llvm-project/clang/lib/CodeGen
Mark de Wever 08196e0b2e Implements [[likely]] and [[unlikely]] in IfStmt.
This is the initial part of the implementation of the C++20 likelihood
attributes. It handles the attributes in an if statement.

Differential Revision: https://reviews.llvm.org/D85091
2020-09-09 20:48:37 +02:00
..
ABIInfo.h [ABI][NFC] Fix the confusion of ByVal and ByRef argument names 2020-08-06 15:20:18 +03:00
Address.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
BackendUtil.cpp [gcov] Increment counters with atomicrmw if -fsanitize=thread 2020-08-28 16:32:35 -07:00
CGAtomic.cpp [SVE] Remove calls to VectorType::getNumElements from clang 2020-08-26 11:12:26 -07:00
CGBlocks.cpp [CodeGen] Simplify the way lifetime of block captures is extended 2020-06-11 16:06:22 -07:00
CGBlocks.h [CodeGen] Simplify the way lifetime of block captures is extended 2020-06-11 16:06:22 -07:00
CGBuilder.h Reapply "[IRBuilder] Virtualize IRBuilder" 2020-02-17 19:04:11 +01:00
CGBuiltin.cpp [PowerPC] Fix STRICT_FRINT/STRICT_FNEARBYINT lowering 2020-09-09 22:40:58 +08:00
CGCUDANV.cpp [HIP] Fix rocm detection 2020-07-10 23:20:15 -04:00
CGCUDARuntime.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGCUDARuntime.h Fix GCC warning on enum class bitfield. NFC. 2020-03-28 10:20:34 -04:00
CGCXX.cpp [Alignment][NFC] Use Align with CreateAlignedLoad 2020-01-27 10:58:36 +01:00
CGCXXABI.cpp Fix build error 2020-07-10 17:40:37 -07:00
CGCXXABI.h [CodeGen] Add public function to emit C++ destructor call. 2020-07-01 11:01:23 -07:00
CGCall.cpp Reland "[CodeGen][AArch64] Support arm_sve_vector_bits attribute" 2020-08-28 15:57:09 +00:00
CGCall.h [CodeGen] Emit destructor calls to destruct non-trivial C struct objects 2020-03-20 18:34:22 -07:00
CGClass.cpp [clang/llvm] As part of using inclusive language within 2020-06-20 16:03:58 -07:00
CGCleanup.cpp [CodeGen] Simplify the way lifetime of block captures is extended 2020-06-11 16:06:22 -07:00
CGCleanup.h Remove clang::Codegen::EHPadEndScope as unused 2020-06-23 15:18:49 -07:00
CGCoroutine.cpp [Coroutines] Do not evaluate InitListExpr of a co_return 2020-03-16 12:42:44 +08:00
CGDebugInfo.cpp [DebugInfo] Add size to class declarations in debug info. 2020-09-03 15:42:27 -07:00
CGDebugInfo.h [Clang] implement -fno-eliminate-unused-debug-types 2020-08-10 15:08:48 -07:00
CGDecl.cpp [CodeGen] Make sure the EH cleanup for block captures is conditional when the block literal is in a conditional context 2020-08-31 10:12:17 -04:00
CGDeclCXX.cpp [AIX] Static init frontend recovery and backend support 2020-08-10 10:10:49 -04:00
CGException.cpp [Windows SEH] Fix the frame-ptr of a nested-filter within a _finally 2020-07-12 01:37:56 -07:00
CGExpr.cpp Revert "[ARM] Follow AACPS standard for volatile bit-fields access width" 2020-09-08 18:46:27 +01:00
CGExprAgg.cpp attempt to fix failing buildbots after 3bab88b7ba 2020-06-15 12:58:37 +02:00
CGExprCXX.cpp [Ignore Expressions][NFC] Refactor to better use `IgnoreExpr.h` and nits 2020-09-07 09:32:30 +00:00
CGExprComplex.cpp [clang][NFC] Store a pointer to the ASTContext in ASTDumper and TextNodeDumper 2020-07-03 13:59:22 +01:00
