Commit Graph

968 Commits

Author SHA1 Message Date
Sanjay Patel 2f319420f9 [TargetLowering] refactor setcc folds to fix another miscompile (PR40657)
SimplifySetCC still has much room for improvement, but this should
fix the remaining problem examples from:
https://bugs.llvm.org/show_bug.cgi?id=40657

The initial fix for this problem was rL353615.

llvm-svn: 353639
2019-02-10 14:29:57 +00:00
Sanjay Patel 7467510453 [TargetLowering] add tests to show effect of setcc sub->shift; NFC
There's effectively no difference for the cases with variables.
We just trade a sub for an add on those. But the case with a
subtract from constant would require an extra move instruction
on x86, so this looks like a reasonable generic combine.

llvm-svn: 353619
2019-02-09 17:03:59 +00:00
Sanjay Patel 887ac1b38c [TargetLowering] avoid miscompile in setcc transform (PR40657)
llvm-svn: 353615
2019-02-09 15:59:02 +00:00
Nikita Popov 37bce93e36 Revert "[SelectionDAG] Extract [US]MULO expansion into TL method; NFC"
This reverts commit r353611.

Triggers an assertion during the libcall expansion on ARM.

llvm-svn: 353612
2019-02-09 13:54:02 +00:00
Nikita Popov 7de44ed945 [SelectionDAG] Extract [US]MULO expansion into TL method; NFC
In preparation for supporting vector expansion.

Also drop a variant of ExpandLibCall, of which the MULO expansions
were the only user.

llvm-svn: 353611
2019-02-09 13:29:22 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
Simon Pilgrim eb6a47a462 [TargetLowering] Use ISD::FSHR in expandFixedPointMul
Replace OR(SHL,SRL) pattern with ISD::FSHR (legalization expands this later if necessary) - this helps with the scale == 0 'undefined' drop-through case that was discussed on D55720.

llvm-svn: 353546
2019-02-08 18:57:38 +00:00
Simon Pilgrim 478bb90779 [TargetLowering] Add SimplifyDemandedBits funnel shift support
llvm-svn: 353539
2019-02-08 17:19:01 +00:00
Nirav Dave e5c37958f9 [InlineAsm][X86] Add backend support for X86 flag output parameters.
Allow custom handling of inline assembly output parameters and add X86
flag parameter support.

llvm-svn: 353307
2019-02-06 15:26:29 +00:00
Leonard Chan 68d428e578 [Intrinsic] Unsigned Fixed Point Multiplication Intrinsic
Add an intrinsic that takes 2 unsigned integers with the scale of them
provided as the third argument and performs fixed point multiplication on
them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D55625

llvm-svn: 353059
2019-02-04 17:18:11 +00:00
Sanjay Patel 0279b5b0b8 [TargetLowering] try harder to determine undef elements of vector binops
This might be the start of tracking all vector element constants generally if we take it to its 
logical conclusion, but let's stop here and make sure this is correct/beneficial so far.

The affected tests require a convoluted path before they get simplified currently because we 
don't call SimplifyDemandedVectorElts() from binops directly and don't modify the binop operands 
directly in SimplifyDemandedVectorElts().

That's why the tests all have a trailing shuffle to induce a chain reaction of transforms. So 
something like this is happening:

1. Improve the knowledge of undefs in the binop via a SimplifyDemandedVectorElts() call that 
   originates from a shuffle.
2. Transfer that undef knowledge back to the shuffle mask user as more undef lanes.
3. Combine the modified shuffle by calling SimplifyDemandedVectorElts() again.
4. Translate the improved shuffle mask as undemanded lanes of build vector constants causing 
   those to become full undef constants.
5. Simplify the binop now that it has a full undef operand.

As we can see from the unchanged 'and' and 'or' tests, tracking undefs alone isn't a full solution. 
We would need to track zero and all-ones constants to improve those opcodes. We'd probably need to 
track NaN for FP ops too (assuming we don't have fast-math-flags set).

Differential Revision: https://reviews.llvm.org/D57066

llvm-svn: 352880
2019-02-01 15:35:12 +00:00
Leonard Chan ae527ac603 [Intrinsic] Expand SMULFIX to MUL, MULH[US], or [US]MUL_LOHI on vector arguments
r zero scale SMULFIX, expand into MUL which produces better code for X86.

For vector arguments, expand into MUL if SMULFIX is provided with a zero scale.
Otherwise, expand into MULH[US] or [US]MUL_LOHI.

Differential Revision: https://reviews.llvm.org/D56987

llvm-svn: 352783
2019-01-31 19:15:37 +00:00
James Y Knight 5d71fc5d7b Adjust documentation for git migration.
This fixes most references to the paths:
 llvm.org/svn/
 llvm.org/git/
 llvm.org/viewvc/
 github.com/llvm-mirror/
 github.com/llvm-project/
 reviews.llvm.org/diffusion/

to instead point to https://github.com/llvm/llvm-project.

This is *not* a trivial substitution, because additionally, all the
checkout instructions had to be migrated to instruct users on how to
use the monorepo layout, setting LLVM_ENABLE_PROJECTS instead of
checking out various projects into various subdirectories.

I've attempted to not change any scripts here, only documentation. The
scripts will have to be addressed separately.

Additionally, I've deleted one document which appeared to be outdated
and unneeded:
  lldb/docs/building-with-debug-llvm.txt

Differential Revision: https://reviews.llvm.org/D57330

llvm-svn: 352514
2019-01-29 16:37:27 +00:00
Nikita Popov 8e1a464e6a [CodeGen][X86] Expand UADDSAT to NOT+UMIN+ADD
Followup to D56636, this time handling the UADDSAT case by expanding
uadd.sat(a, b) to umin(a, ~b) + b.

Differential Revision: https://reviews.llvm.org/D56869

llvm-svn: 352409
2019-01-28 19:19:09 +00:00
Simon Pilgrim 2f018de6a3 [TargetLowering] Rename getExpandedFixedPointMultiplication to expandFixedPointMul. NFCI.
Match the (much shorter) name used in various legalization methods.

llvm-svn: 352056
2019-01-24 15:46:54 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Nikita Popov d3b86b79fa Reapply "[CodeGen][X86] Expand USUBSAT to UMAX+SUB, also for vectors"
Related to https://bugs.llvm.org/show_bug.cgi?id=40123.

Rather than scalarizing, expand a vector USUBSAT into UMAX+SUB,
which produces much better code for X86.

Reapplying with updated SLPVectorizer tests.

Differential Revision: https://reviews.llvm.org/D56636

llvm-svn: 351219
2019-01-15 18:43:41 +00:00
Nikita Popov 5885eec35a Revert "[CodeGen][X86] Expand USUBSAT to UMAX+SUB, also for vectors"
This reverts commit r351125.

I missed test changes in an SLPVectorizer test, due to the cost model
changes. Reverting for now.

llvm-svn: 351129
2019-01-14 22:18:39 +00:00
Nikita Popov 8e9a8432a8 [CodeGen][X86] Expand USUBSAT to UMAX+SUB, also for vectors
Related to https://bugs.llvm.org/show_bug.cgi?id=40123.

Rather than scalarizing, expand a vector USUBSAT into UMAX+SUB,
which produces much better code for X86.

Differential Revision: https://reviews.llvm.org/D56636

llvm-svn: 351125
2019-01-14 21:43:30 +00:00
Nikita Popov 0400e50445 [X86] Rename overly verbose method; NFC
As suggested on D56636.

llvm-svn: 351021
2019-01-13 16:41:26 +00:00
Simon Pilgrim 0d92c4debc Use getShiftAmountTy for shift amounts.
llvm-svn: 351005
2019-01-12 12:00:43 +00:00
Simon Pilgrim ca0de0363b [X86][AARCH64] Improve ISD::ABS support
This patch takes some of the code from D49837 to allow us to enable ISD::ABS support for all SSE vector types.

Differential Revision: https://reviews.llvm.org/D56544

llvm-svn: 350998
2019-01-12 09:59:32 +00:00
Stanislav Mekhanoshin ed0d6c60af Remove check for single use in ShrinkDemandedConstant
This removes check for single use from general ShrinkDemandedConstant
to the BE because of the AArch64 regression after D56289/rL350475.

After several hours of experiments I did not come up with a testcase
failing on any other targets if check is not performed.

Moreover, direct call to ShrinkDemandedConstant is not really needed
and superceed by SimplifyDemandedBits.

Differential Revision: https://reviews.llvm.org/D56406

llvm-svn: 350684
2019-01-09 02:24:22 +00:00
Craig Topper 826f44b550 [TargetLowering][AMDGPU] Remove the SimplifyDemandedBits function that takes a User and OpIdx. Stop using it in AMDGPU target for simplifyI24.
As we saw in D56057 when we tried to use this function on X86, it's unsafe. It allows the operand node to have multiple users, but doesn't prevent recursing past the first node when it does have multiple users. This can cause other simplifications earlier in the graph without regard to what bits are needed by the other users of the first node. Ideally all we should do to the first node if it has multiple uses is bypass it when its not needed by the user we started from. Doing any other transformation that SimplifyDemandedBits can do like turning ZEXT/SEXT into AEXT would result in an increase in instructions.

Fortunately, we already have a function that can do just that, GetDemandedBits. It will only make transformations that involve bypassing a node.

This patch changes AMDGPU's simplifyI24, to use a combination of GetDemandedBits to handle the multiple use simplifications. And then uses the regular SimplifyDemandedBits on each operand to handle simplifications allowed when the operand only has a single use. Unfortunately, GetDemandedBits simplifies constants more aggressively than SimplifyDemandedBits. This caused the -7 constant in the changed test to be simplified to remove the upper bits. I had to modify computeKnownBits to account for this by ignoring the upper 8 bits of the input.

Differential Revision: https://reviews.llvm.org/D56087

llvm-svn: 350560
2019-01-07 19:30:43 +00:00
Stanislav Mekhanoshin 35a3a3bd11 Added single use check to ShrinkDemandedConstant
Fixes cvt_f32_ubyte combine. performCvtF32UByteNCombine() could shrink
source node to demanded bits only even if there are other uses.

Differential Revision: https://reviews.llvm.org/D56289

llvm-svn: 350475
2019-01-05 19:20:00 +00:00
Simon Pilgrim 911dce2f30 [SelectionDAG] Always use the version of computeKnownBits that returns a value. NFCI.
Continues the work started by @bogner in rL340594 to remove uses of the KnownBits output paramater version.

llvm-svn: 349907
2018-12-21 14:56:18 +00:00
Simon Pilgrim 6c95bea072 [TargetLowering] Fix propagation of undefs in zero extension ops (PR40091)
As described on PR40091, we have several places where zext (and zext_vector_inreg) fold an undef input into an undef output. For zero extensions this is incorrect as the output should guarantee to least have the new upper bits set to zero.

SimplifyDemandedVectorElts is the worst offender (and its the most likely to cause new undefs to appear) but DAGCombiner's tryToFoldExtendOfConstant has a similar issue.

Thanks to @dmgreen for catching this.

Differential Revision: https://reviews.llvm.org/D55883

llvm-svn: 349625
2018-12-19 13:37:59 +00:00
Simon Pilgrim af6fbbf18b [TargetLowering] Fallback from SimplifyDemandedVectorElts to SimplifyDemandedBits
For opcodes not covered by SimplifyDemandedVectorElts, SimplifyDemandedBits might be able to help now that it supports demanded elts as well.

llvm-svn: 349466
2018-12-18 09:33:25 +00:00
JF Bastien 1811217e4d NFC: remove unused variable
D55768 removed its use.

llvm-svn: 349377
2018-12-17 19:03:24 +00:00
Simon Pilgrim 9274f17a5e [TargetLowering] Add DemandedElts mask to SimplifyDemandedBits (PR40000)
This is an initial patch to add the necessary support for a DemandedElts argument to SimplifyDemandedBits, more closely matching computeKnownBits and to help improve vector codegen.

