Commit Graph

24541 Commits

Author SHA1 Message Date
Mikael Holmen 42f7bc96dd [DebugInfo] Make sure all DBG_VALUEs' reguse operands have IsDebug property
Summary:
In some cases, these operands lacked the IsDebug property, which is meant to signal that
they should not affect codegen. This patch adds a check for this property in the
MachineVerifier and adds it where it was missing.

This includes refactorings to use MachineInstrBuilder construction functions instead of
manually setting up the intrinsic everywhere.

Patch by: JesperAntonsson

Reviewers: aprantl, rnk, echristo, javed.absar

Reviewed By: aprantl

Subscribers: qcolombet, sdardis, nemanjai, JDevlieghere, atanasyan, llvm-commits

Differential Revision: https://reviews.llvm.org/D48319

llvm-svn: 335214
2018-06-21 10:03:34 +00:00
David Green a465188500 [DAGCombine] Fix alignment for offset loads/stores
The alignment parameter to getExtLoad is treated as a base alignment,
not the alignment of the load (base + offset). When we infer a better
alignment for a Ptr we need to ensure that it applies to the base to
prevent the alignment on the load from being wrong.

This fixes a bug where the alignment could then be used to incorrectly
prove noalias between a load and a store, leading to a miscompile.

Differential Revision: https://reviews.llvm.org/D48029

llvm-svn: 335210
2018-06-21 08:30:07 +00:00
Eric Christopher 76cfef46f3 Add some explanatory text to the associated symbol support.
llvm-svn: 335207
2018-06-21 07:15:14 +00:00
Mikael Holmen 57b33f6aac [DebugInfo] Keep DBG_VALUE undef in LiveDebugVariables
Summary:
Fixes PR36579.

For cases where we had e.g.

 DBG_VALUE 42
 [...]
 DBG_VALUE undef

LiveDebugVariables would discard all undef DBG_VALUEs and then it would
look like the variable had the value 42 throughout the rest of the
function, which is incorrect.

With this patch we don't remove all undef DBG_VALUEs in LiveDebugVariables
so they will be kept after register allocation just like other DBG_VALUEs
which will yield more correct debug information.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: bjope, Ka-Ka, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D48277

llvm-svn: 335205
2018-06-21 07:02:46 +00:00
Alina Sbirlea dfd14adeb0 Generalize MergeBlockIntoPredecessor. Replace uses of MergeBasicBlockIntoOnlyPred.
Summary:
Two utils methods have essentially the same functionality. This is an attempt to merge them into one.
1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred
2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor

Prior to the patch:
1. MergeBasicBlockIntoOnlyPred
Updates either DomTree or DeferredDominance
Moves all instructions from Pred to BB, deletes Pred
Asserts BB has single predecessor
If address was taken, replace the block address with constant 1 (?)

2. MergeBlockIntoPredecessor
Updates DomTree, LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken

After the patch:
Method 2. MergeBlockIntoPredecessor is attempting to become the new default:
Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken

Uses of MergeBasicBlockIntoOnlyPred that need to be replaced:

1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp
Updated in this patch. No challenges.

2. lib/CodeGen/CodeGenPrepare.cpp
Updated in this patch.
  i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation.
  ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks
Some interesting aspects:
  - Since Pred is not deleted (BB is), the entry block does not need updating.
  - The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred.
  - isMergingEmptyBlockProfitable assumes BB is the one to be deleted.
  - eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead.
  - adding some test owner as subscribers for the interesting tests modified:
    test/CodeGen/X86/avx-cmp.ll
    test/CodeGen/AMDGPU/nested-loop-conditions.ll
    test/CodeGen/AMDGPU/si-annotate-cf.ll
    test/CodeGen/X86/hoist-spill.ll
    test/CodeGen/X86/2006-11-17-IllegalMove.ll

3. lib/Transforms/Scalar/JumpThreading.cpp
Not covered in this patch. It is the only use case using the DeferredDominance.
I would defer to Brian Rzycki to make this replacement.

Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar

Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits

Differential Revision: https://reviews.llvm.org/D48202

llvm-svn: 335183
2018-06-20 22:01:04 +00:00
Stanislav Mekhanoshin 20279dc025 Allow binop C1, (select cc, CF, CT) -> select folding
Previously this folding was done only if select is a first operand.
However, for non-commutative operations constant may go before
select.

Differential Revision: https://reviews.llvm.org/D48223

llvm-svn: 335167
2018-06-20 20:24:20 +00:00
Bjorn Pettersson 7bf676662a [DAG] Don't map a TableId to itself in the ReplacedValues map
Summary:
Found some regressions (infinite loop in DAGTypeLegalizer::RemapId)
after r334880. This patch makes sure that we do map a TableId to
itself.

Reviewers: niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48364

llvm-svn: 335141
2018-06-20 16:06:09 +00:00
Nirav Dave cd558887d3 [DAG] Fix and-mask folding when narrowing loads.
Summary:
Check that and masks are strictly smaller than implicit mask from
narrowed load.

Fixes PR37820.

Reviewers: samparker, RKSimon, nemanjai

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48335

llvm-svn: 335137
2018-06-20 15:36:29 +00:00
Hiroshi Inoue c73b6d6bf7 [NFC] fix trivial typos in comments
llvm-svn: 335096
2018-06-20 05:29:26 +00:00
Craig Topper ddd88a559f [DAGCombiner] Add some comments to some true/false arguments to make it obvious what they are. NFC
llvm-svn: 335095
2018-06-20 04:32:07 +00:00
Craig Topper 59da74370b [SelectionDAG] Don't crash on inline assembly errors when the inline assembly return type is a struct.
Summary:
If we get an error building the SelectionDAG for inline assembly we try to continue and still build the DAG.

But if the return type for the inline assembly is a struct we end up crashing because we try to create an UNDEF node with a struct type which isn't valid.

Instead we need to create an UNDEF for each element of the struct and join them with merge_values.

This patch relies on single operand merge_values being handled gracefully by getMergeValues. If the return type is void there will be no VTs returned by ComputeValueVTs and now we just return instead of calling setValue. Hopefully that's ok, I assumed nothing would need to look up the mapped value for void node.

Fixes PR37359

Reviewers: rengolin, rovka, echristo, efriedma, bogner

Reviewed By: efriedma

Subscribers: craig.topper, llvm-commits

Differential Revision: https://reviews.llvm.org/D46560

llvm-svn: 335093
2018-06-20 04:32:05 +00:00
Philip Reames 8befa295ea [InlineSpiller] Fix a crash due to lack of forward progress from remat specifically for STATEPOINT
This patch covers up a fairly fundemental issue around remat and register allocation which shows up with psuedo instructions with more vreg uses than there are physical registers.  This patch essentially just disables remat for STATEPOINTs which are the only case we've seen so far, but long term we need a better fix.

For STATEPOINTs specifically, this is a strict improvement.  It unblocks progress towards enabling a currently off-by-default mode which integrates deopt bundle operand lowering with register allocator spilling so that we end up with smaller stack sizes and more optimally placed spills.  Assming no other issues turn up during my next round of integration testing - which based on experience so far, is admittedly unlikely - we might finally be able to enable something I've been working towards in small bits and pieces for years now.  :)

For psuedo ops in general, there are a couple of ideas for a "proper fix" discussed on the bug, but I'm far enough outside my knowledge area to not be able to see any of them through to a successful conclusion.  If anyone wants to help out here, please do.  

Differential Revision: https://reviews.llvm.org/D41098

llvm-svn: 335077
2018-06-19 21:19:59 +00:00
Jessica Paquette 32de26d432 [MachineOutliner] NFC: Remove insertOutlinerPrologue, rename insertOutlinerEpilogue
insertOutlinerPrologue was not used by any target, and prologue-esque code was
beginning to appear in insertOutlinerEpilogue. Refactor that into one function,
buildOutlinedFrame.

This just removes insertOutlinerPrologue and renames insertOutlinerEpilogue.

llvm-svn: 335076
2018-06-19 21:14:48 +00:00
Matt Davis a245c765a8 [MIRParser] Update a diagnostic message to use the correct register sigil. NFC
Summary:
Patch r323922 changed the sigil for physical registers to '$',  instead of '%'.
An error message was missed during this change, and reports the wrong sigil.
This patch corrects that diagnostic and the tests that check that error string.


