1874 Commits

Author SHA1 Message Date
OCHyams
06f28f2451 [Assignment Tracking][NFC] Cache debug-info-assignment-tracking module flag
This reduces CTMark LTO-O3-g compile time by a geomean of 0.1%.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D146985
2023-03-29 12:51:59 +01:00
Phoebe Wang
0efe111365 Reland "[Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 2"
This reverts commit db6a979ae82410e42430e47afa488936ba8e3025.

Reland D102817 without any change. The previous revert was a mistake.

Differential Revision: https://reviews.llvm.org/D102817
2023-03-29 08:59:56 +08:00
Kazu Hirata
e844638946 [llvm] Use isIntOrFPConstant (NFC) 2023-03-27 22:32:23 -07:00
OCHyams
7d89437455 [Assignment Tracking][NFC] Use RawLocationWrapper in VarLocInfo [2/x]
Use RawLocationWrapper rather than a Value to represent the location operand(s)
so that it's possible to represent multiple location
operands. AssignmentTrackingAnalysis still converts variadic debug intrinsics
to kill locations so this patch is NFC.

Reviewed By: StephenTozer

Differential Revision: https://reviews.llvm.org/D145911
2023-03-16 09:55:15 +00:00
Sander de Smalen
170e7a0ec2 [AArch64][SME2] Add CodeGen support for target("aarch64.svcount").
This patch adds AArch64 CodeGen support such that the type can be passed
and returned to/from functions, and also adds support to use this type in
load/store operations and PHI nodes.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D136862
2023-03-02 12:07:41 +00:00
J. Ryan Stinnett
22b8e82c12 [DebugInfo] Remove dbg.addr from CodeGen
As part of this work, removing `SDDbgValue::clearIsEmitted` originally added for
`dbg.addr` in 045c67769d7fe577fc38cccb6fb40fd814437447 was attempted, but it
appears some tests for `DBG_INSTR_REF` now depend on that behaviour as well, so
it was kept and comments were updated instead.

Part of `dbg.addr` removal
Discussed in https://discourse.llvm.org/t/what-is-the-status-of-dbg-addr/62898

Differential Revision: https://reviews.llvm.org/D144800
2023-03-02 09:29:43 +00:00
Serge Pavlov
7f81dd4dd6 [NFC] Make FPClassTest a bitmask enumeration
This is recommit of 2e416cdd52, fixed to be accepatble by GCC.
The original commit message is below.

With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-24 15:12:16 +07:00
Nikita Popov
8347ca7dc8 [PatternMatch] Don't require DataLayout for m_VScale()
The m_VScale() matcher is unusual in that it requires a DataLayout.
It is currently used to determine the size of the GEP type. However,
I believe it is sufficient to check for the canonical
<vscale x 1 x i8> form here -- I don't think there's a need to
recognize exotic variations like <vscale x 1 x i4> as a vscale
constant representation as well.

Differential Revision: https://reviews.llvm.org/D144566
2023-02-23 15:30:29 +01:00
Yeting Kuo
419948fe67 [VP] Reorder is_int_min_poison/is_zero_poison operand before mask for vp.abs/ctlz/cttz.
The patch ensures last two operands of vp.abs/ctlz/cttz are mask and evl.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D144536
2023-02-23 13:58:21 +08:00
Serge Pavlov
08a09235b6 Revert "[NFC] Make FPClassTest a bitmask enumeration"
This reverts commit e7613c1d9b259bdf2b0b06b4169d9a10dd553406.

GCC issues an error:

In file included from /home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/unittests/ADT/BitmaskEnumTest.cpp:9:
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:66:22: error: explicit specialization of template<class E, class Enable> struct llvm::is_bitmask_enum outside its namespace must use a nested-name-specifier [-fpermissive]
   66 |   template <> struct is_bitmask_enum<Enum> : std::true_type {};                \
      |                      ^~~~~~~~~~~~~~~~~~~~~
/home/buildbot/as-builder-4/lld-x86_64-ubuntu-fast/llvm-project/llvm/unittests/ADT/BitmaskEnumTest.cpp:30:1: note: in expansion of macro LLVM_DECLARE_ENUM_AS_BITMASK
   30 | LLVM_DECLARE_ENUM_AS_BITMASK(Flags2, V4);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
2023-02-23 12:55:58 +07:00
Serge Pavlov
e7613c1d9b [NFC] Make FPClassTest a bitmask enumeration
This is recommit of 2e416cdd52, reverted in 8555ab2fcd, because GCC
complains on extra qualification. The macro LLVM_DECLARE_ENUM_AS_BITMASK
does not specify llvm:: anymore, so the macro must occur in the namespace
llvm. Documentation updated accordingly. The original commit message is below.

