molloy
cca49027ef 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237528 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 21:27:14 +00:00
James Molloy
ea08c0b975 Update to r237520 - swap order of CHECK-NEXT lines.
... I'd copied the check-next lines from a previous test so they were
slightly wrong, and had managed to test the wrong source tree. D'oh!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237521 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 13:26:25 +00:00
James Molloy
bc71c2fd8e 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237520 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 13:10:45 +00:00
Ahmed Bougacha
8081057fca [MemCpyOpt] Turn memcpy from just-memset'd source into memset.
There's no point in copying around constants, so, when all else fails,
we can still transform memcpy of memset into two independent memsets.

To quote the example, we can turn:
  memset(dst1, c, dst1_size);
  memcpy(dst2, dst1, dst2_size);
into:
  memset(dst1, c, dst1_size);
  memset(dst2, c, dst2_size);
When dst2_size <= dst1_size.

Like r235232 for copy constructors, this can occur in move constructors.

Differential Revision: http://reviews.llvm.org/D9682


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237506 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 01:32:26 +00:00
Ahmed Bougacha
43c7aeef66 Remove dead code in testcase. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-16 01:10:40 +00:00
Jingyue Wu
85e632de29 Add a speculative execution pass
Summary:
This is a pass for speculative execution of instructions for simple if-then (triangle) control flow. It's aimed at GPUs, but could perhaps be used in other contexts. Enabling this pass gives us a 1.0% geomean improvement on Google benchmark suites, with one benchmark improving 33%.

Credit goes to Jingyue Wu for writing an earlier version of this pass.

Patched by Bjarke Roune. 

Test Plan:
This patch adds a set of tests in test/Transforms/SpeculativeExecution/spec.ll
The pass is controlled by a flag which defaults to having the pass not run.

Reviewers: eliben, dberlin, meheff, jingyue, hfinkel

Reviewed By: jingyue, hfinkel

Subscribers: majnemer, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9360

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237459 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 17:54:48 +00:00
James Molloy
c683eb2d37 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...)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237458 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 17:45:09 +00:00
Jingyue Wu
ef0b6c4b1e [SLSR] handle (B | i) * S
Summary:
Consider (B | i) * S as (B + i) * S if B and i have no bits set in
common.

Test Plan: @or in slsr-mul.ll

Reviewers: broune, meheff

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9788

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237456 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 17:07:48 +00:00
James Molloy
49f69b8e25 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237453 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 16:10:59 +00:00
Nemanja Ivanovic
08709687ef NFC - Test case invokes llc on a file rather than redirected from a file.
This has caused some local failures. Updating the test case to be more
like the majority of the similar test cases.
Committing on behalf of Hubert Tong (hstong@ca.ibm.com).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237449 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 15:29:53 +00:00
Sanjoy Das
fa93d0e1c6 [PlaceSafepoints] Fix a bug that came in with rL236672.
Transfer the calling convention from the invoke being replaced by
PlaceStatepoints to the new invoke to gc.statepoint created.  Add a test
case that would have caught this issue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237414 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 00:26:21 +00:00
Sanjoy Das
4c4b944e83 [PlaceSafepoints] Fix a bug that came in with rL236672.
rL236672 would generate all invoke statepoints with deopt args set to a
list containing the single element "0", instead of an empty list.

Also add a test case that would have caught this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237413 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 00:26:15 +00:00
Jingyue Wu
19eda5312a [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237407 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 23:53:19 +00:00
Wei Mi
95f7517f1b Add another InstCombine pass after LoopUnroll.
This is to cleanup some redundency generated by LoopUnroll pass. Such redundency may not be cleaned up by existing passes after LoopUnroll.

Differential Revision: http://reviews.llvm.org/D9777


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237395 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 22:02:54 +00:00
Andrea Di Biagio
56a5661c60 [ConstantFolding] Fix wrong folding of intrinsic 'convert.from.fp16'.
Function 'ConstantFoldScalarCall' (in ConstantFolding.cpp) works under the
wrong assumption that a call to 'convert.from.fp16' returns a value of
type 'float'.
However, intrinsic 'convert.from.fp16' can be overloaded; for example, we
can call 'convert.from.fp16.f64' to convert from half to double; etc.

Before this patch, the following example would have triggered an assertion
failure in opt (with -constprop):

```
define double @foo() {
entry:
  %0 = call double @llvm.convert.from.fp16.f64(i16 0)
  ret double %0
}
```

This patch fixes the problem in ConstantFolding.cpp. When folding a call to
convert.from.fp16, we perform a different kind of conversion based on the call
return type.

