This renames the primary methods for creating a zero value to `getZero`
instead of `getNullValue` and renames predicates like `isAllOnesValue`
to simply `isAllOnes`. This achieves two things:
1) This starts standardizing predicates across the LLVM codebase,
following (in this case) ConstantInt. The word "Value" doesn't
convey anything of merit, and is missing in some of the other things.
2) Calling an integer "null" doesn't make any sense. The original sin
here is mine and I've regretted it for years. This moves us to calling
it "zero" instead, which is correct!
APInt is widely used and I don't think anyone is keen to take massive source
breakage on anything so core, at least not all in one go. As such, this
doesn't actually delete any entrypoints, it "soft deprecates" them with a
comment.
Included in this patch are changes to a bunch of the codebase, but there are
more. We should normalize SelectionDAG and other APIs as well, which would
make the API change more mechanical.
Differential Revision: https://reviews.llvm.org/D109483
This patch adds a new clang builtin, __arithmetic_fence. The purpose of the
builtin is to provide the user fine control, at the expression level, over
floating point optimization when -ffast-math (-ffp-model=fast) is enabled.
The builtin prevents the optimizer from rearranging floating point expression
evaluation. The new option fprotect-parens has the same effect on
parenthesized expressions, forcing the optimizer to respect the parentheses.
Reviewed By: aaron.ballman, kpn
Differential Revision: https://reviews.llvm.org/D100118
This patch adds a new clang builtin, __arithmetic_fence. The purpose of the
builtin is to provide the user fine control, at the expression level, over
floating point optimization when -ffast-math (-ffp-model=fast) is enabled.
The builtin prevents the optimizer from rearranging floating point expression
evaluation. The new option fprotect-parens has the same effect on
parenthesized expressions, forcing the optimizer to respect the parentheses.
Reviewed By: aaron.ballman, kpn
Differential Revision: https://reviews.llvm.org/D100118
<string> is currently the highest impact header in a clang+llvm build:
https://commondatastorage.googleapis.com/chromium-browser-clang/llvm-include-analysis.html
One of the most common places this is being included is the APInt.h header, which needs it for an old toString() implementation that returns std::string - an inefficient method compared to the SmallString versions that it actually wraps.
This patch replaces these APInt/APSInt methods with a pair of llvm::toString() helpers inside StringExtras.h, adjusts users accordingly and removes the <string> from APInt.h - I was hoping that more of these users could be converted to use the SmallString methods, but it appears that most end up creating a std::string anyhow. I avoided trying to use the raw_ostream << operators as well as I didn't want to lose having the integer radix explicit in the code.
Differential Revision: https://reviews.llvm.org/D103888
This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.
C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).
Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D103720
The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution. This is that solution.
This implements a builtin to provide a unique name that is stable across
compilations of this TU for the purposes of implementing the library
component of the unnamed kernel feature of SYCL. It does this by
running the Itanium mangler with a few modifications.
Because it is somewhat common to wrap non-kernel-related lambdas in
macros that aren't present on the device (such as for logging), this
uniquely generates an ID for all lambdas involved in the naming of a
kernel. It uses the lambda-mangling number to do this, except replaces
this with its own number (starting at 10000 for readabililty reasons)
for lambdas used to name a kernel.
Additionally, this implements itself as constexpr with a slight catch:
if a name would be invalidated by the use of this lambda in a later
kernel invocation, it is diagnosed as an error (see the Sema tests).
Differential Revision: https://reviews.llvm.org/D103112
This implements C-style type conversions for matrix types, as specified
in clang/docs/MatrixTypes.rst.
Fixes PR47141.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D99037
I have been trying to statically find and analyze all calls to heap
allocation functions to determine how many of them use sizes known at
compile time vs only at runtime. While doing so I saw that quite a few
projects use replaceable function pointers for heap allocation and noticed
that clang was not able to annotate functions pointers with alloc_size.
I have changed the Sema checks to allow alloc_size on all function pointers
and typedefs for function pointers now and added checks that these
attributes are propagated to the LLVM IR correctly.
With this patch we can also compute __builtin_object_size() for calls to
allocation function pointers with the alloc_size attribute.
Reviewed By: aaron.ballman, erik.pilkington
Differential Revision: https://reviews.llvm.org/D55212
omp_is_initial_device() is marked as a built-in function in the current
compiler, and user code guarded by this call may be optimized away,
resulting in undesired behavior in some cases. This patch provides a
possible fix for such cases by defining the routine as a variant
function and removing it from builtin list.
