Commit Graph

38 Commits

Author SHA1 Message Date
Richard Smith 7747ce2260 Internal-linkage variables with constant-evaluatable initializers do not need to be emitted. (Also reduces the set of variables that need to be eagerly deserialized when using PCH / modules.)
llvm-svn: 245497
2015-08-19 20:49:38 +00:00
David Blaikie bdf40a62a7 Test case updates for explicit type parameter to the gep operator
llvm-svn: 232187
2015-03-13 18:21:46 +00:00
David Blaikie a953f2825b Update Clang tests to handle explicitly typed load changes in LLVM.
llvm-svn: 230795
2015-02-27 21:19:58 +00:00
David Majnemer f63bcaa2c5 CodeGen: Weak reference temporaries belong in a COMDAT
llvm-svn: 229902
2015-02-19 19:35:18 +00:00
David Majnemer c9a9c7a673 CodeGen: static constexpr data members should have a linkonce_odr init
Classes can be defined in multiple translation units.  This means that
the static constexpr data members should have identical initializers in
all translation units.  Implement this by giving the reference temporary
linkonce_odr linkage.

llvm-svn: 229900
2015-02-19 19:25:17 +00:00
Nico Weber 220b3ad598 Test that member functions of constexpr constructed templates are instantiated.
They are referenced from the vtable. (This worked fine, but I couldn't find
an existing test for this.  Maybe I didn't look hard enough.)

llvm-svn: 227072
2015-01-26 06:08:07 +00:00
Nico Weber 4a18449c2c Remove -verify from a codegen test that didn't have any expected-foo lines.
Makes the error output of the test more readable when it fails. Also allows
removing a "not" from the run line.

llvm-svn: 227071
2015-01-26 05:47:24 +00:00
Hal Finkel a2347baaec Mark C++ reference parameters as dereferenceable
Because references must be initialized using some evaluated expression, they
must point to something, and a callee can assume the reference parameter is
dereferenceable. Taking advantage of a new attribute just added to LLVM, mark
them as such.

Because dereferenceability in addrspace(0) implies nonnull in the backend, we
don't need both attributes. However, we need to know the size of the object to
use the dereferenceable attribute, so for incomplete types we still emit only
nonnull.

llvm-svn: 213386
2014-07-18 15:52:10 +00:00
Nick Lewycky 9b46eb8112 Add 'nonnull' parameter or return attribute when producing an llvm pointer type in a function type where the C++ type is a reference. Update the tests.
llvm-svn: 209723
2014-05-28 09:56:42 +00:00
David Majnemer 3b3bdb5169 AST: Update reference temporary mangling
Summary:
Update our mangling to match the discussion on cxx-abi-dev.

This involves using a seq-id instead of an optional number.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D3631

llvm-svn: 208140
2014-05-06 22:49:16 +00:00
David Majnemer 846c2833ec CodeGen: Reference temporaries inherit visibility
Reference temporaries inherited many properties from the variable that
they correspond to but visibility wasn't one of them.

llvm-svn: 207496
2014-04-29 06:18:53 +00:00
David Majnemer 27d69dbbd0 CodeGen: Fix linkage of reference temporaries
Summary:
A reference temporary should inherit the linkage of the variable it
initializes.  Otherwise, we may hit cases where a reference temporary
wouldn't have the same value in all translation units.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D3515

llvm-svn: 207451
2014-04-28 22:17:59 +00:00
Rafael Espindola 925213b0fa Add 'not' to commands that are expected to fail.
This is at least good documentation, but also opens the possibility of
using pipefail.

llvm-svn: 185652
2013-07-04 16:16:58 +00:00
Richard Smith faadef7369 Recursively lifetime-extend into array temporaries. These can get implicitly
created through binding a reference-to-array to an initializer list.

llvm-svn: 183594
2013-06-08 00:02:08 +00:00
Richard Smith e6c0144208 Model temporary lifetime-extension explicitly in the AST. Use this model to
handle temporaries which have been lifetime-extended to static storage duration
within constant expressions. This correctly handles nested lifetime extension
(through reference members of aggregates in aggregate initializers) but
non-constant-expression emission hasn't yet been updated to do the same.

