A big-endian version of vpermxor, named vpermxor_be, is added to LLVM
and Clang. vpermxor_be can be called directly on both the little-endian
and the big-endian platforms.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D114540
Over in D114631 and [0] there's a plan for turning instruction referencing
on by default for x86. This patch adds / removes all the relevant bits of
code, with the aim that the final patch is extremely small, for an easy
revert. It should just be a condition in CommandFlags.cpp and removing the
XFail on instr-ref-flag.ll.
[0] https://lists.llvm.org/pipermail/llvm-dev/2021-November/153653.html
Add the capability to simplify more complex constraints where there are 3
symbols in the tree. In this change I extend simplifySVal to query constraints
of children sub-symbols in a symbol tree. (The constraint for the parent is
asked in getKnownValue.)
Differential Revision: https://reviews.llvm.org/D103317
Currently, during symbol simplification we remove the original member symbol
from the equivalence class (`ClassMembers` trait). However, we keep the
reverse link (`ClassMap` trait), in order to be able the query the
related constraints even for the old member. This asymmetry can lead to
a problem when we merge equivalence classes:
```
ClassA: [a, b] // ClassMembers trait,
a->a, b->a // ClassMap trait, a is the representative symbol
```
Now lets delete `a`:
```
ClassA: [b]
a->a, b->a
```
Let's merge the trivial class `c` into ClassA:
```
ClassA: [c, b]
c->c, b->c, a->a
```
Now after the merge operation, `c` and `a` are actually in different
equivalence classes, which is inconsistent.
One solution to this problem is to simply avoid removing the original
member and this is what this patch does.
Other options I have considered:
1) Always merge the trivial class into the non-trivial class. This might
work most of the time, however, will fail if we have to merge two
non-trivial classes (in that case we no longer can track equivalences
precisely).
2) In `removeMember`, update the reverse link as well. This would cease
the inconsistency, but we'd loose precision since we could not query
the constraints for the removed member.
Differential Revision: https://reviews.llvm.org/D114619
We should match GCC's behavior which allows floating-point type for -mno-x87 option on 32-bits. https://godbolt.org/z/KrbhfWc9o
The previous block issues have partially been fixed by D112143.
Reviewed By: asavonic, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D114162
See discussion in D51650, this change was a little aggressive in an
error while doing a 'while we were here', so this removes that error
condition, as it is apparently useful.
This reverts commit bb4934601d.
We don't properly handle lookup through using directives when there is
a linkage spec in the common chain. This is because `CppLookupName` and
`CppNamespaceLookup` end up skipping `LinkageSpec`'s (correctly, as they
are not lookup scopes), but the `UnqualUsingDirectiveSet` does not.
I discovered that when we are calculating the `CommonAncestor` for a
using-directive, we were coming up with the `LinkageSpec`, instead of
the `LinkageSpec`'s parent. Then, when we use
`UnqualUsingDirectiveSet::getNamespacesFor` a scope, we don't end up
finding any that were in the `LinkageSpec` (again, since `CppLookupName`
skips linkage specs), so those don't end up participating in the lookup.
The function `UnqualUsingDirectiveSet::addUsingDirective` calculates
this common ancestor via a loop through the the `DeclSpec::Encloses`
function.
Changing this Encloses function to believe that a `LinkageSpec`
`Encloses` nothing ends up fixing the problem without breaking any other tests,
so I opted to do that. A less aggressive patch could perhaps change only
the `addUsingDirective`, but my examination of all uses of `Encloses`
showed that it seems to be used exclusively in lookup, which makes me think
this is correct everywhere.
Differential Revision: https://reviews.llvm.org/D113709
Musl treats PowerPC SPE as a soft-float target (as the PowerPC SPE ABI
is soft-float compatible).
Reviewed By: jhibbits, MaskRay
Differential Revision: https://reviews.llvm.org/D105869
As reported in https://bugs.freebsd.org/260078, the gnutls Makefiles
pass -Wa,-march=all to compile a number of assembly files. Clang does
not support this -march value, but because of a mistake in handling
the arguments, an unitialized Arg pointer is dereferenced, which can
cause a segfault.
