Commit Graph

1839 Commits

Author SHA1 Message Date
Sanjay Patel
5e45666b12 [SelectionDAG] move splat util functions up from x86 lowering
This was supposed to be NFC, but the change in SDLoc
definitions causes instruction scheduling changes.

There's nothing x86-specific in this code, and it can
likely be used from DAGCombiner's simplifyVBinOp().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358930 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-22 22:43:36 +00:00
Sanjay Patel
6c4fc48cdc [SelectionDAG] soften splat mask assert/unreachable (PR41535)
These are general queries, so they should not die when given
a degenerate input like an all undef mask. Callers should be
able to deal with an op that will eventually be simplified away.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358761 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-19 15:31:11 +00:00
Tim Northover
e69580818f DAG: propagate whether an arg is a pointer for CallingConv decisions.
The arm64_32 ABI specifies that pointers (despite being 32-bits) should be
zero-extended to 64-bits when passed in registers for efficiency reasons. This
means that the SelectionDAG needs to be able to tell the backend that an
argument was originally a pointer, which is implmented here.

Additionally, some memory intrinsics need to be declared as taking an i8*
instead of an iPTR.

There should be no CodeGen change yet, but it will be triggered when AArch64
backend support for ILP32 is added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358398 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-15 12:03:54 +00:00
Bjorn Pettersson
e8116c4ea8 [SelectionDAG] Use KnownBits::computeForAddSub/computeForAddCarry
Summary:
Use KnownBits::computeForAddSub/computeForAddCarry
in SelectionDAG::computeKnownBits when doing value
tracking for addition/subtraction.

This should improve the precision of the known bits,
as we only used to make a simple estimate of known
zeroes. The KnownBits support functions are also
able to deduce bits that are known to be one in the
result.

Reviewers: spatel, RKSimon, nikic, lebedev.ri

Reviewed By: nikic

Subscribers: nikic, javed.absar, lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60460

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358372 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-15 07:19:11 +00:00
David Green
45a375eb6b Revert rL357745: [SelectionDAG] Compute known bits of CopyFromReg
Certain optimisations from ConstantHoisting and CGP rely on Selection DAG not
seeing through to the constant in other blocks. Revert this patch while we come
up with a better way to handle that.

I will try to follow this up with some better tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358113 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-10 18:00:41 +00:00
Simon Pilgrim
4cd136da59 [SelectionDAG] Add fcmp UNDEF handling to SelectionDAG::FoldSetCC
Second half of PR40800, this patch adds DAG undef handling to fcmp instructions to match the behavior in llvm::ConstantFoldCompareInstruction, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).

This involves a lot of tweaking to reduced tests as bugpoint loves to reduce fcmp arguments to undef........

Differential Revision: https://reviews.llvm.org/D60006

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357765 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-05 14:56:21 +00:00
Piotr Sobczak
959b42493f [SelectionDAG] Compute known bits of CopyFromReg
Summary:
Teach SelectionDAG how to compute known bits of ISD::CopyFromReg if
the virtual reg used has one def only.

This can be particularly useful when calling isBaseWithConstantOffset()
with the ISD::CopyFromReg argument, as more optimizations may get enabled
in the result.

Also add a missing truncation on X86, found by testing of this patch.

Change-Id: Id1c9fceec862d118c54a5b53adf72ada5d6daefa

Reviewers: bogner, craig.topper, RKSimon

Reviewed By: RKSimon

Subscribers: lebedev.ri, nemanjai, jvesely, nhaehnle, javed.absar, jsji, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59535

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357745 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-05 07:44:09 +00:00
Evandro Menezes
d71ea05ab7 [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357731 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-04 22:40:06 +00:00
Nirav Dave
cbcef203c2 [DAG] Set up infrastructure to avoid smart constructor-based dangling nodes
Summary:
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations without fully pruning unused result values. This results
in nodes that are never added to the worklist and therefore can not be
pruned.

Add a node inserter for the combiner to make sure such nodes have the
chance of being pruned. This allows a number of additional peephole
optimizations.

Reviewers: efriedma, RKSimon, craig.topper, jyknight

Reviewed By: jyknight

Subscribers: msearles, jyknight, sdardis, nemanjai, javed.absar, hiraditya, jrtc27, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58068

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357279 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-29 17:26:40 +00:00
Nirav Dave
1e93deac15 [DAG] Fix Lifetime Node ID hashing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357179 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-28 15:53:01 +00:00
Nirav Dave
b4adfc21eb Revert r356996 "[DAG] Avoid smart constructor-based dangling nodes."
This patch appears to trigger very large compile time increases in
halide builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357116 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-27 19:54:41 +00:00
Sanjay Patel
be69330b8e [SDAG] add simplifications for FP at node creation time
We have the folds for fadd/fsub/fmul already in DAGCombiner,
so it may be possible to remove that code if we can guarantee that
these ops are zapped before they can exist.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357029 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-26 20:54:15 +00:00
Nirav Dave
de6ac6d211 [DAG] Avoid smart constructor-based dangling nodes.
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations or not fully pruning unused result values. This can
result in nodes that are never added to the worklist and therefore can
not be pruned.

