extractShiftForRotate may fail to return canonicalized shifts due to constant folding or other simplification that can occur in getNode()
Fixes Issue #57283
(ctpop x) == 1 --> (x != 0) && ((x & x-1) == 0)
Adjust the legality check to avoid the poor codegen on AArch64.
We probably only want to use popcount on this pattern when it
is a single instruction.
fixes#57225
Differential Revision: https://reviews.llvm.org/D132237
This patch builds on prior support patches to enable support for
variadic debug values in InstrRefLDV, allowing DBG_VALUE_LISTs to
have their ranges extended.
Differential Revision: https://reviews.llvm.org/D128212
musttail should be honored even in the presence of attributes like "disable-tail-calls". SelectionDAG properly handles this.
Update LangRef to explicitly mention that this is the semantics of musttail.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D132193
This patch adds the last of the changes required to enable
DBG_VALUE_LIST handling in InstrRefLDV, handling variadic debug values
during the transfer tracking step. Most of the changes are fairly
straightforward, and based around tracking multiple locations per
variable in TransferTracker::VLocTracker.
Differential Revision: https://reviews.llvm.org/D128211
In preparation for supporting DBG_VALUE_LIST in InstrRefLDV, this patch
adds the logic for emitting DBG_VALUE_LIST instructions from
InstrRefLDV. The logical changes here are fairly simple, with the main
change being that instead of directly prepending offsets to the DIExpr,
we use appendOpsToArg to modify the expression for individual debug
operands in the expression. The function emitLoc is also changed to take
a list of debug ops, with an empty list meaning an undef value.
Differential Revision: https://reviews.llvm.org/D128209
CodeGenPrepare pass can sink pointer comparison across statepoint
to the point of use (see comment in IR/SafepointIRVerifier.cpp)
Due to specifics of statepoints, it is still legal to have tied
def and use rewritten to the same register in TwoAddress pass.
However, properly updating LiveIntervals and LiveVariables becomes
complicated. For simplicity, let's fall back to generic handling of
tied registers when we detect such case.
TODO: This fixes functional (assertion) failure. Ideally we should
try to recompute new live range/liveness in place.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D132255
In preparation for adding support for DBG_VALUE_LIST instructions in
InstrRefLDV, this patch updates the logic for joining variables at block
joins to support joining variables that use multiple debug operands.
This is one of the more meaty "logical" changes, although the line count
isn't too high - this changes pickVPHILoc to find a valid joined
location for every operand, with part of the function being split off
into pickValuePHILoc which finds a location for a single operand.
Differential Revision: https://reviews.llvm.org/D128180
This interface allows a target to reject a proposed
SMS schedule. For Hexagon/PowerPC, all schedules
are accepted, leaving behavior unchanged. For ARM,
schedules which exceed register pressure limits are
rejected.
Also, two RegisterPressureTracker methods now need to be public so
that register pressure can be computed by more callers.
Reapplication of D128941/(reversion:D132037) with small fix.
Differential Revision: https://reviews.llvm.org/D132170
This completes the client side transition to the OperandValueInfo version of this routine. Backend TTI implementations still use the prior versions for now.
This patch fixes:
llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.h:330:5: error:
anonymous types declared in an anonymous union are an extension
[-Werror,-Wnested-anon-types]
In preparation for allowing InstrRefBasedLDV to handle DBG_VALUE_LIST,
this patch updates the internal representation that it uses to represent
debug values to store a list of values. This is one of the more
significant changes in terms of line count, but is fairly simple and
should not affect the output of this pass.
Differential Revision: https://reviews.llvm.org/D128177
`RegisterClassInfo` caches information like allocation orders and reuses
it for multiple machine functions where possible. However the `MCPhysReg
*CalleeSavedRegs` field used to test whether the set of callee saved
registers changed did not work: After D28566
`MachineRegisterInfo::getCalleeSavedRegs()` can return dynamically
computed CSR sets that are only valid while the `MachineRegisterInfo`
object of the current function exists.
This changes the code to make a copy of the CSR list instead of keeping
a possibly invalid pointer around.
Differential Revision: https://reviews.llvm.org/D132080
Currently, InstrRefLDV only handles DBG_VALUE instructions, not
DBG_VALUE_LIST, and as a result of this it handles these instructions
using functions that only work for that type of debug value, i.e. using
getOperand(0) to get the debug operand. This patch changes this to use
the generic debug value functions, such as getDebugOperand and
isDebugOffsetImm, as well as adding an IsVariadic field to the
DbgValueProperties class and a few other minor changes to acknowledge
DBG_VALUE_LISTs. Note that this patch does not add support for
DBG_VALUE_LIST here, but is a precursor to other patches that do add
that support.
Differential Revision: https://reviews.llvm.org/D128174
In the InstrRefBasedImpl for LiveDebugValues, we attempt to propagate
debug values through basic blocks in part by checking to see whether all
a variable's incoming debug values to a BB "agree", i.e. whether their
properties match and they refer to the same underlying value.
Prior to this patch, the check for agreement between incoming values
relied on exact equality, which meant that a VPHI and a Def DbgValue
that referred to the same underlying value would be seen as disagreeing.
This patch changes this behaviour to treat them as referring to the same
value, allowing the shared value to propagate into the BB.
Differential Revision: https://reviews.llvm.org/D125953
Following the comment's thread of D117235, I added checks for the widening + splitting case, which also causes a split with one of the resulting vectors to be empty. Due to the same issues described in that same thread, the `fixed-vectors-strided-store.ll` test is missing the widening + splitting case, while the same case in the `strided-vpload.ll` test requires to manually split the loaded vector.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D121784
Test for a case we observed after the initial implementation of D129997
landed, in which case we observed a crash while building the ppc64le
Linux kernel. In that case, we had one block with two exits, both to the
same successor. Removing one of the exits corrupted the
successor/predecessor lists.
So when we have an INLINEASM_BR, check a few things for each indirect
target:
1. that it exists.
2. that it is listed in our successors.
3. that its predecessor list contains the parent MBB of INLINEASM_BR.
This would have caught the regression discovered after D129997 landed,
after the pass that was problematic (early-tailduplication) rather than
getting a stack trace in a later pass (regalloc) that doesn't understand
the anomaly and crashes.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D130290
Registers used for arguments are listed as "live-ins" into the starting
basic block. This means we don't have to go through a potentially
expensive search through all possible argument registers when we only
care about used argument registers.
Differential Revision: https://reviews.llvm.org/D132181
This patch introduces the priority analysis and the priority advisor,
the default implementation, and the scaffolding for introducing the
other implementations of the advisor.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D131220
Extends findMoreOptimalIndexType to allow ISD::BUILD_VECTOR based
indices to be truncated when such truncation is lossless. This can
enable the use of 32bit gather/scatter indices thus making it less
likely to have to split a gather/scatter in two.
Depends on D125194
Differential Revision: https://reviews.llvm.org/D130533
* Replace getUserCost with getInstructionCost, covering all cost kinds.
* Remove getInstructionLatency, it's not implemented by any backends, and we should fold the functionality into getUserCost (now getInstructionCost) to make it easier for targets to handle the cost kinds with their existing cost callbacks.
Original Patch by @samparker (Sam Parker)
Differential Revision: https://reviews.llvm.org/D79483
TragetLowering had two last InstructionCost related `getTypeLegalizationCost()`
and `getScalingFactorCost()` members, but all other costs are processed in TTI.
E.g. it is not comfortable to use other TTI members in these two functions
overrided in a target.
Minor refactoring: `getTypeLegalizationCost()` now doesn't need DataLayout
parameter - it was always passed from TTI.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D117723
This is a potentially better alternative to D131452 that also
should avoid the infinite loop bug from:
issue #56403
This is again a minimal fix to reduce merging pain for the
release. But if this makes sense, then we might want to guard
all of the RTLIB generation (and other libcalls?) with a
similar name check.
Differential Revision: https://reviews.llvm.org/D131521
Improve copy statistics:
- Count copies from or to physical registers: They are used to model function parameters and calling conventions and the register allocator optimizes for them.
- Check physical registers assigned to virtual registers and stop counting "identity" `COPY`s where source and destination is the same physical registers; they will be removed in the `virtregmap` pass anyway.
Differential Revision: https://reviews.llvm.org/D131932
The current machine function splitter is reliant on profile data to do profile summary analysis to split blocks into cold section. This may sometimes limit the usage of machine function splitter especially in cases where we could do some form of static analysis to split out cold blocks if profile data is absent or profile data which may be faulty (Consider Sample PGO).
Of all code that could statically be marked cold Exception handling blocks are one of them (In fact BFI framework also tends to mark them as cold), and the most in size contribution. In my experiments I found out Exception handling pads and all code reachable from there account for up to 6-8% of the .text section on modern production binaries. This patch introduces a flag to split out all Exception handling blocks and blocks only reachable from Exceptional Handling pad to cold section. This flag has shown to give a performance win of up to 0.1% in terms of average cycles and instructions executed on internal facebook search service.
Reviewed By: snehasish
Differential Revision: https://reviews.llvm.org/D131824
This reverts commit 8c4aea438c.
Needed because buildbot failures (warnings) gave a clue that there was
a functional bug in the ARM rejection logic.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D132037
This interface allows a target to reject a proposed
SMS schedule. For Hexagon/PowerPC, all schedules
are accepted, leaving behavior unchanged. For ARM,
schedules which exceed register pressure limits are
rejected.
Also, two RegisterPressureTracker methods now need to be public so
that register pressure can be computed by more callers.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D128941
There are two different senses in which a block can be "address-taken".
There can be a BlockAddress involved, which means we need to map the
IR-level value to some specific block of machine code. Or there can be
constructs inside a function which involve using the address of a basic
block to implement certain kinds of control flow.
Mixing these together causes a problem: if target-specific passes are
marking random blocks "address-taken", if we have a BlockAddress, we
can't actually tell which MachineBasicBlock corresponds to the
BlockAddress.
So split this into two separate bits: one for BlockAddress, and one for
the machine-specific bits.
Discovered while trying to sort out related stuff on D102817.
Differential Revision: https://reviews.llvm.org/D124697
This patch fixes an issue where an instruction reading a whole register would be moved during register allocation into a spot where one of the subregisters was dead.
The code to check whether an instruction can be rematerialized at a given point or not was already checking for subranges to ensure that subregisters are live, but only when the instruction being moved was using a subregister, this patch changes that so the subranges are checked even when the moved instruction uses the full register.
This patch also adds a case to the original test for the subrange checking that trigger the issue described above.
The original subrange checking code was introduced in this revision: https://reviews.llvm.org/D115278
And I've encountered this issue on AMDGPUs while working with DPC++: https://github.com/intel/llvm/issues/6209
Essentially the greedy register allocator attempts to move the following instruction:
```
%3961:vreg_64 = V_LSHLREV_B64_e64 3, %3078:vreg_64, implicit $exec
```
From `@3440` into the body of a loop `@16312`, but `%3078` has the following live ranges:
```
%3078 [2224r,2240r:0)[2240r,3488B:1)[16192B,38336B:1) 0@2224r 1@2240r L0000000000000003 [2224r,3440r:0) 0@2224r L000000000000000C [2240r,3488B:0)[16192B,38336B:0) 0@2240r
```
So `@16312e` `%3078.sub1` is alive but `%3078.sub0` is dead, so this instruction being moved there leads to invalid memory accesses as `3078.sub0` ends up being trashed and the result of this instruction is used as part of an address calculation for a load.
On the original ticket this issue showed up on gfx906 and gfx90a but not on gfx908, this turned out to be because on gfx908 instead of moving the shift instruction into the loop, its value is spilled into an ACC register, gfx906 doesn't have ACC registers and for gfx90a ACC registers are used like regular vector registers and so aren't used for spilling.
With this patch the original application from the DPC++ ticket works properly on gfx906, and the result of the shift instruction is correctly spilled instead of moving the instruction in the loop.
Original Author: npmiller
Reviewed by: rampitec
Submitted by: rampitec
Differential Revision: https://reviews.llvm.org/D131884
Currently we treat initializers with init_seg(compiler/lib) as similar
to any other init_seg, they simply have a global variable in the proper
section (".CRT$XCC" for compiler/".CRT$XCL" for lib) and are added to
llvm.used. However, this doesn't match with how LLVM sees normal (or
init_seg(user)) initializers via llvm.global_ctors. This
causes issues like incorrect init_seg(compiler) vs init_seg(user)
ordering due to GlobalOpt evaluating constructors, and the
ability to remove init_seg(compiler/lib) initializers at all.
