The Size either needs to be 0 meaning we aren't folding
a stack reload. Or the stack slot needs to be at least
16 bytes. I've also added a paranoia check ensure the
RCSize is at leat 16 bytes as well. This avoids any
FR32/FR64 surprises, but I think we already filtered
those earlier.
All of our test case have Size as either 0 or 16 and
RCSize == 16. So the Size <= 16 check worked for those
cases.
llvm-svn: 365234
The indirect call sequence on PPC requires that the TOC base register be saved
prior to the indirect call and restored after the call since the indirect call
may branch to a global entry point in another DSO which will update the TOC
base. Over the last couple of years, we have improved this to:
- be able to hoist TOC saves from loops (with changes to MachineLICM)
- avoid multiple saves when one dominates the other[s]
However, it is still possible to have multiple TOC saves dynamically in the
execution path if there is no dominance relationship between them.
This patch moves the TOC save to the prologue when one of the TOC saves is in a
block that post-dominates entry (i.e. it cannot be avoided) or if it is in a
block that is hotter than entry.
Differential revision: https://reviews.llvm.org/D63803
llvm-svn: 365232
For x86_64, since we don't clobber %rsi (2nd argument) anymore, we don't
have to save/restore it.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D63946
llvm-svn: 365229
Change the interface to return an expected, instead of taking a Status
pointer.
Differential revision: https://reviews.llvm.org/D64163
llvm-svn: 365226
These patterns use 128-bit loads, but the instructions only load
64-bits. We shouldn't narrow the load if its volatile.
Fixes another variant of PR42079
llvm-svn: 365225
This was identical to a pattern for MOVPQI2QImr with a bitcast
as an input. But we should be able to turn MOVPQI2QImr into
MOVLPSmr in the execution domain fixup pass so we shouldn't
need this.
llvm-svn: 365224
Summary:
Otherwise, when libcxxabi is not an enabled project in the monorepo, we
get a link error because we try to link against non-existent cxxabi_shared.
More generally, we shouldn't change the behavior of the build based on
implicit things like whether a file happens to be at a specific path or
not.
Reviewers: EricWF
Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D63883
llvm-svn: 365222
--section-data, --section-relocations and --section-symbols have no
effect for GNU style ouput. This patch changes the docs to point this
out, as it has caught me out on a couple of occasions.
See also https://bugs.llvm.org/show_bug.cgi?id=42522.
llvm-svn: 365221
Summary:
This patch changes expression support to use one instance of
FileCheckNumericVariable per numeric variable rather than one per
variable and per definition. The current system was only necessary for
the last patch of the numeric expression support patch series in order
to handle a line using a variable defined earlier on the same line from
the input text. However this can be dealt more efficiently.
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: JonChesterfield, rogfer01, hfinkel, kristina, rnk, tra, arichardson, grimar, dblaikie, probinson, llvm-commits, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64229
llvm-svn: 365220
Summary:
Diagnosing use of undefined variables takes place in
parseNumericVariableUse() and printSubstitutions() for numeric variables
but only takes place in printSubstitutions() for string variables. The
reason for the split location of diagnostics is that parsing is not
aware of the clearing of variables due to --enable-var-scope and thus
use of variables cleared in this way can only be catched by
printSubstitutions().
Beyond the code level inconsistency, there is also a user facing
inconsistency since diagnostics look different between the two
functions. While the diagnostic in printSubstitutions is more verbose,
doing the diagnostic there allows to diagnose all undefined variables
rather than just the first one and error out.
This patch create dummy variable definition when encountering a use of
undefined variable so that parsing can proceed and be diagnosed by
printSubstitutions() later. Tests that were testing whether parsing
fails in such case are thus modified accordingly.
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: JonChesterfield, rogfer01, hfinkel, kristina, rnk, tra, arichardson, grimar, dblaikie, probinson, llvm-commits, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64228
llvm-svn: 365219
When looking for uses/defs to add kill flags, the iterator was double
incremented, skipping the first instruction in the bundle. The use
register in the first bundle instruction was then incorrectly killed.
The "First" instruction should be the BUNDLE itself as the proper
reverse iterator endpoint.
llvm-svn: 365216
This case implicitly falls-through, which is fine now as it's at the end of the
function, but it seems like an accident waiting to happen.
llvm-svn: 365210
This patch is a major part of my GSoC project, aimed to improve the bug
reports of the analyzer.
TL;DR: Help the analyzer understand that some conditions are important,
and should be explained better. If an CFGBlock is a control dependency
of a block where an expression value is tracked, explain the condition
expression better by tracking it.
if (A) // let's explain why we believe A to be true
10 / x; // division by zero
This is an experimental feature, and can be enabled by the
off-by-default analyzer configuration "track-conditions".
In detail:
This idea was inspired by the program slicing algorithm. Essentially,
two things are used to produce a program slice (a subset of the program
relevant to a (statement, variable) pair): data and control
dependencies. The bug path (the linear path in the ExplodedGraph that leads
from the beginning of the analysis to the error node) enables to
analyzer to argue about data dependencies with relative ease.
Control dependencies are a different slice of the cake entirely.