Add a node inserter as the current node deleter to make sure such
nodes have the chance of being pruned.

Many minor changes, mostly positive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356996 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-26 15:08:14 +00:00
Simon Pilgrim
92948ec17b [SelectionDAG] Add icmp UNDEF handling to SelectionDAG::FoldSetCC
First half of PR40800, this patch adds DAG undef handling to icmp instructions to match the behaviour in llvm::ConstantFoldCompareInstruction and SimplifyICmpInst, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).

This involved a lot of tweaking to reduced tests as bugpoint loves to reduce icmp arguments to undef........

Differential Revision: https://reviews.llvm.org/D59363

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356938 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-25 18:51:57 +00:00
Tim Renouf
9a80c7c838 [CodeGen] Prepare for introduction of v3 and v5 MVTs
AMDGPU would like to have MVTs for v3i32, v3f32, v5i32, v5f32. This
commit does not add them, but makes preparatory changes:

* Exclude non-legal non-power-of-2 vector types from ComputeRegisterProp
  mechanism in TargetLoweringBase::getTypeConversion.

* Cope with SETCC and VSELECT for odd-width i1 vector when the other
  vectors are legal type.

Some of this patch is from Matt Arsenault, also of AMD.

Differential Revision: https://reviews.llvm.org/D58899

Change-Id: Ib5f23377dbef511be3a936211a0b9f94e46331f8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356350 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-17 21:43:12 +00:00
Simon Pilgrim
5fd3b9019a [DAG] Move integer setcc %x, %x folding into FoldSetCC
First step towards PR40800 - I intend to move the float case in a separate future patch.

I had to tweak the (overly reduced) thumb2 test and the x86 widening test change is annoying (no longer rematerializable) but we should address this separately.

Differential Revision: https://reviews.llvm.org/D59244

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356040 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-13 11:08:57 +00:00
Simon Pilgrim
0280621b31 [DAG] FoldSetCC - reuse valuetype + ensure its simple.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355847 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-11 17:56:18 +00:00
Simon Pilgrim
4e3754ce69 [DAG] Move SetCC NaN handling into FoldSetCC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355845 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-11 17:43:10 +00:00
Sanjay Patel
33f09cfa49 [SDAG] move FP constant folding to helper function; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355411 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-05 16:42:33 +00:00
Simon Pilgrim
a53711984d Use SDValue::getConstantOperandAPInt helper where possible. NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355267 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-02 11:11:22 +00:00
Bjorn Pettersson
85de1fd399 Add support for computing "zext of value" in KnownBits. NFCI
Summary:
The description of KnownBits::zext() and
KnownBits::zextOrTrunc() has confusingly been telling
that the operation is equivalent to zero extending the
value we're tracking. That has not been true, instead
the user has been forced to explicitly set the extended
bits as known zero afterwards.

This patch adds a second argument to KnownBits::zext()
and KnownBits::zextOrTrunc() to control if the extended
bits should be considered as known zero or as unknown.

Reviewers: craig.topper, RKSimon

Reviewed By: RKSimon

Subscribers: javed.absar, hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58650

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355099 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-28 15:45:29 +00:00
Simon Pilgrim
13703d57e9 [SelectionDAG] Add demanded elts variants to isConstOrConstSplat helpers. NFCI.
These helpers extend the existing isConstOrConstSplat helper checks to support DemandedElts masks as well.

We already had a local version of this in SelectionDAG that computeKnownBits/ComputeNumSignBits made use of, but this adds the functionality directly to the BuildVectorSDNode node and extends isConstOrConstSplat etc. to use that.

This will allow us to reuse the functionality in SimplifyDemandedVectorElts/SimplifyDemandedBits.

Differential Revision: https://reviews.llvm.org/D58503

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354797 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-25 16:31:58 +00:00
Craig Topper
b3fc281e55 [LegalizeTypes][AArch64][X86] Make type legalization of vector (S/U)ADD/SUB/MULO follow getSetCCResultType for the overflow bits. Make UnrollVectorOverflowOp properly convert from scalar boolean contents to vector boolean contents
Summary:
When promoting the over flow vector for these ops we should use the target's desired setcc result type. This way a v8i32 result type will use a v8i32 overflow vector instead of a v8i16 overflow vector. A v8i16 overflow vector will cause LegalizeDAG/LegalizeVectorOps to have to use v8i32 and truncate to v8i16 in its expansion. By doing this in type legalization instead, we get the truncate into the DAG earlier and give DAG combine more of a chance to optimize it.