Currently we use 'A' for priorities less than 200. Use 200 for
init_seg(compiler) (".CRT$XCC") and 400 for init_seg(lib) (".CRT$XCL"),
which do not append the priority to the section name. Priorities
between 200 and 400 use ".CRT$XCC${Priority}". This allows for
some wiggle room for people/future extensions that want to add
initializers between compiler and lib.
Fixes#56922
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D131910
Static variables declared within a routine or lexical block should
be emitted with a non-qualified name. This allows the variables to
be visible to the Visual Studio watch window.
Differential Revision: https://reviews.llvm.org/D131400
When no landing pads exist for a function, `@LPStart` is undefined and must be omitted.
EH table is generally not emitted for functions without landing pads, except when the personality function is uknown (`!isNoOpWithoutInvoke(classifyEHPersonality(Per))`). In that case, we must omit `@LPStart` even when machine function splitting is enabled.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D131626
Currently there is no way to add in development features to the ML
regalloc evict advisor which is useful to have when working on feature
engineering/improving the current model. This patch adds in the ability
to add in development features to the ML regalloc evict advisor which
are gated by a runtime flag and not added in at all if not compiled in
LLVM development mode. This sets the stage for future work where we are
planning on upstreaming some of the newer features that we are currently
experimenting with.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D131209
This is a followup to D131350, which caused another problem for i64
types being split into i32 on i32 targets. This patch tries to make sure
that either Illegal types are OK, or that the element types of a
buildvector are legal and bigger than or equal to the size of the
original elements.
Differential Revision: https://reviews.llvm.org/D131883
This patch really just extends D39946 towards stores as well as loads.
While the patch is in SelectionDAGBuilder, it only applies to AVR (the
only target that supports unaligned atomic operations).
Differential Revision: https://reviews.llvm.org/D128483
The outer signext_inreg is redundant in the following:
Fold (signext_inreg (extract_subvector (zext|anyext|sext iN_value to _) _) from iN)
-> (extract_subvector (signext iN_value to iM))
Tests are precommitted and clone those by analogy from the AND case in
the same file. Add a negative test to check extension width is handled
correctly.
This patch supersedes D130700.
Differential Revision: https://reviews.llvm.org/D131503
These are guaranteed not to create undef/poison (although they may pass through) - the associated ISD::VALUETYPE node is also guaranteed never to generate poison
Reland commit 719658d078
The base RA support infrastructure that only allow a specific register
class be allocated in RA pss. Since greedy RA, basic RA derived from
base RA, they all allow allocating specific register class. Fast RA
doesn't support allocating register for specific register class. This
patch is to enable ShouldAllocateClass in fast RA, so that it can
support allocating register for specific register class.
Differential Revision: https://reviews.llvm.org/D131825
SimplifyMultipleUseDemandedBits shouldn't be creating general nodes like this - although we allow bitcasts, even general constant folding is avoided.
Removing it causes a number of regressions that need addressing first, but I've added a TODO for now.
TLS debug on AIX is not ready for now.
The location generated in no-integrated-as mode is wrong and
in integrated-as mode causes AIX linker error.
Reviewed By: Esme
Differential Revision: https://reviews.llvm.org/D130245
Expand TypePromotion pass to try to promote PHI-nodes in loops that are the
operand of a ZExt, using the ZExt's result type to determine the Promote Width.
Differential Revision: https://reviews.llvm.org/D111237
This patch makes the variants of `mm*_cast*` intel intrinsics that use `shufflevector(freeze(poison), ..)` emit efficient assembly.
(These intrinsics are planned to use `shufflevector(freeze(poison), ..)` after shufflevector's semantics update; relevant thread: D103874)
To do so, this patch
1. Updates `LowerAVXCONCAT_VECTORS` in X86ISelLowering.cpp to recognize `FREEZE(UNDEF)` operand of `CONCAT_VECTOR` in addition to `UNDEF`
2. Updates X86InstrVecCompiler.td to recognize `insert_subvector` of `FREEZE(UNDEF)` vector as its first operand.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D130339
canCreateUndefOrPoison currently only handles unary ops, but we intend to change that soon - this more closely matches the pushFreezeToPreventPoisonFromPropagating behaviour where the freeze is pushed up to a single operand value, as long as all others are guaranteed not to be poison/undef.
However, pushFreezeToPreventPoisonFromPropagating would freeze all uses of the value - whilst this variant requires the frozen value to be only used in the op - we can look at generalize multiple uses later if the need arises.
Currently fcopysign for VLS vectors lowers through NEON even when the
vector width is wider than a NEON vector, causing bad codegen as the
vectors are split. This patch causes SVE to be used for these vectors
instead, giving much better codegen on wide VLS vectors.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D128642
This is a follow-up patch to D130999. In the test, the MIR contains an
unreachable MBB but the code attempts to look it up in MLocs. This
patch fixes this issue by checking for the default-constructed value.
rdar://97226240
Differential Revision: https://reviews.llvm.org/D131453
The register operand of DBG_VALUE is not selected to a proper register
bank in both AArch64 and X86. This would cause getRegClass crash after
global ISel. After discussion, we think the MIR should assume all
vritual register should be set proper register class after global ISel,
so this patch is to fix the gap of DBG_VALUE for AArch64 and X86.
Differential Revision: https://reviews.llvm.org/D129037
The previous code overwrites VRMap for prologue stages during Phi
generation if a register spans many stages.
As a result, the wrong register is used as the one coming from
the prologue in Phis at later stages. (A process exists to correct
this, but it does not work in all cases.)
In addition, VRMap for prologue must be preserved until addBranches().
This patch fixes them by separating the map for Phis into a different
variable (VRMapPhi).
Reviewed By: bcahoon
Differential Revision: https://reviews.llvm.org/D127840
The build breakages should be addressed by d4abdd2e3d:
[CMake] Check CMAKE_CXX_STANDARD and error if it's to old
Thanks to Tobias and Roy for addressing these issues.
This patch adds basic support for a DAG variant of the canCreateUndefOrPoison call and updates DAGCombiner::visitFREEZE to use it, further Opcodes (including target specific Opcodes) can be handled when we have test coverage.
So far, I've left visitFREEZE to just use this for unary nodes (which currently means the existing BITCAST/FREEZE cases) - later patches will add other unary opcodes (with test coverage) and we can also refactor visitFREEZE to support a general number of operands like we do in InstCombinerImpl::pushFreezeToPreventPoisonFromPropagating.
I'm not aware of any vector test freeze coverage so the DemandedElts (and the Depth) args are not being used yet - but they are in place. Similarly we will be able to handle poison generating SDNodeFlags as and when it becomes an issue.
Part of the work for D106675 / PR50468
Differential Revision: https://reviews.llvm.org/D130646
This patch emits table lookup in expandCTTZ.
Context -
https://reviews.llvm.org/D113291 transforms set of IR instructions to
cttz intrinsic but there are some targets which does not support CTTZ or
CTLZ. Hence, I generate a table lookup in TargetLowering::expandCTTZ().
Differential Revision: https://reviews.llvm.org/D128911
FoldConstantArithmetic can fold constant vectors hidden behind bitcasts (e.g. vXi64 -> v2Xi32 on 32-bit platforms), but currently bails if either vector contains undef elements. These undefs can often occur due to SimplifyDemandedBits/VectorElts calls recognising that the upper bits are often unnecessary (e.g. funnel-shift/rotate implicit-modulo and AND masks).
This patch adds a basic 'FoldValueWithUndef' handler that will attempt to constant fold if one or both of the ops are undef - so far this just handles the AND and MUL cases where we always fold to zero.
The RISCV codegen increase is interesting - it looks like the BUILD_VECTOR lowering was loading a constant pool entry but now (with all elements defined constant) it can materialize the constant instead?
Differential Revision: https://reviews.llvm.org/D130839
D129150 added a combine from shuffles to And that creates a BUILD_VECTOR
of constant elements. We need to ensure that the elements are of a legal
type, to prevent asserts during lowering.
Fixes#56970.
Differential Revision: https://reviews.llvm.org/D131350
A const reference is preferred over a non-null const pointer.
`Type *` is kept as is to match the other overload.
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D131197
1) Overloaded (instruction-based) method is a wrapper around the current (opcode-based) method.
2) This patch also changes a few callsites (VectorCombine.cpp,
SLPVectorizer.cpp, CodeGenPrepare.cpp) to call the overloaded method.
3) This is a split of D128302.
Differential Revision: https://reviews.llvm.org/D131114
This just shuffles implementations and declarations around. Now the
logger and the TF C API-based model evaluator are separate.
Differential Revision: https://reviews.llvm.org/D131116
The testcase was delta-reduced from an LTO build with sanitizer
coverage and the MIR tail duplication pass caused a machine basic
block to become unreachable in MIR. This caused the MBB to be invisible
to the reverse post-order traversal used to initialize the MBB <->
RPONumber lookup tables.
rdar://97226240
Differential Revision: https://reviews.llvm.org/D130999
The function `handleDebugValue` has custom logic to handle certain kinds
constants, namely integers, floats and null pointers. However, it does
not handle constant pointers created from IntToPtr ConstantExpressions.
This patch addresses the issue by replacing the Constant with its
integer operand.
A similar bug was addressed for GlobalISel in D130642.
Reviewed By: aprantl, #debug-info
Differential Revision: https://reviews.llvm.org/D130908
This patch ensures consistency in the construction of FP_ROUND nodes
such that they always use ISD::TargetConstant instead of ISD::Constant.
This additionally fixes a bug in the AArch64 SVE backend where patterns
were matching against TargetConstant nodes and sometimes failing when
passed a Constant node.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D130370
In this patch we replace common code patterns with the use of utility
functions for dealing with profiling metadata. There should be no change
in functionality, as the existing checks should be preserved in all
cases.
Reviewed By: bogner, davidxl
Differential Revision: https://reviews.llvm.org/D128860
The LegalizerHelper misses the code to lower G_MUL to a library call,
which this change adds.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D130987
matchRotateSub is given shift amounts that will already have stripped any/zero-extend nodes from - so make sure those values are wide enough to take a mask.
Follow-up to D130434.
Move doSystemDiff to PrintPasses.cpp and call it in MachineFunctionPass.cpp.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D130833
Eliminate an AND by redefining an anyext|sext|zext.
(and (extract_subvector (anyext|sext|zext v) _) iN_mask)
=> (extract_subvector (zeroext_iN v))
Differential Revision: https://reviews.llvm.org/D130782
Salvage debug info of instruction that is about to be deleted as dead in
Combiner pass. Currently supported instructions are COPY and G_TRUNC.
It allows to salvage debug info of some dead arguments of functions, by putting
DWARF expression corresponding to the instruction being deleted into related
DBG_VALUE instruction.
Here is an example of missing variables location https://godbolt.org/z/K48osb9dK.
We see that arguments x, y of function foo are not available in debugger, and
corresponding DBG_VALUE instructions have undefined register operand instead of
variables locaton after Aarch64PreLegalizerCombiner pass. The reason is that
registers where variables are located are removed as dead (with instruction
G_TRUNC). We can use salvageDebugInfo analogue for gMIR to preserve debug
locations of dead variables.
Statistics of llvm object files built with vs without this commit on -O2
optimization level (CMAKE_BUILD_TYPE=RelWithDebInfo, -fglobal-isel) on Aarch64 (macOS):
Number of variables with 100% of parent scope covered by DW_AT_location has been increased by 7,9%.
Number of variables with 0% coverage of parent scope has been decreased by 1,2%.
Number of variables processed by location statistics has been increased by 2,9%.
Average PC ranges coverage has been increased by 1,8 percentage points.
Coverage can be improved by supporting more instructions, or by calling
salvageDebugInfo for instructions that are deleted during Combiner rules exection.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D129909
This belongs to a series of patches which try to solve the thread
identification problem in coroutines. See
https://discourse.llvm.org/t/address-thread-identification-problems-with-coroutine/62015
for a full background.
The problem consists of two concrete problems: TLS variable and readnone
functions. This patch tries to convert the TLS problem to readnone
problem by converting the access of TLS variable to an intrinsic which
is marked as readnone.
The readnone problem would be addressed in following patches.
Reviewed By: nikic, jyknight, nhaehnle, ychen
Differential Revision: https://reviews.llvm.org/D125291
Expand load address pseudo-instructions earlier (pre-ra) to allow follow-up
patches to fold the addi of PseudoLLA instructions into the immediate
operand of load/store instructions.