Work around this by adding a check if the local WaMArch variable is
initialized, and if so, using its value in the diagnostic message.
Reviewed By: tschuett
Differential Revision: https://reviews.llvm.org/D114677
After 04f30795f1, -Wreturn-type has an effect on functions that
contain @try/@catch statements. CheckFallThrough() was missing
a case for ObjCAtTryStmts, leading to a false positive.
(What about the other two places in CheckFallThrough() that handle
CXXTryStmt but not ObjCAtTryStmts?
- I think the last use of CXXTryStmt is dead in practice: 04c6851cd made it so
that calls never add edges to try bodies, and the CFG block for a try
statement is always an empty block containing just the try element itself as
terminator (the try body itself is part of the normal flow of the function
and not connected to the block for the try statement itself. The try statment
cfg block is only connected to the catch bodies, and only reachable from
throw expressions within the try body.)
- The first use of CXXTryStmt might be important. It looks similar to
the code that adds all cfg blocks for try statements as roots of
the reachability graph for the reachability warnings, but I can't
find a way to trigger it. So I'm omitting it for now. The CXXTryStmt
code path seems to only be hit by try statements that are function
bodies without a surrounding compound statements
(`f() try { ... } catch ...`), and those don't exist for ObjC
@try statements.
)
Fixes PR52473.
Differential Revfision: https://reviews.llvm.org/D114660
GPUs are not supported on AIX, so this patch sets these tests as unsupported.
Reviewed By: stevewan
Differential Revision: https://reviews.llvm.org/D114381
Currently variables appearing inside private/firstprivate/lastprivate
clause of openmp task construct are not visible inside lldb debugger.
This is because compiler does not generate debug info for it.
Please consider the testcase debug_private.c attached with patch.
```
28 #pragma omp task shared(res) private(priv1, priv2) firstprivate(fpriv)
29 {
30 priv1 = n;
31 priv2 = n + 2;
32 printf("Task n=%d,priv1=%d,priv2=%d,fpriv=%d\n",n,priv1,priv2,fpriv);
33
-> 34 res = priv1 + priv2 + fpriv + foo(n - 1);
35 }
36 #pragma omp taskwait
37 return res;
(lldb) p priv1
error: <user expression 0>:1:1: use of undeclared identifier 'priv1'
priv1
^
(lldb) p priv2
error: <user expression 1>:1:1: use of undeclared identifier 'priv2'
priv2
^
(lldb) p fpriv
error: <user expression 2>:1:1: use of undeclared identifier 'fpriv'
fpriv
^
```
After the current patch, lldb is able to show the variables
```
(lldb) p priv1
(int) $0 = 10
(lldb) p priv2
(int) $1 = 12
(lldb) p fpriv
(int) $2 = 14
```
Reviewed By: djtodoro
Differential Revision: https://reviews.llvm.org/D114504
From GCC's manpage:
-fplugin-arg-name-key=value
Define an argument called key with a value of value for the
plugin called name.
Since we don't have a key-value pair similar to gcc's plugin_argument
struct, simply accept key=value here anyway and pass it along as-is to
plugins.
This translates to the already existing '-plugin-arg-pluginname arg'
that clang cc1 accepts.
There is an ambiguity here because in clang, both the plugin name
as well as the option name can contain dashes, so when e.g. passing
-fplugin-arg-foo-bar-foo
it is not clear whether the plugin is foo-bar and the option is foo,
or the plugin is foo and the option is bar-foo. GCC solves this by
interpreting all dashes as part of the option name. So dashes can't be
part of the plugin name in this case.
Differential Revision: https://reviews.llvm.org/D113250
The clang portion of c933c2eb33 was missed as I made
some kind of mistake squashing the commits with git.
This patch just adds those.