With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-23 12:38:57 +07:00
Nikita Popov
8555ab2fcd Revert "[NFC] Make FPClassTest a bitmask enumeration"
This reverts commit 2e416cdd52c1079b8c7cb1f7d7e557c889a4fb56.

Breaks the GCC build:

In file included from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:18,
                 from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/APFloat.h:20,
                 from /home/npopov/repos/llvm-project/llvm/lib/Support/APFloat.cpp:14:
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:66:22: error: extra qualification not allowed [-fpermissive]
   66 |   template <> struct llvm::is_bitmask_enum<Enum> : std::true_type {};          \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:67:22: error: extra qualification not allowed [-fpermissive]
   67 |   template <> struct llvm::largest_bitmask_enum_bit<Enum> {                    \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
[43/4396] Building CXX object lib/Supp...iles/LLVMSupport.dir/CommandLine.cpp.o
2023-02-22 08:56:19 +01:00
Serge Pavlov
2e416cdd52 [NFC] Make FPClassTest a bitmask enumeration
With this change bitwise operations are allowed for FPClassTest
enumeration, it must simplify using this type. Also some functions
changed to get argument of type FPClassTest instead of unsigned.

Differential Revision: https://reviews.llvm.org/D144241
2023-02-22 14:20:04 +07:00
Caroline Concatto
d515ecca68 [IR] Add new intrinsics interleave and deinterleave vectors
This patch adds 2 new intrinsics:

  ; Interleave two vectors into a wider vector
  <vscale x 4 x i64> @llvm.vector.interleave2.nxv2i64(<vscale x 2 x i64> %even, <vscale x 2 x i64> %odd)

  ; Deinterleave the odd and even lanes from a wider vector
  {<vscale x 2 x i64>, <vscale x 2 x i64>} @llvm.vector.deinterleave2.nxv2i64(<vscale x 4 x i64> %vec)

The main motivator for adding these intrinsics is to support vectorization of
complex types using scalable vectors.

The intrinsics are kept simple by only supporting a stride of 2, which makes
them easy to lower and type-legalize. A stride of 2 is sufficient to handle
complex types which only have a real/imaginary component.

The format of the intrinsics matches how `shufflevector` is used in
LoopVectorize. For example:

  using cf = std::complex<float>;

  void foo(cf * dst, int N) {
      for (int i=0; i<N; ++i)
          dst[i] += cf(1.f, 2.f);
  }

For this loop, LoopVectorize:
  (1) Loads a wide vector (e.g. <8 x float>)
  (2) Extracts odd lanes using shufflevector (leading to <4 x float>)
  (3) Extracts even lanes using shufflevector (leading to <4 x float>)
  (4) Performs the addition
  (5) Interleaves the two <4 x float> vectors into a single <8 x float> using
      shufflevector
  (6) Stores the wide vector.

In this example, we can 1-1 replace shufflevector in (2) and (3) with the
deinterleave intrinsic, and replace the shufflevector in (5) with the
interleave intrinsic.

The SelectionDAG nodes might be extended to support higher strides (3, 4, etc)
as well in the future.

Similar to what was done for vector.splice and vector.reverse, the intrinsic
is lowered to a shufflevector when the type is fixed width, so to benefit from
existing code that was written to recognize/optimize shufflevector patterns.

Note that this approach does not prevent us from adding new intrinsics for other
strides, or adding a more generic shuffle intrinsic in the future. It just solves
the immediate problem of being able to vectorize loops with complex math.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D141924
2023-02-20 12:21:59 +00:00
Nick Desaulniers
5cc1016a57 [llvm][SelectionDAGBuilder] codegen callbr.landingpad intrinsic
Given a CallBrInst, retain its first virtual register in SelectionDagBuilder's
FunctionLoweringInfo if there's corresponding landingpad. Walk the list
of COPY MachineInstr to find the original virtual and physical registers
defined by the INLINEASM_BR MachineInst.

