llvm-project/clang/lib/CodeGen
David Majnemer 0c0b6d9ac6 MS ABI: Properly call global delete when invoking virtual destructors
Summary:
The Itanium ABI approach of using offset-to-top isn't possible with the
MS ABI, it doesn't have that kind of information lying around.

Instead, we do the following:
- Call the virtual deleting destructor with the "don't delete the object
  flag" set.  The virtual deleting destructor will return a pointer to
  'this' adjusted to the most derived class.
- Call the global delete using the adjusted 'this' pointer.

Reviewers: rnk

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D5996

llvm-svn: 220993
2014-10-31 20:09:12 +00:00
..
ABIInfo.h Fix ARM HVA classification of classes with non-virtual bases 2014-10-31 17:10:41 +00:00
BackendUtil.cpp Add a new -fmerge-functions -cc1 flag that enables function merging. 2014-10-24 00:49:29 +00:00
CGAtomic.cpp CodeGen: Don't completely mess-up optimized atomic libcalls 2014-08-29 07:27:49 +00:00
CGBlocks.cpp Fix a crash when compiling blocks in OpenCL with multiple 2014-08-14 09:37:50 +00:00
CGBlocks.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGBuilder.h typo 2014-09-10 16:59:01 +00:00
CGBuiltin.cpp Get rid of SanitizerOptions::Disabled global. NFC. 2014-10-30 19:33:44 +00:00
CGCUDANV.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-12 06:41:41 +00:00
CGCUDARuntime.cpp Pass expressions instead of argument ranges to EmitCall/EmitCXXConstructorCall. 2014-08-21 20:26:47 +00:00
CGCUDARuntime.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGCXX.cpp ignore -mconstructor-aliases when adding field paddings for asan 2014-10-31 19:01:02 +00:00
CGCXXABI.cpp MS ABI: Implement thread_local for global variables 2014-10-05 05:05:40 +00:00
CGCXXABI.h MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CGCall.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CGCall.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGClass.cpp Get rid of SanitizerOptions::Disabled global. NFC. 2014-10-30 19:33:44 +00:00
CGCleanup.cpp Revert r218865 because it introduced PR21236, a crash in codegen emitting the try block. 2014-10-10 04:05:00 +00:00
CGCleanup.h Replace a destructor of EHCleanupScope with a Destroy() method to reflect the current usage. 2014-10-08 18:31:54 +00:00
CGDebugInfo.cpp Fix 80-column and other odd formatting. 2014-10-26 23:40:33 +00:00
CGDebugInfo.h Include debug info for types referenced only via explicit cast expressions. 2014-09-24 17:01:27 +00:00
CGDecl.cpp Revert r218865 because it introduced PR21236, a crash in codegen emitting the try block. 2014-10-10 04:05:00 +00:00
CGDeclCXX.cpp SanitizerBlacklist: blacklist functions by their source location. 2014-10-17 00:20:19 +00:00
CGException.cpp CodeGen: Strip qualifiers from qualified array types in catches 2014-10-12 06:58:22 +00:00
CGExpr.cpp Get rid of SanitizerOptions::Disabled global. NFC. 2014-10-30 19:33:44 +00:00
CGExprAgg.cpp PR18097: Support initializing an _Atomic(T) from an object of C++ class type T 2014-07-31 06:31:19 +00:00
CGExprCXX.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CGExprComplex.cpp Remove CastKind typedef from CastExpr since CastKind is in the clang namespace. 2014-10-31 06:57:10 +00:00
CGExprConstant.cpp CodeGen: ConstStructBuilder must verify packed constraints after padding 2014-10-19 23:40:06 +00:00
CGExprScalar.cpp Get rid of SanitizerOptions::Disabled global. NFC. 2014-10-30 19:33:44 +00:00
CGLoopInfo.cpp Rename metadata llvm.loop.vectorize.unroll to llvm.loop.vectorize.interleave. 2014-07-21 23:10:56 +00:00
CGLoopInfo.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGObjC.cpp Objective-C. revert patch for rdar://17554063. 2014-10-28 18:28:16 +00:00
CGObjCGNU.cpp Fix some cases where StringRef was being passed by const reference. Remove const from some other StringRefs since its implicitly const already. 2014-08-30 16:55:52 +00:00
CGObjCMac.cpp Allow protocols to be just declared. 2014-09-12 20:14:20 +00:00
CGObjCRuntime.cpp Update for llvm api change. 2014-06-04 18:51:46 +00:00
CGObjCRuntime.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGOpenCLRuntime.cpp [C++11] Use 'nullptr'. CodeGen edition. 2014-05-21 05:09:00 +00:00
CGOpenCLRuntime.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGOpenMPRuntime.cpp Fix unicode chars into ascii in comment lines. 2014-10-27 08:08:18 +00:00
CGOpenMPRuntime.h [OPENMP] Codegen for 'num_threads' clause in 'parallel' directive. 2014-10-13 08:23:51 +00:00
CGRecordLayout.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGRecordLayoutBuilder.cpp CodeGen: Cleanup CGRecordLowering::lowerUnion a little 2014-10-15 16:36:11 +00:00
CGStmt.cpp Improved capturing variable-length array types in CapturedStmt. 2014-10-29 12:21:55 +00:00
CGStmtOpenMP.cpp [OPENMP] Codegen for 'private' clause in 'parallel' directive. 2014-10-21 03:16:40 +00:00
CGVTT.cpp Remove the -fhidden-weak-vtables -cc1 option. It was dead, 2014-02-08 00:41:16 +00:00
CGVTables.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CGVTables.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGValue.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CMakeLists.txt Move SanitizerBlacklist to clangBasic. NFC. 2014-10-15 19:57:45 +00:00
CodeGenABITypes.cpp Add coverage mapping generation. 2014-08-04 18:41:51 +00:00
CodeGenAction.cpp Update for LLVM API change. 2014-10-28 00:29:51 +00:00
CodeGenFunction.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CodeGenFunction.h MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
CodeGenModule.cpp [ASan] Improve blacklisting of global variables. 2014-10-17 22:37:33 +00:00
CodeGenModule.h [ASan] Improve blacklisting of global variables. 2014-10-17 22:37:33 +00:00
CodeGenPGO.cpp Reapply "InstrProf: Update for the LLVM API change in r218879" 2014-10-02 16:44:01 +00:00
CodeGenPGO.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CodeGenTBAA.cpp [C++11] Use 'nullptr'. CodeGen edition. 2014-05-21 05:09:00 +00:00
CodeGenTBAA.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CodeGenTypes.cpp MS ABI: Don't ICE for pointers to pointers to members of incomplete classes 2014-09-18 22:05:54 +00:00
CodeGenTypes.h Use ClangToLLVMArgsMapping in CodeGenTypes::GetFunctionType(). NFC. 2014-09-29 22:08:00 +00:00
CoverageMappingGen.cpp Reapply "InstrProf: Update for the LLVM API change in r218879" 2014-10-02 16:44:01 +00:00
CoverageMappingGen.h Reapply "InstrProf: Update for the LLVM API change in r218879" 2014-10-02 16:44:01 +00:00
EHScopeStack.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
ItaniumCXXABI.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
Makefile
MicrosoftCXXABI.cpp MS ABI: Properly call global delete when invoking virtual destructors 2014-10-31 20:09:12 +00:00
ModuleBuilder.cpp [modules] Fix a rejects-valid resulting from emitting an inline function 2014-08-13 21:15:09 +00:00
README.txt
SanitizerMetadata.cpp [ASan] Improve blacklisting of global variables. 2014-10-17 22:37:33 +00:00
SanitizerMetadata.h [ASan] Improve blacklisting of global variables. 2014-10-17 22:37:33 +00:00
TargetInfo.cpp Fix ARM HVA classification of classes with non-virtual bases 2014-10-31 17:10:41 +00:00
TargetInfo.h [OPENMP] Codegen of the ‘aligned’ clause for the ‘omp simd’ directive. 2014-09-30 05:29:28 +00:00