llvm-svn: 183283
2013-06-05 00:46:14 +00:00
Richard Smith 2bcde3a74c PR12848: When emitting a local variable declared 'constexpr', always initialize it with a store or a memcpy, not by emitting the initializer expression. This is not required for correctness, but more closely aligns with people's expectations, and is cheap (since we've already evaluated the initializer).
llvm-svn: 183082
2013-06-02 00:09:52 +00:00
Richard Smith 5a1104bd3a DR1472: A reference isn't odr-used if it has preceding initialization,
initialized by a reference constant expression.

Our odr-use modeling still needs work here: we don't yet implement the 'set of
potential results of an expression' DR.

llvm-svn: 166361
2012-10-20 01:38:33 +00:00
Richard Smith 0421ce7b22 Teach Expr::HasSideEffects about all the Expr types, and fix a bug where it
was mistakenly classifying dynamic_casts which might throw as having no side
effects.

Switch it from a visitor to a switch, so it is kept up-to-date as future Expr
nodes are added. Move it from ExprConstant.cpp to Expr.cpp, since it's not
really related to constant expression evaluation.

Since we use HasSideEffect to determine whether to emit an unused global with
internal linkage, this has the effect of suppressing emission of globals in
some cases.

I've left many of the Objective-C cases conservatively assuming that the
expression has side-effects. I'll leave it to someone with better knowledge
of Objective-C than mine to improve them.

llvm-svn: 161388
2012-08-07 04:16:51 +00:00
Richard Smith 1b9f2eb76b PR13290: Constant-evaluation support for CXXConstructExprs which construct a
multidimensional array of class type. Also, preserve zero-initialization when
evaluating an initializer list for an array, in case the initializers refer to
later elements (which have preceding zero-initialization).

llvm-svn: 159904
2012-07-07 22:48:24 +00:00
Richard Smith d86812d95c PR13273: When performing list-initialization with an empty initializer list,
actually perform value initialization rather than trying to fake it with a call
to the default constructor. Fixes various bugs related to the previously-missing
zero-initialization in this case.

I've also moved this and the other list initialization 'special case' from
TryConstructorInitialization into TryListInitialization where they belong.

llvm-svn: 159733
2012-07-05 08:39:21 +00:00
Richard Smith e2648bac3a A union can have a constexpr defaulted default constructor, if it has an
in-class initializer for one of its fields. Value-initialization of such
a type should use the in-class initializer!

The former was just a bug, the latter is a (reported) standard defect.

llvm-svn: 156274
2012-05-07 01:07:30 +00:00
Richard Smith 9ec1e48b59 PR12226: don't generate wrong code if a braced string literal is used to
initialize an array of unsigned char. Outside C++11 mode, this bug was benign,
and just resulted in us emitting a constant which was double the required
length, padded with 0s. In C++11, it resulted in us generating an array whose
first element was something like  i8 ptrtoint ([n x i8]* @str to i8).

llvm-svn: 154756
2012-04-15 02:50:59 +00:00
Richard Smith 4051ff7650 Don't forget to evaluate the subexpression in a null pointer cast. If we're
converting from std::nullptr_t, the subexpression might have side-effects.

llvm-svn: 154278
2012-04-08 08:02:07 +00:00
Eli Friedman a154dd5b33 ConstStructBuilder: fix offset math for base classes so it works correctly in general. Found by inspection.
llvm-svn: 153720
2012-03-30 03:55:31 +00:00
Richard Smith 8c029611a6 Don't even try to directly emit the value of a DeclRefExpr if that declaration
is not usable in a constant expression. ~2.5% speedup on 403.gcc / combine.c.

llvm-svn: 152193
2012-03-07 01:58:44 +00:00
Richard Smith bc638767f8 Reinstate r151879, r151880, reverted in r151922, along with a bugfix for
scalar emission of DeclRefExprs to const bools: emit scalar bools as i1,
not as i8.

