The existing (default) calling convention for memrefs in standard-to-LLVM
conversion was motivated by interfacing with LLVM IR produced from C sources.
In particular, it passes a pointer to the memref descriptor structure when
calling the function. Therefore, the descriptor is allocated on stack before
the call. This convention leads to several problems. PR44644 indicates a
problem with stack exhaustion when calling functions with memref-typed
arguments in a loop. Allocating outside of the loop may lead to concurrent
access problems in case the loop is parallel. When targeting GPUs, the contents
of the stack-allocated memory for the descriptor (passed by pointer) needs to
be explicitly copied to the device. Using an aggregate type makes it impossible
to attach pointer-specific argument attributes pertaining to alignment and
aliasing in the LLVM dialect.
Change the default calling convention for memrefs in standard-to-LLVM
conversion to transform a memref into a list of arguments, each of primitive
type, that are comprised in the memref descriptor. This avoids stack allocation
for ranked memrefs (and thus stack exhaustion and potential concurrent access
problems) and simplifies the device function invocation on GPUs.
Provide an option in the standard-to-LLVM conversion to generate auxiliary
wrapper function with the same interface as the previous calling convention,
compatible with LLVM IR porduced from C sources. These auxiliary functions
pack the individual values into a descriptor structure or unpack it. They also
handle descriptor stack allocation if necessary, serving as an allocation
scope: the memory reserved by `alloca` will be freed on exiting the auxiliary
function.
The effect of this change on MLIR-generated only LLVM IR is minimal. When
interfacing MLIR-generated LLVM IR with C-generated LLVM IR, the integration
only needs to require auxiliary functions and change the function name to call
the wrapper function instead of the original function.
This also opens the door to forwarding aliasing and alignment information from
memrefs to LLVM IR pointers in the standrd-to-LLVM conversion.
The DebugInfo/dwarfdump-invalid-line-table test used a pre-canned binary
generated by a fuzzer to demonstrate a bug fix. Unfortunately, the
binary is rigid and requires hand-editing if we change behaviour, such
as rejecting certain properties within it (as I plan on doing in another
change).
Rather than hand-edit the binary, I have replaced it with two tests. The
first tests the high-level code path from the debug line parser that
produces the same error as this test previously did, and the second is a
set of unit test cases that comprehensively cover the
FormValue::skipValue method, which in turn covers the area that the
original bug fix touched.
Reviewed by: MaskRay, dblaikie
Differential Revision: https://reviews.llvm.org/D74202
This change implements the llvm intrinsic llvm.read_register for
the SystemZ platform which returns the value of the specified
register
(http://llvm.org/docs/LangRef.html#llvm-read-register-and-llvm-write-register-intrinsics).
This implementation returns the value of the stack register, and
can be extended to return the value of other registers. The
implementation for this intrinsic exists on various other platforms
including Power, x86, ARM, etc. but missing on SystemZ.
Reviewers: uweigand
Differential Revision: https://reviews.llvm.org/D73378
Both methods have compile time constraints that we should test against.
Patch by Michael Schellenberger Costa
Differential Revision: https://reviews.llvm.org/D71999
On macOS, libc++ headers are distributed with the compiler, not
the sysroot. Without this, compiling a file that includes something
like <string> won't compile with gn-built clang without manual tweaks.
I used to do the manual tweaks, but now that other people are starting
to use this on mac, let's make it Just Work.
(This is marginally nicer than the cmake build now in that you can
just build 'clang' and it'll do the right thing.)
Differential Revision: https://reviews.llvm.org/D74247
As noted on PR44379, we didn't attempt to lower vector shuffles using bit rotations on XOP/AVX512F targets.
This patch lowers to uniform ISD:ROTL nodes - ROTR isn't supported by XOP and they are interchangeable for constant values anyway.
There might be cases where targets without ISD:ROTL support would benefit from this (expanding to SRL+SHL+OR), which I'll investigate in a future patch.
Also, non-AVX512BW targets fail to concatenate 256-bit rotations back to 512-bits (split during shuffle lowering as they don't have v32i16/v64i8 types).
---
Internal shuffle tests indicate theres a bug somewhere that I haven't been able to track down yet.
m_size can only be 1 or 0 and indicates if the optional has a value. Calling
it 'm_size', giving it a size_t data type and then also comparing indices against
'size' is very confusing. Let's just make this a bool.
This patch adds a first version of a MemorySSA based DSE. It is missing
a lot of features, which will get added as follow-ups, to help to keep
the review manageable.
The patch uses the following general approach: given a MemoryDef, walk
upwards to find clobbering MemoryDefs that may be killed by the
starting def. Then check that there are no uses that may read the
location of the original MemoryDef in between both MemoryDefs. A bit
more concretely:
For all MemoryDefs StartDef:
1. Get the next dominating clobbering MemoryDef (DomAccess) by walking upwards.
2. Check that there no reads between DomAccess and the StartDef by checking
all uses starting at DomAccess and walking until we see StartDef.