Test cases from https://reviews.llvm.org/D139565.
Link: https://github.com/llvm/llvm-project/issues/59538

Part 3 from
https://discourse.llvm.org/t/rfc-syncing-asm-goto-with-outputs-with-gcc/65453/8

Follow up patches still need to wire up CallBrPrepare into the pass
pipelines.

Reviewed By: efriedma, void

Differential Revision: https://reviews.llvm.org/D140160
2023-02-16 17:58:34 -08:00
Archibald Elliott
62c7f035b4 [NFC][TargetParser] Remove llvm/ADT/Triple.h
I also ran `git clang-format` to get the headers in the right order for
the new location, which has changed the order of other headers in two
files.
2023-02-07 12:39:46 +00:00
Marco Elver
98f0e4f611 Revert "[SelectionDAG] Add pcsections recursively on SDNode values"
Revert "[SelectionDAG] Add missing setValue calls in visitIntrinsicCall"

This reverts commit 0c64e1b68f36640ffe82fc90e6279c50617ad1cc.
This reverts commit 1142e6c7c795de7f80774325a07ed49bc95a48c9.

It spuriously added !pcsections where they shouldn't be. See added test
case in test/CodeGen/X86/pcsections.ll as an example. The reason is that
the SelectionDAG chains operations in a basic block as "operands"
pointing to preceding instructions. This resulted in setting the
metadata on _all_ instructions preceding the one that should have the
metadata.

Reverting for now because the semantics of !pcsections was completely
buggy now.
2023-02-03 18:57:34 +01:00
Sanjay Patel
fb3e3ef62e [SDAG] fix miscompiles caused by using ValueTracking matchSelectPattern to create FMINIMUM/FMAXIMUM
ValueTracking attempts to match compare+select patterns to FP min/max
operations, but it was created before the newer IEEE-754-2019
minimum/maximum ops were defined. Ie, matchSelectPattern() does not
account for the -0.0/+0.0 behavior that is specified in the newer
standard.

FMINIMUM/FMAXIMUM nodes were created to map to the newer standard:

/// FMINIMUM/FMAXIMUM - NaN-propagating minimum/maximum that also treat -0.0
/// as less than 0.0. While FMINNUM_IEEE/FMAXNUM_IEEE follow IEEE 754-2008
/// semantics, FMINIMUM/FMAXIMUM follow IEEE 754-2018 draft semantics.

We could adjust ValueTracking to deal with signed zero, but it seems like
a moot point given the divergent NaN behavior discussed in D143056, so just
delete this possibility to avoid bugs when converting IR to SDAG.

Differential Revision: https://reviews.llvm.org/D143106
2023-02-03 09:53:47 -05:00
Matt Arsenault
8bdb149c0a DAG: Remove redundant check for return alignment
This is already what the CallBase getRetAlign does
2023-01-31 08:43:56 -04:00
Kazu Hirata
55e2cd1609 Use llvm::count{lr}_{zero,one} (NFC) 2023-01-28 12:41:20 -08:00
Stefan Gränitz
3b387d1070 Lift EHPersonalities from Analysis to IR (NFC)
Computing EH-related information was only relevant for analysis passes so far. Lifting it to IR will allow the IR Verifier to calculate EH funclet coloring and validate funclet operand bundles in a follow-up step.

Reviewed By: rnk, compnerd

Differential Revision: https://reviews.llvm.org/D138122
2023-01-27 18:05:13 +01:00
Martin Fink
1142e6c7c7 [SelectionDAG] Add missing setValue calls in visitIntrinsicCall
Add missing setValue calls in SelectionDAGBuilder for mem-transfer
intrinsic calls. These setValue calls are required in order to propagate
pcsections metadata from IR to MIR.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D141048
2023-01-26 16:13:46 +01:00
Nick Desaulniers
def20427b4 [llvm][DiagnosticInfo] handle function pointer casts
As pointed out by @arsenm in https://reviews.llvm.org/D141451#4045099,
we don't handle ConstantExpressions for dontcall-{warn|error} IR Fn
Attrs.