Differential Revision: https://reviews.llvm.org/D123264
This patch fixes the error llvm/lib/CodeGen/MachineScheduler.cpp(755): error C2065: 'MISchedCutoff': undeclared identifier in case of NDEBUG and LLVM_ENABLE_ABI_BREAKING_CHECKS.
Note MISchedCutoff is declared under #ifndef NDEBUG.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D130425
If the subregister uses were dead, this would leave the main range
segment pointing to a deleted instruction.
Not sure if this should try to avoid shrinking if we know we don't
have dead components.
Add a method for the various cases where we need to concatenate 2 KnownBits together (BUILD_PAIR and SHIFT_PARTS in particular) - uses the existing APInt::concat 'HiBits.concat(LoBits)' convention
Differential Revision: https://reviews.llvm.org/D130557
Currently, the LLVM IR -> MIR translator fails to translate dbg.values
whose first argument is a null pointer. However, in other portions of
the code, such pointers are always lowered to the constant zero, for
example see IRTranslator::Translate(Constant, Register).
This patch addresses the limitation by following the same approach of
lowering null pointers to zero.
A prior test was checking that null pointers were always lowered to
$noreg; this test is changed to check for zero, and the previous
behavior is now checked by introducing a dbg.value whose first argument
is the address of a global variable.
Differential Revision: https://reviews.llvm.org/D130721
The getOperand method already returns a Constant when it is called on
a ConstantExpression, as such the cast is not needed. To prevent a type
mismatch between the different return statements of the lambda, the
lambda return type is explicitly provided.
Differential Revision: https://reviews.llvm.org/D130719
GetDemandedBits is mainly a wrapper around SimplifyMultipleUseDemandedBits now, and is only used by DAGCombiner::visitSTORE so I've moved all remaining functionality there.
visitSTORE was making use of this to 'simplify' constants for a trunc-store. Just removing this code left to a mixture of regressions and gains - it came down to whether a target preferred a sign or zero extended constant for materialization/truncation. I've just moved the code over for now, but a next step would be to move this to targetShrinkDemandedConstant, but some targets that override the method expect a basic binop, and might react badly to a store node.....
I'm actually trying to get rid of GetDemandedBits - but while dismantling it I noticed that we were altering opaque constants. Fixing that causes a FP_TO_INT_SAT regression that should be addressed separately - I'll raise a bug.
This patch allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits in cases where the ISD::SRL source operand has other uses, enabling us to peek through the shifted value if we don't demand all the bits/elts.
This is another step towards removing SelectionDAG::GetDemandedBits and just using TargetLowering::SimplifyMultipleUseDemandedBits.
There a few cases where we end up with extra register moves which I think we can accept in exchange for the increased ILP.
Differential Revision: https://reviews.llvm.org/D77804
It simplifies the code overall and removes the need for manual bookkeeping.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D130447
It simplifies the code overall and removes the need for manual bookkeeping.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D130444
DebugLocEntry assumes that it either contains 1 item that has no fragment
or many items that all have fragments (see the assert in addValues).
When EXPENSIVE_CHECKS is enabled, _GLIBCXX_DEBUG is defined. On a few machines
I've checked, this causes std::sort to call the comparator even
if there is only 1 item to sort. Perhaps to check that it is implemented
properly ordering wise, I didn't find out exactly why.
operator< for a DbgValueLoc will crash if this happens because the
optional Fragment is empty.
Compiler/linker/optimisation level seems to make this happen
or not. So I've seen this happen on x86 Ubuntu but the buildbot
for release EXPENSIVE_CHECKS did not have this issue.
Add an explicit check whether we have 1 item.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D130156
tryLastChanceRecoloring iterates over the set of LiveInterval pointers
and used that to seed the recoloring stack, which was
nondeterministic. Fixes a future test failing about 20% of the time.
This just takes the order the interfering vreg was encountered. Not
sure if we should try to order this more intelligently.
In this patch we replace common code patterns with the use of utility
functions for dealing with profiling metadata. There should be no change
in functionality, as the existing checks should be preserved in all
cases.
Reviewed By: bogner, davidxl
Differential Revision: https://reviews.llvm.org/D128860
Currently, the IR to MIR translator can only handle two kinds of constant
inputs to dbg.values intrinsics: constant integers and constant floats. In
particular, it cannot handle pointers created from IntToPtr ConstantExpression
objects.
This patch addresses the limitation above by replacing the IntToPtr with
its input integer prior to converting the dbg.value input.
Patch by Felipe Piovezan!
Differential Revision: https://reviews.llvm.org/D130642
This adds similar heuristics to G_GLOBAL_VALUE, querying the cost of
materializing a specific constant in code size. Doing so prevents us from
sinking constants which require multiple instructions to generate into
use blocks.
Code size savings on CTMark -Os:
Program size.__text
before after diff
ClamAV/clamscan 381940.00 382052.00 0.0%
lencod/lencod 428408.00 428428.00 0.0%
SPASS/SPASS 411868.00 411876.00 0.0%
kimwitu++/kc 449944.00 449944.00 0.0%
Bullet/bullet 463588.00 463556.00 -0.0%
sqlite3/sqlite3 284696.00 284668.00 -0.0%
consumer-typeset/consumer-typeset 414492.00 414424.00 -0.0%
7zip/7zip-benchmark 595244.00 594972.00 -0.0%
mafft/pairlocalalign 247512.00 247368.00 -0.1%
tramp3d-v4/tramp3d-v4 372884.00 372044.00 -0.2%
Geomean difference -0.0%
Differential Revision: https://reviews.llvm.org/D130554
SimplifyDemandedBits currently early-outs for multi-use values beyond the root node (just returning the knownbits), which is missing a number of optimizations as there are plenty of cases where we can still simplify when initially demanding all elements/bits.
@lenary has confirmed that the test cases in aea-erratum-fix.ll need refactoring and the current increase codegen is not a major concern.
Differential Revision: https://reviews.llvm.org/D129765
This patch fixes the following error with MSVC 16.9.2 in case of NDEBUG and LLVM_ENABLE_DUMP:
llvm/lib/CodeGen/CodeGenPrepare.cpp(2581): error C2872: 'ExtAddrMode': ambiguous symbol
llvm/include/llvm/CodeGen/TargetInstrInfo.h(86): note: could be 'llvm::ExtAddrMode'
llvm/lib/CodeGen/CodeGenPrepare.cpp(2447): note: or '`anonymous-namespace'::ExtAddrMode'
llvm/lib/CodeGen/CodeGenPrepare.cpp(2581): error C2039: 'print': is not a member of 'llvm::ExtAddrMode'
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D130426
-print-changed for new pass manager is handy beside -print-after-all.
Port it to MachineFunctionPass.
Note: lib/Passes/StandardInstrumentations.cpp implements a number of
misc features. If we want to use them for codegen, we may need to lift
some functionality to LLVMIR.
Reviewed By: aeubanks, jamieschmeiser
Differential Revision: https://reviews.llvm.org/D130434
WinEHPrepare marks any function call from EH funclets as unreachable, if it's not a nounwind intrinsic or has no proper funclet bundle operand. This
affects ARC intrinsics on Windows, because they are lowered to regular function calls in the PreISelIntrinsicLowering pass. It caused silent binary truncations and crashes during unwinding with the GNUstep ObjC runtime: https://github.com/gnustep/libobjc2/issues/222
This patch adds a new function `llvm::IntrinsicInst::mayLowerToFunctionCall()` that aims to collect all affected intrinsic IDs.
* Clang CodeGen uses it to determine whether or not it must emit a funclet bundle operand.
* PreISelIntrinsicLowering asserts that the function returns true for all ObjC runtime calls it lowers.
* LLVM uses it to determine whether or not a funclet bundle operand must be propagated to inlined call sites.
Reviewed By: theraven
Differential Revision: https://reviews.llvm.org/D128190
This patch starts small, only detecting sequences of the form
<a, a+n, a+2n, a+3n, ...> where a and n are ConstantSDNodes.
Differential Revision: https://reviews.llvm.org/D125194
I think what we need is the least Log2(EltSize) significant bits are known to be ones.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D130251
Optimizing (a * 0 + b) to (b) requires assuming that a is finite and not
NaN. DAGCombiner will do this optimization when the reassoc fast math
flag is set, which is not correct. Change DAGCombiner to only consider
UnsafeMath for this optimization.
Differential Revision: https://reviews.llvm.org/D130232
Co-authored-by: Andrea Faulds <andrea.faulds@arm.com>
When using a ptrtoint to a size larger than the pointer width in a
global initializer, we currently create a ptr & low_bit_mask style
MCExpr, which will later result in a relocation error during object
file emission.
This patch rejects the constant expression already during
lowerConstant(), which results in a much clearer error message
that references the constant expression at fault.
This fixes https://github.com/llvm/llvm-project/issues/56400,
for certain definitions of "fix".
Differential Revision: https://reviews.llvm.org/D130366
This would create a new interval missing the subrange and hit this
verifier error:
*** Bad machine code: Live interval for subreg operand has no subranges ***
- function: test_remat_subreg_def
- basic block: %bb.0 (0xa568758) [0B;128B)
- instruction: 32B dead undef %4.sub0:vreg_64 = V_MOV_B32_e32 2, implicit $exec
We still haven't found a solution that correctly handles 'don't care' sub elements properly - given how close it is to the next release branch, I'm making this fail safe change and we can revisit this later if we can't find alternatives.
NOTE: This isn't a reversion of D128570 - it's the removal of undef handling across bitcasts entirely
Fixes#56520
llvm::sort is beneficial even when we use the iterator-based overload,
since it can optionally shuffle the elements (to detect
non-determinism). However llvm::sort is not usable everywhere, for
example, in compiler-rt.
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D130406
This will fix the SystemZ v3i31 memcpy regression in D77804 (with the help of D129765 as well....).
It should also allow us to /bend/ the oneuse limitation for cases where we can use demanded bits to safely peek though multiple uses of the AND ops.
As noticed on D127115, when splitting ADD/SUB nodes we often end up with cases where overflow from the lower bits is impossible - in such cases we're better off breaking the carry chain dependency as soon as possible.
This path is being exercised by llvm/test/CodeGen/ARM/dsp-mlal.ll, although I haven't been able to get any codegen diff without a topological worklist.
Concat KnownBits from ISD::SHL_PARTS / ISD::SRA_PARTS / ISD::SRL_PARTS lo/hi operands and perform the KnownBits calculation by the shift amount on the extended type, before splitting the KnownBits based on the requested lo/hi result.
This change adds a nop instruction if section starts with landing pad. This change is like [D73739](https://reviews.llvm.org/D73739) which avoids zero offset landing pad in basic block sections.
Detailed description:
The current machine functions splitter can create ˜sections which start with a landing pad themselves. This places landing pad at offset zero from LPStart.
```
.section .text.split.foo10,"ax",@progbits
foo10.cold: # %lpad
.cfi_startproc
.cfi_personality 3, __gxx_personality_v0
.cfi_lsda 3, .Lexception5
.cfi_def_cfa %rsp, 16
.Ltmp11: <--- This is a Landing pad and also LP Start as it is start of this section
movq %rax, %rdi <--- first instruction is at offest 0 from LPStart
callq _Unwind_Resume@PLT
```
This will cause landing pad entries to become zero (.Ltmp11-foo10.cold)
```
.Lcst_begin4:
.uleb128 .Ltmp9-.Lfunc_begin2 # >> Call Site 1 <<
.uleb128 .Ltmp10-.Ltmp9 # Call between .Ltmp9 and .Ltmp10
.uleb128 .Ltmp11-foo10.cold <---This is zero # jumps to .Ltmp11
.byte 3 # On action: 2
.uleb128 .Ltmp10-.Lfunc_begin2 # >> Call Site 2 <<
.uleb128 .Lfunc_end9-.Ltmp10 # Call between .Ltmp10 and .Lfunc_end9
.byte 0 # has no landing pad
.byte 0 # On action: cleanup
.p2align 2
```
The C++ ABI somehow assumes that no landing pads point directly to LPStart (which works in the normal case since the function begin is never a landing pad), and uses LP.offset = 0 to specify no landing pad. This change adds a nop instruction at start of such sections so that such a case could be avoided. Output:
```
.section .text.split.foo10,"ax",@progbits
foo10.cold: # %lpad
.cfi_startproc
.cfi_personality 3, __gxx_personality_v0
.cfi_lsda 3, .Lexception5
.cfi_def_cfa %rsp, 16
nop <--- new instruction that is added
.Ltmp11:
movq %rax, %rdi
callq _Unwind_Resume@PLT
```
Reviewed By: modimo, snehasish, rahmanl
Differential Revision: https://reviews.llvm.org/D130133
We were looking for loads or any_extend+load. reduceLoadWidth
hasn't known how to look through such an any_extend to find the
load since D40667 almost 5 years ago.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D130333
Move this out of the switch, so that different branches can
indicate an error by breaking out of the switch. This becomes
important if there are more than the two current error cases.