Just because we reached a branch during symbolic execution, it
doesn't mean that that particular branch has any effect on whether the
bug would've occured. This means that we can't simply rely on the bug
path to gather control dependencies.
In previous patches, LLVM's IDFCalculator, which works on a control flow
graph rather than the ExplodedGraph was generalized to solve this issue.
We use this information to heuristically guess that the value of a tracked
expression depends greatly on it's control dependencies, and start
tracking them as well.
After plenty of evaluations this was seen as great idea, but still
lacking refinements (we should have different descriptions about a
conditions value), hence it's off-by-default.
Differential Revision: https://reviews.llvm.org/D62883
llvm-svn: 365207
Summary:
Clang-tidy checks may emit duplicated messages (clang-tidy tool
deduplicate them in its custom diagnostic consumer), and we may show
multiple duplicated diagnostics in the UI, which is really bad.
This patch makes clangd do the deduplication, and revert the change
rL363889.
Reviewers: sammccall
Subscribers: ilya-biryukov, MaskRay, jkorous, mgrang, arphaman, kadircet, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64127
llvm-svn: 365204
Reintroduces the scalable vector IR type from D32530, after it was reverted
a couple of times due to increasing chromium LTO build times. This latest
incarnation removes the walk over aggregate types from the verifier entirely,
in favor of rejecting scalable vectors in the isValidElementType methods in
ArrayType and StructType. This removes the 70% degradation observed with
the second repro tarball from PR42210.
Reviewers: thakis, hans, rengolin, sdesmalen
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D64079
llvm-svn: 365203
Revision r365061 changed a skip of debug instructions for a skip
of meta instructions. This is not safe, as IMPLICIT_DEF is classed
as a meta instruction.
llvm-svn: 365202
On RISC-V, the `cycle` CSR holds a 64-bit count of the number of clock
cycles executed by the core, from an arbitrary point in the past. This
matches the intended semantics of `@llvm.readcyclecounter()`, which we
currently leave to the default lowering (to the constant 0).
With this patch, we will now correctly lower this intrinsic to the
intended semantics, using the user-space instruction `rdcycle`. On
64-bit targets, we can directly lower to this instruction.
On 32-bit targets, we need to do more, as `rdcycle` only returns the low
32-bits of the `cycle` CSR. In this case, we perform a custom lowering,
based on the PowerPC lowering, using `rdcycleh` to obtain the high
32-bits of the `cycle` CSR. This custom lowering inserts a new basic
block which detects overflow in the high 32-bits of the `cycle` CSR
during reading (because multiple instructions are required to read). The
emitted assembly matches the suggested assembly in the RISC-V
specification.
Differential Revision: https://reviews.llvm.org/D64125
llvm-svn: 365201
Since OPT_UNKNOWN args never have any values and consist only of
spelling (and are never aliased), this doesn't make any difference in
practice, but it's more consistent with Arg's guidance to use
getAsString() for diagnostics, and it matches what clang does.
Also tweak two tests to use an unknown option that contains '=' for
additional coverage while here. (The new tests pass fine with the old
code too though.)
llvm-svn: 365200
Revision r365061 changed a skip of debug instructions for a skip
of meta instructions. This is not safe, as IMPLICIT_DEF is classed
as a meta instruction.
llvm-svn: 365198
I intend to improve the analyzer's bug reports by tracking condition
expressions.
01 bool b = messyComputation();
02 int i = 0;
03 if (b) // control dependency of the bug site, let's explain why we assume val
04 // to be true
05 10 / i; // warn: division by zero
I'll detail this heuristic in the followup patch, strictly related to this one
however:
* Create the new ControlDependencyCalculator class that uses llvm::IDFCalculator
to (lazily) calculate control dependencies for Clang's CFG.
* A new debug checker debug.DumpControlDependencies is added for lit tests
* Add unittests
Differential Revision: https://reviews.llvm.org/D62619
llvm-svn: 365197
Summary:
Comment explaining the interaction between parsing of numeric variable
definition and uses in parseNumericVariableUse is stale since it
suggests both use and definition parsing is done in the same function.
This was the case in a previous version of the patch committed as
71d3f227a7 but is no longer the case. This
patch updates the comment accordingly.
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: JonChesterfield, rogfer01, hfinkel, kristina, rnk, tra, arichardson, grimar, dblaikie, probinson, llvm-commits, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64227
llvm-svn: 365192
Summary:
Both callers of parseNumericVariableDefinition() perform the same extra
check that no character is found after the variable name. This patch
factors out this check into parseNumericVariableDefinition().
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk
Subscribers: JonChesterfield, rogfer01, hfinkel, kristina, rnk, tra, arichardson, grimar, dblaikie, probinson, llvm-commits, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64226
llvm-svn: 365191
It's possible that some function can load and store the same
variable using the same constant expression:
store %Derived* @foo, %Derived** bitcast (%Base** @bar to %Derived**)
%42 = load %Derived*, %Derived** bitcast (%Base** @bar to %Derived**)
The bitcast expression was mistakenly cached while processing loads,
and never examined later when processing store. This caused @bar to
be mistakenly treated as read-only variable. See load-store-caching.ll.
llvm-svn: 365188
Benjamin Kramer