I've added only a small amount of the changes necessary to get at least one test to update - a lot more can be done but I'd like to add these methodically with proper test coverage, at the same time the hope is to slowly move some/all of SimplifyDemandedVectorElts into SimplifyDemandedBits as well.

Differential Revision: https://reviews.llvm.org/D55768

llvm-svn: 349374
2018-12-17 18:43:43 +00:00
Simon Pilgrim 1e1fd9c761 [TargetLowering] Add ISD::OR + ISD::XOR handling to SimplifyDemandedVectorElts
Differential Revision: https://reviews.llvm.org/D55600

llvm-svn: 349264
2018-12-15 11:36:36 +00:00
Simon Pilgrim 77fc551d1a [TargetLowering] Add ISD::ROTL/ROTR vector expansion
Move existing rotation expansion code into TargetLowering and set it up for vectors as well.

Ideally this would share more of the funnel shift expansion, but we handle the shift amount modulo quite differently at the moment.

Begun removing x86 vector rotate custom lowering to use the expansion.

llvm-svn: 349025
2018-12-13 11:20:48 +00:00
Simon Pilgrim f6c898e12f [TargetLowering] Add ISD::AND handling to SimplifyDemandedVectorElts
If either of the operand elements are zero then we know the result element is going to be zero (even if the other element is undef).

Differential Revision: https://reviews.llvm.org/D55558

llvm-svn: 348926
2018-12-12 13:43:07 +00:00
Leonard Chan 118e53fd63 [Intrinsic] Signed Fixed Point Multiplication Intrinsic
Add an intrinsic that takes 2 signed integers with the scale of them provided
as the third argument and performs fixed point multiplication on them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D54719

llvm-svn: 348912
2018-12-12 06:29:14 +00:00
Simon Pilgrim f6371f5f23 [TargetLowering] Add ISD::EXTRACT_VECTOR_ELT support to SimplifyDemandedBits
Let SimplifyDemandedBits attempt to simplify all elements of a vector extraction.

Part of PR39689.

llvm-svn: 348839
2018-12-11 11:08:40 +00:00
Simon Pilgrim fc2c9af99c [TargetLowering] Add UNDEF folding to SimplifyDemandedVectorElts
If all the demanded elements of the SimplifyDemandedVectorElts are known to be UNDEF, we can simplify to an ISD::UNDEF node.

Zero constant folding will be handled in a future patch - its a little trickier as we often have bitcasted zero values.

Differential Revision: https://reviews.llvm.org/D55511

llvm-svn: 348784
2018-12-10 18:29:46 +00:00
Simon Pilgrim 8fdaf5c915 [TargetLowering] Remove ISD::ANY_EXTEND/ANY_EXTEND_VECTOR_INREG opcodes from SimplifyDemandedVectorElts
These have no test coverage and the KnownZero flags can't be guaranteed unlike SIGN/ZERO_EXTEND cases.

llvm-svn: 348361
2018-12-05 12:20:05 +00:00
Simon Pilgrim 180639afe5 [SelectionDAG] Initial support for FSHL/FSHR funnel shift opcodes (PR39467)
This is an initial patch to add a minimum level of support for funnel shifts to the SelectionDAG and to begin wiring it up to the X86 SHLD/SHRD instructions.

Some partial legalization code has been added to handle the case for 'SlowSHLD' where we want to expand instead and I've added a few DAG combines so we don't get regressions from the existing DAG builder expansion code.

Differential Revision: https://reviews.llvm.org/D54698

llvm-svn: 348353
2018-12-05 11:12:12 +00:00
Simon Pilgrim d24730cdda [TargetLowering] SimplifyDemandedVectorElts - don't alter DemandedElts mask
Fix potential issue with the ISD::INSERT_VECTOR_ELT case tweaking the DemandedElts mask instead of using a local copy - so later uses of the mask use the tweaked version.....

Noticed while investigating adding zero/undef folding to SimplifyDemandedVectorElts and the altered DemandedElts mask was causing mismatches.

llvm-svn: 348348
2018-12-05 10:37:45 +00:00
Nirav Dave ce26c27b2a [SelectionDAG] Redefine isGAPlusOffset in terms of unwrapAddress. NFCI.
llvm-svn: 348288
2018-12-04 17:59:43 +00:00
Simon Pilgrim 0add090e24 [TargetLowering] expandFP_TO_UINT - avoid FPE due to out of range conversion (PR17686)
PR17686 demonstrates that for some targets FP exceptions can fire in cases where the FP_TO_UINT is expanded using a FP_TO_SINT instruction.

The existing code converts both the inrange and outofrange cases using FP_TO_SINT and then selects the result, this patch changes this for 'strict' cases to pre-select the FP_TO_SINT input and the offset adjustment.

The X87 cases don't need the strict flag but generates much nicer code with it....

Differential Revision: https://reviews.llvm.org/D53794

llvm-svn: 348251
2018-12-04 11:21:30 +00:00
Simon Pilgrim 666261cdc8 [TargetLowering] Add SimplifyDemandedVectorElts support to EXTEND opcodes
Add support for ISD::*_EXTEND and ISD::*_EXTEND_VECTOR_INREG opcodes.

The extra broadcast in trunc-subvector.ll will be fixed in an upcoming patch.

llvm-svn: 348246
2018-12-04 10:41:06 +00:00
Simon Pilgrim e017ed3245 [SelectionDAG] Improve SimplifyDemandedBits to SimplifyDemandedVectorElts simplification
D52935 introduced the ability for SimplifyDemandedBits to call SimplifyDemandedVectorElts through BITCASTs if the demanded bit mask entirely covered the sub element.

This patch relaxes this to demanding an element if we need any bit from it.

Differential Revision: https://reviews.llvm.org/D54761

llvm-svn: 348073
2018-12-01 12:08:55 +00:00
Simon Pilgrim 5448339889 [TargetLowering] SimplifyDemandedBits - only reduce known bits for integer constants
Avoids fuzzing crash found by Mikael Holmén.

llvm-svn: 347393
2018-11-21 14:26:19 +00:00
Simon Pilgrim 3735105961 [DAGCombine] Add calls to SimplifyDemandedVectorElts from visitINSERT_SUBVECTOR (PR37989)
This uncovered an off-by-one typo in SimplifyDemandedVectorElts's INSERT_SUBVECTOR handling as its bounds check was bailing on safe indices.

llvm-svn: 347313
2018-11-20 15:23:50 +00:00
Simon Pilgrim b356d0463e [TargetLowering] Improve SimplifyDemandedVectorElts/SimplifyDemandedBits support
For bitcast nodes from larger element types, add the ability for SimplifyDemandedVectorElts to call SimplifyDemandedBits by merging the elts mask to a bits mask.

I've raised https://bugs.llvm.org/show_bug.cgi?id=39689 to deal with the few places where SimplifyDemandedBits's lack of vector handling is a problem.

Differential Revision: https://reviews.llvm.org/D54679

llvm-svn: 347301
2018-11-20 12:02:16 +00:00
Simon Pilgrim de3605f56b [TargetLowering] expandFP_TO_UINT - improve fp16 support
As discussed on D53794, for float types with ranges smaller than the destination integer type, then we should be able to just use a regular FP_TO_SINT opcode.

I thought we'd need to provide MSA test cases for very small integer types as well (fp16 -> i8 etc.), but it turns out that promotion will kick in so they're unnecessary.

Differential Revision: https://reviews.llvm.org/D54703

llvm-svn: 347251
2018-11-19 19:16:13 +00:00
Simon Pilgrim 3c8baf4f90 [TargetLowering] Cleanup more of the EXTEND demanded bits cases so that they match. NFCI.
Use the same variable names etc.

llvm-svn: 347045
2018-11-16 12:26:26 +00:00
Simon Pilgrim 6bd468bd8b [TargetLowering] Begin generalizing TargetLowering::expandFP_TO_SINT support. NFCI.
Prior to initial work to add vector expansion support, remove assumptions that we're working on scalar types.

llvm-svn: 346139
2018-11-05 15:49:09 +00:00
Simon Pilgrim b34a052852 [LegalizeDAG] Add generic vector CTPOP expansion (PR32655)
This patch adds support for expanding vector CTPOP instructions and removes the x86 'bitmath' lowering which replicates the same expansion.

Differential Revision: https://reviews.llvm.org/D53258

llvm-svn: 345869
2018-11-01 18:22:11 +00:00
Stanislav Mekhanoshin 222e9c11f7 Check shouldReduceLoadWidth from SimplifySetCC
SimplifySetCC could shrink a load without checking for
profitability or legality of such shink with a target.

Added checks to prevent shrinking of aligned scalar loads
in AMDGPU below dword as scalar engine does not support it.

Differential Revision: https://reviews.llvm.org/D53846

llvm-svn: 345778
2018-10-31 21:24:30 +00:00
Leonard Chan 905abe5b5d [Intrinsic] Signed and Unsigned Saturation Subtraction Intirnsics
Add an intrinsic that takes 2 integers and perform saturation subtraction on
them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D53783

llvm-svn: 345512
2018-10-29 16:54:37 +00:00
Simon Pilgrim 3497d536f7 [TargetLowering] Move i64/vXi64 to f32/vXf32 UINT_TO_FP handling to TargetLowering::expandUINT_TO_FP.
llvm-svn: 345478
2018-10-28 15:34:35 +00:00
Simon Pilgrim 9b77f0c291 [VectorLegalizer] Enable TargetLowering::expandFP_TO_UINT support.
Add vector support to TargetLowering::expandFP_TO_UINT.

This exposes an issue in X86TargetLowering::LowerVSELECT which was assuming that the select mask was the same width as the LHS/RHS ops - as long as the result is a sign splat we can easily sext/trunk this.

llvm-svn: 345473
2018-10-28 13:07:25 +00:00
Simon Pilgrim 3cf33fcdd6 [TargetLowering] Move LegalizeDAG FP_TO_UINT handling to TargetLowering::expandFP_TO_UINT. NFCI.
First step towards fixing PR17686 and adding vector support.

llvm-svn: 345452
2018-10-27 12:15:58 +00:00
Simon Pilgrim 838eb24014 [TargetLowering] Improve vXi64 UINT_TO_FP vXf64 support (P38226)
As suggested on D52965, this patch moves the i64 to f64 UINT_TO_FP expansion code from LegalizeDAG into TargetLowering and makes it available to LegalizeVectorOps as well.

Not only does this help perform X86 lowering as a true vectorization instead of (partially vectorized) scalar conversions, it avoids the HADDPD op from the scalar code which can be slow on most targets.

The AVX512F does have the vcvtusi2sdq scalar operation but we don't unroll to use it as it seems to only help for the v2f64 case - otherwise the unrolling cost will certainly be too high. My feeling is that we should leave it to the vectorizers - and if it generates the vector UINT_TO_FP we should use it.

Differential Revision: https://reviews.llvm.org/D53649

llvm-svn: 345256
2018-10-25 11:15:57 +00:00
Simon Pilgrim 6f53b38fd4 [TargetLowering] Add SimplifyDemandedBitsForTargetNode callback
Add a SimplifyDemandedBitsForTargetNode callback to handle target nodes.

Differential Revision: https://reviews.llvm.org/D53643

llvm-svn: 345179
2018-10-24 19:00:56 +00:00
Simon Pilgrim 8c4796deb4 [LegalizeDAG] Share Vector/Scalar CTPOP Expansion
As suggested on D53258, this patch move the CTPOP expansion code from SelectionDAGLegalize to TargetLowering to allow it to be reused by the VectorLegalizer.

Proper vector support will be added by D53258.

llvm-svn: 345066
2018-10-23 18:28:24 +00:00
Simon Pilgrim d705ba97dd [LegalizeDAG] Share Vector/Scalar CTLZ Expansion
As suggested on D53258, this patch shares common CTLZ expansion code between VectorLegalizer and SelectionDAGLegalize by putting it in TargetLowering.

