(Based on D87170 by dsanders)
I recently had need to call out to an external API to emit a JSON object as part
of one an LLVM tool was emitting. However, our JSON support didn't provide a way
to delegate part of the JSON output to that API.
Add rawValueBegin() and rawValueEnd() to maintain and check the internal state
while something else is writing to the stream. It's the users responsibility to
ensure that the resulting JSON output is still valid.
Differential Revision: https://reviews.llvm.org/D88902
This allows overload sets containing function_ref arguments to work correctly
Otherwise they're ambiguous as anything "could be" converted to a function_ref.
This matches proposed std::function_ref, absl::function_ref, etc.
Differential Revision: https://reviews.llvm.org/D88901
The `Group` class represents a group section and it is
named inconsistently with other sections which all has
the "Section" suffix. It is sometimes confusing,
this patch addresses the issue.
Differential revision: https://reviews.llvm.org/D88892
This patch fix the device_num and device_type clauses used in the init clause. device_num was not
spelled correctly in the parser and was to restrictive with scalarIntConstantExpr instead of scalarIntExpr.
device_type is now taking a list of ScalarIntExpr.
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D88571
This is one of many subsequent similar changes. Note that we're ok with
the parameter being typed as MCPhysReg, as MCPhysReg -> MCRegister is a
correct conversion; Register -> MCRegister assumes the former is indeed
physical, so we stop relying on the implicit conversion and use the
explicit, value-asserting asMCReg().
Differential Revision: https://reviews.llvm.org/D88862
When performing call slot optimization for a non-local destination,
we need to check whether there may be throwing calls between the
call and the copy. Otherwise, the early write to the destination
may be observable by the caller.
This was already done for call slot optimization of load/store,
but not for memcpys. For the sake of clarity, I'm moving this check
into the common optimization function, even if that does need an
additional instruction scan for the load/store case.
As efriedma pointed out, this check is not sufficient due to
potential accesses from another thread. This case is left as a TODO.
Differential Revision: https://reviews.llvm.org/D88799
This diff adds support for universal binaries to llvm-objcopy.
This is a recommit of 32c8435ef7 with the asan issue fixed.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D88400
Current Statepoint MI format is this:
STATEPOINT
<id>, <num patch bytes >, <num call arguments>, <call target>,
[call arguments...],
<StackMaps::ConstantOp>, <calling convention>,
<StackMaps::ConstantOp>, <statepoint flags>,
<StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
<gc base/derived pairs...> <gc allocas...>
Note that GC pointers are listed in pairs <base,derived>.
This causes base pointers to appear many times (at least twice) in
instruction, which is bad for us when VReg lowering is ON.
The problem is that machine operand tiedness is 1-1 relation, so
it might look like this:
%vr2 = STATEPOINT ... %vr1, %vr1(tied-def0)
Since only one instance of %vr1 is tied, that may lead to incorrect
codegen (see PR46917 for more details), so we have to always spill
base pointers. This mostly defeats new VReg lowering scheme.
This patch changes statepoint instruction format so that every
gc pointer appears only once in operand list. That way they all can
be tied. Additional set of operands is added to preserve base-derived
relation required to build stackmap.
New statepoint has following format:
STATEPOINT
<id>, <num patch bytes>, <num call arguments>, <call target>,
[call arguments...],
<StackMaps::ConstantOp>, <calling convention>,
<StackMaps::ConstantOp>, <statepoint flags>,
<StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
<StackMaps::ConstantOp>, <num gc pointers>, [gc pointers...],
<StackMaps::ConstantOp>, <num gc allocas>, [gc allocas...]
<StackMaps::ConstantOp>, <num entries in gc map>, [base/derived indices...]
Changes are:
- every gc pointer is listed only once in a flat length-prefixed list;
- alloca list is prefixed with its length too;
- following alloca list is length-prefixed list of base-derived
indices of pointers from gc pointer list. Note that indices are
logical (number of pointer), not absolute (index of machine operand).
Differential Revision: https://reviews.llvm.org/D87154
getNode handling for ISD:SETCC calls FoldSETCC which can canonicalize
FP constants to the RHS. When this happens we should create the node
with the FMF that was requested. By using FlagInserter when can ensure
any calls to getNode/getSetcc during canonicalization will also get the flags.
Differential Revision: https://reviews.llvm.org/D88063
Continuing from D88499, we can now model the normalization function as a
virtual member of VirtRegAuxInfo. Note that the default
(normalizeSpillWeight) is also used stand-alone in RAGreedy.
Differential Revision: https://reviews.llvm.org/D88713
This reverts commit a3caf7f610.
The ReleaseLTO-g test-suite configuration has been failing
to build since this commit, because clang segfaults while
building 7zip.
Use tablegen generic tables to get the index of image intrinsic
arguments.
Before, the computation of which image intrinsic argument is at which
index was scattered in a few places, tablegen, the SDag instruction
selection and GlobalISel. This patch changes that, so only tablegen
contains code to compute indices and the ImageDimIntrinsicInfo table
provides these information.
