This allows better code size for aarch64 floating point materialization
in a future patch.
Reviewers: evandro
Differential Revision: https://reviews.llvm.org/D58690
llvm-svn: 356389
AMDGPU target run out of Subtarget feature flags hitting the limit of 64.
AssemblerPredicates uses at most uint64_t for their representation.
At the same time CodeGen has exhausted this a long time ago and switched
to a FeatureBitset with the current limit of 192 bits.
This patch completes transition to the bitset for feature bits extending
it to asm matcher and MC code emitter.
Differential Revision: https://reviews.llvm.org/D59002
llvm-svn: 355839
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.
Original commit message:
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355784
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.
llvm-svn: 355433
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355224
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
llvm-svn: 355099
At the moment, we mark every atomic memory access as being also volatile. This is unnecessarily conservative and prohibits many legal transforms (DCE, folding, etc..).
This patch removes MOVolatile from the MachineMemOperands of atomic, but not volatile, instructions. This should be strictly NFC after a series of previous patches which have gone in to ensure backend code is conservative about handling of isAtomic MMOs. Once it's in and baked for a bit, we'll start working through removing unnecessary bailouts one by one. We applied this same strategy to the middle end a few years ago, with good success.
To make sure this patch itself is NFC, it is build on top of a series of other patches which adjust code to (for the moment) be as conservative for an atomic access as for a volatile access and build up a test corpus (mostly in test/CodeGen/X86/atomics-unordered.ll)..
Previously landed
D57593 Fix a bug in the definition of isUnordered on MachineMemOperand
D57596 [CodeGen] Be conservative about atomic accesses as for volatile
D57802 Be conservative about unordered accesses for the moment
rL353959: [Tests] First batch of cornercase tests for unordered atomics.
rL353966: [Tests] RMW folding tests w/unordered atomic operations.
rL353972: [Tests] More unordered atomic lowering tests.
rL353989: [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface
rL354740: [Hexagon, SystemZ] Be super conservative about atomics
rL354800: [Lanai] Be super conservative about atomics
rL354845: [ARM] Be super conservative about atomics
Attention Out of Tree Backend Owners: This patch may break you. If it does, you can use the TLI getMMOFlags hook to restore the MOVolatile to any instruction you need to. (See llvm-dev thread titled "PSA: Changes to how atomics are handled in backends" started Feb 27, 2019.)
Differential Revision: https://reviews.llvm.org/D57601
llvm-svn: 355025
Since there is no "Load-and-Test-High" instruction, the 32 bit load of a
register to be compared with 0 can only be implemented with LT if the virtual
GRX32 register ends up in a low part (GR32 register).
This patch detects these cases and passes the GR32 registers (low parts) as
(soft) hints in getRegAllocationHints().
Review: Ulrich Weigand.
llvm-svn: 354935
This patch aims to make sure that any such constant that can be generated
with a vector instruction (for example VGBM) is recognized as such during
legalization and kept as a target independent node through post-legalize
DAGCombining.
Two new functions named isVectorConstantLegal() and loadVectorConstant()
replace old ways of handling vector/FP constants.
A new struct named SystemZVectorConstantInfo is used to cache the results of
isVectorConstantLegal() and pass them onto loadVectorConstant().
Support for fp128 constants in the presence of FeatureVectorEnhancements1
(z14) has been added.
Review: Ulrich Weigand
https://reviews.llvm.org/D58270
llvm-svn: 354896
As requested during review of D57601, be equally conservative for atomic MMOs as for volatile MMOs in all in tree backends. At the moment, all atomic MMOs are also volatile, but I'm about to change that.
Reviewed as part of https://reviews.llvm.org/D58490, with other backends still pending review.
llvm-svn: 354740
It seems there were some problem with using a .mir test. For some reason
doing '-stop-before=codegenprepare' and then '-start-before=codegenprepare'
on the output .mir file results in the NoVRegs Property after instruction
selection.
Recommitting the same test as an .ll file instead.
llvm-svn: 354160
isFPImmLegal() has been extended to recognize certain FP immediates that can
be built with VGM (Vector Generate Mask).
These scalar FP immediates (that were previously loaded from the constant
pool) are now selected as VGMF/VGMG in Select().
Review: Ulrich Weigand
https://reviews.llvm.org/D58003
llvm-svn: 353867
Since SystemZ supports counting of leading zeros with the FLOGR instruction,
isCheapToSpeculateCtlz() should return true, which it now does.
ISD::CTLZ_ZERO_UNDEF i32 is now handled the same way as ISD::CTLZ is, which
is needed since promotion to i64 is required and CTLZ_ZERO_UNDEF is only
expanded to CTLZ if it is Legal or Custom.
Review: Ulrich Weigand
https://reviews.llvm.org/D57710
llvm-svn: 353330
Don't lower BUILD_VECTORs to BYTE_MASK, but instead expose the BUILD_VECTORs
to the DAGCombiner and select them to VGBM in Select(). This allows the
DAGCombiner to understand the constant vector values.