Differential Revision: https://reviews.llvm.org/D99447
This would assert if we hit the evaluation step limit between starting
to delay the call and finishing. In any case, delaying the call was
largely pointless as it doesn't really matter when we mark the
evaluation as having had side effects.
The only time we would consider allowing this is inside a call to
std::allocator<T>::deallocate, whose contract does not permit deletion
of null pointers.
mode.
We use that mode when evaluating ICEs in C, and those shortcuts could
result in ICE evaluation producing the wrong answer, specifically if we
evaluate a statement-expression as part of evaluating the ICE.
Add the types for the RISC-V V extension builtins.
These types will be used by the RISC-V V intrinsics which require
types of the form <vscale x 1 x i64>(LMUL=1 element size=64) or
<vscale x 4 x i32>(LMUL=2 element size=32), etc. The vector_size
attribute does not work for us as it doesn't create a scalable
vector type. We want these types to be opaque and have no operators
defined for them. We want them to be sizeless. This makes them
similar to the ARM SVE builtin types. But we will have quite a bit
more types. This patch adds around 60. Later patches will add
another 230 or so types representing tuples of these types similar
to the x2/x3/x4 types in ARM SVE. But with extra complexity that
these types are combined with the LMUL concept that is unique to
RISCV.
For more background see this RFC
http://lists.llvm.org/pipermail/llvm-dev/2020-October/145850.html
Authored-by: Roger Ferrer Ibanez <roger.ferrer@bsc.es>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>
Differential Revision: https://reviews.llvm.org/D92715
during the same evaluation.
It looks like the only case for which this matters is determining
whether mutable subobjects of a heap allocation can be modified during
constant evaluation.
variable's destruction if it didn't do so during construction.
The standard doesn't give any guidance as to what to do here, but this
approach seems reasonable and conservative, and has been proposed to the
standard committee.
If an initial value is given for a bitfield that does not fit in the
bitfield, the value should be truncated. Constant folding for
expressions did not account for this truncation in the case of union
member functions, despite a warning being emitted. In some contexts,
evaluation of expressions was not enabled unless C++11, ROPI or RWPI
was enabled.
Differential Revision: https://reviews.llvm.org/D93101
The included test case triggered a sign assertion on the result in
`Success()`. This was caused by the APSInt created for a bitcast
having its signedness bit inverted. The second APSInt constructor
argument is `isUnsigned`, so invert the result of
`isSignedIntegerType`.
Relanding this patch after reverting. The test case had to be updated
to be insensitive to 32/64-bit extractelement indices.
Differential Revision: https://reviews.llvm.org/D95135
The included test case triggered a sign assertion on the result in
`Success()`. This was caused by the APSInt created for a bitcast
having its signedness bit inverted. The second APSInt constructor
argument is `isUnsigned`, so invert the result of
`isSignedIntegerType`.
Differential Revision: https://reviews.llvm.org/D95135
This reverts commit 275f30df8a.
As noted on the code review (https://reviews.llvm.org/D92892), this
change causes us to reject valid code in a few cases. Reverting so we
have more time to figure out what the right fix{es are, is} here.
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.
Additionally it reverts changes that were dependent on this one, see
below.
> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b8, and
> reverted because a dependency commit was reverted.
This reverts commit 5a391d38ac.
It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb.
Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."
> Previously committed as 9e08e51a20, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81 by Simon Pilgrim
> ed13d8c667 by me
> 95c7b6cadb by Sam McCall
> 430d5d8429 by Dave Zarzycki
This reverts commit 4b574008ae.
Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"
> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.
This reverts commit 18e093faf7.
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
Previously committed as 8c1f2d15b8, and
reverted because a dependency commit was reverted.
Motivating example:
```
struct { int v[10]; } t[10];
__builtin_object_size(
&t[0].v[11], // access past end of subobject
1 // request remaining bytes of closest surrounding
// subobject
);
```
In GCC, this returns 0. https://godbolt.org/z/7TeGs7
In current clang, however, this returns 356, the number of bytes
remaining in the whole variable, as if the `type` was 0 instead of 1.
https://godbolt.org/z/6Kffox
This patch checks for the specific case where we're requesting a
subobject's size (type 1) but the subobject is invalid.
Differential Revision: https://reviews.llvm.org/D92892
to dependent declarations.
Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.
This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.
This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
This patch enables the Clang type __vector_pair and its associated LLVM
intrinsics even when MMA is disabled. With this patch, the type is now controlled
by the PPC paired-vector-memops option. The builtins and intrinsics will be
renamed to drop the mma prefix in another patch.