Differential Revision: https://reviews.llvm.org/D86270
Use SCEV to salvage additional @llvm.dbg.value that have turned into
referencing undef after transformation (and traditional
salvageDebugInfo). Before transformation compute SCEV for each
@llvm.dbg.value in the loop body and store it (along side its current
DIExpression). After transformation update those @llvm.dbg.value now
referencing undef by comparing its stored SCEV to the SCEV of the
current loop-header PHI-nodes. Allow match with offset by inserting
compensation code in the DIExpression.
Fixes : PR38815
Differential Revision: https://reviews.llvm.org/D87494
Rename the DwarfFile class in DWARFLinker to DWARFFile. This is
consistent with the other DWARF classes and avoids a ODR violation with
the DwarfFile class in AsmPrinter.
It's not possible to do this in complete generality - a CU using a
sec_offset DW_AT_ranges has no way of knowing where its rnglists
contribution starts, so should not attempt to parse any full rnglist
table/header to do so. And even using FORM_rnglistx there's no need to
parse the header - the offset can be computed using the CU's DWARF
format (32 or 64) to compute offset entry sizes, and then the list
parsed at that offset without ever trying to find a rnglist contribution
header immediately prior to the rnglists_base.
This is one of the reason for extra invalidations in D84959. In
practice, I don't think we have use cases needing this. This simplifies
the pipeline a bit and prune corner cases when considering
invalidations.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D85676
i.e. they cannot be unreachable from the entry (which usually indicate usage errors).
This change allows the removal of some nullptr checks.
Reviewed By: kuhar
Differential Revision: https://reviews.llvm.org/D88758
Summary: This patch implements the builtins for xvtdivdp, xvtdivsp, xvtsqrtdp, xvtsqrtsp.
The instructions correspond to the following builtins:
int vec_test_swdiv(vector double v1, vector double v2);
int vec_test_swdivs(vector float v1, vector float v2);
int vec_test_swsqrt(vector double v1);
int vec_test_swsqrts(vector float v1);
This patch depends on D88274, which fixes the bug in copying from CRRC to GPRC/G8RC.
Reviewed By: steven.zhang, amyk
Differential Revision: https://reviews.llvm.org/D88278
This diff refactors writeUniversalBinary and adds writeUniversalBinaryToBuffer.
This is a preparation for adding support for universal binaries to llvm-objcopy.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D88372
The signature of the ctor expects a MCRegister, but currently any
unsigned value can be converted to a MCRegister.
This patch checks that indeed the provided value is a physical register
only. We want to eventually stop implicitly converting unsigned or
Register to MCRegister (which is incorrect). The next step after this
patch is changing uses of MCRegUnitIterator to explicitly cast Register
or unsigned values to MCRegister. To that end, this patch also
introduces 2 APIs that make that conversion checked and explicit.
Differential Revision: https://reviews.llvm.org/D88705
Next to erasing the instruction, we also always want to remove
it from MSSA and MD. Use a common function to do so.
This is a refactoring split out from D26739.
While looping through all args or all return values, we may mark a use
of a later iteration as live. Previously when we got to that later value
it would ignore that and continue adding to Uses instead of marking it
live. For example, when looping through arg#0 and arg#1,
MarkValue(arg#0, Live) may cause some use of arg#1 to be live, but
MarkValue(arg#1, MaybeLive) will not notice that and continue adding
into Uses.
Now MarkValue(RA, MaybeLive) will MarkLive(RA) if any use is live.
Fixes PR47444.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88529
We will need to add intrinsics to the switch (such as
the ones that are currently in the switch above this
one) that deal with special cases and then break to
the default handling.
This adds support for -mcpu=cortex-r82. Some more information about this
core can be found here:
https://www.arm.com/products/silicon-ip-cpu/cortex-r/cortex-r82
One note about the system register: that is a bit of a refactoring because of
small differences between v8.4-A AArch64 and v8-R AArch64.
This is based on patches from Mark Murray and Mikhail Maltsev.
Differential Revision: https://reviews.llvm.org/D88660
When we know that a particular type is always going to be fixed
width we have so far been writing code like this:
getSizeInBits().getFixedSize()
Since we are doing this in quite a few places now it seems to make
sense to add a new helper function that allows us to replace
these calls with a single getFixedSizeInBits() call.
Differential Revision: https://reviews.llvm.org/D88649
A new hidden option -print-changed is added along with code to support
printing the IR as it passes through the opt pipeline in the new pass
manager. Only those passes that change the IR are reported, with others
only having the banner reported, indicating that they did not change the
IR, were filtered out or ignored. Filtering of output via the
-filter-print-funcs is supported and a new supporting hidden option
-filter-passes is added. The latter takes a comma separated list of pass
names and filters the output to only show those passes in the list that
change the IR. The output can also be modified via the -print-module-scope
function.
The code introduces an abstract template base class that generalizes the
comparison of IRs that takes an IR representation as template parameter.