Vector fptosi_sat and fptoui_sat were being expanded by unrolling the
vector operation. This doesn't work for scalable vector, so this patch
adds a call to TLI.expandFP_TO_INT_SAT if the vector is scalable.
Scalable tests are added for AArch64 and RISCV. Some of the AArch64
fptoi_sat operations should be legal, but that will be handled in
another patch.
Differential Revision: https://reviews.llvm.org/D130028
Similar to what we already do in getNode for basic ADD/SUB nodes, return the X operand directly, but here we know that there will be no/zero overflow as well.
As noted on D127115 - this path is being exercised by llvm/test/CodeGen/ARM/dsp-mlal.ll, although I haven't been able to get any codegen without a topological worklist.
PromoteIntRes_BUILD_VECTOR currently always ANY_EXTENDs build vector operands, but if this is a constant boolean vector we're losing the useful ability to keep the vector matching the BooleanContents mode used by the target.
This patch extends constant boolean vectors according to target BooleanContents, allowing a number of additional all-bits folds (notable XOR -> NOT conversions) to occur.
Differential Revision: https://reviews.llvm.org/D129641
Add promotion and expansion of integer operands for
experimental_vp_strided SelectionDAG nodes; the expansion is actually
just a truncation of the stride operand.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D123112
When determining if an `and` should be merged into an extending load
the constant argument to the `and` is currently not checked if the
argument requires truncation. This prevents the combine happening when
the vector width is half the normal available vector width for SVE VLA
vectors.
Reviewed By: c-rhodes
Differential Revision: https://reviews.llvm.org/D129281
Unlike the name suggests this can reuse any store as a base for a
memory-based vector extract. If that store is underaligned the loads
created to extract will have an invalid alignment. Since most CPUs are
forgiving wrt alignment this is almost never an issue, on x86 this is
only reproducible by extracting a 128 bit vector out of a wider vector.
I tried making a test case in the context of
https://reviews.llvm.org/D127982 but it's really really fragile, as the
output pretty much looks like a missed optimization.
The "xor (X >> ShiftC), XorC --> (not X) >> ShiftC" fold is currently limited to the XOR mask being a shifted all-bits mask, but we can relax this to only need to match under the demanded bits.
This helps expose more bit extraction/clearing patterns and fixes the PowerPC testCompares*.ll regressions from D127115
Alive2: https://alive2.llvm.org/ce/z/fl7T7K
Differential Revision: https://reviews.llvm.org/D129933
This revision supports to scalarize a binary operation of two scalable splat vectors.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D122791
This was stored in LiveIntervals, but not actually used for anything
related to LiveIntervals. It was only used in one check for if a load
instruction is rematerializable. I also don't think this was entirely
correct, since it was implicitly assuming constant loads are also
dereferenceable.
Remove this and rely only on the invariant+dereferenceable flags in
the memory operand. Set the flag based on the AA query upfront. This
should have the same net benefit, but has the possible disadvantage of
making this AA query nonlazy.
Preserve the behavior of assuming pointsToConstantMemory implying
dereferenceable for now, but maybe this should be changed.
r175673 changed repairIntervalsInRange to find anchoring end points for
ranges automatically, but the calculation of Begin included the first
instruction found that already had an index. This patch changes it to
exclude that instruction:
1. For symmetry, so that the half open range [Begin,End) only includes
instructions that do not already have indexes.
2. As a possible performance improvement, since repairOldRegInRange
will scan fewer instructions.
3. Because repairOldRegInRange hits assertion failures in some cases
when it sees a def that already has a live interval.
(3) fixes about ten tests in the CodeGen lit test suite when
-early-live-intervals is forced on.
Differential Revision: https://reviews.llvm.org/D110182
The DAG Combiner unnecessarily restricts commutative CSE
to nodes with a single result value. This commit removes
that restriction.
Signed-off-by: Itay Bookstein <ibookstein@gmail.com>
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D129666
Undef tokens may appear in unreached code as result of RAUW of some optimization,
and it should not be considered as bad IR.
Patch by Dmitry Bakunevich!
Differential Revision: https://reviews.llvm.org/D128904
Reviewed By: mkazantsev
Added function to the ExpandVectorPredication pass to handle VP loads
and stores.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D109584
trunc (sign_ext_inreg X, iM) to iN --> sign_ext_inreg (trunc X to iN), iM
There are improvements on existing tests from this, and there are a pair
of large regressions in D127115 for Thumb2 caused by not folding this
pattern.
Differential Revision: https://reviews.llvm.org/D129890
D127595 added the ability to recurse up a (one-use) INSERT_VECTOR_ELT chain to create a BUILD_VECTOR before other combines manage to break the chain, something that is particularly bad in D127115.
The patch generalises this so it doesn't have to build the chain starting from the last element insertion, instead it can now start from any insertion and will recurse up the chain until it finds all elements or finds a UNDEF/BUILD_VECTOR/SCALAR_TO_VECTOR which represents that start of the chain.
Fixes several regressions in D127115
In https://reviews.llvm.org/D30114, support for mismatching address
spaces was introduced to CodeGenPrepare's optimizeMemoryInst, using
addrspacecast as it was argued that only no-op addrspacecasts would be
considered when constructing the address mode. However, by doing
inttoptr/ptrtoint, it's possible to get CGP to emit an addrspace
that's not actually no-op, introducing a miscompilation:
define void @kernel(i8* %julia_ptr) {
%intptr = ptrtoint i8* %julia_ptr to i64
%ptr = inttoptr i64 %intptr to i32 addrspace(3)*
br label %end
end:
store atomic i32 1, i32 addrspace(3)* %ptr unordered, align 4
ret void
}
Gets compiled to:
define void @kernel(i8* %julia_ptr) {
end:
%0 = addrspacecast i8* %julia_ptr to i32 addrspace(3)*
store atomic i32 1, i32 addrspace(3)* %0 unordered, align 4
ret void
}
In the case of NVPTX, this introduces a cvta.to.shared, whereas
leaving out the %end block and branch doesn't trigger this
optimization. This results in illegal memory accesses as seen in
https://github.com/JuliaGPU/CUDA.jl/issues/558
In this change, I introduced a check before doing the pointer cast
that verifies address spaces are the same. If not, it emits a
ptrtoint/inttoptr combination to get a no-op cast between address
spaces. I decided against disallowing ptrtoint/inttoptr with
non-default AS in matchOperationAddr, because now its still possible
to look through multiple sequences of them that ultimately do not
result in a address space mismatch (i.e. the second lit test).
As mentioned on D127115, this patch that attempts to recognise shuffle masks that could be simplified to a AND mask - we already have a similar transform that will fold AND -> 'clear mask' shuffle, but this patch handles cases where the referenced elements are not from the same lane indices but are known to be zero.
Differential Revision: https://reviews.llvm.org/D129150
combineShiftAnd1ToBitTest already matches "and (not (srl X, C)), 1 --> (and X, 1<<C) == 0" patterns, but we can end up with situations where the not is before the shift.
Part of some yak shaving for D127115 to generalise the "xor (X >> ShiftC), XorC --> (not X) >> ShiftC" fold.
SimplifyDemandedBits is called slightly later which allows the not(sext(x)) -> sext(not(x)) fold to occur via foldLogicOfShifts
As mentioned on D127115, we should be able to further generalise this based off the demanded bits.
This is similar to D125680, but for llvm.experimental.patchpoint
(instead of llvm.experimental.stackmap).
Differential review: https://reviews.llvm.org/D129268
Following some recent discussions, this changes the representation
of callbrs in IR. The current blockaddress arguments are replaced
with `!` label constraints that refer directly to callbr indirect
destinations:
; Before:
%res = callbr i8* asm "", "=r,r,i"(i8* %x, i8* blockaddress(@test8, %foo))
to label %asm.fallthrough [label %foo]
; After:
%res = callbr i8* asm "", "=r,r,!i"(i8* %x)
to label %asm.fallthrough [label %foo]
The benefit of this is that we can easily update the successors of
a callbr, without having to worry about also updating blockaddress
references. This should allow us to remove some limitations:
* Allow unrolling/peeling/rotation of callbr, or any other
clone-based optimizations
(https://github.com/llvm/llvm-project/issues/41834)
* Allow duplicate successors
(https://github.com/llvm/llvm-project/issues/45248)
This is just the IR representation change though, I will follow up
with patches to remove limtations in various transformation passes
that are no longer needed.
Differential Revision: https://reviews.llvm.org/D129288
If we have a variable shift amount and the demanded mask has leading
zeros, we can propagate those leading zeros to not demand those bits
from operand 0. This can allow zero_extend/sign_extend to become
any_extend. This pattern can occur due to C integer promotion rules.
This transform is already done by InstCombineSimplifyDemanded.cpp where
sign_extend can be turned into zero_extend for example.
Reviewed By: spatel, foad
Differential Revision: https://reviews.llvm.org/D121833
Widening a G_FCONSTANT by extending and then generating G_FPTRUNC doesn't produce
the same result all the time. Instead, we can just transform it to a G_CONSTANT
of the same bit pattern and truncate using a plain G_TRUNC instead.
Fixes https://github.com/llvm/llvm-project/issues/56454
Differential Revision: https://reviews.llvm.org/D129743
If an MI will not generate a target instruction, we should not compute its
latency. Then we can compute more precise instruction sequence cost, and get
better result.
Differential Revision: https://reviews.llvm.org/D129615
isSafeToExpand() for addrecs depends on whether the SCEVExpander
will be used in CanonicalMode. At least one caller currently gets
this wrong, resulting in PR50506.
Fix this by a) making the CanonicalMode argument on the freestanding
functions required and b) adding member functions on SCEVExpander
that automatically take the SCEVExpander mode into account. We can
use the latter variant nearly everywhere, and thus make sure that
there is no chance of CanonicalMode mismatch.
Fixes https://github.com/llvm/llvm-project/issues/50506.
Differential Revision: https://reviews.llvm.org/D129630
The SI machine scheduler inherits from ScheduleDAGMI.
This patch adds support for a few features that are implemented
in ScheduleDAGMI (or its base classes) that were missing so far
because their support is implemented in overridden functions.
* Support cl::opt -view-misched-dags
This option allows to open a graphical window of the scheduling DAG.
* Support cl::opt -misched-print-dags
This option allows to print the scheduling DAG in text form.
* After constructing the scheduling DAG, call postprocessDAG()
to apply any registered DAG mutations.
Note that currently there are no mutations defined in AMDGPUTargetMachine.cpp
in case SIScheduler is used.
Still add this to avoid surprises in the future in case mutations are added.
Differential Revision: https://reviews.llvm.org/D128808
We shouldn't use getOpcodeDef() if we need to guarantee the def has only one
user since under the hood it may look through copies and optimization hints,
which themselves may have multiple users.
When doing scalable vectorization, the loop vectorizer uses a urem in the computation of the vector trip count. The RHS of that urem is a (possibly shifted) call to @llvm.vscale.
vscale is effectively the number of "blocks" in the vector register. (That is, types such as <vscale x 8 x i8> and <vscale x 1 x i8> both fill one 64 bit block, and vscale is essentially how many of those blocks there are in a single vector register at runtime.)
We know from the RISCV V extension specification that VLEN must be a power of two between ELEN and 2^16. Since our block size is 64 bits, the must be a power of two numbers of blocks. (For everything other than VLEN<=32, but that's already broken.)
It is worth noting that AArch64 SVE specification explicitly allows non-power-of-two sizes for the vector registers and thus can't claim that vscale is a power of two by this logic.
Differential Revision: https://reviews.llvm.org/D129609
We have the same fold in InstCombine - though implemented via OrZero flag on isKnownToBePowerOfTwo. The reasoning here is that either a) the result of the lshr is a power-of-two, or b) we have a div-by-zero triggering UB which we can ignore.
Differential Revision: https://reviews.llvm.org/D129606
Some rework of getStackGuard() based on comments in
https://reviews.llvm.org/D129505.
