llvm-project/clang/lib/CodeGen
Itay Bookstein 9efce0baee [clang] Run LLVM Verifier in modes without CodeGen too
Previously, the Backend_Emit{Nothing,BC,LL} modes did
not run the LLVM verifier since it is usually added via
the TargetMachine::addPassesToEmitFile method according
to the DisableVerify parameter. This is called from
EmitAssemblyHelper::AddEmitPasses, which is only relevant
for BackendAction-s that require CodeGen.

Note:
* In these particular situations the verifier is added
  to the optimization pipeline rather than the codegen
  pipeline so that it runs prior to the BC/LL emission
  pass.
* This change applies to both the old and the new PMs.
* Because the clang tests use -emit-llvm ubiquitously,
  this change will enable the verifier for them.
* A small bug is fixed in emitIFuncDefinition so that
  the clang/test/CodeGen/ifunc.c test would pass:
  the emitIFuncDefinition incorrectly passed the
  GlobalDecl of the IFunc itself to the call to
  GetOrCreateLLVMFunction for creating the resolver.

Signed-off-by: Itay Bookstein <ibookstein@gmail.com>

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D113352
2021-11-09 23:57:13 +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
BackendUtil.cpp [clang] Run LLVM Verifier in modes without CodeGen too 2021-11-09 23:57:13 +02:00
CGAtomic.cpp [clang][compiler-rt][atomics] Add `__c11_atomic_fetch_nand` builtin and support `__atomic_fetch_nand` libcall 2021-10-28 02:18:43 +00:00
CGBlocks.cpp Reland [IR] Increase max alignment to 4GB 2021-10-06 13:29:23 -07:00
CGBlocks.h
CGBuilder.h [OpaquePtr] Remove uses of CreateGEP() without element type 2021-07-17 22:56:27 +02:00
CGBuiltin.cpp Revert "[OpenMP] Lower printf to __llvm_omp_vprintf" 2021-11-08 20:28:57 +00:00
CGCUDANV.cpp [IR] Merge createReplacementInstr into ConstantExpr::getAsInstruction 2021-10-29 15:02:58 +01:00
CGCUDARuntime.cpp
CGCUDARuntime.h [HIP] Emit kernel symbol 2021-03-01 16:31:40 -05:00
CGCXX.cpp [OpaquePtr] Remove uses of CGF.Builder.CreateConstInBoundsGEP1_64() without type 2021-07-17 17:07:46 +02:00
CGCXXABI.cpp Fix PR35902: incorrect alignment used for ubsan check. 2020-12-28 18:11:17 -05:00
CGCXXABI.h [clang][aarch64] Precondition isHomogeneousAggregate on isCXX14Aggregate 2021-01-12 19:44:01 +00:00
CGCall.cpp Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default" 2021-11-09 02:15:55 +09:00
CGCall.h Replace `T(x)` with `reinterpret_cast<T>(x)` everywhere it means reinterpret_cast. NFC. 2020-12-22 19:54:29 -05:00
CGClass.cpp Don't update the vptr at the start of the destructor of a final class. 2021-10-08 19:59:42 -07:00
CGCleanup.cpp [Windows SEH]: Fix -O2 crash for Windows -EHa 2021-06-04 14:07:44 -07:00
CGCleanup.h [XCOFF][AIX] Generate LSDA data and compact unwind section on AIX 2020-12-02 18:42:44 +00:00
CGCoroutine.cpp Revert "[Coroutines] Set presplit attribute in Clang instead of CoroEarly pass" 2021-04-18 17:22:28 -07:00
CGDebugInfo.cpp [Clang][Attr] fix a btf_type_attr CGDebugInfo codegen bug 2021-11-06 18:19:00 -07:00