Derived classes provide overrides that provide an event based API
for generalized reporting of IRs as they are changed in the opt pipeline
through the new pass manager.
The first of several instantiations is provided that prints the IR
in a form similar to that produced by -print-after-all with the above
mentioned filtering capabilities. This version, and the others to
follow will be introduced at the upcoming developer's conference.
Reviewed By: aeubanks (Arthur Eubanks), yrouban (Yevgeny Rouban), ychen (Yuanfang Chen), MaskRay (Fangrui Song)
Differential Revision: https://reviews.llvm.org/D86360
The user is expected to make the isStackSlot check before calling isPhysicalRegister
or isVirtualRegister. The APIs assert otherwise. We can improve the usability
of these APIs by carrying out the check in the 2 APIs: they become a
complete "source of truth" and remove an extra responsibility from the
user.
Differential Revision: https://reviews.llvm.org/D88598
When adding an archive member with a problem, e.g. a new bitcode with an
old archiver, containing an unsupported attribute, or an ELF file with a
malformed symbol table, the archiver would throw away the error and
simply add the member to the archive without any symbol entries. This
meant that the resultant archive could be silently unusable when not
using --whole-archive, and result in unexpected undefined symbols.
This change fixes this issue by addressing two FIXMEs and only throwing
away not-an-object errors. However, this meant that some LLD tests which
didn't need symbol tables and were using invalid members deliberately to
test the linker's malformed input handling no longer worked, so this
patch also stops the archiver from looking for symbols in an object if
it doesn't require a symbol table, and updates the tests accordingly.
Differential Revision: https://reviews.llvm.org/D88288
Reviewed by: grimar, rupprecht, MaskRay
This is a simple pass that flattens nested loops. The intention is to optimise
loop nests like this, which together access an array linearly:
for (int i = 0; i < N; ++i)
for (int j = 0; j < M; ++j)
f(A[i*M+j]);
into one loop:
for (int i = 0; i < (N*M); ++i)
f(A[i]);
It can also flatten loops where the induction variables are not used in the
loop. This can help with codesize and runtime, especially on simple cpus
without advanced branch prediction.
This is only worth flattening if the induction variables are only used in an
expression like i*M+j. If they had any other uses, we would have to insert a
div/mod to reconstruct the original values, so this wouldn't be profitable.
This partially fixes PR40581 as this pass triggers on one of the two cases. I
will follow up on this to learn LoopFlatten a few more (small) tricks. Please
note that LoopFlatten is not yet enabled by default.
Patch by Oliver Stannard, with minor tweaks from Dave Green and myself.
Differential Revision: https://reviews.llvm.org/D42365
This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D87544
If we know that some predicate is true for AddRec and an invariant
(w.r.t. this AddRec's loop), this fact is, in particular, true on the first
iteration. We can try to prove the facts we need using the start value.
The motivating example is proving things like
```
isImpliedCondOperands(>=, X, 0, {X,+,-1}, 0}
```
Differential Revision: https://reviews.llvm.org/D88208
Reviewed By: reames
The legacy pass's default constructor sets UseCommandLine = true and
goes down a separate testing route. Match that in the NPM pass.
This fixes all tests in llvm/test/Transforms/WholeProgramDevirt under NPM.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D88588
Stored Error objects have to be checked, even if they are success
values.
This reverts commit 8d250ac3cd.
Relands commit 49b3459930655d879b2dc190ff8fe11c38a8be5f..
Original commit message:
-----------------------------------------
This makes type merging much faster (-24% on chrome.dll) when multiple
threads are available, but it slightly increases the time to link (+10%)
when /threads:1 is passed. With only one more thread, the new type
merging is faster (-11%). The output PDB should be identical to what it
was before this change.
To give an idea, here is the /time output placed side by side:
BEFORE | AFTER
Input File Reading: 956 ms | 968 ms
Code Layout: 258 ms | 190 ms
Commit Output File: 6 ms | 7 ms
PDB Emission (Cumulative): 6691 ms | 4253 ms
Add Objects: 4341 ms | 2927 ms
Type Merging: 2814 ms | 1269 ms -55%!
Symbol Merging: 1509 ms | 1645 ms
Publics Stream Layout: 111 ms | 112 ms
TPI Stream Layout: 764 ms | 26 ms trivial
Commit to Disk: 1322 ms | 1036 ms -300ms
----------------------------------------- --------
Total Link Time: 8416 ms 5882 ms -30% overall
The main source of the additional overhead in the single-threaded case
is the need to iterate all .debug$T sections up front to check which
type records should go in the IPI stream. See fillIsItemIndexFromDebugT.
With changes to the .debug$H section, we could pre-calculate this info
and eliminate the need to do this walk up front. That should restore
single-threaded performance back to what it was before this change.
This change will cause LLD to be much more parallel than it used to, and
for users who do multiple links in parallel, it could regress
performance. However, when the user is only doing one link, it's a huge
improvement. In the future, we can use NT worker threads to avoid
oversaturating the machine with work, but for now, this is such an
improvement for the single-link use case that I think we should land
this as is.