We also have to fix unrolling to use the scalar setcc result type for the scalarized operation, and convert it to the required vector element type after the scalar operation. We have to observe the vector boolean contents when doing this conversion. The previous code was just taking the scalar result and putting it in the vector. But for X86 and AArch64 that would have only put a the boolean value in bit 0 of the element and left all other bits in the element 0. We need to ensure all bits in the element are the same. I'm using a select with constants here because that's what setcc unrolling in LegalizeVectorOps used.

Reviewers: spatel, RKSimon, nikic

Reviewed By: nikic

Subscribers: javed.absar, kristof.beyls, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58567

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354753 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-24 19:23:36 +00:00
Matt Arsenault
90d12ee005 DAG: Add helper for creating shifts with correct type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354649 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-22 03:38:47 +00:00
Clement Courbet
1fe90de461 Re-land part of r354244 "[DAGCombiner] Eliminate dead stores to stack."
This part introduces the lifetime node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354578 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-21 12:59:36 +00:00
Craig Topper
febe1abd95 [SelectionDAG] Teach GetDemandedBits to look at the known zeros of the LHS when handling ISD::AND
If the LHS has known zeros, then the RHS immediate mask might have been simplified to remove those bits.

This patch adds a call to computeKnownBits to get the known zeroes to handle that possibility. I left an early out to skip the call if all of the demanded bits are set in the mask.

Differential Revision: https://reviews.llvm.org/D58464

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354514 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-20 20:52:26 +00:00
Nikita Popov
8781462495 [SDAG] Support vector UMULO/SMULO
Second part of https://bugs.llvm.org/show_bug.cgi?id=40442.

This adds an extra UnrollVectorOverflowOp() method to SDAG, because
the general UnrollOverflowOp() method can't deal with multiple results.

Additionally we need to expand UMULO/SMULO during vector op
legalization, as it may result in unrolling, which may need additional
type legalization.

Differential Revision: https://reviews.llvm.org/D57997

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354513 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-20 20:41:44 +00:00
Craig Topper
9bba64895e Revert r354498 "[X86] Add test case to show missed opportunity to remove an explicit AND on the bit position from BT when it has known zeros."
I accidentally committed more than just the test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354499 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-20 18:47:26 +00:00
Craig Topper
350bc2910b [X86] Add test case to show missed opportunity to remove an explicit AND on the bit position from BT when it has known zeros.
If the bit position has known zeros in it, then the AND immediate will likely be optimized to remove bits.

This can prevent GetDemandedBits from recognizing that the AND is unnecessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354498 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-20 18:45:38 +00:00
Clement Courbet
3cfd39d61c Revert r354244 "[DAGCombiner] Eliminate dead stores to stack."
Breaks some bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354245 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-18 08:24:29 +00:00
Clement Courbet
89d8d90473 [DAGCombiner] Eliminate dead stores to stack.
Summary:
A store to an object whose lifetime is about to end can be removed.

See PR40550 for motivation.

Reviewers: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D57541

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354244 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-18 07:59:01 +00:00
Philip Reames
359683ab14 [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface [NFC]
For D57601, we need to know whether the instruction is volatile.  We'd either have to pass yet another parameter, or just standardize on the MMO interface.  I chose the second.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353989 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-13 23:01:11 +00:00
Philip Reames
5a03a071de [SelectionDAG] Kill last uses of getAtomic w/o a MMO operand [NFC]
The helper function was used by only two callers, and largely ended up providing distinct functionality based on optional arguments and opcode.  Inline and simply to make the functionality much more clear.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353977 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-13 20:42:59 +00:00
Simon Pilgrim
86334b318c [DAG] Add optional AllowUndefs to isNullOrNullSplat
No change in default behaviour (AllowUndefs = false)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353646 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-10 17:42:15 +00:00
Sanjay Patel
3ebe457432 [SDAG] improve variable names; NFC
The version of FoldConstantArithmetic() that takes arbitrary nodes
was confusingly naming those nodes as constants when they might
not be; also "Cst" reads like "Cast".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352884 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-01 16:06:53 +00:00
Matt Arsenault
1f5f9eca96 Codegen support for atomicrmw fadd/fsub
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351851 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-22 18:36:06 +00:00
Chandler Carruth
6b547686c5 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Florian Hahn
b4620a4948 [SelectionDAG] Add getTokenFactor, which splits nodes with > 64k operands.
This functionality is required at multiple places which potentially
create large operand lists, like SelectionDAGBuilder or DAGCombiner.