Extension to D53474

llvm-svn: 345060
2018-10-23 17:48:30 +00:00
Simon Pilgrim b975ff4700 [LegalizeDAG] Share Vector/Scalar CTTZ Expansion
As suggested on D53258, this patch demonstrates sharing common CTTZ expansion code between VectorLegalizer and SelectionDAGLegalize by putting it in TargetLowering.

I intend to move CTLZ and (scalar) CTPOP over as well and then update D53258 accordingly.

Differential Revision: https://reviews.llvm.org/D53474

llvm-svn: 345039
2018-10-23 15:37:19 +00:00
Leonard Chan 0acfc6be38 [Intrinsic] Unigned Saturation Addition Intrinsic
Add an intrinsic that takes 2 integers and perform unsigned saturation
addition on them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D53340

llvm-svn: 344971
2018-10-22 23:08:40 +00:00
Matt Arsenault 687ec75d10 DAG: Change behavior of fminnum/fmaxnum nodes
Introduce new versions that follow the IEEE semantics
to help with legalization that may need quieted inputs.

There are some regressions from inserting unnecessary
canonicalizes when these are matched from fast math
fcmp + select which should be fixed in a future commit.

llvm-svn: 344914
2018-10-22 16:27:27 +00:00
Leonard Chan 699b3b54da [Intrinsic] Signed Saturation Addition Intrinsic
Add an intrinsic that takes 2 integers and perform saturation addition on them.

This is a part of implementing fixed point arithmetic in clang where some of
the more complex operations will be implemented as intrinsics.

Differential Revision: https://reviews.llvm.org/D53053

llvm-svn: 344629
2018-10-16 17:35:41 +00:00
Sanjay Patel 4cf1da0e02 [SelectionDAG] allow FP binops in SimplifyDemandedVectorElts
This is intended to make the backend on par with functionality that was 
added to the IR version of SimplifyDemandedVectorElts in:
rL343727
...and the original motivation is that we need to improve demanded-vector-elements 
in several ways to avoid problems that would be exposed in D51553.

Differential Revision: https://reviews.llvm.org/D52912

llvm-svn: 344541
2018-10-15 18:05:34 +00:00
Simon Pilgrim bc7b6251b6 [TargetLowering] SimplifyDemandedBits - rename demanded mask args. NFCI.
Help stop bugs like rL343935 by making the 'original' DemandedBits arg more obviously not the mask that is actually used.

llvm-svn: 344138
2018-10-10 13:00:49 +00:00
Simon Pilgrim 53a503f6ac [TargetLowering] SimplifyDemandedBits - pull out repeated getOperands. NFCI.
Part of a minor cleanup to make all the switch statements more consistent prior to improving vector support.

llvm-svn: 344136
2018-10-10 12:32:13 +00:00
Simon Pilgrim 5cb3a82892 [TargetLowering] Add root node back to work list after successful SimplifyDemandedBits/SimplifyDemandedVectorElts
Similar to what already happens in the DAGCombiner wrappers, this patch adds the root nodes back onto the worklist if the DCI wrappers' SimplifyDemandedBits/SimplifyDemandedVectorElts were successful.

Differential Revision: https://reviews.llvm.org/D53026

llvm-svn: 344132
2018-10-10 10:44:15 +00:00
Simon Pilgrim 23f880317a [SelectionDAG] Add SIGN_EXTEND_VECTOR_INREG and CONCAT_VECTORS support to SimplifyDemandedBits
Fix for AVX1 masked load/store regression on D52964

llvm-svn: 344043
2018-10-09 13:13:35 +00:00
Simon Pilgrim 3b04a4e322 [SelectionDAG] Respect multiple uses in SimplifyDemandedBits to SimplifyDemandedVectorElts simplification
rL343913 was using SimplifyDemandedBits's original demanded mask instead of the adjusted 'NewMask' that accounts for multiple uses of the op (those variable names really need improving....).

Annoyingly many of the test changes (back to pre-rL343913 state) are actually safe - but only because their multiple uses are all by PMULDQ/PMULUDQ.

Thanks to Jan Vesely (@jvesely) for bisecting the bug.

llvm-svn: 343935
2018-10-07 11:45:46 +00:00
Simon Pilgrim 9c9c97bcf4 [SelectionDAG] Add SimplifyDemandedBits to SimplifyDemandedVectorElts simplification
This patch enables SimplifyDemandedBits to call SimplifyDemandedVectorElts in cases where the demanded bits mask covers entire elements of a bitcasted source vector.

There are a couple of cases here where simplification at a deeper level (such as through bitcasts) prevents further simplification - CommitTargetLoweringOpt only adds immediate uses/users back to the worklist when we might want to combine the original caller again to see what else it can simplify.

As well as that I had to disable handling of bool vector until SimplifyDemandedVectorElts better supports some of their opcodes (SETCC, shifts etc.).

Fixes PR39178

Differential Revision: https://reviews.llvm.org/D52935

llvm-svn: 343913
2018-10-06 10:20:04 +00:00
David Green 353cb3d4e5 [CodeGen] Enable tail calls for functions with NonNull attributes.
Adding NonNull as attributes to returned pointers has the unfortunate side
effect of disabling tail calls. This patch ignores the NonNull attribute when
we decide whether to tail merge, in the same way that we ignore the NoAlias
attribute, as it has no affect on the call sequence.

Differential Revision: https://reviews.llvm.org/D52238

llvm-svn: 343091
2018-09-26 10:46:18 +00:00
Matt Arsenault 842cda6312 DAG: Fix expansion of unaligned FP loads and stores
This was trying to scalarizing a scalar FP type,
resulting in an assert.

Fixes unaligned f64 stack stores for AMDGPU.

llvm-svn: 342132
2018-09-13 12:14:23 +00:00
Sanjay Patel 6ebf218e4c [SelectionDAG] enhance vector demanded elements to look at a vector select condition operand
This is the DAG equivalent of D51433.
If we know we're not using all vector lanes, use that knowledge to potentially simplify a vselect condition.

The reduction/horizontal tests show that we are eliminating AVX1 operations on the upper half of 256-bit 
vectors because we don't need those anyway.
I'm not sure what the pr34592 test is showing. That's run with -O0; is SimplifyDemandedVectorElts supposed 
to be running there?

Differential Revision: https://reviews.llvm.org/D51696

llvm-svn: 341762
2018-09-09 14:13:22 +00:00
Scott Linder cab029f474 [CodeGen] Fix remaining zext() assertions in SelectionDAG
Fix remaining cases not committed in https://reviews.llvm.org/D49574

Differential Revision: https://reviews.llvm.org/D50659

llvm-svn: 341380
2018-09-04 16:33:34 +00:00
Roman Lebedev d7a6244475 [DAGCombine] optimizeSetCCOfSignedTruncationCheck(): handle inverted pattern
Summary:
A follow-up for D49266 / rL337166 + D49497 / rL338044.

This is still the same pattern to check for the [lack of]
signed truncation, but in this case the constants and the predicate
are negated.

https://rise4fun.com/Alive/BDV
https://rise4fun.com/Alive/n7Z

Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma, dmgreen

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51532

llvm-svn: 341287
2018-09-02 13:56:22 +00:00
Simon Pilgrim 72b324de4d [TargetLowering] Add BuildSDiv support for division by one or negone.
This reduces most of the sdiv stages (the MULHS, shifts etc.) to just zero/identity values and use the numerator scale factor to multiply by +1/-1.

llvm-svn: 340260
2018-08-21 10:20:36 +00:00
Simon Pilgrim 6ac905926f [TargetLowering] Disable BuildSDiv division by one or negone.
Fuzz tests have detected an issue, currently working on a fix.

llvm-svn: 340195
2018-08-20 18:23:54 +00:00
Simon Pilgrim 87d0039a45 [TargetLowering] Add support for non-uniform vectors to BuildSDIV
This patch refactors the existing TargetLowering::BuildSDIV base implementation to support non-uniform constant vector denominators.

This is the last patch necessary to close PR36545

Differential Revision: https://reviews.llvm.org/D50765

llvm-svn: 339908
2018-08-16 17:44:33 +00:00
Simon Pilgrim ede4905375 [TargetLowering] Refactor BuildSDIV in preparation for D50765. NFCI.
Pull out magic factor calculators into a helper function, use 0/+1/-1 multiplication factor to (optionally) add/sub the numerator.

llvm-svn: 339898
2018-08-16 16:54:06 +00:00
Matt Arsenault 0f2c1cf429 DAG: Use getObjectOffset helper
llvm-svn: 339813
2018-08-15 21:03:44 +00:00
Simon Pilgrim 4b2317ebfb [TargetLowering] Minor cleanup of TargetLowering::BuildSDIV. NFCI.
Pull out some types to match layout in TargetLowering::BuildUDIV. Early step towards adding non-uniform vector support.

llvm-svn: 339763
2018-08-15 11:11:05 +00:00
Simon Pilgrim a4ba43d3d3 [TargetLowering] Minor refactor to TargetLowering::BuildUDIV to merge scalar/vector magic value collection. NFCI.
Use the same ISD::matchUnaryPredicate pattern that was used in D50392.

llvm-svn: 339758
2018-08-15 10:11:13 +00:00
Simon Pilgrim a272fa9b0c [TargetLowering] Add support for non-uniform vectors to BuildExactSDIV
This patch refactors the existing BuildExactSDIV implementation to support non-uniform constant vector denominators.

Differential Revision: https://reviews.llvm.org/D50392

llvm-svn: 339756
2018-08-15 09:35:12 +00:00
Craig Topper 60177f1aee [TargetLowering] Simplify one of the special cases in SimplifyDemandedBits for XOR. NFCI
We were checking for all bits being Known by checking Known.Zero|Known.One, but if all the bits are known then the value should be a Constant and we can just check for that instead.

llvm-svn: 339509
2018-08-12 06:52:03 +00:00
Craig Topper d112206004 [TargetLowering] Use APInt::isSubsetOf to simplify some code. NFC
llvm-svn: 339508
2018-08-12 05:34:15 +00:00
Simon Pilgrim a9f95429d9 [TargetLowering] Add BuildSDIVPattern helper to BuildExactSDIV (NFCI).
As requested in D50392, pull the magic constant calculations out into a helper function.

llvm-svn: 339346
2018-08-09 13:56:04 +00:00
Simon Pilgrim 164e8b0b5c [TargetLowering] BuildUDIV - Add support for divide by one (PR38477)
Provide a pass-through of the numerator for divide by one cases - this is the same approach we take in DAGCombiner::visitSDIVLike.

I investigated whether we could achieve this by magic MULHU/SRL values but nothing appeared to work as we don't have a way for MULHU(x,c) -> x

llvm-svn: 339254
2018-08-08 14:51:19 +00:00
Simon Pilgrim e4a4cf5a8b [TargetLowering] Remove APInt divisor argument from BuildExactSDIV (NFCI).
As requested in D50392, this is a minor refactor to BuildExactSDIV to stop taking the uniform constant APInt divisor and instead extract it locally.

I also cleanup the operands and valuetypes to better match BuildUDiv (and BuildSDIV in the near future).

llvm-svn: 339246
2018-08-08 13:59:44 +00:00
Simon Pilgrim a10cfcc1db [TargetLowering] BuildUDIV - Early out for divide by one (PR38477)
We're not handling the UDIV by one special case properly - for now just early out.

llvm-svn: 339229
2018-08-08 10:00:54 +00:00
Simon Pilgrim 6943e39353 [TargetLowering] Use pre-computed Shift value type in BuildUDIV (NFCI)
This was missed in D49248

llvm-svn: 339146
2018-08-07 14:40:21 +00:00
Simon Pilgrim 7e18938793 [TargetLowering] Add support for non-uniform vectors to BuildUDIV
This patch refactors the existing TargetLowering::BuildUDIV base implementation to support non-uniform constant vector denominators.