Added test 'Transform/ConstProp/convert-from-fp16.ll'.

Differential Revision: http://reviews.llvm.org/D9771


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237377 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 18:01:48 +00:00
Adam Nemet
dd469afe15 New Loop Distribution pass
Summary:
This implements the initial version as was proposed earlier this year
(http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-January/080462.html).
Since then Loop Access Analysis was split out from the Loop Vectorizer
and was made into a separate analysis pass.  Loop Distribution becomes
the second user of this analysis.

The pass is off by default and can be enabled
with -enable-loop-distribution.  There is currently no notion of
profitability; if there is a loop with dependence cycles, the pass will
try to split them off from other memory operations into a separate loop.

I decided to remove the control-dependence calculation from this first
version.  This and the issues with the PDT are actively discussed so it
probably makes sense to treat it separately.  Right now I just mark all
terminator instruction required which keeps identical CFGs for each
distributed loop.  This seems to be working pretty well for 456.hmmer
where even though there is an empty if-then block in the distributed
loop initially, it gets completely removed.

The pass keeps DominatorTree and LoopInfo updated.  I've tested this
with -loop-distribute-verify with the testsuite where we distribute ~90
loops.  SimplifyLoop is violated in some cases and I have a FIXME
covering this.

Reviewers: hfinkel, nadav, aschwaighofer

Reviewed By: aschwaighofer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8831

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237358 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 12:05:18 +00:00
Sanjoy Das
3f0ca03e94 [PlaceSafepoints] New attributes for patchable statepoints.
Summary:
This patch teaches the PlaceSafepoints pass about two `CallSite`
function attributes:

 * "statepoint-id": if the string value of this attribute can be parsed
   as an integer, then it is propagated to the ID parameter of the
   statepoint created.

 * "statepoint-num-patch-bytes": if the string value of this attribute
   can be parsed as an integer, then it is propagated to the `num patch
   bytes` parameter of the statepoint created.

This change intentionally does not assert on a malformed value for these
attributes, given that they're not "official" attributes.

Reviewers: reames, pgavlin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9735

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237286 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 20:11:31 +00:00
Jingyue Wu
12b5fa5f6e [NaryReassociate] avoid running forever
Avoid running forever by checking we are not reassociating an expression into
the same form.

Tested with @avoid_infinite_loops in nary-add.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237269 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 18:12:24 +00:00
Diego Novillo
0e0929ed98 Add function entry counts from sample profiles.
This patch uses the new function profile metadata "function_entry_count"
to annotate entry counts from sample profiles.

In a sampling profile, the total samples collected at the function entry
are an approximation for the number of times that function was invoked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 17:04:29 +00:00
Jingyue Wu
3062272092 [SLSR] handles non-canonicalized Mul candidates
such as (2 + B) * S.

Tested by @non_canonicalized in slsr-mul.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237216 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 00:03:17 +00:00
Sanjoy Das
ead2d1fbe0 [Statepoints] Support for "patchable" statepoints.
Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`.  `id` gets propagated to the ID field
in the generated StackMap section.  If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.

This change brings statepoints one step closer to patchpoints.  With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.

PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`.  This can be made more sophisticated
later.

Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9546

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237214 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 23:52:24 +00:00
Bjorn Steinbrink
1b8b7d61ee CVP: Improve handling of Selects used as incoming PHI values
Summary:
If the branch that leads to the PHI node and the Select instruction
depend on correlated conditions, we might be able to directly use the
corresponding value from the Select instruction as the incoming value
for the PHI node, allowing later removal of the select instruction.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9051

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237201 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 22:31:47 +00:00
Philip Reames
6865b977ae [RewriteStatepointsForGC] Extend base pointer to handle more cases w/vectors
When relocating a pointer, we need to determine a base pointer for the derived pointer being relocated. We have limited support for handling a pointer extracted from a vector; the current code only handled the case where the entire vector was known to contain base pointers. This patch extends the reasoning to handle chains of insertelements where the indices are constants. This case turns out to be fairly common in vectorized code. We can now handle vectors which contains mixtures of base and derived pointers provided the insertelements use constant indices.

Note that this doesn't solve the general problem. To handle variable indexed insertelements, we'd need to scalarize and introduce conditional branching based on the index. Alternatively, we could eagerly scalarize, but the code structure doesn't currently make either fix easy. The patch also doesn't handle shufflevector or other vector manipulation for much the same reasons. I plan to defer this work until I have a motivating test case.