Reviewers: zer0, bjope

Reviewed By: bjope

Subscribers: bjope, thegameg, plotfi, llvm-commits

Differential Revision: https://reviews.llvm.org/D48086

llvm-svn: 335066
2018-06-19 18:39:40 +00:00
Heejin Ahn 33c3fce592 [WebAssembly] Add WasmEHFuncInfo for unwind destination information
Summary:
Add WasmEHFuncInfo and routines to calculate and fill in this struct to
keep track of unwind destination information. This will be used in
other EH related passes.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, chrib, llvm-commits

Differential Revision: https://reviews.llvm.org/D48263

llvm-svn: 335005
2018-06-19 00:26:39 +00:00
Michael Berg 7b993d762f Utilize new SDNode flag functionality to expand current support for fadd
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.

Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar

Reviewed By: spatel

Subscribers: wdng, nhaehnle

Differential Revision: https://reviews.llvm.org/D47909

llvm-svn: 334996
2018-06-18 23:44:59 +00:00
Michael Berg 932ba20af8 refactor of visitFADD for AllowNewConst cases
Summary: Refactoring for all constant cases which require AllowNewConst and some staging for future fmf usage.

Reviewers: spatel, hfinkel, wristow

Reviewed By: spatel

Subscribers: nhaehnle

Differential Revision: https://reviews.llvm.org/D48289

llvm-svn: 334984
2018-06-18 21:12:21 +00:00
Michael Berg cafe947445 [NFC] make MIFlag accessor functions consistant with usage model
llvm-svn: 334970
2018-06-18 18:37:48 +00:00
Krzysztof Parzyszek 546017322f Shrink interval after moving copy in removePartialRedundancy
llvm-svn: 334963
2018-06-18 17:16:39 +00:00
Nirav Dave d4ff2f8a74 Avoid needing to walk out legalization tables. NFCI.
Relanding after fixing expensive check from modifying tables.

To avoid redundant work, during DAG legalization we keep tables
mapping pre-legalized SDValues to post-legalized SDValues and a
SDValue-to-SDValue map to enable fast node replacements. However, as
the keys are nodes which may be reused it is possible that an entry in
a table refers to a now deleted node N (that should have been renamed
by the value replacement map) while a new node N' exists. If N' is
then replaced that entry would be wrong. Previously we avoided this by
when potentially violating this property, walking every table and
updating all node pointers. This is very expensive but hopefully rare
occurance.

This patch assigns each instance of a SDValue used in legalization a
unique id and uses these ids in the legalization tables. This avoids
any such aliasing issue, avoiding the full table search and allowing
more aggressive incremental table pruning.

In some cases this is a 1000x speedup to compilation.

Reviewers: jyknight, echristo, bogner, tra

Reviewed By: bogner

Subscribers: dberris, grandinj, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47959

llvm-svn: 334880
2018-06-16 02:51:29 +00:00
Michael Berg 8e570c3390 Utilize new SDNode flag functionality to expand current support for fma
Summary: This patch originated from D47388 and is a proper subset of the originating changes, containing only the fmf optimization guard extensions.

Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar, rampitec, nhaehnle, nemanjai

Reviewed By: rampitec, nhaehnle

Subscribers: tpr, nemanjai, wdng

Differential Revision: https://reviews.llvm.org/D47918

llvm-svn: 334876
2018-06-16 00:03:06 +00:00
Francis Visoiu Mistrih dc705a6a89 Revert r334729 "[DAG] Avoid needing to walk out legalization tables. NFCI."
This reverts commit r334729.

llvm-svn: 334869
2018-06-15 23:05:41 +00:00
Francis Visoiu Mistrih 1c9df30eca Revert r334731 "Avoid unused variable in non-assert builds."
This reverts commit r334731.

It breaks EXPENSIVE_CHECKS bots.

llvm-svn: 334868
2018-06-15 23:05:40 +00:00
Cameron McInally 7caac670b2 [FPEnv] Expand constrained FP POWI
Modify ExpandStrictFPOp(...) to handle nodes that have scalar
operands. 

