Commit Graph

1578 Commits

Author SHA1 Message Date
Sanjay Patel fedc01ad76 [DAG] make isConstantSplatVector() available to the rest of lowering
llvm-svn: 275025
2016-07-10 21:27:06 +00:00
Sanjay Patel 303326541b reformat, fix comments/names; NFCI
llvm-svn: 275015
2016-07-10 13:05:57 +00:00
Matt Arsenault 3fb8f9eabf Reapply r274829 with fix for FP vectors
llvm-svn: 274937
2016-07-08 21:25:33 +00:00
Nico Weber 28410c6846 Revert r274829, it caused PR28472.
llvm-svn: 274916
2016-07-08 19:52:19 +00:00
Sjoerd Meijer 1ee119f897 Do not expand SDIV when compiling for minimum code size
Differential Revision: http://reviews.llvm.org/D22139

llvm-svn: 274855
2016-07-08 15:32:01 +00:00
Sjoerd Meijer 46c4c3d31c Addressing post-commit comments regarding not expanding UDIV;
we don't expand only when compiling for minimum code size.

llvm-svn: 274847
2016-07-08 14:17:09 +00:00
Sjoerd Meijer a625af3feb Code size optimisation: don't expand a div to a mul and and a shift sequence.
As a result, the urem instruction will not be expanded to a sequence of umull,
lsrs, muls and sub instructions, but just a call to __aeabi_uidivmod.

Differential Revision: http://reviews.llvm.org/D22131

llvm-svn: 274843
2016-07-08 12:54:43 +00:00
Matt Arsenault c3a6fe6ecd Bug 28444: Fix assertion when extract_vector_elt has mismatched type
For some reason extract_vector_elt is sometimes allowed to have
a different result type than the vector element type.

llvm-svn: 274829
2016-07-08 07:05:00 +00:00
Tim Shen 1c3c0afc53 [DAGCombiner] Fix visitSTORE to continue processing current SDNode, if findBetterNeighborChains doesn't actually CombineTo it.
Summary:
findBetterNeighborChains may or may not find a better chain for each node it finds, which include the node ("St") that visitSTORE is currently processing. If no better chain is found for St, visitSTORE should continue instead of return SDValue(St, 0), as if it's CombinedTo'ed.

This fixes bug 28130. There might be other ways to make the test pass (see D21409). I think both of the patches are fixing actual bugs revealed by the same testcase.

Reviewers: echristo, wschmidt, hfinkel, kbarton, amehsan, arsenm, nemanjai, bogner

Subscribers: mehdi_amini, nemanjai, llvm-commits

Differential Revision: http://reviews.llvm.org/D21692

llvm-svn: 274644
2016-07-06 17:44:03 +00:00
Balaram Makam d4acd7ed10 Revert r259387: "AArch64: Implement missed conditional compare sequences."
This reverts commit r259387 because it inserts illegal code after legalization
    in some backends where i64 OR type is illegal for example.

llvm-svn: 274573
2016-07-05 20:24:05 +00:00
Matt Arsenault 2d79389508 DAGCombiner: Fold away vector extract of insert with the same index
This only really matters when the index is non-constant since the
constant case already gets taken care of by other combines.

llvm-svn: 274569
2016-07-05 18:25:02 +00:00
Craig Topper d1eca0f32c [CodeGen] Teach OR combine of shuffles involving zero vectors to better handle undef indices.
Undef indices can now be treated as zeros. Or if its undef ORed with zero, we will keep the undef.

llvm-svn: 274472
2016-07-03 19:37:12 +00:00
Craig Topper 2bd8b4b180 [CodeGen,Target] Remove the version of DAG.getVectorShuffle that takes a pointer to a mask array. Convert all callers to use the ArrayRef version. No functional change intended.
For the most part this simplifies all callers. There were two places in X86 that needed an explicit makeArrayRef to shorten a statically sized array.

llvm-svn: 274337
2016-07-01 06:54:47 +00:00
Craig Topper 3a011de10c [DAGCombine] Teach DAG combine to handle ORs of shuffles involving zero vectors where the zero vector is the first operand to the shuffle instead of the second.
llvm-svn: 274097
2016-06-29 03:29:12 +00:00
Matt Arsenault f0f721a682 DAGCombiner: Don't narrow volatile vector loads + extract
llvm-svn: 273909
2016-06-27 19:31:04 +00:00
Craig Topper 9c809bee1c [SelectionDAG] Use DAG.getCommutedVectorShuffle instead of reimplementing it.
llvm-svn: 273802
2016-06-26 05:10:49 +00:00
Nirav Dave bfdb483755 Preserve DebugInfo when replacing values in DAGCombiner
Recommiting after correcting over-eager Debug Value transfer fixing PR28270.

