llvm-project/clang/lib/CodeGen
Reid Kleckner eb9dd5b87f Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899
2017-04-10 23:31:05 +00:00
..
ABIInfo.h [IRGen] Make header standalone. 2017-01-30 15:39:18 +00:00
Address.h Work around build failure due to GCC 4.8.1 bug. We don't completely understand 2016-02-02 23:11:49 +00:00
BackendUtil.cpp [Driver] Don't crash on invalid values of -mrelocation-model=. 2017-04-01 21:07:07 +00:00
CGAtomic.cpp Retry: [ubsan] Detect UB loads from bitfields 2017-03-09 16:06:27 +00:00
CGBlocks.cpp Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CGBlocks.h [CodeGen][ObjC] Block captures should inherit the type of the captured 2016-09-16 00:02:06 +00:00
CGBuilder.h IRGen: Remove an unused overload of CreateAlignedLoad. 2016-12-05 00:02:18 +00:00
CGBuiltin.cpp Implement _interlockedbittestandset as a builtin 2017-04-07 16:41:47 +00:00
CGCUDANV.cpp Promote ConstantInitBuilder to be a public CodeGen API; it's 2017-03-02 20:04:19 +00:00
CGCUDARuntime.cpp Refactor call emission to package the function pointer together with 2016-10-26 23:46:34 +00:00
CGCUDARuntime.h [CUDA] Emit host-side 'shadows' for device-side global variables 2016-03-02 18:28:50 +00:00
CGCXX.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGCXXABI.cpp Refactor call emission to package the function pointer together with 2016-10-26 23:46:34 +00:00
CGCXXABI.h Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CGCall.cpp Update for AllocaInst construction changes 2017-04-10 22:28:02 +00:00
CGCall.h Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGClass.cpp PR32042: Create inlined debug info for EmitInlinedInheritingCXXConstructorCall. 2017-02-27 21:30:05 +00:00
CGCleanup.cpp Don't assume cleanup emission preserves dominance in expr evaluation 2017-03-06 22:18:34 +00:00
CGCleanup.h Use the correct ObjC EH personality 2017-01-08 22:58:07 +00:00
CGCoroutine.cpp [coroutines] Add coro.end handling 2017-04-05 04:55:03 +00:00
CGDebugInfo.cpp Modules: Use hash of PCM content for SIGNATURE 2017-03-13 18:45:08 +00:00
CGDebugInfo.h [DebugInfo] Append extended dereferencing mechanism to variables' DIExpression for targets that support more than one address space 2017-03-09 18:06:23 +00:00
CGDecl.cpp Update for lifetime intrinsic signature change 2017-04-10 20:18:45 +00:00
CGDeclCXX.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGException.cpp [ObjC++] Use the correct EH personality in GNU mode 2017-04-01 17:59:01 +00:00
CGExpr.cpp Update for AllocaInst construction changes 2017-04-10 22:28:02 +00:00
CGExprAgg.cpp Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CGExprCXX.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGExprComplex.cpp [coroutines] Add codegen for await and yield expressions 2017-03-26 02:18:05 +00:00
CGExprConstant.cpp [CodeGen] Unique constant CompoundLiterals. 2016-12-28 07:27:40 +00:00
CGExprScalar.cpp Set FMF for -ffp-contract=fast 2017-04-04 21:18:30 +00:00
CGGPUBuiltin.cpp [OpenMP][NVPTX][CUDA] Adding support for printf for an NVPTX OpenMP device. 2017-01-29 20:49:31 +00:00
CGLoopInfo.cpp [CodeGen] Pass objects that are expensive to copy by const ref. 2016-11-24 16:01:20 +00:00
CGLoopInfo.h [CodeGen] Pass objects that are expensive to copy by const ref. 2016-11-24 16:01:20 +00:00
CGObjC.cpp Encapsulate FPOptions and use it consistently 2017-03-27 19:17:25 +00:00
CGObjCGNU.cpp [CodeGen][ObjC] Fix a bug where the type of an ivar wasn't encoded 2017-03-14 04:00:52 +00:00
CGObjCMac.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGObjCRuntime.cpp CodeGen: ensure that the runtime calling convention matches 2016-10-13 19:45:08 +00:00
CGObjCRuntime.h Clean up CGObjCMac's APIs for deriving class references. NFC. 2016-11-30 23:54:50 +00:00
CGOpenCLRuntime.cpp [OpenCL] Correct ndrange_t implementation 2017-02-16 12:27:47 +00:00
CGOpenCLRuntime.h [OpenCL] Augment pipe built-ins with pipe packet size and alignment. 2016-09-23 14:20:00 +00:00