Algorithm
----------
Before this change, we essentially used a
DenseMap<GloballyHashedType, TypeIndex> to check if a type has already
been seen, and if it hasn't been seen, insert it now and use the next
available type index for it in the destination type stream. DenseMap
does not support concurrent insertion, and even if it did, the linker
must be deterministic: it cannot produce different PDBs by using
different numbers of threads. The output type stream must be in the same
order regardless of the order of hash table insertions.
In order to create a hash table that supports concurrent insertion, the
table cells must be small enough that they can be updated atomically.
The algorithm I used for updating the table using linear probing is
described in this paper, "Concurrent Hash Tables: Fast and General(?)!":
https://dl.acm.org/doi/10.1145/3309206
The GHashCell in this change is essentially a pair of 32-bit integer
indices: <sourceIndex, typeIndex>. The sourceIndex is the index of the
TpiSource object, and it represents an input type stream. The typeIndex
is the index of the type in the stream. Together, we have something like
a ragged 2D array of ghashes, which can be looked up as:
tpiSources[tpiSrcIndex]->ghashes[typeIndex]
By using these side tables, we can omit the key data from the hash
table, and keep the table cell small. There is a cost to this: resolving
hash table collisions requires many more loads than simply looking at
the key in the same cache line as the insertion position. However, most
supported platforms should have a 64-bit CAS operation to update the
cell atomically.
To make the result of concurrent insertion deterministic, the cell
payloads must have a priority function. Defining one is pretty
straightforward: compare the two 32-bit numbers as a combined 64-bit
number. This means that types coming from inputs earlier on the command
line have a higher priority and are more likely to appear earlier in the
final PDB type stream than types from an input appearing later on the
link line.
After table insertion, the non-empty cells in the table can be copied
out of the main table and sorted by priority to determine the ordering
of the final type index stream. At this point, item and type records
must be separated, either by sorting or by splitting into two arrays,
and I chose sorting. This is why the GHashCell must contain the isItem
bit.
Once the final PDB TPI stream ordering is known, we need to compute a
mapping from source type index to PDB type index. To avoid starting over
from scratch and looking up every type again by its ghash, we save the
insertion position of every hash table insertion during the first
insertion phase. Because the table does not support rehashing, the
insertion position is stable. Using the array of insertion positions
indexed by source type index, we can replace the source type indices in
the ghash table cells with the PDB type indices.
Once the table cells have been updated to contain PDB type indices, the
mapping for each type source can be computed in parallel. Simply iterate
the list of cell positions and replace them with the PDB type index,
since the insertion positions are no longer needed.
Once we have a source to destination type index mapping for every type
source, there are no more data dependencies. We know which type records
are "unique" (not duplicates), and what their final type indices will
be. We can do the remapping in parallel, and accumulate type sizes and
type hashes in parallel by type source.
Lastly, TPI stream layout must be done serially. Accumulate all the type
records, sizes, and hashes, and add them to the PDB.
Differential Revision: https://reviews.llvm.org/D87805
This makes type merging much faster (-24% on chrome.dll) when multiple
threads are available, but it slightly increases the time to link (+10%)
when /threads:1 is passed. With only one more thread, the new type
merging is faster (-11%). The output PDB should be identical to what it
was before this change.
To give an idea, here is the /time output placed side by side:
BEFORE | AFTER
Input File Reading: 956 ms | 968 ms
Code Layout: 258 ms | 190 ms
Commit Output File: 6 ms | 7 ms
PDB Emission (Cumulative): 6691 ms | 4253 ms
Add Objects: 4341 ms | 2927 ms
Type Merging: 2814 ms | 1269 ms -55%!
Symbol Merging: 1509 ms | 1645 ms
Publics Stream Layout: 111 ms | 112 ms
TPI Stream Layout: 764 ms | 26 ms trivial
Commit to Disk: 1322 ms | 1036 ms -300ms
----------------------------------------- --------
Total Link Time: 8416 ms 5882 ms -30% overall
The main source of the additional overhead in the single-threaded case
is the need to iterate all .debug$T sections up front to check which
type records should go in the IPI stream. See fillIsItemIndexFromDebugT.
With changes to the .debug$H section, we could pre-calculate this info
and eliminate the need to do this walk up front. That should restore
single-threaded performance back to what it was before this change.
This change will cause LLD to be much more parallel than it used to, and
for users who do multiple links in parallel, it could regress
performance. However, when the user is only doing one link, it's a huge
improvement. In the future, we can use NT worker threads to avoid
oversaturating the machine with work, but for now, this is such an
improvement for the single-link use case that I think we should land
this as is.