It also includes a fold for MULHU by pow2 constants to SRL which can now more readily occur from BuildUDIV.

Differential Revision: https://reviews.llvm.org/D49248

llvm-svn: 339121
2018-08-07 09:51:34 +00:00
Matt Arsenault c3dc8e65e2 DAG: Enhance isKnownNeverNaN
Add a parameter for testing specifically for
sNaNs - at least one instruction pattern on AMDGPU
needs to check specifically for this.

Also handle more cases, and add a target hook
for custom nodes, similar to the hooks for known
bits.

llvm-svn: 338910
2018-08-03 18:27:52 +00:00
Simon Pilgrim 94112ebc75 [TargetLowering] Generalise BuildSDIV function
First step towards a BuildSDIV equivalent to D49248 for non-uniform vector support - this just pushes the splat detection down into TargetLowering::BuildSDIV where its still used.

Differential Revision: https://reviews.llvm.org/D50185

llvm-svn: 338838
2018-08-03 10:00:54 +00:00
Hsiangkai Wang 615540d0f2 Test commit.
llvm-svn: 338352
2018-07-31 06:09:29 +00:00
Craig Topper 2f60ef2c78 [DAGCombiner][TargetLowering] Pass a SmallVector instead of a std::vector to BuildSDIV/BuildUDIV/etc.
The vector contains the SDNodes that these functions create. The number of nodes is always a small number so we should use SmallVector to avoid a heap allocation.

llvm-svn: 338329
2018-07-30 23:22:00 +00:00
Craig Topper 42d312bb83 [TargetLowering] In BuildSDIV, add the MULHS/SMUL_LOHI to the Created vector.
BuildUDIV was already correct.

llvm-svn: 338304
2018-07-30 21:04:38 +00:00
Craig Topper a568a27dfa [DAGCombiner][PowerPC][AArch64] Pass Created vector by reference to BuildSDIVPow2.
llvm-svn: 338303
2018-07-30 21:04:34 +00:00
Craig Topper 9db3573d3a [SelectionDAG] Pass std::vector by reference instead of by pointer to BuildSDIV/BuildUDIV.
This removes the need for an assert to ensure the pointer isn't null.

Years ago we had ifs the checked the pointer was non-null before very access to the vector. These checks were removed and replaced with a single assert. But a reference seems more suitable here.

llvm-svn: 338205
2018-07-28 19:44:20 +00:00
Roman Lebedev 41ba5c1455 [DAGCombine] optimizeSetCCOfSignedTruncationCheck(): handle ule,ugt CondCodes.
Summary:
A follow-up for D49266 / rL337166.

At least one of these cases is more canonical,
so we really do have to handle it.
https://godbolt.org/g/pkzP3X
https://rise4fun.com/Alive/pQyhZZ

We won't get to these cases with I1 being -1,
as that will be constant-folded to true or false.

I'm also not sure we actually hit the 'ule' case,
but i think the worst think that could happen is that being dead code.

Reviewers: spatel, craig.topper, RKSimon, javed.absar, efriedma

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49497

llvm-svn: 338044
2018-07-26 17:34:28 +00:00
Nirav Dave eac2ca4e28 [Legalize] Elide MERGE_VALUES created by scalarizeVectorLoad.
scalarizeVectorLoad creates MERGE_VALUES nodes which are immediately
decomposed in expandLoad. Elide the node in these cases.

llvm-svn: 337708
2018-07-23 16:43:42 +00:00
Stephen Canon 8995c5f0f6 Skip out of SimplifyDemandedBits for BITCAST of f16 to i16
Mirrors the existing exit path for f128, avoiding a crash later on.

Differential Revision: https://reviews.llvm.org/D49524

llvm-svn: 337506
2018-07-19 22:46:42 +00:00
Roman Lebedev de506632aa [X86][AArch64][DAGCombine] Unfold 'check for [no] signed truncation' pattern
Summary:

[[ https://bugs.llvm.org/show_bug.cgi?id=38149 | PR38149 ]]

As discussed in https://reviews.llvm.org/D49179#1158957 and later,
the IR for 'check for [no] signed truncation' pattern can be improved:
https://rise4fun.com/Alive/gBf
^ that pattern will be produced by Implicit Integer Truncation sanitizer,
https://reviews.llvm.org/D48958 https://bugs.llvm.org/show_bug.cgi?id=21530
in signed case, therefore it is probably a good idea to improve it.

But the IR-optimal patter does not lower efficiently, so we want to undo it..

This handles the simple pattern.
There is a second pattern with predicate and constants inverted.

NOTE: we do not check uses here. we always do the transform.

Reviewers: spatel, craig.topper, RKSimon, javed.absar

Reviewed By: spatel

Subscribers: kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D49266

llvm-svn: 337166
2018-07-16 12:44:10 +00:00
Simon Pilgrim 0a36daa5a2 Use const APInt& to avoid extra copy. NFCI.
As discussed on D48825.

llvm-svn: 336491
2018-07-07 17:33:48 +00:00
Simon Pilgrim c1d1944053 [DAGCombiner] Add EXTRACT_SUBVECTOR to SimplifyDemandedVectorElts
As discussed on PR37989, this patch adds EXTRACT_SUBVECTOR handling to TargetLowering::SimplifyDemandedVectorElts and calls it from DAGCombiner::visitEXTRACT_SUBVECTOR.

Differential Revision: https://reviews.llvm.org/D48825

llvm-svn: 336490
2018-07-07 17:30:06 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
David Blaikie 6054e650ff Move TargetLoweringObjectFile from CodeGen to Target to fix layering
It's implemented in Target & include from other Target headers, so the
header should be in Target.

llvm-svn: 328392
2018-03-23 23:58:19 +00:00
Craig Topper 508a5b2466 [TargetLowering] Remove redundant term in two ifs in SimplifySetCC. NFC
If we get into the right hand side of the OR, we know that isOpaque is true since the left hand size is just a check that it's false.

llvm-svn: 327179
2018-03-09 22:24:12 +00:00
Craig Topper 3d2af5038a [TargetLowering] Remove redundant if condition in SimplifySetcc. NFC
We were checking the condition code a second time when we were already in a block with this same condition code check.

llvm-svn: 327069
2018-03-08 21:53:36 +00:00
Simon Pilgrim ca38c762e4 [TargetLowering] Add vector BITCAST support to SimplifyDemandedVectorElts
Notably helps cleanup after legalization of vector types

Differential Revision: https://reviews.llvm.org/D43674

llvm-svn: 326838
2018-03-06 22:32:01 +00:00
Craig Topper eedfbc4ab7 [SelectionDAG] Support some SimplifySetCC cases for comparing against vector splats of constants.
This supports things like

(setcc ugt X, 0) -> (setcc ne X, 0)

I've restricted to only make changes to vectors before legalize ops because I doubt all targets have accurate condition code legality information for vectors given how little we did before.

Differential Revision: https://reviews.llvm.org/D42948

llvm-svn: 326495
2018-03-01 22:15:39 +00:00
Simon Pilgrim 295e8b4e12 [TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through ADD/SUB ops
llvm-svn: 326044
2018-02-24 20:59:14 +00:00
Simon Pilgrim c0dbdb86c3 [TargetLowering] SimplifyDemandedVectorElts - pass demanded elts through TRUNCATE ops
llvm-svn: 326043
2018-02-24 19:28:34 +00:00
Craig Topper a2cc3c055c [TargetLowering] Rename isCondCodeLegal to isCondCodeLegalOrCustom. Add real isCondCodeLegal. Update callers to use one or the other.
isCondCodeLegal internally checked Legal or Custom which is misleading. Though no targets set any cond code action to Custom today.

So I've renamed isCondCodeLegal to isCondCodeLegalOrCustom and added a real isCondCodeLegal that only checks Legal.

I've changed legalization code to use isCondCodeLegalOrCustom and left things reachable via DAG combine as isCondCodeLegal. I've also changed some places that called getCondCodeAction and compared to Legal to just use isCondCodeLegal.

I'm looking at trying to keep SETCC all the way to isel for the AVX512 integer comparisons and I suspect I'll need to make some condition codes Custom to stop DAG combine from changing things post LegalizeOps. Prior to this only Expand stopped DAG combine, but that causes LegalizeOps to try to swap operands or invert rather than calling our Custom handler.

Differential Revision: https://reviews.llvm.org/D43607

llvm-svn: 325829
2018-02-22 20:51:26 +00:00
Craig Topper 7fbea20b90 [SelectionDAG] Support known true/false SimplifySetCC cases for comparing against vector splats of constants.
This is split off from D42948 and includes just the cases that constant fold to true or false. It also includes some refactoring to keep predicate checks together.

This supports things like

(setcc uge X, 0) -> true

Differential Revision: https://reviews.llvm.org/D43489

llvm-svn: 325627
2018-02-20 21:48:14 +00:00
Craig Topper 35801fa5ce [SelectionDAG] Add LegalTypes flag to getShiftAmountTy. Use it to unify and simplify DAGCombiner and simplifySetCC code and fix a bug.
DAGCombiner and SimplifySetCC both use getPointerTy for shift amounts pre-legalization. DAGCombiner uses a single helper function to hide this. SimplifySetCC does it in multiple places.

This patch adds a defaulted parameter to getShiftAmountTy that can make it return getPointerTy for scalar types. Use this parameter to simplify the SimplifySetCC and DAGCombiner.

Additionally, there were two places in SimplifySetCC that were creating shifts using the target's preferred shift amount pre-legalization. If the target uses a narrow type and the type is illegal, this can cause SimplfiySetCC to create a shift with an amount that can't represent all possible shift values for the type. To fix this we should use pointer type there too.

Alternatively we could make getScalarShiftAmountTy for each target return a safe value for large types as proposed in D43445. And maybe we should still do that, but fixing the SimplifySetCC code keeps other targets from tripping over this in the future.

Fixes PR36250.

Differential Revision: https://reviews.llvm.org/D43449

llvm-svn: 325602
2018-02-20 17:41:05 +00:00
Simon Pilgrim 8da142bff1 [SelectionDAG] SimplifyDemandedVectorElts - add support for VECTOR_INSERT_ELT
Differential Revision: https://reviews.llvm.org/D43431

llvm-svn: 325449
2018-02-17 21:49:40 +00:00
Simon Pilgrim 1b81064d1e Fix signed/unsigned comparison warning. NFCI.
llvm-svn: 325363
2018-02-16 17:26:59 +00:00
Simon Pilgrim 5d005a359e Fix signed/unsigned comparison warning. NFCI.
llvm-svn: 325359
2018-02-16 16:52:50 +00:00
Simon Pilgrim ff53a4a234 [SelectionDAG] Enable SimplifyDemandedVectorElts support for simplifying shuffle masks
Based off the DemandedElts mask the and UNDEF elements returned from the SimplifyDemandedVectorElts calls to the shuffle operands, we can attempt to simplify the shuffle mask.

I had to be very conservative here as accepting post-legalized shuffle masks could cause problems for targets that legalize UNDEF mask elements back to inrange values (PowerPC), similarly combining to identity shuffle masks could cause too much UNDEF information to disappear for later combines.

llvm-svn: 325354
2018-02-16 16:22:14 +00:00
Simon Pilgrim 0ffde50f9c [SelectionDAG] Add initial SimplifyDemandedVectorElts support for simplifying VSELECT operands
This just adds a basic pass through - we can add constant selection mask handling in a future patch to fully match InstCombine.

llvm-svn: 325338
2018-02-16 12:21:08 +00:00
Simon Pilgrim 80663ee986 [SelectionDAG] Add initial implementation of TargetLowering::SimplifyDemandedVectorElts
This is mainly a move of simplifyShuffleOperands from DAGCombiner::visitVECTOR_SHUFFLE to create a more general purpose TargetLowering::SimplifyDemandedVectorElts implementation.