3. For each found DomDef, check that:
1. There are no barrier instructions between DomDef and StartDef (like
throws or stores with ordering constraints).
2. StartDef is executed whenever DomDef is executed.
3. StartDef completely overwrites DomDef.
4. Erase DomDef from the function and MemorySSA.
The patch uses a very simple approach to guarantee that no throwing
instructions are between 2 stores: We only allow accesses to stack
objects, access that are in the same basic block if the block does not
contain any throwing instructions or accesses in functions that do
not contain any throwing instructions. This will get lifted later.
Besides adding support for the missing cases, there is plenty of additional
potential for improvements as follow-up work, e.g. the way we visit stores
(could be just a traversal of the MemorySSA, rather than collecting them
up-front), using the alias information discovered during walking to optimize
the MemorySSA.
This is loosely based on D40480 by Dave Green.
Reviewers: dmgreen, rnk, efriedma, bryant, asbirlea, Tyker
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D72700
Summary:
Clangd does not find references of designated iniitializers yet and, as a
result, is unable to rename such references. This patch addresses this issue.
Resolves: https://github.com/clangd/clangd/issues/247
Reviewers: sammccall
Reviewed By: sammccall
Subscribers: merge_guards_bot, ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72867
This copies the DSE tests into a MSSA subdirectory to test the MemorySSA
backed DSE implementation, without disturbing the original tests.
Differential Revision: https://reviews.llvm.org/D72145
1) Fix a regression in llvmorg-11-init-2485-g0e3a4877840 that would
reject some cases where a class name is shadowed by a typedef-name
causing a destructor declaration to be rejected. Prefer a tag type over
a typedef in destructor name lookup.
2) Convert the "type in destructor declaration is a typedef" error to an
error-by-default ExtWarn to allow codebases to turn it off. GCC and MSVC
do not enforce this rule.
Summary:
Proposal and roadmap towards vector predication in LLVM.
This patch documents that
a) It is recognized that current LLVM is ill-equipped for vector predication.
b) The community is working on a solution.
c) A concrete prototype exists in the VP extension (D57504).
Reviewers: rkruppe, rengolin, cameron.mcinally, SjoerdMeijer, andrew.w.kaylor, craig.topper, sdesmalen, k-ishizaka, lattner, fhahn
Reviewed By: andrew.w.kaylor
Subscribers: rogfer01, merge_guards_bot, simoncook, s.egerton, llvm-commits, efocht
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73889
D73303 was failing on Fedora Linux and so it was disabled by Skip the
AssertFrameRecognizer test for Linux.
I find no easy way how to find out if it gets recognized as
`__assert_fail` or `__GI___assert_fail` as during `Process` ctor
libc.so.6 is not yet loaded by the debuggee.
DWARF symbol `__GI___assert_fail` overrides the ELF symbol `__assert_fail`.
While external debug info (=DWARF) gets disabled for testsuite (D55859)
that sure does not apply for real world usage.
Differential Revision: https://reviews.llvm.org/D74252
When specifying -march=arch[8|9|10], those CPU types do NOT support
the vector extension. In this case the vector ABI must be disabled.
The generated data layout should NOT contain 64-v128.
Reviewers: uweigand
Differential Revision: https://reviews.llvm.org/D74146
Use the isCandidateForCallSiteEntry().
This should mostly be an NFC, but there are some parts ensuring
the moveCallSiteInfo() and copyCallSiteInfo() operate with call site
entry candidates (both Src and Dest should be the call site entry
candidates).
Differential Revision: https://reviews.llvm.org/D74122
Remove all beginning > from the sample commands as my accidental
copy-paste (multiple times...) will discard ./bin/llvm-lit which is
difficult to rebuild (I have to rm -rf and cmake it all again).
Differential Revision: https://reviews.llvm.org/D74296
This actually tests all the different situations in which we can call virtual
functions. This removes also all skipIfs as the first skipIf for Linux is
apparently fixed and the second skipIf was just failing due to the constructor
call (which should be its own test and not be tested here).
Based on D72931
This adds a new feature called A16 which is enabled for gfx10.
gfx9 keeps the R128A16 feature so it can share all the instruction encodings
with gfx7/8.
Differential Revision: https://reviews.llvm.org/D73956
This is a minimal but important advancement over the existing code. A
cast with an operand that is only used in the cast retains the no-alias
property of the operand.
Traversing PHI nodes is natural with the genericValueTraversal but also
a bit tricky. The problem is similar to the ones we have seen in AAAlign
and AADereferenceable, namely that we continue to increase the range in
each iteration. We use a pessimistic approach here to stop the
iterations. Nevertheless, optimistic information can now be propagated
through a PHI node.
The change is performed as stated by the FIXME and the tests are
adjusted. All changes look fine to me and values can be inferred as
undef without it being an error.
Casts can be handled natively by the ConstantRange class. We do limit it
to extends for now as we assume an integer type in different locations.
A TODO and a test case with a FIXME was added to remove that restriction
in the future.