Algorithm
----------
Before this change, we essentially used a
DenseMap<GloballyHashedType, TypeIndex> to check if a type has already
been seen, and if it hasn't been seen, insert it now and use the next
available type index for it in the destination type stream. DenseMap
does not support concurrent insertion, and even if it did, the linker
must be deterministic: it cannot produce different PDBs by using
different numbers of threads. The output type stream must be in the same
order regardless of the order of hash table insertions.
In order to create a hash table that supports concurrent insertion, the
table cells must be small enough that they can be updated atomically.
The algorithm I used for updating the table using linear probing is
described in this paper, "Concurrent Hash Tables: Fast and General(?)!":
https://dl.acm.org/doi/10.1145/3309206
The GHashCell in this change is essentially a pair of 32-bit integer
indices: <sourceIndex, typeIndex>. The sourceIndex is the index of the
TpiSource object, and it represents an input type stream. The typeIndex
is the index of the type in the stream. Together, we have something like
a ragged 2D array of ghashes, which can be looked up as:
tpiSources[tpiSrcIndex]->ghashes[typeIndex]
By using these side tables, we can omit the key data from the hash
table, and keep the table cell small. There is a cost to this: resolving
hash table collisions requires many more loads than simply looking at
the key in the same cache line as the insertion position. However, most
supported platforms should have a 64-bit CAS operation to update the
cell atomically.
To make the result of concurrent insertion deterministic, the cell
payloads must have a priority function. Defining one is pretty
straightforward: compare the two 32-bit numbers as a combined 64-bit
number. This means that types coming from inputs earlier on the command
line have a higher priority and are more likely to appear earlier in the
final PDB type stream than types from an input appearing later on the
link line.
After table insertion, the non-empty cells in the table can be copied
out of the main table and sorted by priority to determine the ordering
of the final type index stream. At this point, item and type records
must be separated, either by sorting or by splitting into two arrays,
and I chose sorting. This is why the GHashCell must contain the isItem
bit.
Once the final PDB TPI stream ordering is known, we need to compute a
mapping from source type index to PDB type index. To avoid starting over
from scratch and looking up every type again by its ghash, we save the
insertion position of every hash table insertion during the first
insertion phase. Because the table does not support rehashing, the
insertion position is stable. Using the array of insertion positions
indexed by source type index, we can replace the source type indices in
the ghash table cells with the PDB type indices.
Once the table cells have been updated to contain PDB type indices, the
mapping for each type source can be computed in parallel. Simply iterate
the list of cell positions and replace them with the PDB type index,
since the insertion positions are no longer needed.
Once we have a source to destination type index mapping for every type
source, there are no more data dependencies. We know which type records
are "unique" (not duplicates), and what their final type indices will
be. We can do the remapping in parallel, and accumulate type sizes and
type hashes in parallel by type source.
Lastly, TPI stream layout must be done serially. Accumulate all the type
records, sizes, and hashes, and add them to the PDB.
Differential Revision: https://reviews.llvm.org/D87805
The patch adds a new TargetMachine member "registerPassBuilderCallbacks" for targets to add passes to the pass pipeline using the New Pass Manager (similar to adjustPassManager for the Legacy Pass Manager).
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D88138
Failing tests on Arm due to the tests automatically populating
incomatible pointer width architectures. Reverting until the tests are
updated. Failing tests:
OpenMP/distribute_parallel_for_num_threads_codegen.cpp
OpenMP/distribute_parallel_for_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_if_codegen.cpp
OpenMP/distribute_parallel_for_simd_num_threads_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_if_codegen.cpp
OpenMP/target_teams_distribute_parallel_for_simd_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_if_codegen.cpp
OpenMP/teams_distribute_parallel_for_simd_if_codegen.cpp
This reverts commit 90eaedda9b.
This is part of the Propeller framework to do post link code layout optimizations. Please see the RFC here: https://groups.google.com/forum/#!msg/llvm-dev/ef3mKzAdJ7U/1shV64BYBAAJ and the detailed RFC doc here: https://github.com/google/llvm-propeller/blob/plo-dev/Propeller_RFC.pdf
This patch provides exception support for basic block sections by splitting the call-site table into call-site ranges corresponding to different basic block sections. Still all landing pads must reside in the same basic block section (which is guaranteed by the the core basic block section patch D73674 (ExceptionSection) ). Each call-site table will refer to the landing pad fragment by explicitly specifying @LPstart (which is omitted in the normal non-basic-block section case). All these call-site tables will share their action and type tables.
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. In the case of basic block section where one section contains all the landing pads, the landing pad offset relative to LPStart could actually be zero. Thus, we avoid zero-offset landing pads by inserting a **nop** operation as the first non-CFI instruction in the exception section.
**Background on Exception Handling in C++ ABI**
https://github.com/itanium-cxx-abi/cxx-abi/blob/master/exceptions.pdf
Compiler emits an exception table for every function. When an exception is thrown, the stack unwinding library queries the unwind table (which includes the start and end of each function) to locate the exception table for that function.