The original review: https://reviews.llvm.org/D114088
The PCH reader looks for `__clangast` section in the precompiled module file, which is not present in the file on AIX, and we don't support writing this custom section in XCOFF yet.
Reviewed By: daltenty
Differential Revision: https://reviews.llvm.org/D114481
The XL implementation of vec_round for vector double uses
"round-to-nearest, ties to even" just as the vector float
`version does. However clang and gcc use "round-to-nearest-away"
for vector double and "round-to-nearest, ties to even"
for vector float.
The XL behaviour is implemented under the __XL_COMPAT_ALTIVEC__
macro similarly to other instances of incompatibility.
Differential revision: https://reviews.llvm.org/D113642
Make the SValBuilder capable to simplify existing
SVals based on a newly added constraints when evaluating a BinOp.
Before this patch, we called `simplify` only in some edge cases.
However, we can and should investigate the constraints in all cases.
Differential Revision: https://reviews.llvm.org/D113753
Add an AtomicScopeModel for HIP and support for OpenCL builtins
that are missing in HIP.
Patch by: Michael Liao
Revised by: Anshil Ghandi
Reviewed by: Yaxun Liu
Differential Revision: https://reviews.llvm.org/D113925
All supported FreeBSD releases use libc++, so default to it if the
target's major version is not specified.
Reviewed by: dim, emaste
Differential Revision: https://reviews.llvm.org/D77776
This enables Intel intrinsics support on FreeBSD.
Thanks to @pkubaj who noticed this feature was missing
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D113451
[NFC] As part of using inclusive language within the llvm project, this patch
replaces master with controller in these tests.
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D114108
The test specified amd64-unknown-freebsd40.0 rather than 14.0. Since
40 is greater than 14 the test (for behaviour new in FreeBSD 14) worked
despite the typo.
Fixes: 699d47472c
Reviewed by: dim (in D77776)
Make the SimpleSValBuilder capable to simplify existing IntSym
expressions based on a newly added constraint on the sub-expression.
Differential Revision: https://reviews.llvm.org/D113754
The form 'for co_await' is part of CoroutineTS instead of C++20.
So if we detected the use of 'for co_await' in C++20, we should emit
a warning at least.
The `llvm.instrprof.increment` intrinsic uses `i32` for the index. We should use this same type for the index into the GEP instructions.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D114268
This change allows SwiftAttr to be used with #pragma clang attribute push
to add Swift attributes to large regions of header files.
We plan to use this to annotate headers with concurrency information.
Patch by: Becca Royal-Gordon
Differential Revision: https://reviews.llvm.org/D112773
Eachempati.
This patch adds clang (parsing, sema, serialization, codegen) support for the 'depend' clause on the 'taskwait' directive.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D113540
Operations are emulated by software emulation and “float” instructions.
This patch is allowing the support of _Float16 type without the use of
-max512fp16 flag. The final goal being, perform _Float16 emulation for
all arithmetic expressions.
This test case had been missing when the original code
was introduced by 2fcb863b2b.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D114207
[NFC] This patch replaces `masterPort` with `mainPort` in these
testcases.
Reviewed By: ZarkoCA
Differential Revision: https://reviews.llvm.org/D113505
This covers both C-style variadic functions and template variadic w/
parameter packs.
Previously we would return no signatures when working with template
variadic functions once activeParameter reached the position of the
parameter pack (except when it was the only param, then we'd still
show it when no arguments were given). With this commit, we now show
signathure help correctly.
Additionally, this commit fixes the activeParameter value in LSP output
of clangd in the presence of variadic functions (both kinds). LSP does
not allow the activeParamter to be higher than the number of parameters
in the active signature. With "..." or parameter pack being just one
argument, for all but first argument passed to "..." we'd report
incorrect activeParameter value. Clients such as VSCode would then treat
it as 0, as suggested in the spec) and highlight the wrong parameter.
In the future, we should add support for per-signature activeParamter
value, which exists in LSP since 3.16.0. This is not part of this
commit.