- getStackGuard() now creates and returns the destination
register, simplifying calls
- the pointer type is passed to getStackGuard() to avoid
recomputation
- removed PtrMemTy in emitSPDescriptorParent(), because
this type is only used here when loading the value but
not when storing the value
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D129576
To convert CTLZ to popcount we do
x = x | (x >> 1);
x = x | (x >> 2);
...
x = x | (x >>16);
x = x | (x >>32); // for 64-bit input
return popcount(~x);
This smears the most significant set bit across all of the bits
below it then inverts the remaining 0s and does a population count.
To support non-power of 2 types, the last shift amount must be
more than half of the size of the type. For i15, the last shift
was previously a shift by 4, with this patch we add another shift
of 8.
Fixes PR56457.
Differential Revision: https://reviews.llvm.org/D129431
When lowering llvm::stackprotect intrinsic, the SDAG implementation
checks useLoadStackGuardNode() to either create a LOAD_STACK_GUARD or use
the first argument of the intrinsic. This check is not present in the
IRTranslator, which results in always generating a LOAD_STACK_GUARD even
if the target does not support it.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D129505
Noticed while investigating the SystemZ regressions in D77804, prefer handling the knownbits analysis/simplification in the bitop nodes directly before falling back to SimplifyMultipleUseDemandedBits
Verify the LiveStacks analysis after a pass that claims to preserve it,
even if there are no further passes (apart from the verifier itself)
that would use the analysis.
Differential Revision: https://reviews.llvm.org/D129200
visitInlineAsm() in SDAGBuilder was duplicating a lot of the code
in ParseConstraints(), in particular all the logic to determine the
operand value and constraint VT.
Rely on the data computed by ParseConstraints() instead, and update
its ConstraintVT implementation to match getCallOperandValEVT()
more precisely.
As far as I can tell what was happening in the original code is
that the getNode call receives the same operands as the original
node with different SDNodeFlags. The logic inside getNode detects
that the node already exists and intersects the flags into the
existing node and returns it. This results in Op and NewOp for the
TLO.CombineTo call always being the same node.
We may have already called CombineTo as part of the recursive handling.
A second call to CombineTo as we unwind the recursion overwrites
the previous CombineTo. I think this means any time we updated the
poison flags that was the only change that ends up getting made
and we relied on DAGCombiner to revisit and call SimplifyDemandedBits
again. The second time the poison flags wouldn't need to be dropped
and we would keep the CombineTo call from further down the recursion.
We can instead call setFlags to drop the poison flags and remove the
call to TLO.CombineTo. This way we keep the CombineTo from deeper in
the recursion which should be more efficient.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D129511
As suggested in the post-commit feedback for D128123,
we can ease the mask constraint to ignore the MSB
(and make the code easier to read by adjusting the check).
https://alive2.llvm.org/ce/z/bbvqWv
Pointed out in Issue #56432: the current reference models may not be
quite friendly to open source projects. Their purpose is only
illustrative - the expectation is that projects would train their own.
To avoid unintentionally pulling such a model, made the URL cmake
setting require explicit user setting.
Differential Revision: https://reviews.llvm.org/D129342
Currently, an error exists when InstrRefBasedLDV observes transfers of
variables across copies, which causes it to lose track of variables
under certain circumstances, resulting in shorter lifetimes for those
variables as LDV gives up searching for live locations for them. This
patch fixes this issue by storing the currently tracked values in
the destination first, then updating them manually later without
clobbering or assigning them the wrong value.
Differential Revision: https://reviews.llvm.org/D128101
This patch restores calls to has_value to make it clear that we are
checking the presence of an optional value, not the underlying value.
This patch partially reverts d08f34b592.
Differential Revision: https://reviews.llvm.org/D129454
D89489 added some logic to the interleaved access pass to attempt to
undo the folding of shuffles into binops, that instcombine performs. If
early-cse is run too, the binops may be commoned into a single operation
with multiple shuffle uses. It is still profitable reverse the transform
though, so long as all the uses are shuffles.
Differential Revision: https://reviews.llvm.org/D129419
(Reapply after revert in e9ce1a5880 due to
Fuchsia test failures. Removed changes in lib/ExecutionEngine/ other
than error categories, to be checked in more detail and reapplied
separately.)
Bulk remove many of the more trivial uses of ManagedStatic in the llvm
directory, either by defining a new getter function or, in many cases,
moving the static variable directly into the only function that uses it.
Differential Revision: https://reviews.llvm.org/D129120
Bulk remove many of the more trivial uses of ManagedStatic in the llvm
directory, either by defining a new getter function or, in many cases,
moving the static variable directly into the only function that uses it.
Differential Revision: https://reviews.llvm.org/D129120
We already handled this case for add with a constant RHS. A
similar pattern can occur for sub with a constant left hand side.
Test cases use add and a mul representing (neg (shl X, C)) because
that's what I saw in the wild. The mul will be decomposed and then
the new transform can kick in.
Tests have not been committed, but this patch shows the changes.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D128769
Originally encountered with RUST, but also there are cases with distributed LTO
where debug info dwo units contain structurally the same debug information, with
difference in DW_AT_linkage_name. This causes collision on DWO ID.
Differential Revision: https://reviews.llvm.org/D129317
SelectionDAG has a target hook, getExtendForAtomicOps, which it uses
in the computeKnownBits implementation for ATOMIC_LOAD. This is pretty
ugly (as is having a separate load opcode for atomics), so instead
allow making use of atomic zextload. Enable this for AArch64 since the
DAG path defaults in to the zext behavior.
The tablegen changes are pretty ugly, but partially helps migrate
SelectionDAG from using ISD::ATOMIC_LOAD to regular ISD::LOAD with
atomic memory operands. For now the DAG emitter will emit matchers for
patterns which the DAG will not produce.
I'm still a bit confused by the intent of the isLoad/isStore/isAtomic
bits. The DAG implementation rejects trying to use any of these in
combination. For now I've opted to make the isLoad checks also check
isAtomic, although I think having isLoad and isAtomic set on these
makes most sense.
If all the demanded bits of the AND mask covering the inserted subvector 'X' are known to be one, then the mask isn't affecting the subvector at all.
In which case, if the base vector 'C' is undef/constant, then move the AND mask up to just (constant) fold it directly.
Addresses some of the regressions from D129150, particularly the cases where we're attempting to zero the upper elements of a widened vector.
Differential Revision: https://reviews.llvm.org/D129290
After D82916 `updateAllRanges()` started to fix holes in main range with
subranges but it fails on instructions with two subregs def which are parts of
one reg. The main range constructed with //all// subranges of subregs just after
processing the first operand. So the main range gets intervals from subranges
those are not updated yet.
The patch takes into account lane mask to update the main range.
Reviewed By: rampitec, arsenm
Differential Revision: https://reviews.llvm.org/D128553
This is almost the same as the abandoned D48529, but it
allows splat vector constants too.
This replaces the x86-specific code that was added with
the alternate patch D48557 with the original generic
combine.
This transform is a less restricted form of an existing
InstCombine and the proposed SDAG equivalent for that
in D128080:
https://alive2.llvm.org/ce/z/OUm6N_
Differential Revision: https://reviews.llvm.org/D128123
This patchs adds a new metadata kind `exclude` which implies that the
global variable should be given the necessary flags during code
generation to not be included in the final executable. This is done
using the ``SHF_EXCLUDE`` flag on ELF for example. This should make it
easier to specify this flag on a variable without needing to explicitly
check the section name in the target backend.
Depends on D129053 D129052
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D129151
Currently we use the `.llvm.offloading` section to store device-side
objects inside the host, creating a fat binary. The contents of these
sections is currently determined by the name of the section while it
should ideally be determined by its type. This patch adds the new
`SHT_LLVM_OFFLOADING` section type to the ELF section types. Which
should make it easier to identify this specific data format.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D129052
This is done during type legalization since the target representation of
these nodes may not be valid until after type legalization, and after
type legalization the fact that these are dealing with i1 types may be
lost.
Differential Revision: https://reviews.llvm.org/D128996
Truncates and compares require some changes to generic legalisation functions
to use ElementCount instead of getNumElements.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D129082
Prior to this change, live variable operands passed to
`llvm.experimental.stackmap` would be emitted directly to target nodes,
meaning that they don't get legalised. The upshot of this is that LLVM
may crash when encountering illegally typed target nodes.
e.g. https://github.com/llvm/llvm-project/issues/21657
This change introduces a platform independent stackmap DAG node whose
operands are legalised as per usual, thus avoiding aforementioned
crashes.
Note that some kinds of argument are still not handled properly, namely
vectors, structs, and large integers, like i128s. These will need to be
addressed in follow-up changes.
Note also that this does not change the behaviour of
`llvm.experimental.patchpoint`. A follow up change will do the same for
this intrinsic.
Differential review:
https://reviews.llvm.org/D125680
This patch adds the support for `fmax` and `fmin` operations in `atomicrmw`
instruction. For now (at least in this patch), the instruction will be expanded
to CAS loop. There are already a couple of targets supporting the feature. I'll
create another patch(es) to enable them accordingly.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D127041
As constant expressions can no longer trap, it only makes sense to
call isSafeToSpeculativelyExecute on Instructions, so limit the
API to accept only them, rather than general Operators or Values.
As integer div/rem constant expressions are no longer supported,
constants can no longer trap and are always safe to speculate.
Remove the Constant::canTrap() method and its usages.
This removes the insertvalue constant expression, as part of
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179.
This is very similar to the extractvalue removal from D125795.
insertvalue is also not supported in bitcode, so no auto-ugprade
is necessary.
ConstantExpr::getInsertValue() can be replaced with
IRBuilder::CreateInsertValue() or ConstantFoldInsertValueInstruction(),
depending on whether a constant result is required (with the latter
being fallible).
The ConstantExpr::hasIndices() and ConstantExpr::getIndices()
methods also go away here, because there are no longer any constant
expressions with indices.
Differential Revision: https://reviews.llvm.org/D128719
variable with its multiple aliases.
This patch handles the case where a variable has
multiple aliases.
AIX's assembly directive .set is not usable for the
aliasing purpose, and using different labels allows
AIX to emulate symbol aliases. If a value is emitted
between any two labels, meaning they are not aligned,
XCOFF will automatically calculate the offset for them.
This patch implements:
1) Emits the label of the alias just before emitting
the value of the sub-element that the alias referred to.
2) A set of aliases that refers to the same offset
should be aligned.
3) We didn't emit aliasing labels for common and
zero-initialized local symbols in
PPCAIXAsmPrinter::emitGlobalVariableHelper, but
emitted linkage for them in
AsmPrinter::emitGlobalAlias, which caused a FAILURE.
This patch fixes the bug by blocking emitting linkage
for the alias without a label.
Reviewed By: shchenz
Differential Revision: https://reviews.llvm.org/D124654
Before merging two instructions together, GISel does some sanity checks
that the folding is legal. However that check was missing that the
source of the pattern may be convergent. When the destination location
is in a different basic block, the folding is invalid.
Differential Revision: https://reviews.llvm.org/D128539
One motivation to add support for these types are the LD1Q/ST1Q
instructions in SME, for which we have defined a number of load/store
intrinsics which at the moment still take a `<vscale x 16 x i1>` predicate
regardless of their element type.
This patch adds basic support for the nxv1i1 type such that it can be passed/returned
from functions, as well as some basic support to support some existing tests that
result in a nxv1i1 type. It also adds support for splats.
Other operations (e.g. insert/extract subvector, logical ops, etc) will be
supported in follow-up patches.
Reviewed By: paulwalker-arm, efriedma
Differential Revision: https://reviews.llvm.org/D128665
In X86 we split greddy register allocation into 2 passes. The 1st pass
is to allocate tile register, and the 2nd pass is to allocate the rest
of virtual register. In most cases there is no tile register, so the 1st
pass is unnecessary. To improve the compiling time, we check if there is
any register need to be allocated by invoking callback
`ShouldAllocateClass`. If there is no register to be allocated, just
return false in the pass. This would improve the 1st greed RA pass for
normal cases.
Differential Revision: https://reviews.llvm.org/D128804
The filter clause in the landingpad may not have a GlobalVariable operand.
It may instead have a ConstantArray of operands and each operand within this
ConstantArray should also be checked to see if it is a GlobalVariable.
This patch add the check for the ConstantArray as well as a debug message that
outputs the contents of MustKeepGlobalVariables.
Reviewed By: lei, amyk, scui
Differential Revision: https://reviews.llvm.org/D128287
lowerConstant() currently accepts a number of constant expressions
which have corresponding MC expressions, but which cannot be
evaluated as a relocatable expression (unless the operands are
constant, in which case we'll just fold the expression to a constant).