The exception table includes a call site table for the function, which is used to guide the exception handling runtime to take the appropriate action upon an exception. Each call site record in this table is structured as follows:
| CallSite | --> Position of the call site (relative to the function entry)
| CallSite length | --> Length of the call site.
| Landing Pad | --> Position of the landing pad (relative to the landing pad fragment’s begin label)
| Action record offset | --> Position of the first action record
The call site records partition a function into different pieces and describe what action must be taken for each callsite. The callsite fields are relative to the start of the function (as captured in the unwind table).
The landing pad entry is a reference into the function and corresponds roughly to the catch block of a try/catch statement. When execution resumes at a landing pad, it receives an exception structure and a selector value corresponding to the type of the exception thrown, and executes similar to a switch-case statement. The landing pad field is relative to the beginning of the procedure fragment which includes all the landing pads (@LPStart). The C++ ABI requires all landing pads to be in the same fragment. Nonetheless, without basic block sections, @LPStart is the same as the function @Start (found in the unwind table) and can be omitted.
The action record offset is an index into the action table which includes information about which exception types are caught.
**C++ Exceptions with Basic Block Sections**
Basic block sections break the contiguity of a function fragment. Therefore, call sites must be specified relative to the beginning of the basic block section. Furthermore, the unwinding library should be able to find the corresponding callsites for each section. To do so, the .cfi_lsda directive for a section must point to the range of call-sites for that section.
This patch introduces a new **CallSiteRange** structure which specifies the range of call-sites which correspond to every section:
`struct CallSiteRange {
// Symbol marking the beginning of the precedure fragment.
MCSymbol *FragmentBeginLabel = nullptr;
// Symbol marking the end of the procedure fragment.
MCSymbol *FragmentEndLabel = nullptr;
// LSDA symbol for this call-site range.
MCSymbol *ExceptionLabel = nullptr;
// Index of the first call-site entry in the call-site table which
// belongs to this range.
size_t CallSiteBeginIdx = 0;
// Index just after the last call-site entry in the call-site table which
// belongs to this range.
size_t CallSiteEndIdx = 0;
// Whether this is the call-site range containing all the landing pads.
bool IsLPRange = false;
};`
With N basic-block-sections, the call-site table is partitioned into N call-site ranges.
Conceptually, we emit the call-site ranges for sections sequentially in the exception table as if each section has its own exception table. In the example below, two sections result in the two call site ranges (denoted by LSDA1 and LSDA2) placed next to each other. However, their call-sites will refer to records in the shared Action Table. We also emit the header fields (@LPStart and CallSite Table Length) for each call site range in order to place the call site ranges in separate LSDAs. We note that with -basic-block-sections, The CallSiteTableLength will not actually represent the length of the call site table, but rather the reference to the action table. Since the only purpose of this field is to locate the action table, correctness is guaranteed.
Finally, every call site range has one @LPStart pointer so the landing pads of each section must all reside in one section (not necessarily the same section). To make this easier, we decide to place all landing pads of the function in one section (hence the `IsLPRange` field in CallSiteRange).
| @LPStart | ---> Landing pad fragment ( LSDA1 points here)
| CallSite Table Length | ---> Used to find the action table.
| CallSites |
| … |
| … |
| @LPStart | ---> Landing pad fragment ( LSDA2 points here)
| CallSite Table Length |
| CallSites |
| … |
| … |
…
…
| Action Table |
| Types Table |
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D73739
Summary:
Replace the OpenMP Runtime Library functions used in CGOpenMPRuntimeGPU
for OpenMP device code generation with ones in OMPKinds.def and use
OMPIRBuilder for generating runtime calls. This allows us to consolidate
more OpenMP code generation into the OMPIRBuilder. This patch also
invalidates specifying target architectures with conflicting pointer
sizes.
Reviewers: jdoerfert
Subscribers: aaron.ballman cfe-commits guansong llvm-commits sstefan1 yaxunl
Tags: #OpenMP #Clang #LLVM
Differential Revision: https://reviews.llvm.org/D88430
This patch achieves two things:
1. It breaks up the `join_blocks` interface between the SDA to the DA to
return two separate sets for divergent loops exits and divergent,
disjoint path joins.
2. It updates the SDA algorithm to run in O(n) time and improves the
precision on divergent loop exits.
This fixes `https://bugs.llvm.org/show_bug.cgi?id=46372` (by virtue of
the improved `join_blocks` interface) and revealed an imprecise expected
result in the `Analysis/DivergenceAnalysis/AMDGPU/hidden_loopdiverge.ll`
test.
Reviewed By: sameerds
Differential Revision: https://reviews.llvm.org/D84413
All the state of VRAI is allocator-wide, so we can avoid creating it
every time we need it. In addition, the normalization function is
allocator-specific. In a next change, we can simplify that design in
favor of just having it as a virtual member.