Differential Revision: https://reviews.llvm.org/D91819
When the evaluator encounters an error-dependent returnstmt, before this patch
it returned a ESR_Returned without setting the result, the callsides think this
is a successful execution, and try to access the Result which causes the crash.
The fix is to always return failed as we don't know the result of the
error-dependent return stmt.
Differential Revision: https://reviews.llvm.org/D92969
Fix a crash when evaluating a constexpr function which contains
recovery-exprs. https://bugs.llvm.org/show_bug.cgi?id=46837
Would be nice to have constant expression evaluator support general template
value-dependent expressions, but it requires more work.
This patch is a good start I think, to handle the error-only
value-dependent expressions.
Differential Revision: https://reviews.llvm.org/D84637
Define the __vector_pair and __vector_quad types that are used to manipulate
the new accumulator registers introduced by MMA on PowerPC. Because these two
types are specific to PowerPC, they are defined in a separate new file so it
will be easier to add other PowerPC specific types if we need to in the future.
Differential Revision: https://reviews.llvm.org/D81508
The local variable CmpResult added in that change shadowed the
type CmpResult, which confused an older gcc. Rename the variable
CmpResult to APFloatCmpResult.
non-type template parameters.
Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.
No IR generation support yet; that will follow in a separate patch.
Permitting non-standards-driven "do the best you can" constant-folding
of array bounds is permitted solely as a GNU compatibility feature. We
should not be doing it in any language mode that is attempting to be
conforming.
From https://reviews.llvm.org/D20090 it appears the intent here was to
permit `__constant int` globals to be used in array bounds, but the
change in that patch only added half of the functionality necessary to
support that in the constant evaluator. This patch adds the other half
of the functionality and turns off constant folding for array bounds in
OpenCL.
I couldn't find any spec justification for accepting the kinds of cases
that D20090 accepts, so a reference to where in the OpenCL specification
this is permitted would be useful.
Note that this change also affects the code generation in one test:
because after 'const int n = 0' we now treat 'n' as a constant
expression with value 0, it's now a null pointer, so '(local int *)n'
forms a null pointer rather than a zero pointer.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D89520
This fixes miscomputation of __builtin_constant_evaluated in the
initializer of a variable that's not usable in constant expressions, but
is readable when constant-folding.
If evaluation of a constant initializer fails, we throw away the
evaluated result instead of keeping it as a non-constant-initializer
value for the variable, because it might not be a correct value.
To avoid regressions for initializers that are foldable but not formally
constant initializers, we now try constant-evaluating some globals in
C++ twice: once to check for a constant initializer (in an mode where
is_constannt_evaluated returns true) and again to determine the runtime
value if the initializer is not a constant initializer.
Instead of framing the interface around whether the variable is an ICE
(which is only interesting in C++98), primarily track whether the
initializer is a constant initializer (which is interesting in all C++
language modes).
No functionality change intended.
for which it matters.
This is a step towards separating checking for a constant initializer
(in which std::is_constant_evaluated returns true) and any other
evaluation of a variable initializer (in which it returns false).
This addresses a regression where pretty much all C++ compilations using
-frounding-math now fail, due to rounding being performed in constexpr
function definitions in the standard library.
This follows the "manifestly constant evaluated" approach described in
https://reviews.llvm.org/D87528#2270676 -- evaluations that are required
to succeed at compile time are permitted even in regions with dynamic
rounding modes, as are (unfortunately) the evaluation of the
initializers of local variables of const integral types.
Differential Revision: https://reviews.llvm.org/D89360
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
References to different declarations of the same entity aren't different
values, so shouldn't have different representations.
Recommit of e6393ee813, most recently
reverted in 9a33f027ac due to a bug caused
by ObjCInterfaceDecls not propagating availability attributes along
their redeclaration chains; that bug was fixed in
e2d4174e9c.
Ensure that we evaluate assignment and compound-assignment
right-to-left, and array subscripting left-to-right.
Fixes PR47724.
This is a re-commit of ded79be, reverted in 37c74df, with a fix and test
for the crasher bug previously introduced.
If FP exceptions are ignored, we should not error out of compilation
just because APFloat indicated an exception.
This is required as a preliminary step for D88238
which changes APFloat behavior for signaling NaN convert() to set
the opInvalidOp exception status.
Currently, there is no way to trigger this error because convert()
never sets opInvalidOp. FP binops that set opInvalidOp also create
a NaN, so the path to checkFloatingPointResult() is blocked by a
different diagnostic:
// [expr.pre]p4:
// If during the evaluation of an expression, the result is not
// mathematically defined [...], the behavior is undefined.