Use CallBase::getCalledOperand() and Value::stripPointerCasts() should
the call to CallBase::getCalledFunction return nullptr.

I don't know how to express the IR test case in C, otherwise I'd add a
clang test, too.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D142058
2023-01-24 13:59:34 -08:00
Matt Arsenault
778cf5431c IR: Add atomicrmw uinc_wrap and udec_wrap
These are essentially add/sub 1 with a clamping value.

AMDGPU has instructions for these. CUDA/HIP expose these as
atomicInc/atomicDec. Currently we use target intrinsics for these,
but those do no carry the ordering and syncscope. Add these to
atomicrmw so we can carry these and benefit from the regular
legalization processes.
2023-01-24 17:55:11 -04:00
Kazu Hirata
ca7e849720 [llvm] Use llvm::bit_floor (NFC)
In all these cases, the arguments to Log2_32 are known to be nonzero,
so we don't have to worry about "1 << -1".
2023-01-22 13:41:23 -08:00
Kazu Hirata
caa99a01f5 Use llvm::popcount instead of llvm::countPopulation(NFC) 2023-01-22 12:48:51 -08:00
OCHyams
4ece50737d [Assignment Tracking][NFC] Replace LLVM command line option with a module flag
Remove LLVM flag -experimental-assignment-tracking. Assignment tracking is
still enabled from Clang with the command line -Xclang
-fexperimental-assignment-tracking which tells Clang to ask LLVM to run the
pass declare-to-assign. That pass converts conventional debug intrinsics to
assignment tracking metadata. With this patch it now also sets a module flag
debug-info-assignment-tracking with the value `i1 true` (using the flag conflict
rule `Max` since enabling assignment tracking on IR that contains only
conventional debug intrinsics should cause no issues).

Update the docs and tests too.

Reviewed By: CarlosAlbertoEnciso

Differential Revision: https://reviews.llvm.org/D142027
2023-01-20 14:24:15 +00:00
Matt Arsenault
e70ae0f46b DAG/GlobalISel: Fix broken/redundant setting of MODereferenceable
This was incorrectly setting dereferenceable on unaligned
operands. getLoadMemOperandFlags does the alignment dereferenceabilty
check without alignment, and then both paths went on to check
isDereferenceableAndAlignedPointer. Make getLoadMemOperandFlags check
isDereferenceableAndAlignedPointer, and remove the second call.
2023-01-13 20:30:30 -05:00
Guillaume Chatelet
48f5d77eee [NFC] Use TypeSize::getKnownMinValue() instead of TypeSize::getKnownMinSize()
This change is one of a series to implement the discussion from
https://reviews.llvm.org/D141134.
2023-01-11 16:36:39 +00:00
Stephen Tozer
da0faa0594 [DebugInfo] Produce variadic DBG_INSTR_REFs from ISel
This patch modifies SelectionDAG and FastISel to produce DBG_INSTR_REFs with
variadic expressions, and produce DBG_INSTR_REFs for debug values with variadic
location expressions. The former essentially means just prepending
DW_OP_LLVM_arg, 0 to the existing expression. The latter is achieved in
MachineFunction::finalizeDebugInstrRefs and InstrEmitter::EmitDbgInstrRef.

Reviewed By: jmorse, Orlando

Differential Revision: https://reviews.llvm.org/D133929
2023-01-09 08:58:33 +00:00
James Y Knight
1ae36b1387 Remove special cases for invoke of non-throwing inline-asm.
Non-throwing inline asm infers the nounwind attribute in
instcombine. Thus, it can be handled in the same manner as
non-throwing target functions are generally. Further special casing is
unnecessary complexity.
2023-01-06 13:53:10 -05:00
Stephen Tozer
e10e936315 [DebugInfo][NFC] Add new MachineOperand type and change DBG_INSTR_REF syntax
This patch makes two notable changes to the MIR debug info representation,
which result in different MIR output but identical final DWARF output (NFC
w.r.t. the full compilation). The two changes are:

  * The introduction of a new MachineOperand type, MO_DbgInstrRef, which
    consists of two unsigned numbers that are used to index an instruction
    and an output operand within that instruction, having a meaning
    identical to first two operands of the current DBG_INSTR_REF
    instruction. This operand is only used in DBG_INSTR_REF (see below).
  * A change in syntax for the DBG_INSTR_REF instruction, shuffling the
    operands to make it resemble DBG_VALUE_LIST instead of DBG_VALUE,
    and replacing the first two operands with a single MO_DbgInstrRef-type
    operand.