Differential Revision: https://reviews.llvm.org/D88499
Key Locker provides a mechanism to encrypt and decrypt data with an AES key without having access
to the raw key value by converting AES keys into “handles”. These handles can be used to perform the
same encryption and decryption operations as the original AES keys, but they only work on the current
system and only until they are revoked. If software revokes Key Locker handles (e.g., on a reboot),
then any previous handles can no longer be used.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D88398
This patch improves the assembly output produced for string literals by
using character literals in byte lists. This provides the benefits of
having printable characters appear as such in the assembly output and of
having strings kept as logical units on the same line.
Reviewed By: daltenty
Differential Revision: https://reviews.llvm.org/D80953
Support the "alias" directive.
Required support for emitWeakReference in MCWinCOFFStreamer.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D87403
Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).
Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)
Relanding D87400, now with fewer ms-inline-asm tests broken!
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D88337
This came from @lebedev.ri's suggestion to use m_SpecificInt_ICMP for D88429 - since I was going to change the m_APInt to m_Constant for that patch I thought I would do it for the only other user of the APInt first.
I've added a ConstantExpr::getUMin helper - its trivial to add UMAX/SMIN/SMAX but thought I'd wait until we have use cases.
Differential Revision: https://reviews.llvm.org/D88475
Currently, we have `isLoopEntryGuardedByCond` method in SCEV, which
checks that some fact is true if we enter the loop. In fact, this is just a
particular case of more general concept `isBasicBlockEntryGuardedByCond`
applied to given loop's header. In fact, the logic if this code is largely
independent on the given loop and only cares code above it.
This patch makes this generalization. Now we can query it for any block,
and `isBasicBlockEntryGuardedByCond` is just a particular case.
Differential Revision: https://reviews.llvm.org/D87828
Reviewed By: fhahn
This reverts commit 55c4ff91bd.
Issues were introduced as discussed in https://reviews.llvm.org/D88241
where this change made previous bugs in the linker and BitCodeWriter
visible.
Move abstractMemberAccess and PreserveDIType passes as early as
possible, right after clang code generation.
Currently, compiler may transform the above code
p1 = llvm.bpf.builtin.preserve.struct.access(base, 0, 0);
p2 = llvm.bpf.builtin.preserve.struct.access(p1, 1, 2);
a = llvm.bpf.builtin.preserve_field_info(p2, EXIST);
if (a) {
p1 = llvm.bpf.builtin.preserve.struct.access(base, 0, 0);
p2 = llvm.bpf.builtin.preserve.struct.access(p1, 1, 2);
bpf_probe_read(buf, buf_size, p2);
}
to
p1 = llvm.bpf.builtin.preserve.struct.access(base, 0, 0);
p2 = llvm.bpf.builtin.preserve.struct.access(p1, 1, 2);
a = llvm.bpf.builtin.preserve_field_info(p2, EXIST);
if (a) {
bpf_probe_read(buf, buf_size, p2);
}
and eventually assembly code looks like
reloc_exist = 1;
reloc_member_offset = 10; //calculate member offset from base
p2 = base + reloc_member_offset;
if (reloc_exist) {
bpf_probe_read(bpf, buf_size, p2);
}
if during libbpf relocation resolution, reloc_exist is actually
resolved to 0 (not exist), reloc_member_offset relocation cannot
be resolved and will be patched with illegal instruction.
This will cause verifier failure.
This patch attempts to address this issue by do chaining
analysis and replace chains with special globals right
after clang code gen. This will remove the cse possibility
described in the above. The IR typically looks like
%6 = load @llvm.sk_buff:0:50$0:0:0:2:0
%7 = bitcast %struct.sk_buff* %2 to i8*
%8 = getelementptr i8, i8* %7, %6
for a particular address computation relocation.
But this transformation has another consequence, code sinking
may happen like below:
PHI = <possibly different @preserve_*_access_globals>
%7 = bitcast %struct.sk_buff* %2 to i8*
%8 = getelementptr i8, i8* %7, %6
For such cases, we will not able to generate relocations since
multiple relocations are merged into one.
This patch introduced a passthrough builtin
to prevent such optimization. Looks like inline assembly has more
impact for optimizaiton, e.g., inlining. Using passthrough has
less impact on optimizations.
A new IR pass is introduced at the beginning of target-dependent
IR optimization, which does:
- report fatal error if any reloc global in PHI nodes
- remove all bpf passthrough builtin functions
Changes for existing CORE tests:
- for clang tests, add "-Xclang -disable-llvm-passes" flags to
avoid builtin->reloc_global transformation so the test is still
able to check correctness for clang generated IR.
- for llvm CodeGen/BPF tests, add "opt -O2 <ir_file> | llvm-dis" command
before "llc" command since "opt" is needed to call newly-placed
builtin->reloc_global transformation. Add target triple in the IR
file since "opt" requires it.
- Since target triple is added in IR file, if a test may produce
different results for different endianness, two tests will be
created, one for bpfeb and another for bpfel, e.g., some tests
for relocation of lshift/rshift of bitfields.
- field-reloc-bitfield-1.ll has different relocations compared to
old codes. This is because for the structure in the test,
new code returns struct layout alignment 4 while old code
is 8. Align 8 is more precise and permits double load. With align 4,
the new mechanism uses 4-byte load, so generating different
relocations.