// FIXME: C++ rules require us to not conform to IEEE 754 here.
if (LHS.isNaN()) {
Info.CCEDiag(E, diag::note_constexpr_float_arithmetic) << LHS.isNaN();
return Info.noteUndefinedBehavior();
}
return checkFloatingPointResult(Info, E, St);
Differential Revision: https://reviews.llvm.org/D88664
We previously took a shortcut and said that weak variables never have
constant initializers (because those initializers are never correct to
use outside the variable). We now say that weak variables can have
constant initializers, but are never usable in constant expressions.
References to different declarations of the same entity aren't different
values, so shouldn't have different representations.
Recommit of e6393ee813 with fixed handling
for weak declarations. We now look for attributes on the most recent
declaration when determining whether a declaration is weak. (Second
recommit with further fixes for mishandling of weak declarations. Our
behavior here is fundamentally unsound -- see PR47663 -- but this
approach attempts to not make things worse.)
The change implements evaluation of constant floating point expressions
under non-default rounding modes. The main objective was to support
evaluation of global variable initializers, where constant rounding mode
may be specified by `#pragma STDC FENV_ROUND`.
Differential Revision: https://reviews.llvm.org/D87822
References to different declarations of the same entity aren't different
values, so shouldn't have different representations.
Recommit of e6393ee813 with fixed
handling for weak declarations. We now look for attributes on the most
recent declaration when determining whether a declaration is weak.
On x86, long double has 6 unused trailing bytes. This patch changes the
constant evaluator to treat them as though they were padding bytes, so reading
from them results in an indeterminate value, and nothing is written for them.
Also, fix a similar bug with bool, but instead of treating the unused bits as
padding, enforce that they're zero.
Differential revision: https://reviews.llvm.org/D76323
This enables us to use the __builtin_rotateleft / __builtin_rotateright 8/16/32/64 intrinsics inside constexpr code.
Differential Revision: https://reviews.llvm.org/D86342
This patch moves FixedPointSemantics and APFixedPoint
from Clang to LLVM ADT.
This will make it easier to use the fixed-point
classes in LLVM for constructing an IR builder for
fixed-point and for reusing the APFixedPoint class
for constant evaluation purposes.
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-August/144025.html
Reviewed By: leonardchan, rjmccall
Differential Revision: https://reviews.llvm.org/D85312
Reapply 49e5f603d4
which had been reverted in c94332919b.
Originally reverted because I hadn't updated it in quite a while when I
got around to committing it, so there were a bunch of missing changes to
new code since I'd written the patch.
Reviewers: aaron.ballman
Differential Revision: https://reviews.llvm.org/D76646
We don't allow runtime-sized flexible array members, nor initialization
of flexible array members, but it seems reasonable to support the most
basic case where the flexible array member is empty.
There is a version that just tests (also called
isIntegerConstantExpression) & whereas this version is specifically used
when the value is of interest (a few call sites were actually refactored
to calling the test-only version) so let's make the API look more like
it.
Reviewers: aaron.ballman
Differential Revision: https://reviews.llvm.org/D76646
in places such as constant folding
Previously some places that should have handled
__builtin_expect_with_probability is missing, so in some case it acts
differently than __builtin_expect.
For example it was not handled in constant folding, thus in the
following program, the "if" condition should be constantly true and
folded, but previously it was not handled and cause warning "control may
reach end of non-void function" (while __builtin_expect does not):
__attribute__((noreturn)) extern void bar();
int foo(int x, int y) {
if (y) {
if (__builtin_expect_with_probability(1, 1, 1))
bar();
}
else
return 0;
}
Now it's fixed.
Differential Revisions: https://reviews.llvm.org/D83362
variable's initializer is not known.
The hope is that a better diagnostic for this case will reduce the rate
at which duplicates of non-bug PR41093 are reported.
Summary:
Assignment and comma operators for fixed-point types were being constevaled as other
binary operators, but they need special treatment.
Reviewers: rjmccall, leonardchan, bjope
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73189
Summary:
Diagnostics for overflow were not being produced for fixed-point
evaluation. This patch refactors a bit of the evaluator and adds
a proper diagnostic for these cases.
Reviewers: rjmccall, leonardchan, bjope
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73188
These operations do member-wise versions of the all of the listed
operations. This patch implements all of the binaryoperators for these
types. Note that the test is required to use codegen as I could not come
up with a good way to validate the values without the array-subscript
operator implemented (which is likely a much more involved change).
Differential Reivision: https://reviews.llvm.org/D79755
Prevent IR-gen from emitting consteval declarations
Summary: with this patch instead of emitting calls to consteval function. the IR-gen will emit a store of the already computed result.
Chris Lattner