CGExprConstant.cpp [c++20] consteval functions don't get vtable slots. 2020-06-30 18:22:09 -07:00
CGExprScalar.cpp Reland "[CodeGen][AArch64] Support arm_sve_vector_bits attribute" 2020-08-28 15:57:09 +00:00
CGGPUBuiltin.cpp [Alignment][NFC] Use Align with CreateAlignedStore 2020-01-23 17:34:32 +01:00
CGLoopInfo.cpp [Clang] Add llvm.loop.unroll.disable to loops with -fno-unroll-loops. 2020-04-07 14:01:55 +01:00
CGLoopInfo.h [Clang] Add llvm.loop.unroll.disable to loops with -fno-unroll-loops. 2020-04-07 14:01:55 +01:00
CGNonTrivialStruct.cpp [NFC] Silence compiler warning [-Wmissing-braces]. 2020-06-17 13:01:53 -07:00
CGObjC.cpp [CodeGen][ObjC] Mark calls to objc_unsafeClaimAutoreleasedReturnValue as 2020-08-03 13:25:25 -07:00
CGObjCGNU.cpp [NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec. 2020-04-23 17:21:25 -04:00
CGObjCMac.cpp [SystemZ/ZOS] Add binary format goff and operating system zos to the triple 2020-08-11 05:26:26 -04:00
CGObjCRuntime.cpp [clang] CodeGen: Make getOrEmitProtocol public for Swift 2020-04-01 08:55:56 -07:00
CGObjCRuntime.h [clang] CodeGen: Make getOrEmitProtocol public for Swift 2020-04-01 08:55:56 -07:00
CGOpenCLRuntime.cpp Fix "pointer is null" static analyzer warning. NFCI. 2020-01-08 17:19:08 +00:00
CGOpenCLRuntime.h [OpenCL] Simplify LLVM IR generated for OpenCL blocks 2019-02-21 11:02:10 +00:00
CGOpenMPRuntime.cpp [OPENMP] Fix PR47063: crash when trying to get captured statetment. 2020-08-12 12:05:58 -04:00
CGOpenMPRuntime.h [OPENMP]Fix PR37671: Privatize local(private) variables in untied tasks. 2020-08-12 11:28:19 -04:00
CGOpenMPRuntimeAMDGCN.cpp [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CGOpenMPRuntimeAMDGCN.h [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CGOpenMPRuntimeGPU.cpp [OpenMP][FIX] Do not use TBAA in type punning reduction GPU code PR46156 2020-08-16 14:38:31 -05:00
CGOpenMPRuntimeGPU.h [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CGOpenMPRuntimeNVPTX.cpp [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CGOpenMPRuntimeNVPTX.h [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CGRecordLayout.h Revert "[ARM] Follow AACPS standard for volatile bit-fields access width" 2020-09-08 18:46:27 +01:00
CGRecordLayoutBuilder.cpp Revert "[ARM] Follow AACPS standard for volatile bit-fields access width" 2020-09-08 18:46:27 +01:00
CGStmt.cpp Implements [[likely]] and [[unlikely]] in IfStmt. 2020-09-09 20:48:37 +02:00
CGStmtOpenMP.cpp [OpenMP] Fix typo in CodeGenFunction::EmitOMPWorksharingLoop (PR46412) 2020-09-08 11:59:38 +01:00
CGVTT.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGVTables.cpp [CodeGen] Store the return value of the target function call to the 2020-07-10 17:24:13 -07:00
CGVTables.h [clang] Frontend components for the relative vtables ABI (round 2) 2020-06-11 11:17:08 -07:00
CGValue.h [Matrix] Implement matrix index expressions ([][]). 2020-06-01 20:08:49 +01:00
CMakeLists.txt [OpenMP][AMDGCN] Support OpenMP offloading for AMDGCN architecture - Part 3 2020-08-03 05:38:39 +00:00
CodeGenABITypes.cpp [CodeGen] Add public function to emit C++ destructor call. 2020-07-01 11:01:23 -07:00
CodeGenAction.cpp Reland [Coverage] Add comment to skipped regions 2020-07-28 13:20:57 -07:00