Further features can be moved/added in future patches.

Differential Revision: https://reviews.llvm.org/D42896

llvm-svn: 325232
2018-02-15 12:14:15 +00:00
Craig Topper 5ecea9fff5 [SelectionDAG] Remove duplicate code from TargetLowering::SimplifySetCC.
This exact code already exists a little further up.

llvm-svn: 325101
2018-02-14 06:51:57 +00:00
Sanjay Patel eb8c408e50 [TargetLowering] try to create -1 constant operand for math ops via demanded bits
This reverses instcombine's demanded bits' transform which always tries to clear bits in constants.

As noted in PR35792 and shown in the test diffs:
https://bugs.llvm.org/show_bug.cgi?id=35792
...we can do better in codegen by trying to form -1. The x86 sub test shows a missed opportunity. 

I did investigate changing instcombine's behavior, but it would be more work to change 
canonicalization in IR. Clearing bits / shrinking constants can allow killing instructions, 
so we'd have to figure out how to not regress those cases.

Differential Revision: https://reviews.llvm.org/D42986

llvm-svn: 324839
2018-02-11 14:38:23 +00:00
Craig Topper 36f913ee80 [SelectionDAG] Remove TargetLowering::getConstTrueVal. Use SelectionDAG::getBoolConstant in the one place it was used.
SelectionDAG::getBoolConstant was recently introduced. At the time I didn't know getConstTrueVal existed, but I think getBoolConstant is better as it will use the source VT to make sure it can properly detect floating point if it is configured differently.

llvm-svn: 324832
2018-02-11 04:58:58 +00:00
Craig Topper 9b611e436f [SelectionDAG] Add a helper function for creating a boolean constant based on the target's boolean content
Many in SimplifySetCC and FoldSetCC try to create true or false constants. Some of them query getBooleanContents to figure out whether to use all ones or just 1 for true. But many places do not check and just use 1 without ensuring the VT has an i1 scalar type. Note sure if those places only trigger before type legalization so they only see an i1
type?

To cleanup the inconsistency and reduce some duplicated code, this patch adds a getBoolConstant method to SelectionDAG that takes are of querying getBooleanContents and doing the right thing.

Differential Revision: https://reviews.llvm.org/D43037

llvm-svn: 324634
2018-02-08 18:55:14 +00:00
Sanjay Patel 87ce2fd82d [TargetLowering] use local variable to reduce duplication; NFCI
llvm-svn: 324401
2018-02-06 21:09:42 +00:00
Sanjay Patel e96a9014ab [TargetLowering] use local variables to reduce duplication; NFCI
llvm-svn: 324397
2018-02-06 20:49:28 +00:00
Jonas Paulsson 422dfbf7cc [SelectionDAG] Consider endianness in scalarizeVectorStore().
When handling vectors with non byte-sized elements, reverse the order of the
elements in the built integer if the target is Big-Endian.

SystemZ tests updated.

Review: Eli Friedman, Ulrich Weigand.
https://reviews.llvm.org/D42786

llvm-svn: 324063
2018-02-02 08:48:02 +00:00
Craig Topper 2c570eaa00 [TargetLowering] Teach TargetLowering::SimplifySetCC to simplify setcc of vXi1 vectors into logic ops.
This transform was already being done for setcc of scalar i1. This extends it to vectors.

llvm-svn: 323585
2018-01-27 09:10:58 +00:00
Jonas Paulsson 7ad28863fb [SelectionDAG] Fix codegen of vector stores with non byte-sized elements.
This was completely broken, but hopefully fixed by this patch.

In cases where it is needed, a vector with non byte-sized elements is stored
by extracting, zero-extending, shift:ing and or:ing the elements into an
integer of the same width as the vector, which is then stored.

Review: Eli Friedman, Ulrich Weigand
https://reviews.llvm.org/D42100#inline-369520
https://bugs.llvm.org/show_bug.cgi?id=35520

llvm-svn: 323042
2018-01-20 16:05:10 +00:00
Sanjay Patel 0e690b05d1 [TargetLowering] add punctuation for readability; NFC
llvm-svn: 322855
2018-01-18 15:25:32 +00:00
Simon Pilgrim 998180dad3 [DAG] Fix for Bug PR34620 - Allow SimplifyDemandedBits to look through bitcasts
Allow SimplifyDemandedBits to use TargetLoweringOpt::computeKnownBits to look through bitcasts. This can help simplifying in some cases where bitcasts of constants generated during or after legalization can't be folded away, and thus didn't get picked up by SimplifyDemandedBits. This fixes PR34620, where a redundant pand created during legalization from lowering and lshr <16xi8> wasn't being simplified due to the presence of a bitcasted build_vector as an operand.

Committed on the behalf of @sameconrad (Sam Conrad)

Differential Revision: https://reviews.llvm.org/D41643

llvm-svn: 321969
2018-01-07 19:09:40 +00:00
Craig Topper b2368fbdf4 [SelectionDAG] Reverse the order of operands in the ISD::ADD created by TargetLowering::getVectorElementPointer so that the FrameIndex is on the left.
This seems to improve X86's ability to match this into an address computation. Otherwise the other operand gets assigned to the base register and the stack pointer + frame index ends up in the index register. But index registers can't encode ESP/RSP so we end up having to move it into another register to meet the constraint.

I could try to improve the address matcher in X86, but swapping the producer seemed easier. Several other places already have the operands in this order so this is at least consistent.

llvm-svn: 321370
2017-12-22 17:18:13 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Yaxun Liu 494770403a CodeGen: Fix pointer info in SplitVecOp_EXTRACT_VECTOR_ELT/SplitVecRes_INSERT_VECTOR_ELT
Two issues found when doing codegen for splitting vector with non-zero alloca addr space:

DAGTypeLegalizer::SplitVecRes_INSERT_VECTOR_ELT/SplitVecOp_EXTRACT_VECTOR_ELT uses dummy pointer info for creating
SDStore. Since one pointer operand contains multiply and add, InferPointerInfo is unable to
infer the correct pointer info, which ends up with a dummy pointer info for the target to lower
store and results in isel failure. The fix is to introduce MachinePointerInfo::getUnknownStack to
represent MachinePointerInfo which is known in alloca address space but without other information.

TargetLowering::getVectorElementPointer uses value type of pointer in addr space 0 for
multiplication of index and then add it to the pointer. However the pointer may be in an addr
space which has different size than addr space 0. The fix is to use the pointer value type for
index multiplication.

Differential Revision: https://reviews.llvm.org/D39758

llvm-svn: 319622
2017-12-02 22:13:22 +00:00
Matt Arsenault b655fa9ce2 DAG: Add nuw when splitting loads and stores
The object can't straddle the address space
wrap around, so I think it's OK to assume any
offsets added to the base object pointer can't
overflow. Similar logic already appears to be
applied in SelectionDAGBuilder when lowering
aggregate returns.

llvm-svn: 319272
2017-11-29 01:25:12 +00:00
Jonas Paulsson f0ff20f1f0 Use getStoreSize() in various places instead of 'BitSize >> 3'.
This is needed for cases when the memory access is not as big as the width of
the data type. For instance, storing i1 (1 bit) would be done in a byte (8
bits).

Using 'BitSize >> 3' (or '/ 8') would e.g. give the memory access of an i1 a
size of 0, which for instance makes alias analysis return NoAlias even when
it shouldn't.

There are no tests as this was done as a follow-up to the bugfix for the case
where this was discovered (r318824). This handles more similar cases.

Review: Björn Petterson
https://reviews.llvm.org/D40339

llvm-svn: 319173
2017-11-28 14:44:32 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Matt Arsenault f6ee94c1c6 DAG: Add computeKnownBitsForFrameIndex
Some of the AMDGPU stack addressing modes require knowing the sign
bit is zero. We used to accomplish this by custom lowering
frame indexes, and then putting an AssertZext around a
TargetFrameIndex. This required specifically looking for
the AssextZext + frame index pattern which was moderately
disgusting. The same could probably be accomplished
with a target specific node, but would still
require special handling of frame indexes.

llvm-svn: 317671
2017-11-08 08:52:31 +00:00
Craig Topper 195dad4264 [SelectionDAG] Don't subject ISD:Constant to the depth limit in TargetLowering::SimplifyDemandedBits.
Summary:
We shouldn't recurse any further but it doesn't mean we shouldn't be able to give the known bits for a constant. The caller would probably like that we always return the right answer for a constant RHS. This matches what InstCombine does in this case.

I don't have a test case because this showed up while trying to revive D31724.

Reviewers: RKSimon, spatel

Reviewed By: RKSimon

Subscribers: arsenm, llvm-commits

Differential Revision: https://reviews.llvm.org/D38967

llvm-svn: 316255
2017-10-21 02:27:19 +00:00
Mark Searles 4e3d6160db Use the return value of UpdateNodeOperands(); in some cases, UpdateNodeOperands() modifies the node in-place and using the return value isn’t strictly necessary. However, it does not necessarily modify the node, but may return a resultant node if it already exists in the DAG. See comments in UpdateNodeOperands(). In that case, the return value must be used to avoid such scenarios as an infinite loop (node is assumed to have been updated, so added back to the worklist, and re-processed; however, node hasn’t changed so it is once again passed to UpdateNodeOperands(), assumed modified, added back to worklist; cycle infinitely repeats).
Differential Revision: https://reviews.llvm.org/D38466

llvm-svn: 315957
2017-10-16 23:38:53 +00:00
Craig Topper 6794eb8ba1 [SelectionDAG] Cleanup the SIGN_EXTEND_INREG handling in computeKnownBits. NFCI
Use less temporary APInts. Use bit counting more. Don't call getScalarSizeInBits so many places, just capture it once.

llvm-svn: 315671
2017-10-13 05:35:35 +00:00
Craig Topper bde7abe9c9 [SelectionDAG] Fix typo in comment. NFC
llvm-svn: 315670
2017-10-13 05:35:34 +00:00
Craig Topper 0e8211ea57 [SelectionDAG] Const-correct the DemandedMask argument to one of the overloads of SimplifyDemandedBits. NFC
llvm-svn: 315641
2017-10-12 23:46:05 +00:00
Craig Topper d52cf99f53 [SelectionDAG] Simplify the ISD::SIGN_EXTEND/ZERO_EXTEND handling to use less temporary APInts by counting bits instead. NFCI
llvm-svn: 315628
2017-10-12 21:58:25 +00:00
Yaxun Liu b33607e5a1 CodeGen: Fix pointer info in expandUnalignedLoad/Store
Currently expandUnalignedLoad/Store uses place holder pointer info for temporary memory operand
in stack, which does not have correct address space. This causes unaligned private double16 load/store to be
lowered to flat_load instead of buffer_load for amdgcn target.

This fixes failures of OpenCL conformance test basic/vload_private/vstore_private on target amdgcn---amdgizcl.

Differential Revision: https://reviews.llvm.org/D35361

llvm-svn: 314566
2017-09-29 23:31:14 +00:00
Craig Topper 5bc10ede53 [SelectionDAG] Teach simplifyDemandedBits to handle shifts by constant splat vectors
This teach simplifyDemandedBits to handle constant splat vector shifts.

This required changing some uses of getZExtValue to getLimitedValue since we can't rely on legalization using getShiftAmountTy for the shift amount.

I believe there may have been a bug in the ((X << C1) >>u ShAmt) handling where we didn't check if the inner shift was too large. I've fixed that here.

I had to add new patterns to ARM because the zext/sext the patterns were trying to look for got turned into an any_extend with this patch. Happy to split that out too, but not sure how to test without this change.