CGDebugInfo.h Reland "[Attr] support btf_type_tag attribute" 2021-11-05 11:25:17 -07:00
CGDecl.cpp In spir functions, llvm.dbg.declare intrinsics created 2021-11-05 15:08:09 -07:00
CGDeclCXX.cpp PR48030: Fix COMDAT-related linking problem with C++ thread_local static data members. 2021-08-24 19:53:44 -07:00
CGException.cpp [WebAssembly] Warn on exception spec for Emscripten EH 2021-05-20 13:00:20 -07:00
CGExpr.cpp [clang] Use llvm::reverse. NFCI. 2021-11-07 14:24:33 +01:00
CGExprAgg.cpp No longer crash when a consteval function returns a structure 2021-11-04 09:41:10 -04:00
CGExprCXX.cpp [clang] don't mark as Elidable CXXConstruct expressions used in NRVO 2021-09-21 21:41:20 +02:00
CGExprComplex.cpp [Matrix] Implement C-style explicit type conversions for matrix types. 2021-04-10 11:48:41 +01:00
CGExprConstant.cpp PR52183: Don't emit code for a void-typed constant expression. 2021-10-14 20:55:51 -07:00
CGExprScalar.cpp PR52183: Don't emit code for a void-typed constant expression. 2021-10-14 20:55:51 -07:00
CGGPUBuiltin.cpp Revert "[OpenMP] Lower printf to __llvm_omp_vprintf" 2021-11-08 20:28:57 +00:00
CGLoopInfo.cpp [Clang] Ensure vector predication loop metadata is always emitted when pragma is specified. 2021-02-13 17:35:54 -06:00
CGLoopInfo.h [SVE] Add support to vectorize_width loop pragma for scalable vectors 2021-01-08 11:37:27 +00:00
CGNonTrivialStruct.cpp [CodeGen] Stop creating fake FunctionDecls when generating IR for 2021-06-29 14:22:33 -07:00
CGObjC.cpp [ObjC][ARC] Use operand bundle "clang.arc.attachedcall" on x86-64 2021-11-08 18:38:40 -08:00
CGObjCGNU.cpp Fix a variety of bugs with nil-receiver checks when targeting 2021-10-08 05:44:06 -04:00
CGObjCMac.cpp [clang] Add range accessor for ObjCAtTryStmt catch_stmts and use it 2021-10-27 08:57:05 -04:00
CGObjCRuntime.cpp [clang] Add range accessor for ObjCAtTryStmt catch_stmts and use it 2021-10-27 08:57:05 -04:00
CGObjCRuntime.h Fix a variety of bugs with nil-receiver checks when targeting 2021-10-08 05:44:06 -04:00
CGOpenCLRuntime.cpp
CGOpenCLRuntime.h
CGOpenMPRuntime.cpp Use {DenseSet,SetVector,SmallPtrSet}::contains (NFC) 2021-10-30 19:00:19 -07:00
CGOpenMPRuntime.h [OpenMP] Introduce a new worksharing RTL function for distribute 2021-09-27 11:36:37 -04:00
CGOpenMPRuntimeGPU.cpp [clang][openmp][NFC] Remove arch-specific CGOpenMPRuntimeGPU files 2021-11-09 15:11:05 -05:00
CGOpenMPRuntimeGPU.h [clang][openmp][NFC] Remove arch-specific CGOpenMPRuntimeGPU files 2021-11-09 15:11:05 -05:00
CGRecordLayout.h [ARM] Follow AACPS standard for volatile bit-fields access width 2020-10-13 10:31:48 +01:00
CGRecordLayoutBuilder.cpp [CodeGen] Use getCharWidth() more consistently in CGRecordLowering. NFC 2021-01-22 21:12:17 +01:00
CGStmt.cpp [OpenMP] Initial parsing/sema for the 'omp loop' construct 2021-10-28 08:26:43 -07:00
CGStmtOpenMP.cpp Initial parsing/sema for 'align' clause 2021-11-09 07:34:18 -05:00