[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 273585
2016-06-23 17:52:57 +00:00
Peter Collingbourne 6717803485 Revert r273456, "Preserve DebugInfo when replacing values in DAGCombiner" as it caused pr28270.
llvm-svn: 273518
2016-06-23 00:06:17 +00:00
Nirav Dave 96beb7dee5 Preserve DebugInfo when replacing values in DAGCombiner
Recommiting after fixing over-aggressive assertion

[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 273456
2016-06-22 19:03:26 +00:00
David Majnemer e61e4bfd87 Replace silly uses of 'signed' with 'int'
llvm-svn: 273244
2016-06-21 05:10:24 +00:00
Sanjay Patel f664f3a578 [DAG] Remove redundant FMUL in Newton-Raphson SQRT code
When calculating a square root using Newton-Raphson with two constants,
a naive implementation is to use five multiplications (four muls to calculate
reciprocal square root and another one to calculate the square root itself).
However, after some reassociation and CSE the same result can be obtained
with only four multiplications. Unfortunately, there's no reliable way to do
such a reassociation in the back-end. So, the patch modifies NR code itself
so that it directly builds optimal code for SQRT and doesn't rely on any
further reassociation.

Patch by Nikolai Bozhenov!

Differential Revision: http://reviews.llvm.org/D21127

llvm-svn: 272920
2016-06-16 16:58:54 +00:00
Nirav Dave 194cb55f37 Revert "Preserve DebugInfo when replacing values in DAGCombiner"
Reverting due to assertion failure in
lib/CodeGen/SelectionDAG/InstrEmitter.cpp

This reverts commit r272792.

llvm-svn: 272799
2016-06-15 16:08:50 +00:00
Nirav Dave a72e308403 Preserve DebugInfo when replacing values in DAGCombiner
[DAG] Previously debug values would transfer debuginfo for the selected
start node for a replacement which allows for debug to be dropped.

Push debug value transfer to occur with node/value replacement in
SelectionDAG, remove now extraneous transfers of debug values.

This refixes PR9817 which was being incompletely checked in the
testsuite.

Reviewers: jyknight

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D21037

llvm-svn: 272792
2016-06-15 14:50:08 +00:00
Benjamin Kramer bdc4956bac Pass DebugLoc and SDLoc by const ref.
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
2016-06-12 15:39:02 +00:00
Benjamin Kramer 46e38f3678 Avoid copies of std::strings and APInt/APFloats where we only read from it
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.

llvm-svn: 272126
2016-06-08 10:01:20 +00:00
Sanjay Patel dba8b4c04d transform obscured FP sign bit ops into a fabs/fneg using TLI hook
This is effectively a revert of:
http://reviews.llvm.org/rL249702 - [InstCombine] transform masking off of an FP sign bit into a fabs() intrinsic call (PR24886)
and:
http://reviews.llvm.org/rL249701 - [ValueTracking] teach computeKnownBits that a fabs() clears sign bits
and a reimplementation as a DAG combine for targets that have IEEE754-compliant fabs/fneg instructions.

This is intended to resolve the objections raised on the dev list:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098154.html
and:
https://llvm.org/bugs/show_bug.cgi?id=24886#c4

In the interest of patch minimalism, I've only partly enabled AArch64. PowerPC, MIPS, x86 and others can enable later.

Differential Revision: http://reviews.llvm.org/D19391

llvm-svn: 271573
2016-06-02 20:01:37 +00:00
Sanjay Patel f509d85a6d [DAG] use getBitcast() to reduce code
Although this was intended to be NFC, the test case wiggle shows a change in
code scheduling/RA caused by a difference in the SDLoc() generation.

Depending on how you look at it, this is the (dis)advantage of exact checking
in regression tests.

llvm-svn: 271526
2016-06-02 16:01:15 +00:00
Matt Arsenault 5d06439c54 DAGCombiner: Fix broken size check in isAlias
This should have been converting the size to bytes, but wasn't really.
These should probably all be using getStoreSize instead.

I haven't been able to come up with a meaningful testcase for this.
I can trigger it using combinations of struct loads and stores,
but can't observe a difference in non-broken testcases.

isAlias is only really used during store merging, so I'm not sure how
to get into the vector splitting situation the comment describes
since store merging is only done before type legalization.

llvm-svn: 271356
2016-06-01 01:00:36 +00:00
Michael Kuperstein a75c77b127 [X86] Detect SAD patterns and emit psadbw instructions.
This recommits r267649 with a fix for PR27539.

