17 Commits

Author SHA1 Message Date
Nikita Popov
0f46e31cfb
[IR] Change representation of getelementptr inrange (#84341)
As part of the migration to ptradd
(https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699),
we need to change the representation of the `inrange` attribute, which
is used for vtable splitting.

Currently, inrange is specified as follows:

```
getelementptr inbounds ({ [4 x ptr], [4 x ptr] }, ptr @vt, i64 0, inrange i32 1, i64 2)
```

The `inrange` is placed on a GEP index, and all accesses must be "in
range" of that index. The new representation is as follows:

```
getelementptr inbounds inrange(-16, 16) ({ [4 x ptr], [4 x ptr] }, ptr @vt, i64 0, i32 1, i64 2)
```

This specifies which offsets are "in range" of the GEP result. The new
representation will continue working when canonicalizing to ptradd
representation:

```
getelementptr inbounds inrange(-16, 16) (i8, ptr @vt, i64 48)
```

The inrange offsets are relative to the return value of the GEP. An
alternative design could make them relative to the source pointer
instead. The result-relative format was chosen on the off-chance that we
want to extend support to non-constant GEPs in the future, in which case
this variant is more expressive.

This implementation "upgrades" the old inrange representation in bitcode
by simply dropping it. This is a very niche feature, and I don't think
trying to upgrade it is worthwhile. Let me know if you disagree.
2024-03-20 10:59:45 +01:00
Nikita Popov
1b9a6e58a8 [CodeGenCXX] Convert some tests to opaque pointers (NFC)
Conversion done using the script at
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34.

These are tests where the conversion worked out of the box and no
manual fixup was performed.
2022-10-06 12:22:03 +02:00
Nikita Popov
532dc62b90 [OpaquePtrs][Clang] Add -no-opaque-pointers to tests (NFC)
This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.

The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.

Differential Revision: https://reviews.llvm.org/D123115
2022-04-07 12:09:47 +02:00
Fangrui Song
6b3351792c [test] Add {{.*}} to make tests immune to dso_local/dso_preemptable/(none) differences
For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie
and COFF, but not for Mach-O.  This nuance causes unneeded binary format differences.

This patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `
if there is an explicit linkage.

* Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar.
* Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
2020-12-30 20:52:01 -08:00
Peter Collingbourne
25a2b70cd0 CodeGen: Start using inrange annotations on vtable getelementptr.
This annotation allows the optimizer to split vtable groups, as permitted by
a change to the Itanium ABI [1] that prevents compilers from adjusting virtual
table pointers between virtual tables.

[1] https://github.com/MentorEmbedded/cxx-abi/pull/7

Differential Revision: https://reviews.llvm.org/D24431

llvm-svn: 289585
2016-12-13 20:50:44 +00:00
Peter Collingbourne
2849c4e841 CodeGen: New vtable group representation: struct of vtable arrays.
In a future change, this representation will allow us to use the new inrange
annotation on getelementptr to allow the optimizer to split vtable groups.

Differential Revision: https://reviews.llvm.org/D22296

llvm-svn: 289584
2016-12-13 20:40:39 +00:00
Peter Collingbourne
4e6a540024 CodeGen: Use 32-bit gep offsets to address vtable address points.
The relative vtable ABI will use a struct rather than an array as the type
of a vtable. LLVM only allows 32-bit integers as struct indices, so we need
to use 32-bit integers to get addresses of address points. In order to keep
the code simple, we might as well do that unconditionally.

It's probably a reasonable implementation limit to support no more than 2
billion virtual functions per class.

This change causes quite a bit of churn in the test suite, so I'm making
it separately.

Differential Revision: http://reviews.llvm.org/D18113

llvm-svn: 263469
2016-03-14 19:07:10 +00:00
Peter Collingbourne
0446e7cfae CodeGen: Mark functions used in vtables as unnamed_addr.
This marks virtual function declarations, as well as runtime library functions
__cxa_pure_virtual, __cxa_deleted_virtual and _purecall, as unnamed_addr. This
will allow us to correctly form relative references to them from vtables in
the relative vtable ABI.

Differential Revision: http://reviews.llvm.org/D18071

llvm-svn: 263464
2016-03-14 18:41:59 +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
Rafael Espindola
e5df59ff78 Emit DeferredDeclsToEmit in a DFS order.
Currently we emit DeferredDeclsToEmit in reverse order. This patch changes that.

The advantages of the change are that

* The output order is a bit closer to the source order. The change to
test/CodeGenCXX/pod-member-memcpys.cpp is a good example.

* If we decide to deffer more, it will not cause as large changes in the
estcases as it would without this patch.

llvm-svn: 226751
2015-01-22 00:24:57 +00:00
David Blaikie
eb7d598cec PR13684: Emit vtable entries for deleted functions as __cxa_deleted_function.
This is consistent/interoperable with GCC 4.7 (& __cxa_deleted_function isn't
present in 4.4 - not sure when it got added, but you'll need something with
that function available for this to work).

llvm-svn: 166069
2012-10-16 22:56:05 +00:00
David Blaikie
8db50561b0 Test pure virtual vtable entries in the Itanium ABI.
(original functionality committed in r99807, refactored in r160373)

llvm-svn: 166059
2012-10-16 21:03:19 +00:00
Anders Carlsson
571e2ad042 Mark VTables and RTTI data linkonce_odr instead of weak_odr, with the exception of explicit template instantiations, which have to be weak_odr.
This fixes PR6996.

llvm-svn: 124089
2011-01-24 00:46:19 +00:00
Rafael Espindola
bb7f7686c5 Set unnamed_addr in VTTs.
llvm-svn: 123280
2011-01-11 22:29:55 +00:00
Chris Lattner
369721a16e stop looking for #uses comments.
llvm-svn: 112898
2010-09-02 22:48:26 +00:00
Anders Carlsson
07894e8a0e More VTT builder fixes. With these fixes we now correctly handle the very complex VTT example from the Itanium ABI spec.
llvm-svn: 93725
2010-01-18 17:13:59 +00:00
Anders Carlsson
1af3df854f Fix a bunch of VTT layout bugs, add simple tests for VTT layout.
llvm-svn: 93709
2010-01-18 04:25:18 +00:00