The motivation here is to clarify which constant expressions are
really needed for https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179,
and in particular clarify that we do not need to support any
division expressions, which are particularly problematic.
Differential Revision: https://reviews.llvm.org/D127972
When we fill the shape to tile configure memory, the shape is gotten
from AMX pseudo instruction. However the register for the shape may be
split or spilled by greedy RA. That cause we fill the shape to config
memory after ldtilecfg is executed, so that the shape configuration
would be wrong.
This patch is to split the tile register allocation from greedy register
allocation, so that after tile registers are allocated the shape
registers are still virtual register. The shape register only may be
redefined or multi-defined by phi elimination pass, two address pass.
That doesn't affect tile register configuration.
Differential Revision: https://reviews.llvm.org/D128584
Add a new pattern A - (B + C) ==> (A - B) - C to give machine combiner a chance
to evaluate which instruction sequence has lower latency.
Differential Revision: https://reviews.llvm.org/D124564
This is a resurrection of D106421 with the change that it keeps backward-compatibility. This means decoding the previous version of `LLVM_BB_ADDR_MAP` will work. This is required as the profile mapping tool is not released with LLVM (AutoFDO). As suggested by @jhenderson we rename the original section type value to `SHT_LLVM_BB_ADDR_MAP_V0` and assign a new value to the `SHT_LLVM_BB_ADDR_MAP` section type. The new encoding adds a version byte to each function entry to specify the encoding version for that function. This patch also adds a feature byte to be used with more flexibility in the future. An use-case example for the feature field is encoding multi-section functions more concisely using a different format.
Conceptually, the new encoding emits basic block offsets and sizes as label differences between each two consecutive basic block begin and end label. When decoding, offsets must be aggregated along with basic block sizes to calculate the final offsets of basic blocks relative to the function address.
This encoding uses smaller values compared to the existing one (offsets relative to function symbol).
Smaller values tend to occupy fewer bytes in ULEB128 encoding. As a result, we get about 17% total reduction in the size of the bb-address-map section (from about 11MB to 9MB for the clang PGO binary).
The extra two bytes (version and feature fields) incur a small 3% size overhead to the `LLVM_BB_ADDR_MAP` section size.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D121346
`commonAlignment` is a shortcut to pick the smallest of two `Align`
objects. As-is it doesn't bring much value compared to `std::min`.
Differential Revision: https://reviews.llvm.org/D128345
Information in the function `Prologue Data` is intentionally opaque.
When a function with `Prologue Data` is duplicated. The self (global
value) references inside `Prologue Data` is still pointing to the
original function. This may cause errors like `fatal error: error in backend: Cannot represent a difference across sections`.
This patch detaches the information from function `Prologue Data`
and attaches it to a function metadata node.
This and D116130 fix https://github.com/llvm/llvm-project/issues/49689.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D115844
This commit modifies the AsmPrinter to avoid emitting any zero-sized symbols to
the .debug_aranges table, by rounding their size up to 1. Entries with zero
length violate the DWARF 5 spec, which states:
> Each descriptor is a triple consisting of a segment selector, the beginning
> address within that segment of a range of text or data covered by some entry
> owned by the corresponding compilation unit, followed by the non-zero length
> of that range.
In practice, these zero-sized entries produce annoying warnings in lld and
cause GNU binutils to truncate the table when parsing it.
Other parts of LLVM, such as DWARFDebugARanges in the DebugInfo module
(specifically the appendRange method), already avoid emitting zero-sized
symbols to .debug_aranges, but not comprehensively in the AsmPrinter. In fact,
the AsmPrinter does try to avoid emitting such zero-sized symbols when labels
aren't involved, but doesn't when the symbol to emitted is a difference of two
labels; this patch extends that logic to handle the case in which the symbol is
defined via labels.
Furthermore, this patch fixes a bug in which `available_externally` symbols
would cause unpredictable values to be emitted into the `.debug_aranges` table
under certain circumstances. In practice I don't believe that this caused
issues up until now, but the root cause of this bug--an invalid DenseMap
lookup--triggered failures in Chromium when combined with an earlier version of
this patch. Therefore, this patch fixes that bug too.
This is a revised version of diff D126257, which was reverted due to breaking
tests. The now-reverted version of this patch didn't distinguish between
symbols that didn't have their size reported to the DwarfDebug handler and
those that had their size reported to be zero. This new version of the patch
instead restricts the special handling only to the symbols whose size is
definitively known to be zero.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D126835
These intrinsics are now fundemental for SVE code generation and have been
present for a year and a half, hence move them out of the experimental
namespace.
Differential Revision: https://reviews.llvm.org/D127976
Patch was reverted in 4c5f10a due to buildbot failures, now being
reapplied with updated AArch64 and RISCV tests.
This patch adds handling for the llvm.powi.* intrinsics in
BasicTTIImplBase::getIntrinsicInstrCost() and improves vectorization.
Closes#53887.
Differential Revision: https://reviews.llvm.org/D128172
If an instruction is sunk into a loop then any kill flags on
operands declared outside the loop must be cleared as these
will be live for all loop iterations.
Fixes#46827
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D126754
According to the vector spec, mf8 is not supported for i8 if ELEN
is 32. Similarily mf4 is not suported for i16/f16 or mf2 for i32/f32.
Since RVVBitsPerBlock is 64 and LMUL is calculated as
((MinNumElements * ElementSize) / RVVBitsPerBlock) this means we
need to disable any type with MinNumElements==1.
For generic IR, these types will now be widened in type legalization.
For RVV intrinsics, we'll probably hit a fatal error somewhere. I plan
to work on disabling the intrinsics in the riscv_vector.h header.
Reviewed By: arcbbb
Differential Revision: https://reviews.llvm.org/D128286
waitcnt vmcnt instructions are currently generated in loop bodies before using
values loaded outside of the loop. In some cases, it is better to flush the
vmcnt counter in a loop preheader before entering the loop body. This patch
detects these cases and generates waitcnt instructions to flush the counter.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D115747
This reverts commit 719658d078.
Breaks a few things, see comments on https://reviews.llvm.org/D128437
There's disagreement about the best fix.
So let's keep HEAD green while discussions are happening.
The base RA support infrastructure that only allow a specific register
class be allocated in RA pss. Since greedy RA, basic RA derived from
base RA, they all allow allocating specific register class. Fast RA
doesn't support allocating register for specific register class. This
patch is to enable ShouldAllocateClass in fast RA, so that it can
support allocating register for specific register class.
Differential Revision: https://reviews.llvm.org/D126771
We're slowly removing SelectionDAG::GetDemandedBits and replacing it with SimplifyMultipleUseDemandedBits, we no longer have any uses for the vector demanded elt variant.
This patch adds handling for the llvm.powi.* intrinsics in
BasicTTIImplBase::getIntrinsicInstrCost() and improves vectorization.
Closes#53887.
Differential Revision: https://reviews.llvm.org/D128172
For below case, virtual register is defined twice in the self loop. We
don't need to spill %0 after the third instruction `%0 = def (tied %0)`,
because it is defined in the second instruction `%0 = def`.
1 bb.1
2 %0 = def
3 %0 = def (tied %0)
4 ...
5 jmp bb.1
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D125079
An AArch64ISD::DUP is just a splat, where the known bits for each lane
are the same as the input. This teaches that to computeKnownBitsForTargetNode.
Problems arise for constants though, as a constant BUILD_VECTOR can be
lowered to an AArch64ISD::DUP, which SimplifyDemandedBits would then
turn back into a constant BUILD_VECTOR leading to an infinite cycle.
This has been prevented by adding a isTargetCanonicalConstantNode node
to prevent the conversion back into a BUILD_VECTOR.
Differential Revision: https://reviews.llvm.org/D128144
Similar to the existing (shl (srl x, c1), c2) fold
Part of the work to fix the regressions in D77804
Differential Revision: https://reviews.llvm.org/D125836
The VT we want to shrink to may not be legal especially after type
legalization.
Fixes PR56110.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D128135
The included test hits a verifier problems as one of the instructions:
```
%113:tgpreven, %114:tgprodd = MVE_VMLSLDAVas16 %12:tgpreven(tied-def 0), %11:tgprodd(tied-def 1), %7:mqpr, %8:mqpr, 0, $noreg, $noreg
```
Has two inputs that come from different PHIs with the same base reg, but
conflicting regclasses:
```
%11:tgprodd = PHI %103:gpr, %bb.1, %16:gpr, %bb.2
%12:tgpreven = PHI %103:gpr, %bb.1, %17:gpr, %bb.2
```
The MachinePipeliner would attempt to use %103 for both the %11 and %12
operands in the prolog, constraining the register class to the common
subset of both. Unfortunately there are no registers that are both odd
and even, so the second constrainRegClass fails. Fix this situation by
inserting a COPY for the second if the call to constrainRegClass fails.
The register allocation can then fold that extra copy away. The register
allocation of Q regs changed with this test, but the R regs were the
same and no new instructions are needed in the final assembly.
Differential Revision: https://reviews.llvm.org/D127971
D125335 makes regsOverlap skip following control flow, which is not entended
in the original code.
Differential Revision: https://reviews.llvm.org/D128039
WidenVecOp_INSERT_SUBVECTOR only supported cases where widening
effectively converts the insert into a copy. However, when the
widened subvector is no bigger than the vector being inserted into
and we can be sure there's no loss of data, we can simply emit
another INSERT_SUBVECTOR.
Fixes: #54982
Differential Revision: https://reviews.llvm.org/D127508
MinRCSize is 4 and prevents constrainRegClass from changing the
register class if the new class has size less than 4.
IMPLICIT_DEF gets a unique vreg for each use and will be removed
by the ProcessImplicitDef pass before register allocation. I don't
think there is any reason to prevent constraining the virtual register
to whatever register class the use needs.
The attached test case was previously creating a copy of IMPLICIT_DEF
because vrm8nov0 has 3 registers in it.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D128005
This helps handling a case where the BUILD_VECTOR has i16 element type
and i32 constant operands
t2: v8i16 = setcc t8, t17, setult:ch
t3: v8i16 = BUILD_VECTOR Constant:i32<1>, ...
t4: v8i16 = and t2, t3
t5: v8i16 = add t8, t4
This can be turned into t5: v8i16 = sub t8, t2, and allows us to remove
t3 and t4 from the DAG.
Differential Revision: https://reviews.llvm.org/D127354
This reverts commit 7207373e1e.
We found another RISC-V bug when landing D126048, and it has been fixed
by D127642 now.
Differential Revision: https://reviews.llvm.org/D126048
This is needed by our downstream and makes bf16 and f16 have the
same set of scalable vector types.
Reviewed By: rui.zhang
Differential Revision: https://reviews.llvm.org/D127877
The use operand may be undefined. In that case we can just continue to
check the next operand since it won't increase register pressure.
Differential Revision: https://reviews.llvm.org/D127848
This is modeled after the half-precision fp support. Two new nodes are
introduced for casting from and to bf16. Since casting from bf16 is a
simple operation I opted to always directly lower it to integer
arithmetic. The other way round is more complicated if you want to
preserve IEEE semantics, so it's handled by a new __truncsfbf2
compiler-rt builtin.
This is of course very bare bones, but sufficient to get a semi-softened
fadd on x86.
Possible future improvements:
- Targets with bf16 conversion instructions can now make fp_to_bf16 legal
- The software conversion to bf16 can be replaced by a trivial
implementation under fast math.
Differential Revision: https://reviews.llvm.org/D126953
When compiling for the RWPI relocation model [1], the debug information
is wrong for readonly global variables.
Writable global variables are accessed by the static base register (R9
on ARM) in the RWPI relocation model. This is being correctly generated
Readonly global variables are not accessed by the static base register
in the RWPI relocation model. This case is incorrectly generating the
same debugging information as for writable global variables.
References:
[1] ARM Read-Write Position Independence: https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#read-write-position-independence-rwpi
Differential Revision: https://reviews.llvm.org/D126361
GetValueInMiddleOfBlock uses result of GetValueAtEndOfBlockInternal if there is no value
defined for current basic block.
If there is already a value it tries (in this order):
to find single register coming from all predecessors
find existing phi node which matches our incoming registers
build new phi.
The compile time improvement is to use current available value if
it is defined out of current BB or it is a PHI register.
This is due to it can be used in the middle basic block.