Also, add a Strict FMA test and do some other light cleanup in the
Strict FP code.

Differential Revision: https://reviews.llvm.org/D48149

llvm-svn: 334863
2018-06-15 20:57:55 +00:00
Michael Berg 02d1c6c0cf Utilize new SDNode flag functionality to expand current support for fdiv
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: wdng, nhaehnle

Differential Revision: https://reviews.llvm.org/D47954

llvm-svn: 334862
2018-06-15 20:44:55 +00:00
Krzysztof Parzyszek 1a70426ac1 Remove <undef> from rematerialized full register
When coalescing a small register into a subregister of a larger register,
if the larger register is rematerialized, the function updateRegDefUses
can add an <undef> flag to the rematerialized definition (since it's
treating it as only definining the coalesced subregister). While with that
assumption doing so is not incorrect, make sure to remove the flag later
on after the call to updateRegDefUses.

llvm-svn: 334845
2018-06-15 16:58:22 +00:00
Matt Arsenault df2f4ef29d DAG: Fix creating concat_vectors with illegal type
Test passes as is, but fails with future patch to make v4i16/v4f16
legal.

llvm-svn: 334823
2018-06-15 12:09:15 +00:00
Michael Berg 0c20447a02 easing the constraint for isNegatibleForFree and GetNegatedExpression
Summary:
Here we relax the old constraint which utilized unsafe with the TargetOption flag HonorSignDependentRoundingFPMathOption, with the assertion that unsafe is no longer needed or never was required for correctness on FDIV/FMUL.  



Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar

Reviewed By: spatel

Subscribers: efriedma, wdng, tpr

Differential Revision: https://reviews.llvm.org/D48057

llvm-svn: 334769
2018-06-14 20:54:13 +00:00
Justin Bogner 3b83edb037 Re-apply "[VirtRegRewriter] Avoid clobbering registers when expanding copy bundles"
This is r334750 (which was reverted in r334754) with a fix for an
uninitialized variable that was caught by msan.

Original commit message:
> If a copy bundle happens to involve overlapping registers, we can end
> up with emitting the copies in an order that ends up clobbering some
> of the subregisters. Since instructions in the copy bundle
> semantically happen at the same time, this is incorrect and we need to
> make sure we order the copies such that this doesn't happen.

llvm-svn: 334756
2018-06-14 19:24:03 +00:00
Justin Bogner 36c7f40f20 Revert "[VirtRegRewriter] Avoid clobbering registers when expanding copy bundles"
There's an msan failure:

  http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/19549

This reverts r334750.

llvm-svn: 334754
2018-06-14 19:10:57 +00:00
Michael Berg 4663ceb63f updating isNegatibleForFree and GetNegatedExpression with fmf for fadd
Summary:  A FMF constraint is added to FADD with unsafe still available as the fallback

Reviewers: spatel, wristow, arsenm, hfinkel

Reviewed By: spatel

Subscribers: wdng

Differential Revision: https://reviews.llvm.org/D48180

llvm-svn: 334753
2018-06-14 18:48:31 +00:00
Sam Clegg 277f898a4d [WebAssembly] Ignore explicit section names for functions
WebAssembly doesn't support more than one function per section
and we rely on function sections being unique. This change ignores
the section provided by the function to avoid two functions being
in the same section.

Without this change the object writer produces the following
error for this test:
 LLVM ERROR: section already has a defining function: baz

Differential Revision: https://reviews.llvm.org/D48178

llvm-svn: 334752
2018-06-14 18:48:19 +00:00
Justin Bogner 866d9f02be [VirtRegRewriter] Avoid clobbering registers when expanding copy bundles
If a copy bundle happens to involve overlapping registers, we can end
up with emitting the copies in an order that ends up clobbering some
of the subregisters. Since instructions in the copy bundle
semantically happen at the same time, this is incorrect and we need to
make sure we order the copies such that this doesn't happen.