Differential Revision: http://reviews.llvm.org/D9676



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237200 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 22:19:52 +00:00
Arnold Schwaighofer
414a781256 MergeFunctions: Two different sized allocas are *not* the same
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237193 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 21:42:22 +00:00
Philip Reames
c89f135a41 [PlaceSafepoints] Remove dependence on LoopSimplify
As a step towards getting rid of internal pass manager hack entirely, remove the need for loop simplify to run in the inner pass manager. The new code does produce slightly different loop structures, so this isn't technically NFC.

Differential Revision: http://reviews.llvm.org/D9585



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237172 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 20:43:48 +00:00
Michael Zolotukhin
e2d9012a38 Reimplement heuristic for estimating complete-unroll optimization effects.
Summary:
This patch reimplements heuristic that tries to estimate optimization beneftis
from complete loop unrolling.

In this patch I kept the minimal changes - e.g. I removed code handling
branches and folding compares. That's a promising area, but now there
are too many questions to discuss before we can enable it.

Test Plan: Tests are included in the patch.

Reviewers: hfinkel, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8816

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237156 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 17:20:03 +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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237150 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 16:47:30 +00:00
Ahmed Bougacha
6eb095d7ae [MemCpyOpt] Look at any dependency -not just source- for memset+memcpy.
This fixes another miscompile introduced by r235232: when there was a
dependency on the memcpy destination other than the memset, we would
ignore it, because we only looked at the source dependency.

It was a mistake to use SrcDepInfo.  Instead, just use DepInfo.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237066 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 23:09:46 +00:00
Sanjoy Das
5b5782c20e [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237009 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 18:49:34 +00:00
Hal Finkel
cdd4737be8 [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>).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236973 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 06:37:03 +00:00
David Majnemer
73f2a7bbb2 Make buildbots happy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236970 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 05:33:27 +00:00
David Majnemer
c88eae46da [InstCombine] Canonicalize single element array store
Use the element type instead of the aggregate type.

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236969 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 05:04:27 +00:00
David Majnemer
3101b1a432 [InstCombine] Canonicalize single element array load
Use the element type instead of the aggregate type.

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236968 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 05:04:22 +00:00
Pat Gavlin
5c7f7462e4 Extend the statepoint intrinsic to allow statepoints to be marked as transitions from GC-aware code to code that is not GC-aware.
This changes the shape of the statepoint intrinsic from:

  @llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 unused, ...call args, i32 # deopt args, ...deopt args, ...gc args)

to:

  @llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 flags, ...call args, i32 # transition args, ...transition args, i32 # deopt args, ...deopt args, ...gc args)

This extension offers the backend the opportunity to insert (somewhat) arbitrary code to manage the transition from GC-aware code to code that is not GC-aware and back.

In order to support the injection of transition code, this extension wraps the STATEPOINT ISD node generated by the usual lowering lowering with two additional nodes: GC_TRANSITION_START and GC_TRANSITION_END. The transition arguments that were passed passed to the intrinsic (if any) are lowered and provided as operands to these nodes and may be used by the backend during code generation.

Eventually, the lowering of the GC_TRANSITION_{START,END} nodes should be informed by the GC strategy in use for the function containing the intrinsic call; for now, these nodes are instead replaced with no-ops.

Differential Revision: http://reviews.llvm.org/D9501

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236888 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-08 18:07:42 +00:00
Jingyue Wu
c417f302cb [NoTTI] reject negative scale in addressing mode
Summary:
I noticed this bug when deubging a WIP on LSR. I wonder whether and how we
should add a regression test for this.

Test Plan: no tests failed.

Reviewers: atrick

Subscribers: hfinkel, llvm-commits

Differential Revision: http://reviews.llvm.org/D9536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236887 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-08 18:07:24 +00:00
Michael Zolotukhin
d7b5144d53 Populate list of vectorizable functions for Accelerate library.
Summary:
This patch adds majority of supported by Accelerate library functions to the
list of vectorizable functions.

The full list of available vector functions could be found here:
https://developer.apple.com/library/mac/documentation/Performance/Conceptual/vecLib/index.html

Test Plan: Unit tests are added.

Reviewers: hfinkel, aschwaighofer, nadav

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9543

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236747 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 17:11:51 +00:00
Mehdi Amini
4d5e059cdb 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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236695 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 05:52:40 +00:00
Philip Reames
16e7e690b7 [JumpThreading] Simplify comparisons when simplifying branches
If we have recognized that a conditional is constant at a particular location in the code (while trying to decide if we can simplify a conditional branch), we can eagerly replace that condition with a constant if it's definition is post dominated by the branch in question.