Reviewed By: sameerds
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D126523
When spilling CSRs, FixupStatepoint pass does simple copy propagation,
trying to find COPY instruction which defines register being spilled
and spill COPY source instead. I.e., if we have CSR $x and found
$x = COPY $y
we will spill $y instead.
But we may be unable to delete COPY instruction for some reason.
Then, spill will be inserted after it, adding another use of $y.
If COPY instruction was last use of $y (killed it), after insertion of
the spill it is not, so `isKill` flag must be cleared. We failed to do
so and this patch fixes this issue.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D127308
This is a fix for https://github.com/llvm/llvm-project/issues/55827.
When register we are trying to re-color is split the original register (we tried to recover)
has no uses after the split. However in rollback actions we assign back physical register to it.
Later it causes different assertions. One of them is in attached test.
This CL fixes this by avoiding assigning physical register back to register which has no usage
or its live interval now is empty.
Reviewed By: arsenm, qcolombet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D127281
The last of getEvictor use was removed on Jun 5, 2022 in commit
5c06f7168f, which was itself a patch to
remove unused code.
Once we remove getEvictor, EvictionTrack becomes a write-only data
structure. The data in it won't affect compilation, so the entire
class is essentially dead.
Another issue unearthed by D127115
We take a long time to canonicalize an insert_vector_elt chain before being able to convert it into a build_vector - even if they are already in ascending insertion order, we fold the nodes one at a time into the build_vector 'seed', leaving plenty of time for other folds to alter it (in particular recognising when they come from extract_vector_elt resulting in a shuffle_vector that is much harder to fold with).
D127115 makes this particularly difficult as we're almost guaranteed to have the lost the sequence before all possible insertions have been folded.
This patch proposes to begin at the last insertion and attempt to collect all the (oneuse) insertions right away and create the build_vector before its too late.
Differential Revision: https://reviews.llvm.org/D127595
This patch allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits in cases where the source operand has other uses, enabling us to peek through the shifted value if we don't demand all the bits/elts.
This helps with several of the regressions from D125836
Previously, omitting unnecessary DWARF unwinds was only done in two
cases:
* For Darwin + aarch64, if no DWARF unwind info is needed for all the
functions in a TU, then the `__eh_frame` section would be omitted
entirely. If any one function needed DWARF unwind, then MC would emit
DWARF unwind entries for all the functions in the TU.
* For watchOS, MC would omit DWARF unwind on a per-function basis, as
long as compact unwind was available for that function.
This diff makes it so that we omit DWARF unwind on a per-function basis
for Darwin + aarch64 as well. In addition, we introduce the flag
`--emit-dwarf-unwind=` which can toggle between `always`,
`no-compact-unwind` (only emit DWARF when CU cannot be emitted for a
given function), and the target platform `default`. `no-compact-unwind`
is particularly useful for newer x86_64 platforms: we don't want to omit
DWARF unwind for x86_64 in general due to possible backwards compat
issues, but we should make it possible for people to opt into this
behavior if they are only targeting newer platforms.
**Motivation:** I'm working on adding support for `__eh_frame` to LLD,
but I'm concerned that we would suffer a perf hit. Processing compact
unwind is already expensive, and that's a simpler format than EH frames.
Given that MC currently produces one EH frame entry for every compact
unwind entry, I don't think processing them will be cheap. I tried to do
something clever on LLD's end to drop the unnecessary EH frames at parse
time, but this made the code significantly more complex. So I'm looking
at fixing this at the MC level instead.
**Addendum:** It turns out that there was a latent bug in the X86
backend when `OmitDwarfIfHaveCompactUnwind` is naively enabled, which is
not too surprising given that this combination has not been heretofore
used.
For functions that have unwind info that cannot be encoded with CU, MC
would end up dropping both the compact unwind entry (OK; existing
behavior) as well as the DWARF entries (not OK). This diff fixes things
so that we emit the DWARF entry, as well as a CU entry with encoding
`UNWIND_X86_MODE_DWARF` -- this basically tells the unwinder to look for
the DWARF entry. I'm not 100% sure the `UNWIND_X86_MODE_DWARF` CU entry
is necessary, this was the simplest fix. ld64 seems to be able to handle
both the absence and presence of this CU entry. Ultimately ld64 (and
LLD) will synthesize `UNWIND_X86_MODE_DWARF` if it is absent, so there
is no impact to the final binary size.
Reviewed By: davide, lhames
Differential Revision: https://reviews.llvm.org/D122258
1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
through.
2. Make sure copied CFI directives refer to the correct instruction.
Fixes https://github.com/llvm/llvm-project/issues/55842
Differential Revision: https://reviews.llvm.org/D126930
In the same spirit as D73543 and in reply to https://reviews.llvm.org/D126768#3549920 this patch is adding support for `__builtin_memset_inline`.
The idea is to get support from the compiler to easily write efficient memory function implementations.
This patch could be split in two:
- one for the LLVM part adding the `llvm.memset.inline.*` intrinsics.
- and another one for the Clang part providing the instrinsic as a builtin.
Differential Revision: https://reviews.llvm.org/D126903
D125887 changed the ctlz/cttz despeculation transform to insert
a freeze for the introduced branch on zero. While this does fix
the "branch on poison" issue, we may still get in trouble if we
pick a different value for the branch and for the ctz argument
(i.e. non-zero for the branch, but zero for the ctz). To avoid
this, we should use the same frozen value in both positions.
This does cause a regression in RISCV codegen by introducing an
additional sext. The DAG looks like this:
t0: ch = EntryToken
t2: i64,ch = CopyFromReg t0, Register:i64 %3
t4: i64 = AssertSext t2, ValueType:ch:i32
t23: i64 = freeze t4
t9: ch = CopyToReg t0, Register:i64 %0, t23
t16: ch = CopyToReg t0, Register:i64 %4, Constant:i64<32>
t18: ch = TokenFactor t9, t16
t25: i64 = sign_extend_inreg t23, ValueType:ch:i32
t24: i64 = setcc t25, Constant:i64<0>, seteq:ch
t28: i64 = and t24, Constant:i64<1>
t19: ch = brcond t18, t28, BasicBlock:ch<cond.end 0x8311f68>
t21: ch = br t19, BasicBlock:ch<cond.false 0x8311e80>
I don't see a really obvious way to improve this, as we can't push
the freeze past the AssertSext (which may produce poison).
Differential Revision: https://reviews.llvm.org/D126638
Clang-format InstructionSimplify and convert all "FunctionName"s to
"functionName". This patch does touch a lot of files but gets done with
the cleanup of InstructionSimplify in one commit.
This is the alternative to the less invasive clang-format only patch: D126783
Reviewed By: spatel, rengolin
Differential Revision: https://reviews.llvm.org/D126889
This should fix a number of shuffle regressions in D127115 where the re-ordered combines mean we fail to fold a EXTRACT_VECTOR_ELT/INSERT_VECTOR_ELT sequence into a BUILD_VECTOR if we extract from more than one vector source.
This matches what we do in IR. For the RISC-V test case, this allows
us to use -8 for the AND mask instead of materializing a constant in a register.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D127335
During lowering of memcmp/bcmp, the check for a size of 0 is done
in 2 different ways. In rare cases this can lead to a crash in
SystemZSelectionDAGInfo::EmitTargetCodeForMemcmp(). The root cause
is that SelectionDAGBuilder::visitMemCmpBCmpCall() checks for a
constant int value which is not yet evaluated. When the value is
turned into a SDValue, then the evaluation is done and results in
a ConstantSDNode. But EmitTargetCodeForMemcmp() expects the special
case of 0 length to be handled, which results in an assertion.
The fix is to turn the value into a SDValue, so that both functions
use the same check.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D126900
Summary:
We use the special section name `.llvm.offloading` to store device
imagees in the host object file. We want these to be stripped by the
linker as they are not used after linking so we use the `SHF_EXCLUDE`
flag to instruct the linker to drop them. We used to do this for all
sections that started with `.llvm.offloading` when we encoded metadata
in the section name itself. Now we embed a special binary containing the
metadata, we should only add the flag on this name specifically.
Extend the TypeWidenVector case of PromoteIntRes_BITCAST to work
with TypeSize directly rather than silently casting to unsigned.
To accomplish this I've extended TypeSize with an interface that
essentially allows TypeSize division when both operands have the
same number of dimensions.
There still exists combinations of scalable vector bitcasts that
cause compiler crashes. I call these out by adding "is missing"
entries to sve-bitcast.
Depends on D126957.
Fixes: #55114
Differential Revision: https://reviews.llvm.org/D127126
Bitcasting between unpacked scalable vector types of different
element counts is not a NOP because the live elements are laid out
differently.
01234567
e.g. nxv2i32 = XX??XX??
nxv4f16 = X?X?X?X?
Differential Revision: https://reviews.llvm.org/D126957
Spliter will try to extend a live range into `r` slot for a use operand,
that's works on most situaion, however that not work correctly when the operand
has tied to def, and the def operand is early clobber.
Give an example to demo what's wrong:
0 %0 = ...
16 early-clobber %0 = Op %0 (tied-def 0), ...
32 ... = Op %0
Before extend:
%0 = [0r, 0d) [16e, 32d)
The point we want to extend is 0d to 16e not 16r in this case, but if
we use 16r here we will extend nothing because that already contained
in [16e, 32d).
This patch add check for detect such case and adjust the extend point.
Detailed explanation for testcase: https://reviews.llvm.org/D126047
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D126048
As noticed on D127115 - we were missing this fold, instead just having the shuffle(shuffle(x,undef,splatmask),undef) fold. We should be able to merge these into one using SelectionDAG::isSplatValue, but we'll need to match the shuffle's undef handling first.
This also exposed an issue in SelectionDAG::isSplatValue which was incorrectly propagating the undef mask across a bitcast (it was trying to just bail with a APInt::isSubsetOf if it found any undefs but that was actually the wrong way around so didn't fire for partial undef cases).
Use the query that doesn't assert if TracksLiveness isn't set, which
needs to always be available. We also need to start printing liveins
regardless of TracksLiveness.
I can't remove the function just yet as it is used in the generated .inc files.
I would also like to provide a way to compare alignment with TypeSize since it came up a few times.
Differential Revision: https://reviews.llvm.org/D126910
These assert that there are no "useless" assertzext/assertsext nodes
(that assert a wider width than a following trunc), but I don't think
there is anything preventing such nodes from reaching this code.
I don't think the assertion is relevant for correctness of this
transform either -- if such an assert is present, then the other
one will always be to a smaller width, and we'll pick that one.
The assertion dates back to D37017.
Fixes https://github.com/llvm/llvm-project/issues/55846.
Differential Revision: https://reviews.llvm.org/D126952
Fixes a bug of us not correctly updating the terminator of the loop's
preheader, if multiple terminating branch instructions are present.
This is tested through existing tests. The bug itself is hard or not
possible to get exposed with the upstream Hexagon backend, because
the machine pipeliner checks for an existing preheader, which is
defined as a block with only 1 edge into the header.
The condition of this bug is a block into the loop with more than 1
edge, and not every downstream target checks for an existing preheader.
Differential Revision: https://reviews.llvm.org/D126386
Patch adds new GICombineRules for G_ADD:
G_ADD(x, G_SUB(y, x)) -> y
G_ADD(G_SUB(y, x), x) -> y
Patch additionally adds new combine tests for AArch64 target for
these new rules.
Reviewed by: paquette
Differential Revision: https://reviews.llvm.org/D87936
Move the code that was added for D126896 after the normal recursive calls
to computeKnownBits. This allows us to calculate trailing zeros.
Previously we would break out of the switch before the recursive calls.
Some cl::ZeroOrMore were added to avoid the `may only occur zero or one times!`
error. More were added due to cargo cult. Since the error has been removed,
cl::ZeroOrMore is unneeded.
Also remove cl::init(false) while touching the lines.
When promoting a shift, make sure we only fetch the second operand
after promoting the first. Load promotion may replace users of the
old load, and we don't want to be left with a dangling reference to
the old load instruction.
The crashing test case is from https://reviews.llvm.org/D126689#3553212.
Differential Revision: https://reviews.llvm.org/D126886
If C is non-negative, the result of the smax must also be
non-negative, so all sign bits of the result are 0.
This allows DAGCombiner to remove a zext_inreg in the modified test.
This zext_inreg started as a sext that became zext before type
legalization then was promoted to a zext_inreg.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D126896
Adds MVT::v128i2, MVT::v64i4, and implied MVT::i2, MVT::i4.
Keeps MVT::i2, MVT::i4 lowering actions as expand, which should be
removed once targets set this explicitly.