Differential Revision: https://reviews.llvm.org/D111318
During explicit modules build, when all modules are provided via `-fmodule-file=<path>` and implicit modules and implicit module maps are disabled (`-fno-implicit-modules`, `-fno-implicit-module-maps`), we don't need to load the original module map files at all. This patch stops emitting the `-fmodule-map-file=` arguments we don't need, saving some compilation time due to avoiding parsing such module maps and making the command line shorter.
Reviewed By: bnbarham
Differential Revision: https://reviews.llvm.org/D113473
Problem:
PCM file includes references to all module maps used in compilation which created PCM. This problem leads to PCM-rebuilds in distributed compilations as some module maps could be missing in isolated compilation. (For example in our distributed build system we create a temp folder for every compilation with only modules and headers that are needed for that particular command).
Solution:
Add only affecting module map files to a PCM-file.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D106876
This is aligned with GCC's behavior.
Also, alias `-mno-fp-ret-in-387` to `-mno-x87`, by which we can fix pr51498.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D112143
AMD64 ABI mandates caller to specify the number of used SSE registers
when passing variable arguments.
GCC also provides option -mskip-rax-setup to skip the setup of rax when
SSE is disabled. This helps to reduce the code size, see pr23258.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D112413
ld.lld used by Android ignores .note.GNU-stack and defaults to noexecstack,
so the `-z noexecstack` linker option is unneeded.
The `--noexecstack` assembler option is unneeded because AsmPrinter.cpp
prints `.section .note.GNU-stack,"",@progbits` (when `llvm.init.trampoline` is unused),
so the assembler won't synthesize an executable .note.GNU-stack.
Reviewed By: danalbert
Differential Revision: https://reviews.llvm.org/D113840
Since we've decided the to not support std::experimental::coroutine*, we
should tell the user they need to update.
Reviewed By: Quuxplusone, ldionne, Mordante
Differential Revision: https://reviews.llvm.org/D113977
With this,
void f() { __asm__("mov eax, ebx"); }
now compiles with clang with -masm=intel.
This matches gcc.
The flag is not accepted in clang-cl mode. It has no effect on
MSVC-style `__asm {}` blocks, which are unconditionally in intel
mode both before and after this change.
One difference to gcc is that in clang, inline asm strings are
"local" while they're "global" in gcc. Building the following with
-masm=intel works with clang, but not with gcc where the ".att_syntax"
from the 2nd __asm__() is in effect until file end (or until a
".intel_syntax" somewhere later in the file):
__asm__("mov eax, ebx");
__asm__(".att_syntax\nmovl %ebx, %eax");
__asm__("mov eax, ebx");
This also updates clang's intrinsic headers to work both in
-masm=att (the default) and -masm=intel modes.
The official solution for this according to "Multiple assembler dialects in asm
templates" in gcc docs->Extensions->Inline Assembly->Extended Asm
is to write every inline asm snippet twice:
bt{l %[Offset],%[Base] | %[Base],%[Offset]}
This works in LLVM after D113932 and D113894, so use that.
(Just putting `.att_syntax` at the start of the snippet works in some but not
all cases: When LLVM interpolates in parameters like `%0`, it uses at&t or
intel syntax according to the inline asm snippet's flavor, so the `.att_syntax`
within the snippet happens to late: The interpolated-in parameter is already
in intel style, and then won't parse in the switched `.att_syntax`.)
It might be nice to invent a `#pragma clang asm_dialect push "att"` /
`#pragma clang asm_dialect pop` to be able to force asm style per snippet,
so that the inline asm string doesn't contain the same code in two variants,
but let's leave that for a follow-up.
Fixes PR21401 and PR20241.
Differential Revision: https://reviews.llvm.org/D113707
There was some confusion during the discussion of a patch as to whether
`any` can be used to blast an attribute with no subject list onto
basically everything in a program by not specifying a subrule. This
patch adds documentation and tests to make it clear that this situation
is not supported and will be diagnosed.
[NFC] As part of using inclusive language within the llvm project, this patch
replaces `_myMaster` with `_myLeader` in these testcases.