This patch is the first of a set that will allow DBG_INSTR_REF
instructions to refer to multiple machine locations in the same manner
as DBG_VALUE_LIST.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D129372
2023-01-06 18:03:48 +00:00
Guillaume Chatelet
87b6b347fc Revert D141134 "[NFC] Only expose getXXXSize functions in TypeSize"
The patch should be discussed further.

This reverts commit dd56e1c92b0e6e6be249f2d2dd40894e0417223f.
2023-01-06 15:27:50 +00:00
Guillaume Chatelet
dd56e1c92b [NFC] Only expose getXXXSize functions in TypeSize
Currently 'TypeSize' exposes two functions that serve the same purpose:
 - getFixedSize / getFixedValue
 - getKnownMinSize / getKnownMinValue

source : bf82070ea4/llvm/include/llvm/Support/TypeSize.h (L337-L338)

This patch offers to remove one of the two and stick to a single function in the code base.

Differential Revision: https://reviews.llvm.org/D141134
2023-01-06 15:24:52 +00:00
Yeting Kuo
5a57ebcc43 [VP][RISCV] Add vp.abs and RISC-V support.
RISC-V uses ISD::ABS lower method (abs x) -> (smax_vl x (sub_vl 0, x)) for ISD::VP_ABS.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D141033
2023-01-06 15:18:12 +08:00
serge-sans-paille
38818b60c5
Move from llvm::makeArrayRef to ArrayRef deduction guides - llvm/ part
Use deduction guides instead of helper functions.

The only non-automatic changes have been:

1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).

Per reviewers' comment, some useless makeArrayRef have been removed in the process.

This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.

Differential Revision: https://reviews.llvm.org/D140955
2023-01-05 14:11:08 +01:00
Yeting Kuo
1e9e1b9cf8 [VP][RISCV] Add vp.ctlz/cttz and RISC-V support.
The patch also adds expandVPCTLZ and expandVPCTTZ to expand vp.ctlz/cttz nodes
and the cost model of vp.ctlz/cttz.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D140370
2023-01-04 15:15:01 +08:00
Qiu Chaofan
a40ef656d8 [Intrinsic] Rename flt.rounds intrinsic to get.rounding
Address the inconsistency between FLT_ROUNDS_ and SET_ROUNDING SDAG
node. Rename FLT_ROUNDS_ to GET_ROUNDING and add llvm.get.rounding
intrinsic to replace flt.rounds.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D139507
2022-12-19 15:22:39 +08:00
Fangrui Song
036e092282 [CodeGen] std::optional::value => operator*/operator->
value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).

This fixes LLVMMIRParser, LLVMGlobalISel, LLVMAsmPrinter, LLVMSelectionDAG.
2022-12-16 23:41:36 +00:00
Kazu Hirata
f7dffc28b3 Don't include None.h (NFC)
I've converted all known uses of None to std::nullopt, so we no longer
need to include None.h.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 11:24:26 -08:00
OCHyams
1d1de7467c [Assignment Tracking][Analysis] Add analysis pass
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add initial revision of assignment tracking analysis pass
---------------------------------------------------------
This patch squashes five individually reviewed patches into one:

    #1 https://reviews.llvm.org/D136320
    #2 https://reviews.llvm.org/D136321
    #3 https://reviews.llvm.org/D136325
    #4 https://reviews.llvm.org/D136331
    #5 https://reviews.llvm.org/D136335

Patch #1 introduces 2 new files: AssignmentTrackingAnalysis.h and .cpp. The
two subsequent patches modify those files only. Patch #4 plumbs the analysis
into SelectionDAG, and patch #5 is a collection of tests for the analysis as
a whole.

The analysis was broken up into smaller chunks for review purposes but for the
most part the tests were written using the whole analysis. It would be possible
to break up the tests for patches #1 through #3 for the purpose of landing the
patches seperately. However, most them would require an update for each
patch. In addition, patch #4 - which connects the analysis to SelectionDAG - is
required by all of the tests.