Adjusts 11 lit tests to reflect slightly different behavior during
DAG combine.
Differential Revision: https://reviews.llvm.org/D125247
Even if CSR list is same between functions, we could have had a different
allocation order if ignoreCSRForAllocationOrder is evaluated differently.
Hence invalidate cached register class information if
ignoreCSRForAllocationOrder changes.
Patch by Srividya Karumuri <srividya_karumuri@apple.com>
Differential Revision: https://reviews.llvm.org/D126565
Adds MVT::v128i2, MVT::v64i4, and implied MVT::i2, MVT::i4.
Keeps MVT::i2, MVT::i4 lowering actions as `expand`, which should be
removed once targets set this explicitly.
Adjusts 11 lit tests to reflect slightly different behavior during
DAG combine.
Differential Revision: https://reviews.llvm.org/D125247
D124631 added special processing for STATEPOINT instructions.
It appears that assertion added there is too strong. We can get two
tied operands with the same register tied to different defs. If we
hit such case, do not process it in statepoint-specific code and
delegate it to common case.
Avoid the dependency on TargetInstrInfo, which depends on the subtarget
and therefore the individual function.
Currently AMDGPU is constructing PseudoSourceValue instances in MachineFunctionInfo.
In order to facilitate copying MachineFunctionInfo, we need to stop allocating these
there. Alternatively we could allow targets to subclass PseudoSourceValueManager,
and allocate them similarly to MachineFunctionInfo.
This includes .seh_* directives for generating it from assembly.
It is designed fairly similarly to the ARM64 handling.
For .seh_handler directives, such as
".seh_handler __C_specific_handler, @except" (which is supported
on x86_64 and aarch64 so far), the "@except" bit doesn't work in
ARM assembly, as '@' is used as a comment character (on all current
platforms).
Allow using '%' instead of '@' for this purpose. This convention
is used by GAS in similar contexts already,
e.g. [1]:
Note on targets where the @ character is the start of a comment
(eg ARM) then another character is used instead. For example the
ARM port uses the % character.
In practice, this unfortunately means that all such .seh_handler
directives will need ifdefs for ARM.
Contrary to ARM64, on ARM, it's quite common that we can't evaluate
e.g. the function length at this point, due to instructions whose
length is finalized later. (Also, inline jump tables end with
a ".p2align 1".)
If unable to to evaluate the function length immediately, emit
it as an MCExpr instead. If we'd implement splitting the unwind
info for a function (which isn't implemented for ARM64 yet either),
we wouldn't know whether we need to split it though.
Avoid calling getFrameIndexOffset() on an unset
FuncInfo.UnwindHelpFrameIdx, to avoid triggering asserts in the
preexisting testcase CodeGen/ARM/Windows/wineh-basic.ll. (Once
MSVC exception handling is fully implemented, those changes
can be reverted.)
[1] https://sourceware.org/binutils/docs/as/Section.html#Section
Differential Revision: https://reviews.llvm.org/D125645
This reverts commit 256a52d9aa (and
also the follow-up commit 38eb4fe74b that moved a test
case to a different directory).
As discussed in https://reviews.llvm.org/D126257 there is a suspicion
that something was wrong with this commit as text section range was
shortened to 1 byte rather than rounded up as shown in the
llvm/test/DebugInfo/X86/dwarf-aranges.ll test case.
STATEPOINT is a special pseudo instruction which represent Moving GC semantic to LLVM.
Every tied def/use VReg pair in STATEPOINT represent same physical register which can
'magically' change during call wrapped by statepoint.
(By construction, tied use operand is not live across STATEPOINT).
This means that when converting into two-address form, there is not need to insert COPY
instruction before stateppoint, what TwoAddressInstruction pass does for 'regular'
instructions.
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D124631
VP intrinsics show UB if the %evl parameter is out of bounds - they must
not carry the speculatable attribute. The out-of-bounds UB disappears
when the %evl parameter is expanded into the mask or expansion replaces
the entire VP intrinsic with non-VP code.
This patch
- Removes the speculatable attribute on all VP intrinsics.
- Generalizes the isSafeToSpeculativelyExecute function to let VP
expansion know whether the VP intrinsic replacement will be
speculatable. VP expansion may only discard %evl where this is the
case.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D125296
This relands commit 4d8d2580c5.
The major change here is using 'addUsedIfAvailable<BasicBlockSectionsProfileReader>()` to make sure we don't change the pipeline tests.
Differential Revision: https://reviews.llvm.org/D126518
Today, text section prefixes (none, .unlikely, .hot, and .unkown) are determined based on PGO profile. However, Propeller may deem a function hot when PGO doesn't. Besides, when `-Wl,-keep-text-section-prefix=true` Propeller cannot enforce a global section ordering as the linker can only reorder sections within each output section (.text, .text.hot, .text.unlikely).
This patch promotes all functions with Propeller profiles (functions listed in the basic-block-sections profile) to .text.hot. The feature is hidden behind the flag `--bbsections-guided-section-prefix` which defaults to `true`.
The new implementation refactors the parsing of basic block sections profile into a new `BasicBlockSectionsProfileReader` analysis pass. This allows us to use the information earlier in `CodeGenPrepare` in order to set the functions text prefix. `BasicBlockSectionsProfileReader` will be used both by `BasicBlockSections` pass and `CodeGenPrepare`.
Differential Revision: https://reviews.llvm.org/D122930
With a fix for an expensive checks build failure exposed by new RISC-V tests.
Something about expanding two rotates in type legalization caused a change
in the remapping tables that the expensive checks verifying wasn't expecting.
See comment in the code for how it was fixed.
Tests came from this commit that exposed the bug
[RISCV] Add test cases showing failure to remove mask on rotate amounts.
If the masking AND has multiple users we fail to remove it.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D126036
treated as Copy instruction in MCP.
This is then used in AArch64 to remove copy instructions after taildup
ran in machine block placement
Differential Revision: https://reviews.llvm.org/D125335
reapply 62a9b36fcf and fix module build
failue:
1: remove MachineCycleInfoWrapperPass in MachinePassRegistry.def
MachineCycleInfoWrapperPass is a anylysis pass, should not be there.
2: move the definition for MachineCycleInfoPrinterPass to cpp file.
Otherwise, there are module conflicit for MachineCycleInfoWrapperPass
in MachinePassRegistry.def and MachineCycleAnalysis.h after
62a9b36fcf.
MachineCycle can handle irreducible loop. Natural loop
analysis (MachineLoop) can not return correct loop depth if
the loop is irreducible loop. And MachineSink is sensitive
to the loop depth, see MachineSinking::isProfitableToSinkTo().
This patch tries to use MachineCycle so that we can handle
irreducible loop better.
Reviewed By: sameerds, MatzeB
Differential Revision: https://reviews.llvm.org/D123995
This commit modifies the AsmPrinter to avoid emitting any zero-sized symbols to
the .debug_aranges table, by rounding their size up to 1. Entries with zero
length violate the DWARF 5 spec, which states:
> Each descriptor is a triple consisting of a segment selector, the beginning
> address within that segment of a range of text or data covered by some entry
> owned by the corresponding compilation unit, followed by the non-zero length
> of that range.
In practice, these zero-sized entries produce annoying warnings in lld and
cause GNU binutils to truncate the table when parsing it.
Other parts of LLVM, such as DWARFDebugARanges in the DebugInfo module
(specifically the appendRange method), already avoid emitting zero-sized
symbols to .debug_aranges, but not comprehensively in the AsmPrinter. In fact,
the AsmPrinter does try to avoid emitting such zero-sized symbols when labels
aren't involved, but doesn't when the symbol to emitted is a difference of two
labels; this patch extends that logic to handle the case in which the symbol is
defined via labels.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D126257
This adds support for pointer types for `atomic xchg` and let us write
instructions such as `atomicrmw xchg i64** %0, i64* %1 seq_cst`. This
is similar to the patch for allowing atomicrmw xchg on floating point
types: https://reviews.llvm.org/D52416.
Differential Revision: https://reviews.llvm.org/D124728
When expanding VP reductions to non VP-code, the reduction pass was
ignoring the mask before. Fix this by keeping the mask and selecting
neutral elements where the mask is zero.
Reviewed By: frasercrmck
Differential Revision: https://reviews.llvm.org/D126362
Use container::size_type directly to avoid type mismatch causing build failures in Windows.
Original commit message:
This patch optimizes the transformation of selects to a branch when the heuristics deemed it profitable.
It aggressively sinks eligible instructions to the newly created true/false blocks to prevent their
execution on the common path and interleaves dependence slices to maximize ILP.
Depends on D120232
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D120233
The second argument to is_fp_class specifies the set of floating-point
class to test against. It can be zero, in this case the intrinsic is
expected to return zero value.
Differential Revision: https://reviews.llvm.org/D112025
Followup to D125988 - FPOW is similar to FREM and will most likely scalarize to libcalls, so unroll before widening to prevent use making additional libcalls with UNDEF args.
Any zext 'sink' should already have an operand that is in the legal
value, so avoid using a trunc and just use the trunc operand instead.
Differential Revision: https://reviews.llvm.org/D118905
Currently, two element vectors produced as the result of a binary op are
widened to four element vectors on x86 by
DAGTypeLegalizer::WidenVecRes_BinaryCanTrap. If the op still isn't legal
after widening it is unrolled into 4 scalar ops in SelectionDAG before
being converted into a libcall. This way we end up with 4 libcalls (two of
them on known undef elements) instead of the original two libcalls.
This patch modifies DAGTypeLegalizer::WidenVectorResult to ensure that if
it is known that a binary op will be tunred into a libcall, it is unrolled
instead of being widened. This prevents the creation of the extra scalar
instructions on known undef elements and (eventually) libacalls with known
undef parameters which would otherwise be created when the op gets expanded
post widening.
Differential Revision: https://reviews.llvm.org/D125988
MachineCycle can handle irreducible loop. Natural loop
analysis (MachineLoop) can not return correct loop depth if
the loop is irreducible loop. And MachineSink is sensitive
to the loop depth, see MachineSinking::isProfitableToSinkTo().
This patch tries to use MachineCycle so that we can handle
irreducible loop better.
Reviewed By: sameerds, MatzeB
Differential Revision: https://reviews.llvm.org/D123995
This patch optimizes the transformation of selects to a branch when the heuristics deemed it profitable.
It aggressively sinks eligible instructions to the newly created true/false blocks to prevent their
execution on the common path and interleaves dependence slices to maximize ILP.
Depends on D120232
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D120233
This patch adds the loop-level heuristics for determining whether branches are more profitable than conditional moves.
These heuristics apply to only inner-most loops.
Depends on D120231
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D120232
This patch adds the base heuristics for determining whether branches are more profitable than conditional moves.
Base heuristics apply to all code apart from inner-most loops.
Depends on D122259
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D120231
This patch implements the actual transformation of selects to branches.
It includes only the base transformation without any sinking.
Depends on D120230
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D122259
RAGreedy has two fields of RegisterClassInfo, one called RCI and another RegClassInfo from its base class.
RCI is initialized without freezeReservedRegs first, while RegClassInfo does. Therefore, if reserved registers
information is changed between last time freezeReservedRegs is called and RAGreedy, it's not picked up by RCI.
Instead of having both fields in RAGreedy, remove RCI and use RegClassInfo instead. Also removed is the TRI field
which is present in its base class.
Reviewed By: MatzeB
Differential Revision: https://reviews.llvm.org/D125926
If the VT is i2, then 2 is really -2.
Test has not been commited yet, but diff shows the change.
Fixes PR55644.
Differential Revision: https://reviews.llvm.org/D126213
Freeze the condition of the newly introduced conditional branch,
to avoid immediate undefined behavior if the input to ctlz/cttz
was originally poison.
Differential Revision: https://reviews.llvm.org/D125887
I had initially assumed this was the problem with
https://github.com/llvm/llvm-project/issues/55271#issuecomment-1133426243
But it turns out that was a simpler issue. This patch is still
more correct than what we were doing before so figured I'd submit
it anyway.
No test case because I'm not sure how to get an undef around
until expansion.
Looking at the test deltas I wonder if it be valid to combine
(sext_inreg (freeze (aextload X))) -> (freeze (sextload X)).
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D126175
abs should only produce a positive value or the signed minimum
value. This means we can't fold abs(undef) to undef as that would
allow more values. Fold to 0 instead to match InstSimplify.
Fixes test mentioned in comment on pr55271.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D126174
Simon Pilgrim