CGVTT.cpp [AMDGPU] Set the default globals address space to 1 2020-11-20 15:46:53 +00:00
CGVTables.cpp [clang] Use llvm::{count,count_if,find_if,all_of,none_of} (NFC) 2021-10-25 09:14:45 -07:00
CGVTables.h
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 [clang][openmp][NFC] Remove arch-specific CGOpenMPRuntimeGPU files 2021-11-09 15:11:05 -05:00
CodeGenABITypes.cpp
CodeGenAction.cpp [clang] Add option to disable -clear-ast-before-backend 2021-10-19 20:51:48 -07:00
CodeGenFunction.cpp Fix inline builtin handling in case of redefinition 2021-11-02 09:53:49 +01:00
CodeGenFunction.h Revert "[OpenMP] Lower printf to __llvm_omp_vprintf" 2021-11-08 20:28:57 +00:00
CodeGenModule.cpp [clang] Run LLVM Verifier in modes without CodeGen too 2021-11-09 23:57:13 +02:00
CodeGenModule.h [OpenMP] Apply OpenMP assumptions to applicable call sites 2021-09-29 16:08:21 -04:00
CodeGenPGO.cpp Implement if consteval (P1938) 2021-10-05 08:04:14 -04:00
CodeGenPGO.h [PGO] Don't reference functions unless value profiling is enabled 2021-05-20 11:09:24 -07:00
CodeGenTBAA.cpp
CodeGenTBAA.h
CodeGenTypeCache.h Fix __attribute__((annotate("")) with non-zero globals AS 2021-08-26 10:09:40 +01:00
CodeGenTypes.cpp [Clang] Add __ibm128 type to represent ppc_fp128 2021-09-06 18:00:58 +08:00
CodeGenTypes.h
ConstantEmitter.h
ConstantInitBuilder.cpp
CoverageMappingGen.cpp Use llvm::any_of and llvm::none_of (NFC) 2021-10-24 17:35:33 -07:00
CoverageMappingGen.h [Driver] Rename -fprofile-{prefix-map,compilation-dir} to -fcoverage-{prefix-map,compilation-dir} 2021-02-25 21:40:12 -08:00
EHScopeStack.h [Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 1 2021-05-17 22:42:17 -07:00
ItaniumCXXABI.cpp PR51079: Treat thread_local variables with an incomplete class type as 2021-10-08 18:46:01 -07:00
MacroPPCallbacks.cpp
MacroPPCallbacks.h
MicrosoftCXXABI.cpp [clang] Use llvm::{count,count_if,find_if,all_of,none_of} (NFC) 2021-10-25 09:14:45 -07:00
ModuleBuilder.cpp [clang/Basic] Make TargetInfo.h not use DataLayout again 2021-04-27 22:26:10 -04:00
ObjectFilePCHContainerOperations.cpp [WebAssembly] Emit clangast in custom section aligned by 4 bytes 2021-10-19 15:50:08 -07:00
PatternInit.cpp
PatternInit.h
README.txt Revert "This is a test commit" 2020-12-23 13:04:37 -06:00
SanitizerMetadata.cpp [clang][patch] Inclusive language, modify filename SanitizerBlacklist.h to NoSanitizeList.h 2021-02-22 15:11:37 -05:00
SanitizerMetadata.h
SwiftCallingConv.cpp Teach the swift calling convention about _Atomic types 2020-08-31 07:07:25 -07:00
TargetInfo.cpp [SPIR-V] Add SPIR-V triple and clang target info. 2021-11-08 13:34:10 +00:00
TargetInfo.h [Clang][AArch64] Inline assembly support for the ACLE type 'data512_t' 2021-07-31 09:51:28 +01:00
VarBypassDetector.cpp [clang,NFC] Fix typos in file headers 2021-02-25 12:47:02 -08:00
VarBypassDetector.h Use {DenseSet,SmallPtrSet}::contains (NFC) 2021-10-29 20:26:07 -07:00

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!

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