If there is build-bot trouble, we might try a different landing sequence.

Analysis problem and goal
-------------------------

Variables values can be stored in memory, or available as SSA values, or both.
Using the Assignment Tracking metadata, it's not possible to determine a
variable location just by looking at a debug intrinsic in
isolation. Instructions without any metadata can change the location of a
variable. The meaning of dbg.assign intrinsics changes depending on whether
there are linked instructions, and where they are relative to those
instructions. So we need to analyse the IR and convert the embedded information
into a form that SelectionDAG can consume to produce debug variable locations
in MIR.

The solution is a dataflow analysis which, aiming to maximise the memory
location coverage for variables, outputs a mapping of instruction positions to
variable location definitions.

API usage
---------

The analysis is named `AssignmentTrackingAnalysis`. It is added as a required
pass for SelectionDAGISel when assignment tracking is enabled.

The results of the analysis are exposed via `getResults` using the returned
`const FunctionVarLocs *`'s const methods:

    const VarLocInfo *single_locs_begin() const;
    const VarLocInfo *single_locs_end() const;
    const VarLocInfo *locs_begin(const Instruction *Before) const;
    const VarLocInfo *locs_end(const Instruction *Before) const;
    void print(raw_ostream &OS, const Function &Fn) const;

Debug intrinsics can be ignored after running the analysis. Instead, variable
location definitions that occur between an instruction `Inst` and its
predecessor (or block start) can be found by looping over the range:

    locs_begin(Inst), locs_end(Inst)

Similarly, variables with a memory location that is valid for their lifetime
can be iterated over using the range:

    single_locs_begin(), single_locs_end()

Further detail
--------------

For an explanation of the dataflow implementation and the integration with
SelectionDAG, please see the reviews linked at the top of this commit message.

Reviewed By: jmorse
2022-12-09 16:17:37 +00:00
Gregory Alfonso
cb38be9ed3 [NFC] Use Register instead of unsigned for variables that receive a Register object
Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D139451
2022-12-07 00:23:34 +00:00
Krzysztof Parzyszek
ab672e9173 FPEnv: convert Optional to std::optional 2022-12-03 13:55:56 -06:00
Kazu Hirata
998960ee1f [CodeGen] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 20:36:08 -08:00
tentzen
db6a979ae8 Revert "[Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 2"
This reverts commit 1a949c871ab4a6b6d792849d3e8c0fa6958d27f5.
2022-12-02 02:44:18 -08:00
tentzen
1a949c871a [Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 2
This patch is the Part-2 (BE LLVM) implementation of HW Exception handling.
Part-1 (FE Clang) was committed in 797ad701522988e212495285dade8efac41a24d4.

This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).

Compiler options:
  For clang-cl.exe, the option is -EHa, the same as MSVC.
  For clang.exe, the extra option is -fasync-exceptions,
  plus -triple x86_64-windows -fexceptions and -fcxx-exceptions as usual.

NOTE:: Without the -EHa or -fasync-exceptions, this patch is a NO-DIFF change.

The rules for C code:
For C-code, one way (MSVC approach) to achieve SEH -EHa semantic is to follow three rules:
  First, no exception can move in or out of _try region., i.e., no "potential faulty
    instruction can be moved across _try boundary.
  Second, the order of exceptions for instructions 'directly' under a _try must be preserved
    (not applied to those in callees).
  Finally, global states (local/global/heap variables) that can be read outside of _try region
    must be updated in memory (not just in register) before the subsequent exception occurs.

The impact to C++ code:
  Although SEH is a feature for C code, -EHa does have a profound effect on C++
  side. When a C++ function (in the same compilation unit with option -EHa ) is
  called by a SEH C function, a hardware exception occurs in C++ code can also
  be handled properly by an upstream SEH _try-handler or a C++ catch(...).
  As such, when that happens in the middle of an object's life scope, the dtor
  must be invoked the same way as C++ Synchronous Exception during unwinding process.

Design:
A natural way to achieve the rules above in LLVM today is to allow an EH edge
added on memory/computation instruction (previous iload/istore idea) so that
exception path is modeled in Flow graph preciously. However, tracking every
single memory instruction and potential faulty instruction can create many
Invokes, complicate flow graph and possibly result in negative performance
impact for downstream optimization and code generation. Making all
optimizations be aware of the new semantic is also substantial.