For floating point, only all-zeros vectors are now generated with VGBM, as it
turned out to be somewhat complicated to handle any arbitrary constants,
while in practice this is very rare and hardly needed.
The SystemZ ISD opcodes z_byte_mask, z_vzero and z_vones have been removed.
Review: Ulrich Weigand
https://reviews.llvm.org/D57152
llvm-svn: 353325
The IPM sequence currently generated to compute the strcmp/memcmp
result will return INT_MIN for the "less than zero" case. While
this is in compliance with the standard, strictly speaking, it
turns out that common applications cannot handle this, e.g. because
they negate a comparison result in order to implement reverse
compares.
This patch changes code to use a different sequence that will result
in -2 for the "less than zero" case (same as GCC). However, this
requires that the two source operands of the compare instructions
are inverted, which breaks the optimization in removeIPMBasedCompare.
Therefore, I've removed this (and all of optimizeCompareInstr), and
replaced it with a mostly equivalent optimization in combineCCMask
at the DAGcombine level.
llvm-svn: 353304
I'm looking at adding a second INLINEASM opcode for better modeling asm-goto
as a terminator. Using the existing predicate will reduce teh number of
places that will need to use the new opcode.
llvm-svn: 353095
This cleans up all CallInst creation in LLVM to explicitly pass a
function type rather than deriving it from the pointer's element-type.
Differential Revision: https://reviews.llvm.org/D57170
llvm-svn: 352909
Summary:
Like with X86, this allows better DAG-level alias analysis and
alignment inference for wrapped addresses.
Reviewers: jonpa, uweigand
Reviewed By: uweigand
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D57407
llvm-svn: 352786
After creating new PHI instructions during isel pseudo expansion, the NoPHIs
property of MF should be reset in case it was previously set.
Review: Ulrich Weigand
llvm-svn: 352030
Two backend optimizations failed to handle cases when compiled with -g, due
to failing to consider DBG_VALUE instructions. This was in
SystemZTargetLowering::emitSelect() and
SystemZElimCompare::getRegReferences().
This patch makes sure that DBG_VALUEs are recognized so that they do not
affect these optimizations.
Tests for branch-on-count, load-and-trap and consecutive selects.
Review: Ulrich Weigand
https://reviews.llvm.org/D57048
llvm-svn: 351928
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
There are several vector instructions which may or may not set the
condition code register, depending on the value of an argument.
For codegen, we use two versions of the instruction, one that sets
CC and one that doesn't, which hard-code appropriate values of that
argument. But we also have a "generic" version of the instruction
that is used for the assembler/disassembler. These generic versions
should always be considered to clobber CC just to be safe.
llvm-svn: 349761
This patch fixes two deficiencies in current code that recognizes
the VLLEZ idiom:
- For the floating-point versions, we have ISel patterns that match
on a bitconvert as the top node. In more complex cases, that
bitconvert may already have been merged into something else.
Fix the patterns to match the inner nodes instead.
- For the 64-bit integer versions, depending on the surrounding code,
we may get either a DAG tree based on JOIN_DWORDS or one based on
INSERT_VECTOR_ELT. Use a PatFrags to simply match both variants.
llvm-svn: 349749
Current code in SystemZDAGToDAGISel::tryGather refuses to perform
any transformation if the Load SDNode has more than one use. This
(erronously) counts uses of the chain result, which prevents the
optimization in many cases unnecessarily. Fixed by this patch.
llvm-svn: 349748
We already have special code (DAG combine support for FP_ROUND)
to recognize cases where we an use a vector version of VLEDB to
perform two floating-point truncates in parallel, but equivalent
support for VLEDB (vector floating-point extends) has been
missing so far. This patch adds corresponding DAG combine
support for FP_EXTEND.
llvm-svn: 349746
When computing register allocation hints for a GRX32Bit register, make sure
that any of the hinted registers that are also copy hints are returned first
in the list.
Review: Ulrich Weigand.
llvm-svn: 349037
Adds fatal errors for any target that does not support the Tiny or Kernel
codemodels by rejigging the getEffectiveCodeModel calls.
Differential Revision: https://reviews.llvm.org/D50141
llvm-svn: 348585
A loaded value with multiple users compared with 0 will become a load and
test single instruction. The load is not folded in this case (multiple
users), but the compare instruction is eliminated.
This patch returns 0 cost for the icmp in these cases.
Review: Ulrich Weigand
https://reviews.llvm.org/D55111
llvm-svn: 348141
Three minor changes to these extra costs:
* For ICmp instructions, instead of adding 2 all the time for extending each
operand, this is only done if that operand is neither a load or an
immediate.
* The operands extension costs for divides removed, because we now use a high
cost already for the divide (20).
* The costs for lhsr/ashr extra costs removed as this did not seem useful.