Differential Revision: https://reviews.llvm.org/D48154

llvm-svn: 334750
2018-06-14 18:32:55 +00:00
Nirav Dave 41e69a8e8b Avoid unused variable in non-assert builds.
llvm-svn: 334731
2018-06-14 15:55:15 +00:00
Nirav Dave a1ee983a95 [DAG] Avoid needing to walk out legalization tables. NFCI.
To avoid redundant work, during DAG legalization we keep tables
mapping pre-legalized SDValues to post-legalized SDValues and a
SDValue-to-SDValue map to enable fast node replacements. However, as
the keys are nodes which may be reused it is possible that an entry in
a table refers to a now deleted node N (that should have been renamed
by the value replacement map) while a new node N' exists. If N' is
then replaced that entry would be wrong. Previously we avoided this by
when potentially violating this property, walking every table and
updating all node pointers. This is very expensive but hopefully rare
occurance.

This patch assigns each instance of a SDValue used in legalization a
unique id and uses these ids in the legalization tables. This avoids
any such aliasing issue, avoiding the full table search and allowing
more aggressive incremental table pruning.

In some cases this is a 1000x speedup to compilation.

Reviewers: jyknight, echristo, bogner, tra

Reviewed By: bogner

Subscribers: dberris, grandinj, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47959

llvm-svn: 334729
2018-06-14 15:46:23 +00:00
Sanjay Patel 7d4929611c [DAGCombiner] remove hasOneUse() check from fadd constants transform
We're constant folding here, so we shouldn't check uses. This matches
the IR optimizer behavior.

The x86 test shows the expected win. The AArch64 test shows something
else. This only seems to happen if the "generic" AArch64 CPU model is 
used by MachineCombiner, so I'll file a bug report to follow-up.

llvm-svn: 334608
2018-06-13 15:22:48 +00:00
Cameron McInally f37bd01ddc [FPEnv] Expand constrained FP operations
Add a helper function to expand constrained FP operations as needed. 
Note that the Strict POWI operation is not handled in this patch since 
the format is slightly different from the others.

Differential Revision: https://reviews.llvm.org/D47491

llvm-svn: 334603
2018-06-13 14:32:12 +00:00
Krzysztof Parzyszek 3e039f86cc Revert "Improve handling of COPY instructions with identical value numbers"
This reverts r334594, it breaks buildbots and fails with expensive checks.

llvm-svn: 334598
2018-06-13 13:49:06 +00:00
Krzysztof Parzyszek 36b816f814 Improve handling of COPY instructions with identical value numbers
Differential Revision: https://reviews.llvm.org/D48102

llvm-svn: 334594
2018-06-13 12:47:17 +00:00
Krzysztof Parzyszek 82d284c1d2 [DAGCombiner] Recognize more patterns for ABS
Differential Revision: https://reviews.llvm.org/D47831

llvm-svn: 334553
2018-06-12 21:51:49 +00:00
Reid Kleckner 98117a47e6 [MS][ARM64] Hoist __ImageBase handling into TargetLoweringObjectFileCOFF
All COFF targets should use @IMGREL32 relocations for symbol differences
against __ImageBase. Do the same for getSectionForConstant, so that
immediates lowered to globals get merged across TUs.

Patch by Chris January

Differential Revision: https://reviews.llvm.org/D47783

llvm-svn: 334523
2018-06-12 18:56:05 +00:00
Roman Tereshin b2d3f2e5da [MIR][MachineCSE] Implementing proper MachineInstr::getNumExplicitDefs()
Apparently, MachineInstr class definition as well as pretty much all of
the machine passes assume that the only kind of MachineInstr's operands
that is variadic for variadic opcodes is explicit non-definitions.

In particular, this assumption is made by MachineInstr::defs(), uses(),
and explicit_uses() methods, as well as by MachineCSE pass.

The assumption is incorrect judging from at least TableGen backend
implementation, that recognizes variable_ops in OutOperandList, and the
very existence of G_UNMERGE_VALUES generic opcode, or ARM load multiple
instructions, all of which have variadic defs.

In particular, MachineCSE pass breaks MIR with CSE'able G_UNMERGE_VALUES
instructions in it.

This commit implements MachineInstr::getNumExplicitDefs() similar to
pre-existing MachineInstr::getNumExplicitOperands(), fixes
MachineInstr::defs(), uses(), and explicit_uses(), and fixes MachineCSE
pass.