This design does not intend to model exception path at instruction level.
Instead, the proposed design tracks and reports EH state at BLOCK-level to
reduce the complexity of flow graph and minimize the performance-impact on CPP
code under -EHa option.
One key element of this design is the ability to compute State number at
block-level. Our algorithm is based on the following rationales:

A _try scope is always a SEME (Single Entry Multiple Exits) region as jumping
into a _try is not allowed. The single entry must start with a seh_try_begin()
invoke with a correct State number that is the initial state of the SEME.
Through control-flow, state number is propagated into all blocks. Side exits
marked by seh_try_end() will unwind to parent state based on existing SEHUnwindMap[].
Note side exits can ONLY jump into parent scopes (lower state number).
Thus, when a block succeeds various states from its predecessors, the lowest
State triumphs others.  If some exits flow to unreachable, propagation on those
paths terminate, not affecting remaining blocks.
For CPP code, object lifetime region is usually a SEME as SEH _try.
However there is one rare exception: jumping into a lifetime that has Dtor but
has no Ctor is warned, but allowed:

Warning: jump bypasses variable with a non-trivial destructor

In that case, the region is actually a MEME (multiple entry multiple exits).
Our solution is to inject a eha_scope_begin() invoke in the side entry block to
ensure a correct State.
Implementation:
Part-1: Clang implementation (already in):
Please see commit 797ad701522988e212495285dade8efac41a24d4).

Part-2 : LLVM implementation described below.

For both C++ & C-code, the state of each block is computed at the same place in
BE (WinEHPreparing pass) where all other EH tables/maps are calculated.
In addition to _scope_begin & _scope_end, the computation of block state also
rely on the existing State tracking code (UnwindMap and InvokeStateMap).

For both C++ & C-code, the state of each block with potential trap instruction
is marked and reported in DAG Instruction Selection pass, the same place where
the state for -EHsc (synchronous exceptions) is done.
If the first instruction in a reported block scope can trap, a Nop is injected
before this instruction. This nop is needed to accommodate LLVM Windows EH
implementation, in which the address in IPToState table is offset by +1.
(note the purpose of that is to ensure the return address of a call is in the
same scope as the call address.

The handler for catch(...) for -EHa must handle HW exception. So it is
'adjective' flag is reset (it cannot be IsStdDotDot (0x40) that only catches
C++ exceptions).
Suppress push/popTerminate() scope (from noexcept/noTHrow) so that HW
exceptions can be passed through.

Original llvm-dev [RFC] discussions can be found in these two threads below:
https://lists.llvm.org/pipermail/llvm-dev/2020-March/140541.html
https://lists.llvm.org/pipermail/llvm-dev/2020-April/141338.html

Differential Revision: https://reviews.llvm.org/D102817/new/
2022-12-01 23:44:25 -08:00
Krzysztof Parzyszek
864aaa21b4 TargetLowering: convert Optional to std::optional 2022-12-01 16:19:10 -08:00
Nicolai Hähnle
43b86bf992 AMDGPU: Remove BufferPseudoSourceValue
The use of a PSV for buffer intrinsics is misleading because it may be
misinterpreted as all buffer intrinsics accessing the same address in
memory, which is clearly not true.

Instead, build MachineMemOperands without a pointer value but with an
address space, so that address space-based alias analysis can still
work.

There is a lot of test churn because previously address space 4
(constant address space) was used as an address space for buffer
intrinsics. This doesn't make much sense and seems to have been an
accident -- see the change in
AMDGPUTargetMachine::getAddressSpaceForPseudoSourceKind.

Differential Revision: https://reviews.llvm.org/D138711
2022-11-29 22:15:11 +01:00
Matt Arsenault
ee29a846c6 DAG: Fix assert when alloca has inconsistent pointer size
Take the type from the alloca, not the type to use for allocas.

Fixes issue 59250.
2022-11-29 11:48:46 -05:00
Kazu Hirata
01e998e752 [SelectionDAG] Use std::optional in SelectionDAGBuilder.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-11-26 15:05:06 -08:00