Differential Revision: https://reviews.llvm.org/D37665

llvm-svn: 314139
2017-09-25 19:26:08 +00:00
Craig Topper f0ba300332 [SelectionDAG] Replace a flag that can never be true with an assert.
llvm-svn: 313847
2017-09-21 00:18:46 +00:00
Craig Topper eb0f71f232 [SelectionDAG] Use APInt::getActivebits instead of Bitwidth - leading zeros.
llvm-svn: 313839
2017-09-20 23:48:56 +00:00
Craig Topper 288b3c9e69 [SelectionDAG] Use APInt::isSubsetOf. NFC
llvm-svn: 305606
2017-06-16 23:19:14 +00:00
Craig Topper ea5b8bc9ef [SelectionDAG] Use APInt::isNullValue/isOneValue. NFC
llvm-svn: 305605
2017-06-16 23:19:12 +00:00
Craig Topper b681907c50 [TargetLowering] Use ConstantSDNode::isOne and getSExtValue instead of getting the underlying APInt first. NFC
llvm-svn: 305604
2017-06-16 23:19:10 +00:00
Simon Pilgrim be8866f691 [DAG] Move SelectionDAG::isCommutativeBinOp to TargetLowering.
This will allow commutation of target-specific DAG nodes in future patches

Differential Revision: https://reviews.llvm.org/D33882

llvm-svn: 304911
2017-06-07 14:05:04 +00:00
Sanjay Patel cdb5dad4cc [TargetLowering] fix formatting; NFC
llvm-svn: 304569
2017-06-02 17:35:02 +00:00
Amaury Sechet 437f7060fe nits in TargetLowering.cpp . NFC
llvm-svn: 304532
2017-06-02 09:18:18 +00:00
Craig Topper 7e0aeeb884 [KnownBits] Use !hasConflict() in asserts in place of Zero & One == 0 or similar. NFC
llvm-svn: 303614
2017-05-23 07:18:37 +00:00
Simon Pilgrim a6ed1b2f12 Use SDValue::getOperand() helper. NFCI.
llvm-svn: 302896
2017-05-12 13:20:24 +00:00
Craig Topper f0aeee01c3 [KnownBits] Add wrapper methods for setting and clear all bits in the underlying APInts in KnownBits.
This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.

Differential Revision: https://reviews.llvm.org/D32637

llvm-svn: 302262
2017-05-05 17:36:09 +00:00
Craig Topper d938fd1397 [KnownBits] Add zext, sext, and trunc methods to KnownBits
This patch adds zext, sext, and trunc methods to KnownBits and uses them where possible.

Differential Revision: https://reviews.llvm.org/D32784

llvm-svn: 302088
2017-05-03 22:07:25 +00:00
Sanjay Patel e1cf61c69f [TargetLowering] use isSubsetOf in SimplifyDemandedBits; NFCI
This is the DAG equivalent of https://reviews.llvm.org/D32255 , 
which will hopefully be committed again. The functionality
(preferring a 'not' op) is already here in the DAG, so this is
just intended to be a clean-up and performance improvement.

llvm-svn: 302087
2017-05-03 21:55:34 +00:00
Amara Emerson d28f0cd448 Generalize the specialized flag-carrying SDNodes by moving flags into SDNode.
This removes BinaryWithFlagsSDNode, and flags are now all passed by value.

Differential Revision: https://reviews.llvm.org/D32527

llvm-svn: 301803
2017-05-01 15:17:51 +00:00
Reid Kleckner 859f8b544a Make getParamAlignment use argument numbers
The method is called "get *Param* Alignment", and is only used for
return values exactly once, so it should take argument indices, not
attribute indices.

Avoids confusing code like:
  IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError);
  Alignment  = CS->getParamAlignment(ArgIdx + 1);

Add getRetAlignment to handle the one case in Value.cpp that wants the
return value alignment.

This is a potentially breaking change for out-of-tree backends that do
their own call lowering.

llvm-svn: 301682
2017-04-28 20:34:27 +00:00
Craig Topper d0af7e8ab8 [SelectionDAG] Use KnownBits struct in DAG's computeKnownBits and simplifyDemandedBits
This patch replaces the separate APInts for KnownZero/KnownOne with a single KnownBits struct. This is similar to what was done to ValueTracking's version recently.

This is largely a mechanical transformation from KnownZero to Known.Zero.

Differential Revision: https://reviews.llvm.org/D32569

llvm-svn: 301620
2017-04-28 05:31:46 +00:00
Craig Topper 0e03e74e95 [SelectionDAG] Use various APInt methods to reduce temporary APInt creation
This patch uses various APInt methods to reduce the number of temporary APInts. These were all found while working through converting SelectionDAG's computeKnownBits to also use the KnownBits struct recently added to the ValueTracking version.

llvm-svn: 301618
2017-04-28 04:57:59 +00:00
Craig Topper 24e71017aa [APInt] Use inplace shift methods where possible. NFCI
llvm-svn: 301612
2017-04-28 03:36:24 +00:00
Sanjay Patel e2ec05a62a [TargetLowering] fix isConstTrueVal to account for build vector truncation
Build vectors have magical truncation powers, so we have things like this:

v4i1 = BUILD_VECTOR Constant:i32<1>, Constant:i32<1>, Constant:i32<1>, Constant:i32<1>
v4i16 = BUILD_VECTOR Constant:i32<1>, Constant:i32<1>, Constant:i32<1>, Constant:i32<1>

If we don't truncate the splat node returned by getConstantSplatNode(), then we won't find 
truth when ZeroOrNegativeOneBooleanContent is the rule.

Differential Revision: https://reviews.llvm.org/D32505

llvm-svn: 301408
2017-04-26 14:05:42 +00:00
Sanjay Patel a4b4e9388c [DAG] add FIXME comments for splat detection; NFC
llvm-svn: 301403
2017-04-26 13:27:57 +00:00
Krzysztof Parzyszek c8e8e2a046 Move value type list from TargetRegisterClass to TargetRegisterInfo
Differential Revision: https://reviews.llvm.org/D31937

llvm-svn: 301234
2017-04-24 19:51:12 +00:00
Krzysztof Parzyszek 98ab4c64c4 Revert r301231: Accidentally committed stale files
I forgot to commit local changes before commit.

llvm-svn: 301232
2017-04-24 19:48:51 +00:00
Krzysztof Parzyszek c0197066d7 Move value type list from TargetRegisterClass to TargetRegisterInfo
Differential Revision: https://reviews.llvm.org/D31937

llvm-svn: 301231
2017-04-24 19:43:45 +00:00
Renato Golin 4abfb3d741 Revert "[APInt] Fix a few places that use APInt::getRawData to operate within the normal API."
This reverts commit r301105, 4, 3 and 1, as a follow up of the previous
revert, which broke even more bots.

For reference:
Revert "[APInt] Use operator<<= where possible. NFC"
Revert "[APInt] Use operator<<= instead of shl where possible. NFC"
Revert "[APInt] Use ashInPlace where possible."

PR32754.

llvm-svn: 301111
2017-04-23 12:15:30 +00:00
Craig Topper cdd5ae6676 [APInt] Use operator<<= where possible. NFC
llvm-svn: 301104
2017-04-23 05:43:02 +00:00
Craig Topper ae9672c96d [APInt] Use ashInPlace where possible.
llvm-svn: 301101
2017-04-23 03:45:59 +00:00
Akira Hatanaka 22e839f4b2 [AArch64] Improve code generation for logical instructions taking
immediate operands.

This commit adds an AArch64 dag-combine that optimizes code generation
for logical instructions taking immediate operands. The optimization
uses demanded bits to change a logical instruction's immediate operand
so that the immediate can be folded into the immediate field of the
instruction.

This recommits r300932 and r300930, which was causing dag-combine to
loop forever. The problem was that optimizeLogicalImm was returning
true even when there was no change to the immediate node (which happened
when the immediate was all zeros or ones), which caused dag-combine to
push and pop the same node to the work list over and over again without
making any progress.

This commit fixes the bug by returning false early in optimizeLogicalImm
if the immediate is all zeros or ones. Also, it changes the code to
compare the immediate with 0 or Mask rather than calling
countPopulation.

rdar://problem/18231627

Differential Revision: https://reviews.llvm.org/D5591

llvm-svn: 301019
2017-04-21 18:53:12 +00:00
Akira Hatanaka 78ccba6a20 Revert r300932 and r300930.
It seems that r300930 was creating an infinite loop in dag-combine when
compling the following file:

MultiSource/Benchmarks/MiBench/consumer-typeset/z21.c

llvm-svn: 300940
2017-04-21 01:31:50 +00:00
Akira Hatanaka 19077aaee0 [AArch64] Improve code generation for logical instructions taking
immediate operands.

This commit adds an AArch64 dag-combine that optimizes code generation
for logical instructions taking immediate operands. The optimization
uses demanded bits to change a logical instruction's immediate operand
so that the immediate can be folded into the immediate field of the
instruction.

This recommits r300913, which broke bots because I didn't fix a call to
ShrinkDemandedConstant in SIISelLowering.cpp after changing the APIs of
TargetLoweringOpt and TargetLowering.

rdar://problem/18231627

Differential Revision: https://reviews.llvm.org/D5591

llvm-svn: 300930
2017-04-21 00:05:16 +00:00
Akira Hatanaka 7b06cebe73 Revert "[AArch64] Improve code generation for logical instructions taking"
This reverts r300913.

This broke bots.

llvm-svn: 300916
2017-04-20 23:03:30 +00:00
Akira Hatanaka e327f09832 [AArch64] Improve code generation for logical instructions taking
immediate operands.

This commit adds an AArch64 dag-combine that optimizes code generation
for logical instructions taking immediate operands. The optimization
uses demanded bits to change a logical instruction's immediate operand
so that the immediate can be folded into the immediate field of the
instruction.

rdar://problem/18231627

Differential Revision: https://reviews.llvm.org/D5591

llvm-svn: 300913
2017-04-20 22:47:56 +00:00
Craig Topper bcfd2d1789 [APInt] Rename getSignBit to getSignMask
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.

Differential Revision: https://reviews.llvm.org/D32108

llvm-svn: 300856
2017-04-20 16:56:25 +00:00
Craig Topper 9ce5ef9475 [SelectionDAG] Fix another place that was passing a large value to APInt::lshrInPlace.
llvm-svn: 300821
2017-04-20 04:55:01 +00:00
Craig Topper d3884b8402 [SelectionDAG] Use getActiveBits() and countTrailingZeros() to avoid creating temporary APInts with lshr and trunc. NFCI
llvm-svn: 300819
2017-04-20 04:23:43 +00:00
Craig Topper 4db0c69373 Recommit "[APInt] Add back the asserts that check that the APInt shift methods aren't called with values larger than BitWidth."
This includes a fix to clamp a right shift of larger than BitWidth in DAG combining.

llvm-svn: 300816
2017-04-20 03:49:18 +00:00
Sanjay Patel ae382bb6af [DAG] add splat vector support for 'xor' in SimplifyDemandedBits
This allows forming more 'not' ops, so we get improvements for ISAs that have and-not.

Follow-up to:
https://reviews.llvm.org/rL300725

llvm-svn: 300763
2017-04-19 21:23:09 +00:00
Sanjay Patel ded7d59f0e [DAG] add splat vector support for 'and' in SimplifyDemandedBits
The patch itself is simple: stop discriminating against vectors in visitAnd() and again in 
SimplifyDemandedBits().

Some notes for reference:

1. We're not consistent about calls to SimplifyDemandedBits in the various visitXXX functions. 
   Sometimes, we check if the RHS is a constant first. Other times (like here), we just dive in.
2. I'd like to break the vector shackles in steps for the sake of risk minimization, but we could
    make similar simultaneous changes in other places if we think that would be better.
3. I don't know what the intent of the changed tests in this patch was supposed to be, but since 
   they wiggled in a positive way, I'm just going with that. :)
4. In the rotate tests, note that we can see through non-splat constants. This is a result of D24253.
5. My motivation for being here now is to make D31944 look better, so this is step 1 of N towards 
   improving the vector codegen in that patch without writing any actual new code.