In practice, this ends up being a compile time savings at most. JumpThreading would have visited each using branch anyways. CVP would have visited the cmp itself again. Unless LVI gives up early, we shouldn't gain any addition power by doing this transformation early. What we do gain is simplicity and compile time.

Differential Revision: http://reviews.llvm.org/D9312



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2015-05-07 00:19:14 +00:00
Akira Hatanaka
e6f0494cd8 Let llc and opt override "-target-cpu" and "-target-features" via command line
options.

This commit fixes a bug in llc and opt where "-mcpu" and "-mattr" wouldn't
override function attributes "-target-cpu" and "-target-features" in the IR.

Differential Revision: http://reviews.llvm.org/D9537


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2015-05-06 23:54:14 +00:00
Sanjoy Das
8a86e2564d [IRBuilder] Add a CreateGCStatepointInvoke.
Renames the original CreateGCStatepoint to CreateGCStatepointCall, and
moves invoke creating functionality from PlaceSafepoints.cpp to
IRBuilder.cpp.

This changes the labels generated for PlaceSafepoints/invokes.ll so use
a regex there to make the basic block labels more resilient.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236672 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 23:53:09 +00:00
Diego Novillo
26e46f2283 Allow 0-weight branches in BranchProbabilityInfo.
Summary:
When computing branch weights in BPI, we used to disallow branches with
weight 0. This is a minor nuisance, because a branch with weight 0 is
different to "don't have information". In the context of
instrumentation, it may mean "never executed", in the context of
sampling, it means "never or seldom executed".

In allowing 0 weight branches, I ran into issues with the switch
expansion code in selection DAG. It is currently hardwired to not handle
branches with weight 0. To maintain the current behaviour, I changed it
to use 1 when it finds 0, but perhaps the algorithm needs changes to
tolerate branches with weight zero.

Reviewers: hansw

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9533

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2015-05-06 17:55:11 +00:00
Wei Mi
cac51be31f [X86] Disable loop unrolling in loop vectorization pass when VF is 1.
The patch disabled unrolling in loop vectorization pass when VF==1 on x86 architecture,
by setting MaxInterleaveFactor to 1. Unrolling in loop vectorization pass may introduce
the cost of overflow check, memory boundary check and extra prologue/epilogue code when
regular unroller will unroll the loop another time. Disable it when VF==1 remove the
unnecessary cost on x86. The same can be done for other platforms after verifying
interleaving/memory bound checking to be not perf critical on those platforms.

Differential Revision: http://reviews.llvm.org/D9515


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2015-05-06 17:12:25 +00:00
David Majnemer
cfdd004e7e [Inliner] Discard empty COMDAT groups
COMDAT groups which have become rendered unused because of inline are
discardable if we can prove that we've made the group empty.

This fixes PR22285.

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2015-05-05 20:14:22 +00:00
Daniel Berlin
7a5c0e599c Update BasicAliasAnalysis to understand that nothing aliases with undef values.
It got this in some cases (if one of them was an identified object), but not in all cases.

This caused stores to undef to block load-forwarding in some cases, etc.

Added test to Transforms/GVN to verify optimization occurs as expected.

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2015-05-05 18:10:49 +00:00
Matthias Braun
af2e236c11 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

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2015-04-30 22:05:30 +00:00
Sanjoy Das
a34038226e [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

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2015-04-30 04:56:04 +00:00
Sanjoy Das
c0730628a4 [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

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2015-04-30 04:56:00 +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.

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2015-04-29 16:38:44 +00:00
Pawel Bylica
59764b94a7 Constfold insertelement to undef when index is out-of-bounds
Summary:
This patch adds constant folding of insertelement instruction to undef value when index operand is constant and is not less than vector size or is undef.

InstCombine does not support this case, but I'm happy to add it there also if this change is accepted.

Test Plan: Unittests and regression tests for ConstProp pass.

Reviewers: majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9287

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2015-04-27 09:30:49 +00:00
Philip Reames
a404b6f421 [RewriteStatepointsForGC] Exclude constant values from being considered live at a safepoint
There can be various constant pointers in the IR which do not get relocated at a safepoint. One example is the address of a global variable. Another example is a pointer created via inttoptr. Note that the optimizer itself likes to create such inttoptrs when locally propagating constants through dynamically dead code.

To deal with this, we need to exclude uses of constants from contributing to the liveness of a safepoint which might reach that use. At some later date, it might be worth exploring what could be done to support the relocation of various special types of "constants", but that's future work.

Differential Revision: http://reviews.llvm.org/D9236



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2015-04-26 19:48:03 +00:00