llvm-project/clang/lib/CodeGen
Justin Bogner 3c32c83daa Revert "Generating assumption loads of vptr after ctor call (fixed)"
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http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/6382/
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/2969

This reverts r245264.

llvm-svn: 245267
2015-08-18 05:40:20 +00:00
..
ABIInfo.h [MIPS] Re-land the change r238200 to fix extension of integer types 2015-05-26 21:07:19 +00:00
BackendUtil.cpp Rangify for loops, NFC. 2015-08-01 19:11:36 +00:00
CGAtomic.cpp Add missing atomic libcall support. 2015-08-05 16:57:36 +00:00
CGBlocks.cpp Wdeprecated: ByrefHelpers are copy constructed by the ::buildByrefHelpers helper, make sure they're safely copyable 2015-08-13 23:53:09 +00:00
CGBlocks.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGBuilder.h Wdeprecated: CGBuilderInserter is copy constructed in some contexts - remove the unnecessarily disabling copy assignment to enable this 2015-08-12 23:16:55 +00:00
CGBuiltin.cpp Rename the non-coding style conformant functions in namespace Builtins 2015-08-06 01:01:12 +00:00
CGCUDANV.cpp Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGCUDARuntime.cpp Pass expressions instead of argument ranges to EmitCall/EmitCXXConstructorCall. 2014-08-21 20:26:47 +00:00
CGCUDARuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGCXX.cpp Get the dll storage class right for structors of classes exported/imported via explicit instantiation (PR23667) 2015-05-28 17:44:56 +00:00
CGCXXABI.cpp [CodeGen] Rename EmitMemberPointer to EmitMemberFunctionPointer 2015-06-23 07:31:01 +00:00
CGCXXABI.h Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
CGCall.cpp Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
CGCall.h [CodeGen] Reuse stack space from unused function results (with more accurate unused result detection) 2015-06-08 10:23:49 +00:00
CGClass.cpp Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
CGCleanup.cpp [MS ABI] Switch catchpad/cleanuppad to use tokens 2015-08-15 03:21:08 +00:00
CGCleanup.h [MS ABI] Hook clang up to the new EH instructions 2015-07-31 17:58:45 +00:00
CGDebugInfo.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CGDebugInfo.h Wdeprecated: ApplyDebugLocation is returned by value yet if it is ever copied (rather than RVO'd) that would be broken, make it movable instead 2015-08-12 23:49:57 +00:00
CGDecl.cpp Fix a case where we forgot to make a static local variable comdat 2015-07-20 20:35:30 +00:00
CGDeclCXX.cpp Avoid clearing an empty PrioritizedCXXGlobalInits, NFC 2015-06-20 15:51:52 +00:00
CGException.cpp [MS ABI] Switch catchpad/cleanuppad to use tokens 2015-08-15 03:21:08 +00:00
CGExpr.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGExprAgg.cpp Implementing C99 partial re-initialization behavior (DR-253) 2015-06-10 00:27:52 +00:00
CGExprCXX.cpp Pass an iterator range to EmitCallArgs 2015-07-21 18:37:18 +00:00
CGExprComplex.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGExprConstant.cpp [CodeGen] Rename EmitMemberPointer to EmitMemberFunctionPointer 2015-06-23 07:31:01 +00:00
CGExprScalar.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGLoopInfo.cpp Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGLoopInfo.h Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGObjC.cpp Pass an iterator range to EmitCallArgs 2015-07-21 18:37:18 +00:00
CGObjCGNU.cpp Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types 2015-05-29 19:42:19 +00:00
CGObjCMac.cpp Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGObjCRuntime.cpp Rely on default zero-arg value for IRBuilder::CreateCall calls to zero-arg functions 2015-07-14 17:27:39 +00:00
CGObjCRuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGOpenCLRuntime.cpp [C++11] Use 'nullptr'. CodeGen edition. 2014-05-21 05:09:00 +00:00
CGOpenCLRuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGOpenMPRuntime.cpp Propagate SourceLocations through to get a Loc on float_cast_overflow 2015-08-11 04:19:28 +00:00
CGOpenMPRuntime.h [OPENMP 4.0] Codegen for 'omp cancel' directive. 2015-07-06 05:50:32 +00:00
CGRecordLayout.h Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGRecordLayoutBuilder.cpp Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGStmt.cpp Use CGLoopInfo to emit metadata for loop hint pragmas. 2015-07-27 20:10:20 +00:00
CGStmtOpenMP.cpp [OPENMP] Fix for http://llvm.org/PR24371: Assert failure compiling blender 2.75. 2015-08-14 12:25:37 +00:00
CGVTT.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CGVTables.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CGVTables.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CGValue.h [opaque pointer type] Update for GEP API changes in LLVM 2015-04-02 18:55:21 +00:00
CMakeLists.txt [CMake] Fill up required libs, corresponding to r241653. 2015-07-08 02:06:21 +00:00
CodeGenABITypes.cpp LLVM API Change: the Module always owns the DataLayout 2015-07-24 16:04:29 +00:00
CodeGenAction.cpp Print vectorization analysis when loop hint is specified. 2015-08-11 01:10:08 +00:00
CodeGenFunction.cpp [MS ABI] Hook clang up to the new EH instructions 2015-07-31 17:58:45 +00:00
CodeGenFunction.h Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
CodeGenModule.cpp Avoid iteration invalidation issues around MaterializedTemporaryExpr 2015-08-13 23:50:15 +00:00
CodeGenModule.h Wdeprecated: ByrefHelpers are copy constructed by the ::buildByrefHelpers helper, make sure they're safely copyable 2015-08-13 23:53:09 +00:00
CodeGenPGO.cpp Switch users of the 'for (StmtRange range = stmt->children(); range; ++range)‘ pattern to range for loops. 2015-07-02 21:03:14 +00:00
CodeGenPGO.h InstrProf: Cede ownership of createProfileWeights to CGF 2015-05-02 05:00:55 +00:00
CodeGenTBAA.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CodeGenTBAA.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CodeGenTypes.cpp LLVM API Change: the Module always owns the DataLayout 2015-07-24 16:04:29 +00:00
CodeGenTypes.h Remove superfluous private:, TypeCache is private by default. 2015-08-13 07:12:03 +00:00
CoverageMappingGen.cpp Use llvm::reverse to make a bunch of loops use foreach. NFC. 2015-07-30 17:22:52 +00:00
CoverageMappingGen.h [cleanup] Re-sort *all* #include lines with llvm/utils/sort_includes.py 2015-01-14 11:29:14 +00:00
EHScopeStack.h [MS ABI] Hook clang up to the new EH instructions 2015-07-31 17:58:45 +00:00
ItaniumCXXABI.cpp Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
Makefile
MicrosoftCXXABI.cpp Revert "Generating assumption loads of vptr after ctor call (fixed)" 2015-08-18 05:40:20 +00:00
ModuleBuilder.cpp Rename DescriptionString -> DataLayoutString as it matches the actual 2015-08-05 23:48:05 +00:00
ObjectFilePCHContainerOperations.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
README.txt
SanitizerMetadata.cpp [ASan] Initial support for Kernel AddressSanitizer 2015-06-19 12:19:07 +00:00
SanitizerMetadata.h Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition. 2015-02-15 22:54:08 +00:00
TargetInfo.cpp Remove raw_svector_ostream::resync and users. It's no-op after r244870. 2015-08-13 12:42:25 +00:00
TargetInfo.h [OPENMP] Introduced type trait "__builtin_omp_required_simd_align" for default simd alignment. 2015-07-02 03:40:19 +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!

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