- test intrinsic-transforms.ll is removed. This is used to test
cse on intrinsics so we do not lose metadata. Now metadata is attached
to global and not instruction, it won't get lost with cse.
Differential Revision: https://reviews.llvm.org/D87153
This hack seems to only have been necessary because of the
constructor bug noted in 33125cffd.
Once again, it's hard to prove NFC, but that's the hope...
This should be NFC unless some target was expecting that
some form of cttz/ctlz/memcpy is free in terms of size/latency
but not free in throughput cost.
This should be close to NFC (no-functional-change), but I
can't completely rule out that some call on some target
travels down a different path. There's an especially large
amount of code spaghetti in this part of the cost model.
The goal is to clean up the intrinsic cost handling so
we can canonicalize to the new min/max intrinsics without
causing regressions.
When we see this:
```
%and = G_AND %x, %y
%xor = G_XOR %and, %y
```
Produce this:
```
%not = G_XOR %x, -1
%new_and = G_AND %not, %y
```
as long as we are guaranteed to eliminate the original G_AND.
Also matches all commuted forms. E.g.
```
%and = G_AND %y, %x
%xor = G_XOR %y, %and
```
will be matched as well.
Differential Revision: https://reviews.llvm.org/D88104
bug 45566 shows the process of building coroutine frame won't consider
that the lifetimes of different local variables are not overlapped,
which means the compiler could generates smaller frame.
This patch calculate the lifetime range of each alloca by StackLifetime
class. Then the patch build non-overlapped sets for allocas whose
lifetime ranges are not overlapped. We use the largest type in a
non-overlapped set as the field type in the frame. In insertSpills
process, if we find the type of field is not the same with the alloca,
we cast the pointer to the field type to the pointer to the alloca type.
Since the lifetime range of alloca in one non-overlapped set is not
overlapped with each other, it should be ok to reuse the storage space
in the frame.
Test plan: check-llvm, check-clang, cppcoro, folly
Reviewers: junparser, lxfind, modocache
Differential Revision: https://reviews.llvm.org/D87596
After some recent upstream discussion we decided that it was best
to avoid having the / operator for both ElementCount and TypeSize,
since this could give the impression that these classes can be used
in the same way as basic integer integer types. However, division
for scalable types is a bit odd because we are only dividing the
minimum quantity by a value, as opposed to something like:
(MinSize * Vscale) / SomeValue
This is why when performing division it's important the caller
first establishes whether the operation makes sense, perhaps by
calling isKnownMultipleOf() prior to division. The caller must now
explictly call divideCoefficientBy() on the class to perform the
operation.
Differential Revision: https://reviews.llvm.org/D87700
Add a flag to getPredicateAt() that allows making use of the block
value. This allows us to take into account range information from
the current block, rather than only information that is threaded
over edges, making the icmp simplification in CVP a lot more
powerful.
I'm not changing getPredicateAt() to use the block value
unconditionally to avoid any impact on the JumpThreading pass,
which is somewhat picky about LVI query order.
Most test changes here are just icmps that now get dropped (while
previously only a result used in a return was replaced). The three
tests in icmp.ll show some representative improvements. Some of
the folds this enables have been covered by IPSCCP in the meantime,
but LVI can reason about some cases which are hard to support in
IPSCCP, such as in test_br_cmp_with_offset.
The compile-time time cost of doing this is fairly minimal, with
a ~0.05% CTMark regression for ReleaseThinLTO:
https://llvm-compile-time-tracker.com/compare.php?from=709d03f8af4da4204849a70f01798e7cebba2e32&to=6236fd503761f43c99f4537121e057a01056f185&stat=instructions
This is because the block values will typically already be queried
and cached by other CVP optimizations anyway.
Differential Revision: https://reviews.llvm.org/D69686
If -enable-constraint-elimination is specified, add it to the -O2/-O3 pipeline.
(-O1 uses a separate function now.)
Reviewed By: fhahn, aeubanks
Differential Revision: https://reviews.llvm.org/D88365
Require CxtI in getConstant() and getConstantRange() APIs.
Accordingly drop the BB parameter, as it is implied by
CxtI->getParent().
This makes sure we don't forget to pass the context instruction,
and makes the API contract clearer (also clean up the comments to
that effect -- the value holds at the context instruction, not
the end of the block).
It is not a good idea to expose raw constants in the LLVM C API. Replace this with an explicit getter.
Differential Revision: https://reviews.llvm.org/D88367
This is like FastMathFlagGuard in IR. Since we use SDAG instance to get
values, it's with SelectionDAG. By creating a FlagInserter in current
scope, all values created by getNode will get the flags if no Flags
argument provided.
In this patch, I applied it to floating point operations folding part in
DAG combiner, and removed Flags passing to getNode to show its effect.
Other places in DAG combiner and other helper methods similar to getNode
also need this. They can be done in follow-up patches.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D87361