llvm-project/clang
Andrea Di Biagio e7347c67cd [x86-64 ABI] Fix for PR23082: an assertion failure when passing/returning a wrapper union in a full YMM register.
This patch fixes an assertion failure in method
'X86_64ABIInfo::GetByteVectorType'.

Method 'GetByteVectorType' (in TargetInfo.cpp) is responsible
for mapping a QualType 'Ty' (for an argument or return value) to an LLVM IR
type that, according to the ABI, must be passed in a XMM/YMM vector register.

When selecting the IR vector type, method 'GetByteVectorType' always tries to
choose the "best" IR vector type for the 'Ty' in input. In particular, if Ty
is a wrapper structure, it keeps unwrapping it until it finds a vector type VTy.
That VTy is the "preferred IR type".

However, function 'isSingleElementStructure' (used to unwrap structures) does
not know how to look through union types. So, before this patch, if Ty was in
a nest of wrapper structures with at least two union types, we would have
triggered an assertion failure (added at revision 230971).

With this patch, if method 'GetByteVectorType' fails to find the preferred
vector type, we just return a valid (although potentially 'less friendly')
vector type based on the type size. So, rather than asserting on an 'unexpected'
'Ty' in input, we conservatively return vector type <2 x double> if Ty is 16
bytes, or <4 x double> if Ty is 32 bytes.

Differential Revision: http://reviews.llvm.org/D10190

llvm-svn: 238861
2015-06-02 19:34:40 +00:00
..
INPUTS
bindings [libclang] Add functions to get information about fields. 2015-04-13 16:55:04 +00:00
cmake/modules Make it easier to build against a pre-built Clang package with CMake 2014-11-05 23:14:59 +00:00
docs Improve user documentation on profiling. 2015-05-28 21:30:04 +00:00
examples Don't leak TemplateIds when a plugin parses late-parsed templates at TU end. 2015-05-17 01:07:16 +00:00
include add the -mrecip driver flag and process its options (2nd try) 2015-06-02 16:55:12 +00:00
lib [x86-64 ABI] Fix for PR23082: an assertion failure when passing/returning a wrapper union in a full YMM register. 2015-06-02 19:34:40 +00:00
runtime [UBSan] Use shared library for UBSan on OS X (Clang part). 2015-03-23 23:14:05 +00:00
test [x86-64 ABI] Fix for PR23082: an assertion failure when passing/returning a wrapper union in a full YMM register. 2015-06-02 19:34:40 +00:00
tools Make vim also output a helpful message in some error cases. 2015-06-02 12:01:50 +00:00
unittests clang-format: Don't try to detect C++ lambdas in other languages. 2015-06-02 15:31:37 +00:00
utils Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types 2015-05-29 19:42:19 +00:00
www "This adds -fconcepts-ts as a cc1 option for enabling the 2015-05-22 01:11:10 +00:00
.arcconfig
.clang-format
.clang-tidy Enable display of compiler diagnostics in clang-tidy. 2014-10-29 17:28:51 +00:00
.gitignore
CMakeLists.txt clang/CMakeLists.txt: s/LLVM_INSTALL_PACKAGE_DIR/CLANG_INSTALL_PACKAGE_DIR/ for the standalone configuration. 2015-05-29 22:58:05 +00:00
CODE_OWNERS.TXT List Alexey Bataev as code owner for Clang's OpenMP support, as discussed offline. 2015-05-12 20:29:41 +00:00
INSTALL.txt
LICENSE.TXT Update copyright year to 2015. 2015-03-12 01:36:10 +00:00
Makefile
ModuleInfo.txt
NOTES.txt
README.txt Reverting test commit. 2015-04-10 08:43:58 +00:00

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source-level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:              http://clang.llvm.org/
Building and using Clang:          http://clang.llvm.org/get_started.html
Clang Static Analyzer:             http://clang-analyzer.llvm.org/
Information on the LLVM project:   http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/