CodeGenFunction.cpp Implements [[likely]] and [[unlikely]] in IfStmt. 2020-09-09 20:48:37 +02:00
CodeGenFunction.h Implements [[likely]] and [[unlikely]] in IfStmt. 2020-09-09 20:48:37 +02:00
CodeGenModule.cpp Fix a -Wparenthesis warning in 8ff44e644b, NFC 2020-09-02 15:01:54 -04:00
CodeGenModule.h [AIX] Static init frontend recovery and backend support 2020-08-10 10:10:49 -04:00
CodeGenPGO.cpp [PGO][CUDA][HIP] Skip generating profile on the device stub and wrong-side functions. 2020-08-10 11:01:46 -04:00
CodeGenPGO.h [CodeGenPGO] Fix shadow variable warning. NFC. 2020-03-02 15:06:34 +00:00
CodeGenTBAA.cpp Reland Implement _ExtInt as an extended int type specifier. 2020-04-17 10:45:48 -07:00
CodeGenTBAA.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CodeGenTypeCache.h [ARM] Add __bf16 as new Bfloat16 C Type 2020-06-05 10:32:43 +01:00
CodeGenTypes.cpp [SVE] Make ElementCount members private 2020-08-28 14:43:53 +01:00
CodeGenTypes.h CodeGenTypes::CGRecordLayouts: Use unique_ptr to simplify memory management 2020-04-28 22:31:16 -07:00
ConstantEmitter.h attempt to fix failing buildbots after 3bab88b7ba 2020-06-15 12:58:37 +02:00
ConstantInitBuilder.cpp Fix ConstantAggregateBuilderBase::getRelativeOffset 2020-06-15 12:23:20 -07:00
CoverageMappingGen.cpp Revert "[Coverage] Enable emitting gap area between macros" 2020-08-25 15:28:42 -07:00
CoverageMappingGen.h Reland [Coverage] Add comment to skipped regions 2020-07-28 13:20:57 -07:00
EHScopeStack.h [CodeGen] Simplify the way lifetime of block captures is extended 2020-06-11 16:06:22 -07:00
ItaniumCXXABI.cpp [AIX] Static init frontend recovery and backend support 2020-08-10 10:10:49 -04:00
MacroPPCallbacks.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
MacroPPCallbacks.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
MicrosoftCXXABI.cpp [CodeGen] Add public function to emit C++ destructor call. 2020-07-01 11:01:23 -07:00
ModuleBuilder.cpp reland "[DebugInfo] Support to emit debugInfo for extern variables" 2019-12-22 18:28:50 -08:00
ObjectFilePCHContainerOperations.cpp Reland "Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)" 2020-08-24 14:52:53 +02:00
PatternInit.cpp Clean up usages of asserting vector getters in Type 2020-04-13 13:01:40 -07:00
PatternInit.h Variable auto-init: also auto-init alloca 2019-04-12 00:11:27 +00:00
README.txt
SanitizerMetadata.cpp [Analysis/Transforms/Sanitizers] As part of using inclusive language 2020-06-20 00:42:26 -07:00
SanitizerMetadata.h [Analysis/Transforms/Sanitizers] As part of using inclusive language 2020-06-20 00:42:26 -07:00
SwiftCallingConv.cpp Teach the swift calling convention about _Atomic types 2020-08-31 07:07:25 -07:00
TargetInfo.cpp Revert "[HIP] Change default --gpu-max-threads-per-block value to 1024" 2020-09-02 16:12:28 -04:00
TargetInfo.h [CodeGen][ObjC] Mark calls to objc_unsafeClaimAutoreleasedReturnValue as 2020-08-03 13:25:25 -07:00
VarBypassDetector.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
VarBypassDetector.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +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!

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