This reverts commit 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e.
This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
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 e6393ee813178e9d3306b8e3c6949a4f32f8a2cb, most recently
reverted in 9a33f027ac7d73e14ae287e78ab554142d1cbc8f due to a bug caused
by ObjCInterfaceDecls not propagating availability attributes along
their redeclaration chains; that bug was fixed in
e2d4174e9c66251d1b408234b53f53d0903c0285.
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 e6393ee813178e9d3306b8e3c6949a4f32f8a2cb 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 e6393ee813178e9d3306b8e3c6949a4f32f8a2cb 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