README.txt

IRgen optimization opportunities.

//===---------------------------------------------------------------------===//

The common pattern of
--
short x; // or char, etc
(x == 10)
--
generates an zext/sext of x which can easily be avoided.

//===---------------------------------------------------------------------===//

Bitfields accesses can be shifted to simplify masking and sign
extension. For example, if the bitfield width is 8 and it is
appropriately aligned then is is a lot shorter to just load the char
directly.

//===---------------------------------------------------------------------===//

It may be worth avoiding creation of alloca's for formal arguments
for the common situation where the argument is never written to or has
its address taken. The idea would be to begin generating code by using
the argument directly and if its address is taken or it is stored to
then generate the alloca and patch up the existing code.

In theory, the same optimization could be a win for block local
variables as long as the declaration dominates all statements in the
block.

NOTE: The main case we care about this for is for -O0 -g compile time
performance, and in that scenario we will need to emit the alloca
anyway currently to emit proper debug info. So this is blocked by
being able to emit debug information which refers to an LLVM
temporary, not an alloca.

//===---------------------------------------------------------------------===//

We should try and avoid generating basic blocks which only contain
jumps. At -O0, this penalizes us all the way from IRgen (malloc &
instruction overhead), all the way down through code generation and
assembly time.

On 176.gcc:expr.ll, it looks like over 12% of basic blocks are just
direct branches!

//===---------------------------------------------------------------------===//