llvm-project/clang/lib/CodeGen
Atmn Patel ac73b73c16 [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction
Since C++11, the C++ standard has a forward progress guarantee
[intro.progress], so all such functions must have the `mustprogress`
requirement. In addition, from C11 and onwards, loops without a non-zero
constant conditional or no conditional are also required to make
progress (C11 6.8.5p6). This patch implements these attribute deductions
so they can be used by the optimization passes.

Differential Revision: https://reviews.llvm.org/D86841
2020-11-04 22:03:14 -05:00
..
ABIInfo.h [ABI][NFC] Fix the confusion of ByVal and ByRef argument names 2020-08-06 15:20:18 +03:00
Address.h
BackendUtil.cpp Reland [NewPM] Add OptimizationLevel param to registerPipelineStartEPCallback 2020-11-04 13:11:40 -08:00
CGAtomic.cpp [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
CGBlocks.cpp [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
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 [Clang] Add more fp128 math library function builtins 2020-11-04 17:58:42 +08:00
CGCUDANV.cpp [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
CGCUDARuntime.cpp
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 [clang] Enable support for #pragma STDC FENV_ACCESS 2020-10-25 06:46:25 -07:00
CGCall.h [CodeGen] Emit destructor calls to destruct non-trivial C struct objects 2020-03-20 18:34:22 -07:00
CGClass.cpp [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
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 Recommit "[CodeView] Emit static data members as S_CONSTANTs." 2020-10-28 16:35:59 -07:00
CGDebugInfo.h [Clang] implement -fno-eliminate-unused-debug-types 2020-08-10 15:08:48 -07:00
CGDecl.cpp [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as 2020-10-21 13:21:41 -07:00
CGDeclCXX.cpp Re-land [DebugInfo] Add debug location to stubs generated by CGDeclCXX and mark them as artificial 2020-10-08 20:49:17 -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 [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as 2020-10-21 13:21:41 -07:00
CGExprAgg.cpp [CodeGen] Emit destructor calls to destruct non-trivial C struct 2020-10-23 14:46:17 -07:00
CGExprCXX.cpp [FE] Use preferred alignment instead of ABI alignment for complete object when applicable 2020-09-30 10:48:28 -04:00
CGExprComplex.cpp [Fixed Point] Add fixed-point to floating point cast types and consteval. 2020-10-13 13:26:56 +02:00
CGExprConstant.cpp [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as 2020-10-21 13:21:41 -07:00
CGExprScalar.cpp [darwin] add support for __isPlatformVersionAtLeast check for if (@available) 2020-11-02 16:28:09 -08:00
CGGPUBuiltin.cpp [Alignment][NFC] Use Align with CreateAlignedStore 2020-01-23 17:34:32 +01:00
CGLoopInfo.cpp [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction 2020-11-04 22:03:14 -05:00
CGLoopInfo.h [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction 2020-11-04 22:03:14 -05:00
CGNonTrivialStruct.cpp [NFC] Silence compiler warning [-Wmissing-braces]. 2020-06-17 13:01:53 -07:00
CGObjC.cpp [darwin] add support for __isPlatformVersionAtLeast check for if (@available) 2020-11-02 16:28:09 -08:00
CGObjCGNU.cpp [clang] Implement objc_non_runtime_protocol to remove protocol metadata 2020-10-02 17:35:50 -04:00
CGObjCMac.cpp [clang] Implement objc_non_runtime_protocol to remove protocol metadata 2020-10-02 17:35:50 -04:00
CGObjCRuntime.cpp Fix a variety of minor issues with ObjC method mangling: 2020-09-29 19:51:53 -04:00
CGObjCRuntime.h [clang] Implement objc_non_runtime_protocol to remove protocol metadata 2020-10-02 17:35:50 -04:00
CGOpenCLRuntime.cpp Fix "pointer is null" static analyzer warning. NFCI. 2020-01-08 17:19:08 +00:00
CGOpenCLRuntime.h
CGOpenMPRuntime.cpp [OpenMP] target nested `use_device_ptr() if()` and is_device_ptr trigger asserts 2020-11-04 12:36:57 -06:00
CGOpenMPRuntime.h [OpenMP] target nested `use_device_ptr() if()` and is_device_ptr trigger asserts 2020-11-04 12:36:57 -06:00
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 [AMDGPU] Add gfx1033 target 2020-11-03 16:27:48 +00:00
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 [ARM] Follow AACPS standard for volatile bit-fields access width 2020-10-13 10:31:48 +01:00
CGRecordLayoutBuilder.cpp [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
CGStmt.cpp [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction 2020-11-04 22:03:14 -05:00
CGStmtOpenMP.cpp [Clang][OpenMP] Avoid unnecessary privatization of mapper array when there is no user defined mapper 2020-10-27 00:02:32 -04:00
CGVTT.cpp
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 [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair. 2020-10-13 13:26:56 +02:00
CMakeLists.txt Remove dependency on clangASTMatchers. 2020-09-10 22:17:48 -04:00
CodeGenABITypes.cpp [CodeGen] Add public function to emit C++ destructor call. 2020-07-01 11:01:23 -07:00
CodeGenAction.cpp clang/CodeGen: Stop using SourceManager::getBuffer, NFC 2020-10-14 23:32:43 -04:00
CodeGenFunction.cpp [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction 2020-11-04 22:03:14 -05:00
CodeGenFunction.h [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction 2020-11-04 22:03:14 -05:00
CodeGenModule.cpp Fix - [Clang] Add the ability to map DLL storage class to visibility 2020-11-03 19:13:54 +00:00
CodeGenModule.h [darwin] add support for __isPlatformVersionAtLeast check for if (@available) 2020-11-02 16:28:09 -08:00
CodeGenPGO.cpp Revert "Use uint64_t for branch weights instead of uint32_t" 2020-10-31 00:25:32 -07:00
CodeGenPGO.h [NFC] Make non-modifying members const. 2020-10-18 18:50:21 +02:00
CodeGenTBAA.cpp Reland Implement _ExtInt as an extended int type specifier. 2020-04-17 10:45:48 -07:00
CodeGenTBAA.h
CodeGenTypeCache.h [ARM] Add __bf16 as new Bfloat16 C Type 2020-06-05 10:32:43 +01:00
CodeGenTypes.cpp [Clang][PowerPC] Add __vector_pair and __vector_quad types 2020-10-28 13:19:20 -05:00
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 [Coverage] Add empty line regions to SkippedRegions 2020-09-21 12:42:53 -07:00
CoverageMappingGen.h [Coverage] Add empty line regions to SkippedRegions 2020-09-21 12:42:53 -07:00
EHScopeStack.h [CodeGen] Simplify the way lifetime of block captures is extended 2020-06-11 16:06:22 -07:00
ItaniumCXXABI.cpp [Clang][PowerPC] Add __vector_pair and __vector_quad types 2020-10-28 13:19:20 -05:00
MacroPPCallbacks.cpp
MacroPPCallbacks.h
MicrosoftCXXABI.cpp [MS] Apply `inreg` to AArch64 sret parms on instance methods 2020-10-15 14:54:42 -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 [SVE] Add fatal error for unnamed SVE variadic arguments 2020-10-30 13:35:47 +00:00
TargetInfo.h [CodeGen][ObjC] Mark calls to objc_unsafeClaimAutoreleasedReturnValue as 2020-08-03 13:25:25 -07:00
VarBypassDetector.cpp
VarBypassDetector.h

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!

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