Differential Revision: http://reviews.llvm.org/D20598

llvm-svn: 271033
2016-05-27 18:53:22 +00:00
Simon Pilgrim 0a6b95a60a Simplify std::all_of predicate (to one line) by using llvm::all_of. NFCI.
llvm-svn: 270747
2016-05-25 20:13:39 +00:00
Sanjay Patel b2bcd95aab reduce indentation; NFCI
llvm-svn: 270007
2016-05-19 00:33:07 +00:00
Simon Pilgrim ed39d150f5 Fix unused variable warning.
llvm-svn: 268867
2016-05-07 20:19:59 +00:00
Simon Pilgrim b6f82c449a [SelectionDAG] Added bitreverse(bitreverse(v)) --> v
Added bitreverse creation testing

llvm-svn: 268865
2016-05-07 20:12:36 +00:00
Matt Arsenault ab2232cf73 DAGCombiner: Reduce truncated shl width
llvm-svn: 268094
2016-04-29 19:53:16 +00:00
Gerolf Hoflehner 50426191d7 [DAGCombiner] Follow coding convention for function name (NFC)
llvm-svn: 267745
2016-04-27 17:27:16 +00:00
Nico Weber e69b9548b8 Revert r267649, it caused PR27539.
llvm-svn: 267723
2016-04-27 15:16:54 +00:00
Cong Hou 6f879d9eb1 Detects the SAD pattern on X86 so that much better code will be emitted once the pattern is matched.
Differential revision: http://reviews.llvm.org/D14840

llvm-svn: 267649
2016-04-27 01:29:18 +00:00
Ahmed Bougacha 128f8732a5 [CodeGen] Add getBuildVector and getSplatBuildVector helpers. NFCI.
Differential Revision: http://reviews.llvm.org/D17176

llvm-svn: 267606
2016-04-26 21:15:30 +00:00
Marcin Koscielnicki 1c1af6ef77 [PR27390] [CodeGen] Reject indexed loads in CombinerDAG.
visitAND, when folding and (load) forgets to check which output of
an indexed load is involved, happily folding the updated address
output on the following testcase:

target datalayout = "e-m:e-i64:64-n32:64"
target triple = "powerpc64le-unknown-linux-gnu"

%typ = type { i32, i32 }

define signext i32 @_Z8access_pP1Tc(%typ* %p, i8 zeroext %type) {
  %b = getelementptr inbounds %typ, %typ* %p, i64 0, i32 1
  %1 = load i32, i32* %b, align 4
  %2 = ptrtoint i32* %b to i64
  %3 = and i64 %2, -35184372088833
  %4 = inttoptr i64 %3 to i32*
  %_msld = load i32, i32* %4, align 4
  %zzz = add i32 %1,  %_msld
  ret i32 %zzz
}

Fix this by checking ResNo.

I've found a few more places that currently neglect to check for
indexed load, and tightened them up as well, but I don't have test
cases for them.  In fact, they might not be triggerable at all,
at least with current targets.  Still, better safe than sorry.

Differential Revision: http://reviews.llvm.org/D19202

llvm-svn: 267420
2016-04-25 15:43:44 +00:00
Gerolf Hoflehner 01b3a6184a [MachineCombiner] Support for floating-point FMA on ARM64 (re-commit r267098)
The original patch caused crashes because it could derefence a null pointer
for SelectionDAGTargetInfo for targets that do not define it.

Evaluates fmul+fadd -> fmadd combines and similar code sequences in the
machine combiner. It adds support for float and double similar to the existing
integer implementation. The key features are:

- DAGCombiner checks whether it should combine greedily or let the machine
combiner do the evaluation. This is only supported on ARM64.
- It gives preference to throughput over latency: the heuristic used is
to combine always in loops. The targets decides whether the machine
combiner should optimize for throughput or latency.
- Supports for fmadd, f(n)msub, fmla, fmls patterns
- On by default at O3 ffast-math

llvm-svn: 267328
2016-04-24 05:14:01 +00:00
Craig Topper 36c133159a [CodeGen] Teach DAG combine to fold select_cc seteq X, 0, sizeof(X), ctlz_zero_undef(X) -> ctlz(X). InstCombine already does this for IR and X86 pattern matches this during isel.
A follow up commit will remove the X86 patterns to allow this to be tested.