Reviewed By: ZarkoCA
Differential Revision: https://reviews.llvm.org/D113433
Calls to MMA builtins that take pointer to void
do not accept other pointers/arrays whereas normal
functions with the same parameter do. This patch
allows MMA built-ins to accept non-void pointers
and arrays.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D113306
InstCombine AArch64 LD1/ST1 to llvm.masked.load/llvm.masked.store
and LD1/ST1 to load/store when a ptrue all predicate pattern operand
is present.
This allows existing IR optimizations such as dead-load removal to
occur.
Differential Revision: https://reviews.llvm.org/D113489
Previously, any change in any function in an SCC would cause all
analyses for all functions in the SCC to be invalidated. With this
change, we now manually invalidate analyses for functions we modify,
then let the pass manager know that all function analyses should be
preserved since we've already handled function analysis invalidation.
So far this only touches the inliner, argpromotion, function-attrs, and
updateCGAndAnalysisManager(), since they are the most used.
This is part of an effort to investigate running the function
simplification pipeline less on functions we visit multiple times in the
inliner pipeline.
However, this causes major memory regressions especially on larger IR.
To counteract this, turn on the option to eagerly invalidate function
analyses. This invalidates analyses on functions immediately after
they're processed in a module or scc to function adaptor for specific
parts of the pipeline.
Within an SCC, if a pass only modifies one function, other functions in
the SCC do not have their analyses invalidated, so in later function
passes in the SCC pass manager the analyses may still be cached. It is
only after the function passes that the eager invalidation takes effect.
For the default pipelines this makes sense because the inliner pipeline
runs the function simplification pipeline after all other SCC passes
(except CoroSplit which doesn't request any analyses).
Overall this has mostly positive effects on compile time and positive effects on memory usage.
https://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=instructionshttps://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=max-rss
D113196 shows that we slightly regressed compile times in exchange for
some memory improvements when turning on eager invalidation. D100917
shows that we slightly improved compile times in exchange for major
memory regressions in some cases when invalidating less in SCC passes.
Turning these on at the same time keeps the memory improvements while
keeping compile times neutral/slightly positive.
Reviewed By: asbirlea, nikic
Differential Revision: https://reviews.llvm.org/D113304
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.
As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith, #libc, ldionne
Differential Revision: https://reviews.llvm.org/D110216
Summary: Specifically, this fixes the case when we get an access to array element through the pointer to element. This covers several FIXME's. in https://reviews.llvm.org/D111654.
Example:
const int arr[4][2];
const int *ptr = arr[1]; // Fixes this.
The issue is that `arr[1]` is `int*` (&Element{Element{glob_arr5,1 S64b,int[2]},0 S64b,int}), and `ptr` is `const int*`. We don't take qualifiers into account. Consequently, we doesn't match the types as the same ones.
Differential Revision: https://reviews.llvm.org/D113480
Required by https://stackoverflow.com/questions/58073606
As the output argument is stripped out in the clang-check tool, it seems impossible for clang-check users to customize the output file name, even with -extra-args and -extra-arg-before.
This patch adds the -analyzer-output-path argument to allow users to adjust the output name. And if the argument is not set or the analyzer is not enabled, the original strip output adjuster will remove the output arguments.
Differential Revision: https://reviews.llvm.org/D97265
Add coverage to demonstrate why including the type of template
parameters is necessary to disambiguate function template
specializations.
Test courtesy of Richard Smith
This reverts commit f0cf544d6f.
Just a small change to fix:
```
/home/buildbot/as-builder-4/llvm-clang-x86_64-expensive-checks-ubuntu/llvm-project/llvm/lib/Support/VirtualFileSystem.cpp: In static member function ‘static llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> > llvm::vfs::File::getWithPath(llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> >, const llvm::Twine&)’:
/home/buildbot/as-builder-4/llvm-clang-x86_64-expensive-checks-ubuntu/llvm-project/llvm/lib/Support/VirtualFileSystem.cpp:2084:10: error: could not convert ‘F’ from ‘std::unique_ptr<llvm::vfs::File>’ to ‘llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> >’
return F;
^
```
Differential Revision: https://reviews.llvm.org/D113832
c17d9b4b12 added REQUIRES lines to a lot of Arm and AArch64
test, but added them to the very beginning, before the existing
update_cc_test_checks lines. This just moves them later so as to not
mess up the existing ordering when the checks are regenerated.