CGOpenMPRuntime.cpp Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CGOpenMPRuntime.h Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CGOpenMPRuntimeNVPTX.cpp [OpenMP] Teams reduction on the NVPTX device. 2017-02-16 16:48:49 +00:00
CGOpenMPRuntimeNVPTX.h [OpenMP] Parallel reduction on the NVPTX device. 2017-02-16 16:20:16 +00:00
CGRecordLayout.h Make CodeGen headers self-contained. 2016-02-02 16:05:18 +00:00
CGRecordLayoutBuilder.cpp revert SVN r265702, r265640 2016-04-08 16:52:00 +00:00
CGStmt.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGStmtOpenMP.cpp [OPENMP] Fix for PR32333: Crash in call of outlined Function. 2017-04-10 19:16:45 +00:00
CGVTT.cpp CodeGen: Start using inrange annotations on vtable getelementptr. 2016-12-13 20:50:44 +00:00
CGVTables.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
CGVTables.h CodeGen: New vtable group representation: struct of vtable arrays. 2016-12-13 20:40:39 +00:00
CGValue.h [Sema] PR26444 fix crash when alignment value is >= 2**16 2016-03-02 06:48:47 +00:00
CMakeLists.txt Promote ConstantInitBuilder to be a public CodeGen API; it's 2017-03-02 20:04:19 +00:00
CodeGenABITypes.cpp Various improvements to the public IRGen interface. 2016-05-18 05:21:18 +00:00
CodeGenAction.cpp Fix -Wunused-lambda-capture warning in new code 2017-03-13 22:33:07 +00:00
CodeGenFunction.cpp [OpenCL] Do not generate "kernel_arg_type_qual" metadata for non-pointer args 2017-03-31 10:14:52 +00:00
CodeGenFunction.h [cfi] Emit __cfi_check stub in the frontend. 2017-04-07 23:00:38 +00:00
CodeGenModule.cpp Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies" 2017-04-10 23:31:05 +00:00
CodeGenModule.h Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
CodeGenPGO.cpp Add a function to MD5 a file's contents. 2017-03-20 23:33:18 +00:00
CodeGenPGO.h Retry: [profiling] Fix profile counter increment when emitting selects (PR32019) 2017-02-25 06:35:45 +00:00
CodeGenTBAA.cpp revert SVN r265702, r265640 2016-04-08 16:52:00 +00:00
CodeGenTBAA.h Make the remaining headers self-contained. 2016-02-02 14:24:21 +00:00
CodeGenTypeCache.h Re-commit [OpenCL] AMDGCN: Fix size_t type 2016-08-19 05:17:25 +00:00
CodeGenTypes.cpp [OpenCL] Correct ndrange_t implementation 2017-02-16 12:27:47 +00:00
CodeGenTypes.h [CodeGen] Fix ExtParameterInfo bugs in C++ CodeGen code. 2017-02-23 22:07:35 +00:00
ConstantInitBuilder.cpp Further fixes and improvements to the ConstantInitBuilder API. 2017-03-06 19:04:16 +00:00
CoverageMappingGen.cpp Fix use-of-temporary with StringRef in code coverage 2016-11-07 17:28:04 +00:00
CoverageMappingGen.h [NFC] Header cleanup 2016-07-18 19:02:11 +00:00
EHScopeStack.h Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
ItaniumCXXABI.cpp Update Clang for LLVM rename AttributeSet -> AttributeList 2017-03-21 16:57:30 +00:00
MacroPPCallbacks.cpp Update C style comments to C++ style. 2017-02-10 00:20:26 +00:00
MacroPPCallbacks.h Wdocumentation fixes 2017-02-10 12:14:01 +00:00
MicrosoftCXXABI.cpp Spelling mistakes in comments. NFCI. (PR27635) 2017-03-30 14:13:19 +00:00
ModuleBuilder.cpp [DebugInfo] Added support to Clang FE for generating debug info for preprocessor macros. 2017-02-09 22:07:24 +00:00
ObjectFilePCHContainerOperations.cpp Modules: Use hash of PCM content for SIGNATURE 2017-03-13 18:45:08 +00:00
README.txt
SanitizerMetadata.cpp Implement no_sanitize_address for global vars 2016-10-14 19:55:09 +00:00
SanitizerMetadata.h
SwiftCallingConv.cpp swiftcc: Add an api to query whether a target ABI stores swifterror in a register 2016-12-01 18:07:38 +00:00
TargetInfo.cpp [AMDGPU] Translate reqd_work_group_size into amdgpu_flat_work_group_size 2017-04-06 18:15:44 +00:00
TargetInfo.h Re-commit r289252 and r289285, and fix PR31374 2016-12-15 08:09:08 +00:00
VarBypassDetector.cpp [CodeGen] Don't emit lifetime intrinsics for some local variables 2016-10-26 05:42:30 +00:00
VarBypassDetector.h [CodeGen] Don't emit lifetime intrinsics for some local variables 2016-10-26 05:42:30 +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!

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