Differential Revision: https://reviews.llvm.org/D32230

llvm-svn: 300725
2017-04-19 18:05:06 +00:00
Craig Topper fc947bcfba [APInt] Use lshrInPlace to replace lshr where possible
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.

This adds an lshrInPlace(const APInt &) version as well.

Differential Revision: https://reviews.llvm.org/D32155

llvm-svn: 300566
2017-04-18 17:14:21 +00:00
Reid Kleckner fb502d2f5e [IR] Make paramHasAttr to use arg indices instead of attr indices
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.

Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.

llvm-svn: 300367
2017-04-14 20:19:02 +00:00
Craig Topper 8b459c24f3 [SelectionDAG] Use APInt move assignment to avoid 2 memory allocations and copies when bit width is larger than 64-bits.
llvm-svn: 300091
2017-04-12 18:39:27 +00:00
Craig Topper 3606e732dd [SelectionDAG] TargetLowering::SimplifyDemandedBits how to properly calculate KnownZero bits for ISD::SETCC and ISD::AssertZExt
Summary:
For SETCC we aren't calculating the KnownZero bits at all. I've copied the code from computeKnownZero over for this.

For AssertZExt we were only setting KnownZero for bits that were demanded. But the upper bits are zero whether they were demanded or not.

I'm interested in fixing this because my belief is the first part of the ISD::AND handling code in SimplifyDemandedBits largely exists because of these two bugs. In that code we go to computeKnownBits for the LHS and optimize a RHS constant. Because computeKnownBits handles SETCC and AssertZExt correctly we get better information sometimes than when we call SimplifyDemandedBits on the LHS later. With these two issues fixed in SimplifyDemandedBits I was able to remove that computeKnownBits call and still pass all X86 tests. I'll submit that change in a separate patch.

Reviewers: RKSimon, spatel

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31715

llvm-svn: 299839
2017-04-10 07:06:44 +00:00
Craig Topper 2ca72f4971 Revert accidental commit of r299619.
llvm-svn: 299622
2017-04-06 04:04:10 +00:00
Craig Topper 6b15606051 Revert accidental commit of r299618
llvm-svn: 299621
2017-04-06 04:03:34 +00:00
Craig Topper 5d7ece8895 bar
llvm-svn: 299619
2017-04-06 04:02:31 +00:00
Craig Topper faf5a8553c foo
llvm-svn: 299618
2017-04-06 04:02:28 +00:00
Simon Pilgrim 3c81c34d8d [DAGCombiner] Add vector demanded elements support to ComputeNumSignBits
Currently ComputeNumSignBits returns the minimum number of sign bits for all elements of vector data, when we may only be interested in one/some of the elements.

This patch adds a DemandedElts argument that allows us to specify the elements we actually care about. The original ComputeNumSignBits implementation calls with a DemandedElts demanding all elements to match current behaviour. Scalar types set this to 1.

I've only added support for BUILD_VECTOR and EXTRACT_VECTOR_ELT so far, all others will default to demanding all elements but can be updated in due course.

Followup to D25691.

Differential Revision: https://reviews.llvm.org/D31311

llvm-svn: 299219
2017-03-31 13:54:09 +00:00
Simon Pilgrim 37b536e4b3 [DAGCombiner] Add vector demanded elements support to computeKnownBitsForTargetNode
Follow up to D25691, this sets up the plumbing necessary to support vector demanded elements support in known bits calculations in target nodes.

Differential Revision: https://reviews.llvm.org/D31249

llvm-svn: 299201
2017-03-31 11:24:16 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Nirav Dave ac6081cb67 Make library calls sensitive to regparm module flag (Fixes PR3997).
Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050

llvm-svn: 298179
2017-03-18 00:44:07 +00:00
Nirav Dave 6de2c77944 Capitalize ArgListEntry fields. NFC.
llvm-svn: 298178
2017-03-18 00:43:57 +00:00
Craig Topper bcb6093610 [CodeGen] Use APInt::setLowBits/setHighBits/setBitsFrom in more places
This patch replaces ORs with getHighBits/getLowBits etc. with setLowBits/setHighBits/setBitsFrom.

In a few of the places we weren't ORing, but the KnownZero/KnownOne vectors were already initialized to zero. We exploit this in most places already there were just some that were inconsistent.

Differential Revision: https://reviews.llvm.org/D30965

llvm-svn: 297860
2017-03-15 16:53:53 +00:00
Sam Parker 916b1ba617 [ARM] Move SMULW[B|T] isel to DAG Combine
Create nodes for smulwb and smulwt and move their selection from
DAGToDAG to DAG combine. smlawb and smlawt can then be selected
using tablegen. Added some helper functions to detect shift patterns
as well as a wrapper around SimplifyDemandBits. Added a couple of
extra tests.

Differential Revision: https://reviews.llvm.org/D30708

llvm-svn: 297716
2017-03-14 09:13:22 +00:00
Simon Pilgrim cf12b5e1a6 Use APInt::getOneBitSet instead of APInt::getBitsSet for sign bit mask creation
Avoids all the unnecessary extra bitrange creation/shift stages.

llvm-svn: 296879
2017-03-03 16:35:57 +00:00
Sanjay Patel 0557a44287 [TargetLowering] fix SETCC SETLT folding with FP types
The bug was introduced with:
https://reviews.llvm.org/rL294863

...and manifests as a selection failure in x86, but that's actually
another bug. This fix prevents wrong codegen with -0.0, but in the
more common case when we have NSZ and NNAN (-ffast-math), we should 
still be able to fold this setcc/compare.

llvm-svn: 294924
2017-02-12 23:07:52 +00:00
Sanjay Patel 63499b61c9 [TargetLowering] check for sign-bit comparisons in SimplifyDemandedBits
I don't know if anything other than x86 vectors is affected by this change, but this may allow 
us to remove target-specific intrinsics for blendv* (vector selects). The simplification arises
from the fact that blendv* instructions only use the sign-bit when deciding which vector element
to choose for the destination vector. The mechanism to fold VSELECT into SHRUNKBLEND nodes already
exists in x86 lowering; this demanded bits change just enables the transform to fire more often.

The original motivation starts with a bug for DSE of masked stores that seems completely unrelated, 
but I've explained the likely steps in this series here:
https://llvm.org/bugs/show_bug.cgi?id=11210

Differential Revision: https://reviews.llvm.org/D29687

llvm-svn: 294863
2017-02-11 18:01:55 +00:00
Sanjay Patel 8c99ca3df0 [TargetLowering] fix formatting and comments for ShrinkDemandedConstant; NFC
llvm-svn: 294325
2017-02-07 18:04:26 +00:00
Matt Arsenault 32e6bfa20f DAG: Fold fneg into compare with constant into the constant
fcmp (fneg x), c, pred -> fcmp x, -c, (swap pred)

InstCombine already does this.

llvm-svn: 293512
2017-01-30 17:57:28 +00:00
Krzysztof Parzyszek ee9aa3ffee Add iterator_range<regclass_iterator> to {Target,MC}RegisterInfo, NFC
llvm-svn: 293077
2017-01-25 19:29:04 +00:00
Matt Arsenault 0b382a7cb8 DAG: Avoid OOB when legalizing vector indexing
If a vector index is out of bounds, the result is supposed to be
undefined but is not undefined behavior. Change the legalization
for indexing the vector on the stack so that an out of bounds
index does not create an out of bounds memory access.

llvm-svn: 291604
2017-01-10 22:02:30 +00:00
Simon Pilgrim bf9c0e7434 [SelectionDAG] Use SelectionDAG.getBuildVector helper. NFCI.
Makes interception of BUILD_VECTOR creation easier for debugging.

llvm-svn: 289218
2016-12-09 15:23:41 +00:00
Nicolai Haehnle f08dc90253 [SelectionDAG] Add expansion and promotion of [US]MUL_LOHI
Summary:
Most targets set the action for these nodes to Expand even though there
isn't actually any code for them in ExpandNode. Instead, targets simply
relied on the fact that no code generates these nodes as long as the
nodes aren't legal or custom.

However, generating these nodes can be useful e.g. for divide-by-constant
in wider integer types.

Expand of [US]MUL_LOHI will use MULH[US] when legal or custom, and
a sequence of half-width multiplications otherwise. Promote uses a wider
multiply.

This patch intends to not change the generated code, but indirect effects
are possible since expansions/promotions that were previously done in
DAGCombine may now be done in LegalizeDAG.

See D24822 for a change that actually uses the new expansion.

Reviewers: spatel, bkramer, venkatra, efriedma, hfinkel, ast, nadav, tstellarAMD

Subscribers: arsenm, jyknight, nemanjai, wdng, nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D24956

llvm-svn: 289050
2016-12-08 14:08:14 +00:00
Sanjay Patel 1f158d6955 [TargetLowering] add special-case for demanded bits analysis of 'not'
We treat bitwise 'not' as a special operation and try not to reduce its all-ones mask. 
Presumably, this is because a 'not' may be cheaper than a generic 'xor' or it may get
folded into another logic op if the target has those. However, if we can remove a logic
instruction by changing the xor's constant mask value, that should always be a win.

Note that the IR version of SimplifyDemandedBits() does not treat 'not' as a special-case
currently (although that's marked with a FIXME). So if you run this IR through -instcombine,
you should get the same end result. I'm hoping to add a different backend transform that 
will expose this problem though, so I need to solve this first.

Differential Revision: https://reviews.llvm.org/D27356

llvm-svn: 288676
2016-12-05 15:58:21 +00:00
Nicolai Haehnle 73a9a27b5a [SelectionDAG] Refactor TargetLowering::expandMUL (NFC)
Summary: Further preparation for the expansion of MUL_LOHI added in D24956.

Reviewers: efriedma, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27064

llvm-svn: 288248
2016-11-30 16:26:33 +00:00
Nicolai Haehnle 934470f536 [SelectionDAG] Early-out in TargetLowering::expandMUL (NFC)
Summary: Reduce indentation level; preparation for D24956.

Reviewers: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27063

llvm-svn: 287831
2016-11-23 22:14:20 +00:00
Elena Demikhovsky 09375d98b8 Type legalization for compressstore and expandload intrinsics.
Implemented widening (v2f32) and splitting (v16f64).
On splitting, I use "popcnt" to calculate memory increment. 
More type legalization work will come in the next patches.

llvm-svn: 287761
2016-11-23 13:58:24 +00:00
Simon Pilgrim c4d733cd6a Fix spelling in comment. NFC.
llvm-svn: 287222
2016-11-17 12:03:05 +00:00
Simon Pilgrim 778596bf59 [TargetLowering] Fix undef vector element issue with true/false result handling
Fixed an issue with vector usage of TargetLowering::isConstTrueVal / TargetLowering::isConstFalseVal boolean result matching.

The comment said we shouldn't handle constant splat vectors with undef elements. But the the actual code was returning false if the build vector contained no undef elements....

This patch now ignores the number of undefs (getConstantSplatNode will return null if the build vector is all undefs).

The change has also unearthed a couple of missed opportunities in AVX512 comparison code that will need to be addressed.

Differential Revision: https://reviews.llvm.org/D26031

llvm-svn: 286238
2016-11-08 15:07:01 +00:00
Sanjay Patel 70c5f02d25 [DAG] disable nsw/nuw for add/sub/mul when simplifying based on demanded bits (PR30841)
This bug was exposed by using nsw/nuw for more aggressive folds in:
https://reviews.llvm.org/rL284844

The changes mimic the IR demanded bits logic in InstCombiner::SimplifyDemandedUseBits(),
but we can't just flip flag bits in the DAG; we have to create a new node that has the
bits cleared.