Review: Ulrich Weigand
https://reviews.llvm.org/D55053
llvm-svn: 347961
CGF/CLGF compares an i64 register with a sign/zero extended loaded i32 value
in memory.
This patch makes such a load considered foldable and so gets a 0 cost.
Review: Ulrich Weigand
https://reviews.llvm.org/D54944
llvm-svn: 347735
AH, SH and MH costs are already covered in the cases where LHS is 32 bits and
RHS is 16 bits of memory sign-extended to i32.
As these instructions are also used when LHS is i16, this patch recognizes
that the loads will get folded then as well.
Review: Ulrich Weigand
https://reviews.llvm.org/D54940
llvm-svn: 347734
Single instructions exist for i8 and i16 comparisons of memory against a
small immediate.
This patch makes sure that if the load in these cases has a single user (the
ICmp), it gets a 0 cost (folded), and also that the ICmp gets a cost of 1.
Review: Ulrich Weigand
https://reviews.llvm.org/D54897
llvm-svn: 347733
Since byte-swapping loads and stores are supported, a 'load -> bswap' or
'bswap -> store' sequence should have the cost of one.
Review: Ulrich Weigand
https://reviews.llvm.org/D54870
llvm-svn: 347732
Summary:
Add a hook to the GCMetadataPrinter for emitting stack maps in
custom format. The hook will be called at stack map generation
time. The default stack map format is used if there is no hook.
For this to be useful a few data structures and accessors are
exposed from the StackMaps class, so the custom printer can
access the stack map data.
This patch authored by Cherry Zhang <cherryyz@google.com>.
Reviewers: thanm, apilipenko, reames
Reviewed By: reames
Subscribers: reames, apilipenko, nemanjai, javed.absar, kbarton, jsji, llvm-commits
Differential Revision: https://reviews.llvm.org/D53892
llvm-svn: 347584
Implement getIntrinsicInstrCost() and return costs reflecting that bswap can
be done with a vperm per vector register.
Review: Ulrich Weigand
https://reviews.llvm.org/D54789
llvm-svn: 347445
If a loaded value is replicated it is best to combine these two operations
into a VLREP (load and replicate), but isel will not produce this if the load
has other users as well.
This patch handles this by putting the other users of the load to use the
REPLICATE 0-element instead of the load. This way the load has only the
REPLICATE node as user, and we get a VLREP.
Review: Ulrich Weigand
https://reviews.llvm.org/D54264
llvm-svn: 346746
Improve getCastInstrCost() by respecting the different types of Src and Dst
for vector integer <-> fp conversions.
This means that extracting from integer becomes more expensive (by the
extraction penalty), and the extraction from fp becomes cheaper (no longer
has a false extraction penalty).
Review: Ulrich Weigand
https://reviews.llvm.org/D54423
llvm-svn: 346663
Iterate over all elements and count the number of uses among them for each
used load. Then make sure to REPLICATE the load which has the most uses in
order to minimize the number of needed element insertions.
Review: Ulrich Weigand
https://reviews.llvm.org/D54322
llvm-svn: 346637
A minor improvement of buildVector() that skips creating an
INSERT_VECTOR_ELT for a Value which has already been used for the
REPLICATE.
Review: Ulrich Weigand
https://reviews.llvm.org/D54315
llvm-svn: 346504
It was discovered in randomized testing that the SystemZ implementation of
shouldCoalesce() could be caused to crash when subreg liveness was
enabled. This was because an undef use of the virtual register was copied
outside current MBB at the point of shouldCoalesce() being called. For more
details, see https://bugs.llvm.org/show_bug.cgi?id=39276.
This patch changes the check for MBB locality from livein/liveout checks to
do checks for all instructions of both intervals being inside MBB. This
avoids the cases with dead defs / undef uses outside MBB, which are not
affecting liveness in/out of MBB.
The original test case included as a reduced .mir test case.
Review: Ulrich Weigand
https://reviews.llvm.org/D54197
llvm-svn: 346406
The main caller of this already has an MVT and several targets called getSimpleVT inside without checking isSimple. This makes the simpleness explicit.
llvm-svn: 346180
Let i8/i16 uint/sint to fp conversions cost 1 if operand is a load.
Since the load already does the extension, there is no extra cost (previously
returned 2).
Review: Ulrich Weigand
https://reviews.llvm.org/D54028
llvm-svn: 346009
Model this function more closely after the BasicTTIImpl version, with
separate handling of loads and stores. For loads, the set of actually loaded
vectors is checked.
This makes it more readable and just slightly more accurate generally.
Review: Ulrich Weigand
https://reviews.llvm.org/D53071
llvm-svn: 345998
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
Scalar i1 to fp conversions are done with a branch sequence, so it should
have a higher cost.
Review: Ulrich Weigand
https://reviews.llvm.org/D53924
llvm-svn: 345818
Adhemerval Zanella