In addition to the extra unit testing, this has successfully bootstrapped.

llvm-svn: 151955
2012-03-02 23:27:11 +00:00
Daniel Dunbar d01281fe0d Revert r151879, r151880, "PR12145: Avoid emitting loads of constexpr variables in contexts where there" and "Fix buildbot: make this test less dependent on the value names in the produced IR."
They broke bootstrap.

llvm-svn: 151922
2012-03-02 16:24:25 +00:00
Richard Smith 545f38c3d2 Fix buildbot: make this test less dependent on the value names in the produced IR.
llvm-svn: 151880
2012-03-02 03:22:38 +00:00
Richard Smith a541a3bbee PR12145: Avoid emitting loads of constexpr variables in contexts where there
is no odr-use of the variable. Go slightly beyond what the standard requires
for variables of reference type.

llvm-svn: 151879
2012-03-02 03:16:32 +00:00
Richard Smith c899892485 PR12067: When emitting an evaluated constant structure in C++11 mode, don't
forget the vptrs.

llvm-svn: 151245
2012-02-23 08:33:23 +00:00
Richard Smith ae819500a1 When performing IRGen on a global, emit it as a constant if:
1) It has a const-qualified type, and
 2) It has no mutable members, and
 3) It has no dynamic initialization, and
 4) It has trivial destruction.
Remove the unnecessary requirement that the type be POD. This allows us to
mark all constexpr objects with no mutable members as 'constant'.

llvm-svn: 150792
2012-02-17 04:54:50 +00:00
Richard Smith 14a941380a Make sure all remaining parts of the constant evaluator are aware that an array
can be represented by an LValue, and use that to simplify the code a little.

llvm-svn: 150789
2012-02-17 03:35:37 +00:00
Richard Smith 5d108606cc PR12012: Fix a regression in r150419 where we would try (and fail) to
zero-initialize class types with virtual bases when constant-evaluating an
initializer.

llvm-svn: 150770
2012-02-17 00:44:16 +00:00
Richard Smith 6331c408b5 Deal with a horrible C++11 special case. If a non-literal type has a constexpr
constructor, and that constructor is used to initialize an object of static
storage duration such that all members and bases are initialized by constant
expressions, constant initialization is performed. In this case, the object
can still have a non-trivial destructor, and if it does, we must emit a dynamic
initializer which performs no initialization and instead simply registers that
destructor.

llvm-svn: 150419
2012-02-13 22:16:19 +00:00
Richard Smith 253c2a390a constexpr: Implement the [dcl.constexpr]p5 check for whether a constexpr
function definition can produce a constant expression. This also provides the
last few checks for [dcl.constexpr]p3 and [dcl.constexpr]p4.

llvm-svn: 149108
2012-01-27 01:14:48 +00:00
Chris Lattner e8c94f7d98 fix to go along with an llvm change: VMCore now returns an UndefValue
when asking for a ConstantStruct with all undef elements.

llvm-svn: 149025
2012-01-26 02:33:22 +00:00
Richard Smith dafff94759 constexpr irgen: Add irgen support for APValue::Struct, APValue::Union,
APValue::Array and APValue::MemberPointer. All APValue values can now be emitted
as constants.

Add new CGCXXABI entry point for emitting an APValue MemberPointer. The other
entrypoints dealing with constant member pointers are no longer necessary and
will be removed in a later change.

Switch codegen from using EvaluateAsRValue/EvaluateAsLValue to
VarDecl::evaluateValue. This performs caching and deals with the nasty cases in
C++11 where a non-const object's initializer can refer indirectly to
previously-initialized fields within the same object.

Building the intermediate APValue object incurs a measurable performance hit on
pathological testcases with huge initializer lists, so we continue to build IR
directly from the Expr nodes for array and record types outside of C++11.

llvm-svn: 148178
2012-01-14 04:30:29 +00:00
Eli Friedman b1bc368ca7 Address Richard's review comments on r147561 (Evaluate support for address-of-label differences).
llvm-svn: 147631
2012-01-05 23:59:40 +00:00