```
/work/omp-vega20-0/openmp-offload-amdgpu-runtime/llvm.src/llvm/lib/Support/VirtualFileSystem.cpp: In static member function 'static llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> > llvm::vfs::File::getWithPath(llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> >, const llvm::Twine&)':
/work/omp-vega20-0/openmp-offload-amdgpu-runtime/llvm.src/llvm/lib/Support/VirtualFileSystem.cpp:2084:10: error: could not convert 'F' from 'std::unique_ptr<llvm::vfs::File>' to 'llvm::ErrorOr<std::unique_ptr<llvm::vfs::File> >'
return F;
^
```
This reverts commit c972175649.
This is a follow up to 0be9ca7c0f to make
paths in the case of falling back to the external file system use the
original format, preserving relative paths, and allow the external
filesystem to canonicalize them if needed.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D109128
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.
As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D110216
category is empty
Currently, if we create a category in ObjC that is empty, we still emit
runtime metadata for that category. This is a scenario that could
commonly be run into when using __attribute__((objc_direct_members)),
which elides the need for much of the category metadata. This is
slightly wasteful and can be easily skipped by checking the category
metadata contents during CodeGen.
rdar://66177182
Differential Revision: https://reviews.llvm.org/D113455
* The format_arg attribute tells the compiler that the attributed function
returns a format string that is compatible with a format string that is being
passed as a specific argument.
* Several NSString methods return copies of their input, so they would ideally
have the format_arg attribute. A previous differential (D112670) added
support for instancetype methods having the format_arg attribute when used
in the context of NSString method declarations.
* D112670 failed to account that instancetype can be sugared in certain narrow
(but critical) scenarios, like by using nullability specifiers. This patch
resolves this problem.
Differential Revision: https://reviews.llvm.org/D113636
Reviewed By: ahatanak
Radar-Id: rdar://85278860
Then we don't have to look into the declaration again. Also it's only
natural to collect this information alongside parameters and return
type, as it's also just a parameter in some sense.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D113690
Change the error message to use ignorelist, and changed some variable and function
names in related code and test.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D113189
Reuses C++ for OpenCL constructor address space test so that it
supports optional generic address spaces in version 2021.
Differential Revision: https://reviews.llvm.org/D110184
D103314 introduced symbol simplification when a new constant constraint is
added. Currently, we simplify existing equivalence classes by iterating over
all existing members of them and trying to simplify each member symbol with
simplifySVal.
At the end of such a simplification round we may end up introducing a
new constant constraint. Example:
```
if (a + b + c != d)
return;
if (c + b != 0)
return;
// Simplification starts here.
if (b != 0)
return;
```
The `c == 0` constraint is the result of the first simplification iteration.
However, we could do another round of simplification to reach the conclusion
that `a == d`. Generally, we could do as many new iterations until we reach a
fixpoint.
We can reach to a fixpoint by recursively calling `State->assume` on the
newly simplified symbol. By calling `State->assume` we re-ignite the
whole assume machinery (along e.g with adjustment handling).
Why should we do this? By reaching a fixpoint in simplification we are capable
of discovering infeasible states at the moment of the introduction of the
**first** constant constraint.
Let's modify the previous example just a bit, and consider what happens without
the fixpoint iteration.
```
if (a + b + c != d)
return;
if (c + b != 0)
return;
// Adding a new constraint.
if (a == d)
return;
// This brings in a contradiction.
if (b != 0)
return;
clang_analyzer_warnIfReached(); // This produces a warning.