This should fix:
https://llvm.org/bugs/show_bug.cgi?id=30841 

llvm-svn: 285656
2016-10-31 23:28:45 +00:00
Tom Stellard ab61007914 TargetLowering: Add SimplifyDemandedBits() helper to TargetLoweringOpt
Summary:
The main purpose of this new helper is to enable simplifying operations that
have multiple uses.  SimplifyDemandedBits does not handle multiple uses
currently, and this new function makes it possible to optimize:

and v1, v0, 0xffffff
mul24 v2, v1, v1      ; Multiply ignoring high 8-bits.

To:

mul24 v2, v0, v0

Where before this would not be optimized, because v1 has multiple uses.

Reviewers: bogner, arsenm

Subscribers: nhaehnle, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D24964

llvm-svn: 284266
2016-10-14 19:14:26 +00:00
Sanjay Patel b1f0a0f4a8 getValueType().getSizeInBits() -> getValueSizeInBits() ; NFCI
llvm-svn: 281493
2016-09-14 16:05:51 +00:00
Sanjay Patel 5f6bb6cd24 getValueType().getScalarSizeInBits() -> getScalarValueSizeInBits() ; NFCI
llvm-svn: 281490
2016-09-14 15:43:44 +00:00
Sanjay Patel bd6fca1419 getScalarType().getSizeInBits() -> getScalarSizeInBits() ; NFCI
llvm-svn: 281489
2016-09-14 15:21:00 +00:00
Simon Pilgrim 153b408433 [SelectionDAG] Ensure DAG::getZeroExtendInReg is called with a scalar type
Fixes issue with rL280927 identified by Mikael Holmén

llvm-svn: 281042
2016-09-09 13:31:52 +00:00
Simon Pilgrim cc7b4b511b [SelectionDAG] Add BUILD_VECTOR support to computeKnownBits and SimplifyDemandedBits
Add the ability to computeKnownBits and SimplifyDemandedBits to extract the known zero/one bits from BUILD_VECTOR, returning the known bits that are shared by every vector element.

This is an initial step towards determining the sign bits of a vector (PR29079).

Differential Revision: https://reviews.llvm.org/D24253

llvm-svn: 280927
2016-09-08 12:57:51 +00:00
Justin Bogner cd1d5aaf2e Replace a few more "fall through" comments with LLVM_FALLTHROUGH
Follow up to r278902. I had missed "fall through", with a space.

llvm-svn: 278970
2016-08-17 20:30:52 +00:00
Pierre Gousseau 051db7d838 [x86] Refactor a PowerPC specific ctlz/srl transformation (NFC).
Following the discussion on D22038, this refactors a PowerPC specific setcc -> srl(ctlz) transformation so it can be used by other targets.

Differential Revision: https://reviews.llvm.org/D23445

llvm-svn: 278799
2016-08-16 13:53:53 +00:00
Eli Friedman 98151d6440 Fix typo in lowering for fp128 ueq.
Regression from r259791.

Differential Revision: https://reviews.llvm.org/D23374

llvm-svn: 278750
2016-08-15 21:46:19 +00:00
Michael Kuperstein c97da7f3a4 [DAGCombine] Make sext(setcc) combine respect getBooleanContents
We used to combine "sext(setcc x, y, cc) -> (select (setcc x, y, cc), -1, 0)"
Instead, we should combine to (select (setcc x, y, cc), T, 0) where the value
of T is 1 or -1, depending on the type of the setcc, and getBooleanContents()
for the type if it is not i1.

This fixes PR28504.

llvm-svn: 277371
2016-08-01 19:39:49 +00:00
Matthias Braun 941a705b7b MachineFunction: Return reference for getFrameInfo(); NFC
getFrameInfo() never returns nullptr so we should use a reference
instead of a pointer.

llvm-svn: 277017
2016-07-28 18:40:00 +00:00
Elena Demikhovsky 2c0780b8e5 AVX-512: Fixed BT instruction selection.
The following condition expression ( a >> n) & 1 is converted to "bt a, n" instruction. It works on all intel targets.
But on AVX-512 it was broken because the expression is modified to (truncate (a >>n) to i1).

I added the new sequence (truncate (a >>n) to i1) to the BT pattern.

Differential Revision: https://reviews.llvm.org/D22354

llvm-svn: 275950
2016-07-19 07:14:21 +00:00
Justin Lebar 9c375817ac [SelectionDAG] Get rid of bool parameters in SelectionDAG::getLoad, getStore, and friends.
Summary:
Instead, we take a single flags arg (a bitset).

Also add a default 0 alignment, and change the order of arguments so the
alignment comes before the flags.

This greatly simplifies many callsites, and fixes a bug in
AMDGPUISelLowering, wherein the order of the args to getLoad was
inverted.  It also greatly simplifies the process of adding another flag
to getLoad.

Reviewers: chandlerc, tstellarAMD

Subscribers: jholewinski, arsenm, jyknight, dsanders, nemanjai, llvm-commits

Differential Revision: http://reviews.llvm.org/D22249

llvm-svn: 275592
2016-07-15 18:27:10 +00:00
Rafael Espindola db6bd02185 Delete unused includes. NFC.
llvm-svn: 274225
2016-06-30 12:19:16 +00:00
Rafael Espindola b1556c42ce Use isPositionIndependent in a few more places.
I think this converts all the simple cases that really just care about
the generated code being position independent or not. The remaining
uses are a bit more complicated and are checking things like "is this
a library or executable" or "can this symbol be preempted".

llvm-svn: 274055
2016-06-28 20:13:36 +00:00
Rafael Espindola 3beef8d6db Move shouldAssumeDSOLocal to Target.
Should fix the shared library build.

llvm-svn: 273958
2016-06-27 23:15:57 +00:00
Rafael Espindola 0a68bf9627 Use isPositionIndependent predicate. NFC.
llvm-svn: 273830
2016-06-26 22:38:44 +00:00
Rafael Espindola 12bb38d367 Use isPositionIndependent predicate.
llvm-svn: 273828
2016-06-26 22:30:06 +00:00
Rafael Espindola ae0d866f56 Refactor a duplicated predicate. NFC.
llvm-svn: 273826
2016-06-26 22:13:55 +00:00
Rafael Espindola 88ae09e9be Use shouldAssumeDSOLocal in isOffsetFoldingLegal.
This makes it slightly more powerful for dynamic-no-pic.

llvm-svn: 273704
2016-06-24 18:48:36 +00:00
Krzysztof Parzyszek e116d500a7 [SDAG] Remove FixedArgs parameter from CallLoweringInfo::setCallee
The setCallee function will set the number of fixed arguments based
on the size of the argument list. The FixedArgs parameter was often
explicitly set to 0, leading to a lack of consistent value for non-
vararg functions.

Differential Revision: http://reviews.llvm.org/D20376

llvm-svn: 273403
2016-06-22 12:54:25 +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
Sanjay Patel f39f42d3fb [SelectionDAG] rename/move isKnownToBeAPowerOfTwo() from TargetLowering (NFC)
There are at least 2 places (DAGCombiner, X86ISelLowering) where this could be used instead
of ad-hoc and watered down code that is trying to match a power-of-2 pattern.

Differential Revision: http://reviews.llvm.org/D20439

llvm-svn: 270073
2016-05-19 15:53:52 +00:00
Sanjay Patel 91592568f9 [TargetLowering] make helper function for SetCC + and optimizations (NFC)
After looking at D19087 again, it occurred to me that we can do better. If we consolidate
the valueHasExactlyOneBitSet() transforms, we won't incur extra overhead from calling it a
2nd time, and we can shrink SimplifySetCC() a bit. No functional change intended.

Differential Revision: http://reviews.llvm.org/D20050

llvm-svn: 268932
2016-05-09 16:42:50 +00:00
Sanjay Patel c2751e7050 [x86, BMI] add TLI hook for 'andn' and use it to simplify comparisons
For the sake of minimalism, this patch is x86 only, but I think that at least
PPC, ARM, AArch64, and Sparc probably want to do this too.

We might want to generalize the hook and pattern recognition for a target like
PPC that has a full assortment of negated logic ops (orc, nand).

Note that http://reviews.llvm.org/D18842 will cause this transform to trigger
more often.

For reference, this relates to:
https://llvm.org/bugs/show_bug.cgi?id=27105
https://llvm.org/bugs/show_bug.cgi?id=27202
https://llvm.org/bugs/show_bug.cgi?id=27203
https://llvm.org/bugs/show_bug.cgi?id=27328

Differential Revision: http://reviews.llvm.org/D19087

llvm-svn: 268858
2016-05-07 15:03:40 +00:00
Sanjay Patel c91351c2b7 clean up; NFCI
llvm-svn: 268564
2016-05-04 22:39:36 +00:00
Matt Arsenault 7846d885ed LegalizeDAG: Move unaligned load/store expansion to TLI
When custom lowered, this is not called if the store is custom
lowered. Move it to be a utility function so targets can
easily expand unaligned accesses when custom lowering.

llvm-svn: 267029
2016-04-21 18:19:11 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Matthias Braun 46b0f03e12 TargetLowering: Factor out common code for tail call eligibility checking; NFC
llvm-svn: 266270
2016-04-14 01:10:42 +00:00
Tom Stellard 52686e4182 TargetRegisterInfo: Add getRegAsmName()
Summary:
The motivation for this new function is to move an invalid assumption
about the relationship between the names of register definitions in
tablegen files and their assembly names into TargetRegisterInfo, so that
we can begin working on fixing this assumption.

The current problem is that if you have a register definition in
TableGen like:

def MYReg0 : Register<"r0", 0>;

The function TargetLowering::getRegForInlineAsmConstraint() derives the
assembly name from the tablegen name: "MyReg0" rather than the given
assembly name "r0".  This is working, because on most targets the
tablegen name and the assembly names are case insensitive matches for
each other (e.g. def EAX : X86Reg<"eax", ...>

getRegAsmName() will allow targets to override this default assumption and
return the correct assembly name.

Reviewers: echristo, hfinkel

Subscribers: SamWot, echristo, hfinkel, llvm-commits

Differential Revision: http://reviews.llvm.org/D15614

llvm-svn: 265955
2016-04-11 16:21:12 +00:00
Manman Ren 9bfd0d03e9 Swift Calling Convention: add swifterror attribute.
A ``swifterror`` attribute can be applied to a function parameter or an
AllocaInst.

This commit does not include any target-specific change. The target-specific
optimization will come as a follow-up patch.

Differential Revision: http://reviews.llvm.org/D18092

llvm-svn: 265189
2016-04-01 21:41:15 +00:00
Matt Arsenault 46ba31650e LegalizeDAG: Don't replace vector store with integer if not legal
For the same reason as the corresponding load change.

Note that ExpandStore is completely broken for non-byte sized element
vector stores, but preserve the current broken behavior which has tests
for it. The behavior should be the same, but now introduces a new typed
store that is incorrectly split later rather than doing it directly.

llvm-svn: 264928
2016-03-30 21:15:18 +00:00
Matt Arsenault a4b1b6ea05 LegalizeDAG: Don't replace vector load with integer unless legal
On AMDGPU we want to be able to promote i64/f64 loads to v2i32.
If the access is unaligned, this would conclude that since i64 is legal,
it would convert it back to i64 and there is an endless legalization
loop.

Extract the logic for scalarizing the load into a new TargetLowering
function, where this can also replace the custom function AMDGPU
has for this.

llvm-svn: 264927
2016-03-30 21:15:10 +00:00
Manman Ren f46262e0b7 Swift Calling Convention: add swiftself attribute.
Differential Revision: http://reviews.llvm.org/D17866

llvm-svn: 264754
2016-03-29 17:37:21 +00:00
Sanjay Patel 7506852709 [DAG] use !isUndef() ; NFCI
llvm-svn: 263453
2016-03-14 18:09:43 +00:00