llvm-svn: 267325
2016-04-24 04:38:32 +00:00
Matt Arsenault 3b748d76f6 DAGCombiner: Relax alignment restriction when changing store type
If the target allows the alignment, this should be OK.

llvm-svn: 267217
2016-04-22 21:01:41 +00:00
Matt Arsenault 629d12de70 DAGCombiner: Relax alignment restriction when changing load type
If the target allows the alignment, this should still be OK.

llvm-svn: 267209
2016-04-22 20:21:36 +00:00
Daniel Sanders 591c379563 Revert r267098 - [MachineCombiner] Support for floating-point FMA on ARM64
It introduced buildbot failures on clang-cmake-mips, clang-ppc64le-linux, among others.

llvm-svn: 267127
2016-04-22 09:37:26 +00:00
Gerolf Hoflehner b32f11fc62 [MachineCombiner] Support for floating-point FMA on ARM64
Evaluates fmul+fadd -> fmadd combines and similar code sequences in the
machine combiner. It adds support for float and double similar to the existing
integer implementation. The key features are:

- DAGCombiner checks whether it should combine greedily or let the machine
combiner do the evaluation. This is only supported on ARM64.
- It gives preference to throughput over latency: the heuristic used is
to combine always in loops. The targets decides whether the machine
combiner should optimize for throughput or latency.
- Supports for fmadd, f(n)msub, fmla, fmls patterns
- On by default at O3 ffast-math

llvm-svn: 267098
2016-04-22 02:15:19 +00:00
Matt Arsenault 8d1052f55c DAGCombiner: Reduce 64-bit BFE pattern to pattern on 32-bit component
If the extracted bits are restricted to the upper half or lower half,
this can be truncated.

llvm-svn: 267024
2016-04-21 18:03:06 +00:00
Nirav Dave 2477491a92 Cleanup Store Merging in UseAA case
This patch fixes a bug (PR26827) when using anti-aliasing in store
merging. This sets the chain users of the component stores to point to
the new store instead of the component stores chain parent.

Reviewers: jyknight

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18909

llvm-svn: 266217
2016-04-13 17:27:26 +00:00
Simon Pilgrim 82e54871d0 [DAGCombiner] Fold xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B)) anytime before LegalizeVectorOprs
xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B)) was only being combined at the AfterLegalizeTypes stage, this patch permits the combine to occur anytime before then as well.

The main aim with this to improve the ability to recognise bitmasks that can be converted to shuffles.

I had to modify a number of AVX512 mask tests as the basic bitcast to/from scalar pattern was being stripped out, preventing testing of the mmask bitops. By replacing the bitcasts with loads we can get almost the same result.

Differential Revision: http://reviews.llvm.org/D18944

llvm-svn: 265998
2016-04-11 21:10:33 +00:00
Nirav Dave 66f485f4e2 Fix Load Control Dependence in MemCpy Generation
In Memcpy lowering we had missed a dependence from the load of the
operation to successor operations. This causes us to potentially
construct an in initial DAG with a memory dependence not fully
represented in the chain sub-DAG but rather require looking at the
entire DAG breaking alias analysis by allowing incorrect repositioning
of memory operations.

To work around this, r200033 changed DAGCombiner::GatherAllAliases to be
conservative if any possible issues to happen. Unfortunately this check
forbade many non-problematic situations as well. For example, it's
common for incoming argument lowering to add a non-aliasing load hanging
off of EntryNode. Then, if GatherAllAliases visited EntryNode, it would
find that other (unvisited) use of the EntryNode chain, and just give up
entirely. Furthermore, the check was incomplete: it would not actually
detect all such potentially problematic DAG constructions, because
GatherAllAliases did not guarantee to visit all chain nodes going up to
the root EntryNode. This is in general fine -- giving up early will just
miss a potential optimization, not generate incorrect results. But, for
this non-chain dependency detection code, it's possible that you could
have a load attached to a higher-up chain node than any which were
visited. If that load aliases your store, but the only dependency is
through the value operand of a non-aliasing store, it would've been
missed by this code, and potentially reordered.

With the dependence added, this check can be removed and Alias Analysis
can be much more aggressive. This fixes code quality regression in the
Consecutive Store Merge cleanup (D14834).

Test Change:

ppc64-align-long-double.ll now may see multiple serializations
of its stores

Differential Revision: http://reviews.llvm.org/D18062

llvm-svn: 265836
2016-04-08 19:44:40 +00:00
Sanjay Patel 769b5fd546 fix typos; NFC
llvm-svn: 265356
2016-04-04 22:45:56 +00:00