// The path is already infeasible...
if (c == 0) // ...but we realize that only when we evaluate `c == 0`.
return;
```
What happens currently, without the fixpoint iteration? As the inline comments
suggest, without the fixpoint iteration we are doomed to realize that we are on
an infeasible path only after we are already walking on that. With fixpoint
iteration we can detect that before stepping on that. With fixpoint iteration,
the `clang_analyzer_warnIfReached` does not warn in the above example b/c
during the evaluation of `b == 0` we realize the contradiction. The engine and
the checkers do rely on that either `assume(Cond)` or `assume(!Cond)` should be
feasible. This is in fact assured by the so called expensive checks
(LLVM_ENABLE_EXPENSIVE_CHECKS). The StdLibraryFuncionsChecker is notably one of
the checkers that has a very similar assertion.
Before this patch, we simply added the simplified symbol to the equivalence
class. In this patch, after we have added the simplified symbol, we remove the
old (more complex) symbol from the members of the equivalence class
(`ClassMembers`). Removing the old symbol is beneficial because during the next
iteration of the simplification we don't have to consider again the old symbol.
Contrary to how we handle `ClassMembers`, we don't remove the old Sym->Class
relation from the `ClassMap`. This is important for two reasons: The
constraints of the old symbol can still be found via it's equivalence class
that it used to be the member of (1). We can spare one removal and thus one
additional tree in the forest of `ClassMap` (2).
Performance and complexity: Let us assume that in a State we have N non-trivial
equivalence classes and that all constraints and disequality info is related to
non-trivial classes. In the worst case, we can simplify only one symbol of one
class in each iteration. The number of symbols in one class cannot grow b/c we
replace the old symbol with the simplified one. Also, the number of the
equivalence classes can decrease only, b/c the algorithm does a merge operation
optionally. We need N iterations in this case to reach the fixpoint. Thus, the
steps needed to be done in the worst case is proportional to `N*N`. Empirical
results (attached) show that there is some hardly noticeable run-time and peak
memory discrepancy compared to the baseline. In my opinion, these differences
could be the result of measurement error.
This worst case scenario can be extended to that cases when we have trivial
classes in the constraints and in the disequality map are transforming to such
a State where there are only non-trivial classes, b/c the algorithm does merge
operations. A merge operation on two trivial classes results in one non-trivial
class.
Differential Revision: https://reviews.llvm.org/D106823
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.
As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D110216
The driver uses class SanitizerArgs to store parsed sanitizer arguments. It keeps a cached
SanitizerArgs object in ToolChain and uses it for different jobs. This does not work if
the sanitizer options are different for different jobs, which could happen when an
offloading toolchain translates the options for different jobs.
To fix this, SanitizerArgs should be created by using the actual arguments passed
to jobs instead of the original arguments passed to the driver, since the toolchain
may change the original arguments. And the sanitizer arguments should be diagnose
once.
This patch also fixes HIP toolchain for handling -fgpu-sanitize: a warning is emitted
for GPU's not supporting sanitizer and skipped. This is for backward compatibility
with existing -fsanitize options. -fgpu-sanitize is also turned on by default.
Reviewed by: Artem Belevich, Evgenii Stepanov
Differential Revision: https://reviews.llvm.org/D111443
As discussed here: https://lwn.net/Articles/691932/
GCC6.0 adds target_clones multiversioning. This functionality is
an odd cross between the cpu_dispatch and 'target' MV, but is compatible
with neither.
This attribute allows you to list all options, then emits a separately
optimized version of each function per-option (similar to the
cpu_specific attribute). It automatically generates a resolver, just
like the other two.
The mangling however, is... ODD to say the least. The mangling format
is:
<normal_mangling>.<option string>.<option ordinal>.
Differential Revision:https://reviews.llvm.org/D51650
If the feature is on the command line we should honor it for all
functions. I don't think we could reliably target a single function
for a less capable processor than what the rest of the program is
compiled for.
Fixes PR52407.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D113647
Tarique Islam