As the issue addressed seems to affect only machine passes that could be
ran mid-GlobalISel pipeline at the moment, the other passes aren't fixed
by this commit, like MachineLICM: that could be done on per-pass basis
when (if ever) they get adopted for GlobalISel.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D45640

llvm-svn: 334520
2018-06-12 18:30:37 +00:00
Michael Berg 5d49f66570 Utilize new SDNode flag functionality to expand current support for fmul
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed for fmul.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: nhaehnle, wdng

Differential Revision: https://reviews.llvm.org/D47911

llvm-svn: 334514
2018-06-12 16:13:11 +00:00
Krzysztof Parzyszek 3d671248ab [SelectionDAG] Provide default expansion for rotates
Implement default legalization of rotates: either in terms of the rotation
in the opposite direction (if legal), or in terms of shifts and ors.

Implement generating of rotate instructions for Hexagon. Hexagon only
supports rotates by an immediate value, so implement custom lowering of
ROTL/ROTR on Hexagon. If a rotate is not legal, use the default expansion.

Differential Revision: https://reviews.llvm.org/D47725

llvm-svn: 334497
2018-06-12 12:49:36 +00:00
Matt Arsenault 5615fa0a87 DAG: Fix extract_subvector combine for a single element
This would fail before because 1x vectors aren't legal,
so instead just use the scalar type.

Avoids regressions in a future AMDGPU commit to add
v4i16/v4f16 as legal types.

Test update is just the one test that this triggers
on in tree now. It wasn't checking anything before.
The result is completely  changed since the selects
are eliminated. Not sure if it's considered better
or not.

llvm-svn: 334440
2018-06-11 21:27:41 +00:00
Brock Wyma b60532f89a [CodeView] Omit forward references for unnamed structs and unions
Codeview references to unnamed structs and unions are expected to refer to the
complete type definition instead of a forward reference so Visual Studio can
resolve the type properly.

Differential Revision: https://reviews.llvm.org/D32498

llvm-svn: 334382
2018-06-11 01:39:34 +00:00
Sanjay Patel 3e5c70cc1d [DAGCombiner] match vector compare and select sizes with extload operand (PR37427)
This patch started off much more general and ambitious, but it's been a nightmare 
seeing all the ways x86 vector codegen can go wrong.

So the code is still structured to allow extending easily, but it's currently 
limited in several ways:

1. Only handle cases with an extending load.
2. Only handle cases with a zero constant compare.
3. Ignore setcc with vector bitmask (SetCCWidth != 1) - so AVX512 should be unaffected.

The motivating case from PR37427:
https://bugs.llvm.org/show_bug.cgi?id=37427
...is the 1st test, and that shows the expected win - we eliminated the unnecessary 
intermediate cast.

There's a clear regression in the last test (sgt_zero_fp_select) because we longer 
recognize a 'SHRUNKBLEND' opportunity. I think that general problem is also present 
in sgt_zero, so I'll try to fix that in a follow-up. We need to match a sign-bit 
setcc from a sign-extended operand and remove it.

Differential Revision: https://reviews.llvm.org/D47330

llvm-svn: 334378
2018-06-10 23:09:50 +00:00
Craig Topper 61998289f9 Use SmallPtrSet instead of SmallSet in places where we iterate over the set.
SmallSet forwards to SmallPtrSet for pointer types. SmallPtrSet supports iteration, but a normal SmallSet doesn't. So if it wasn't for the forwarding, this wouldn't work.

These places were found by hiding the begin/end methods in the SmallSet forwarding

llvm-svn: 334343
2018-06-09 05:04:20 +00:00
Sanjay Patel 498564e6fb [DAGCombiner] clean up comments; NFC
llvm-svn: 334312
2018-06-08 18:00:46 +00:00
Michael Berg bf90d1f263 Utilize new SDNode flag functionality to expand current support for fsub
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed for fsub.

Reviewers: spatel, hfinkel, wristow, arsenm

Reviewed By: spatel

Subscribers: wdng

Differential Revision: https://reviews.llvm.org/D47910

llvm-svn: 334306
2018-06-08 17:39:50 +00:00