Differential Revision: https://reviews.llvm.org/D56739

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351552 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-18 14:05:59 +00:00
Florian Hahn
f55e902740 [SelectionDAG] Add static getMaxNumOperands function to SDNode.
Summary:
Use this helper to make sure we use the same value at various places.
This will likely be needed at more places were we currently crash
because we use more operands than possible.

Also makes it easier to change in the future.

Reviewers: RKSimon, craig.topper, efriedma, aemerson

Reviewed By: RKSimon

Subscribers: hiraditya, arsenm, llvm-commits

Differential Revision: https://reviews.llvm.org/D56859

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351537 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-18 10:00:38 +00:00
Florian Hahn
82a2c96ee8 [SelectionDAG] Update check in createOperands to reflect max() is a valid value.
The value returned by max() is the last valid value, adjust the
comparison accordingly.

The code added in D55073 creates TokenFactors with max() operands.

Reviewers: aemerson, efriedma, RKSimon, craig.topper

Reviewed By: aemerson

Differential Revision: https://reviews.llvm.org/D56738

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351318 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-16 10:06:04 +00:00
Simon Pilgrim
70291ab191 [DAGCombiner] Enable sub saturation constant folding
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351072 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-14 15:28:53 +00:00
Simon Pilgrim
cfe0eb0ee4 [DAGCombiner] Add add/sub saturation undef handling
Match ConstantFolding.cpp:
(add_sat x, undef) -> -1
(sub_sat x, undef) -> 0

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351070 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-14 14:16:24 +00:00
Simon Pilgrim
1041c737ca [DAGCombiner] Enable add saturation constant folding
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351060 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-14 12:34:31 +00:00
Simon Pilgrim
09be36deab [SelectionDAG] Add type sanity assertions for add/sub saturation node creation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351055 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-14 11:56:59 +00:00
Craig Topper
d096eb7cf0 [X86] Add INSERT_SUBVECTOR to ComputeNumSignBits
This adds support for calculating sign bits of insert_subvector. I based it on the computeKnownBits.

My motivating case is propagating sign bits information across basic blocks on AVX targets where concatenating using insert_subvector is common.

Differential Revision: https://reviews.llvm.org/D56283

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350432 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-04 20:50:59 +00:00
Craig Topper
ead22e207a [SelectionDAG] Add SIGN_EXTEND_VECTOR_INREG support to computeKnownBits.
Differential Revision: https://reviews.llvm.org/D56168

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350179 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-31 19:09:30 +00:00
Richard Trieu
671f3a73df Add vtable anchor to classes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350142 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-29 02:02:13 +00:00
Justin Lebar
655a52dced [NVPTX] Allow libcalls that are defined in the current module.
The patch adds a possibility to make library calls on NVPTX.

An important thing about library functions - they must be defined within
the current module. This basically should guarantee that we produce a
valid PTX assembly (without calls to not defined functions). The one who
wants to use the libcalls is probably will have to link against
compiler-rt or any other implementation.

Currently, it's completely impossible to make library calls because of
error LLVM ERROR: Cannot select: i32 = ExternalSymbol '...'. But we can
lower ExternalSymbol to TargetExternalSymbol and verify if the function
definition is available.

Also, there was an issue with a DAG during legalisation. When we expand
instruction into libcall, the inner call-chain isn't being "integrated"
into outer chain. Since the last "data-flow" (call retval load) node is
located in call-chain earlier than CALLSEQ_END node, the latter becomes
a leaf and therefore a dead node (and is being removed quite fast).
Proposed here solution relies on another data-flow pseudo nodes
(ProxyReg) which purpose is only to keep CALLSEQ_END at legalisation and
instruction selection phases - we remove the pseudo instructions before
register scheduling phase.

Patch by Denys Zariaiev!

Differential Revision: https://reviews.llvm.org/D34708

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350069 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-26 19:12:31 +00:00
Craig Topper
4f8964c972 [X86] Use GetDemandedBits to simplify the operands of PMULDQ/PMULUDQ.
This is an alternative to what I attempted in D56057.

GetDemandedBits is a special version of SimplifyDemandedBits that allows simplifications even when the operand has other uses. GetDemandedBits will only do simplifications that allow a node to be bypassed. It won't create new nodes or alter any of the other users.

I had to add support for bypassing SIGN_EXTEND_INREG to GetDemandedBits.

Based on a patch that Simon Pilgrim sent me in email.

Fixes PR40142.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350059 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-24 19:40:20 +00:00
Simon Pilgrim
ad5be70b1a [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349907 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-21 14:56:18 +00:00