llvm-project/clang/lib/CodeGen
Krzysztof Parzyszek b1d47467e2 [Hexagon] Change HVX vector predicate types from v512/1024i1 to v64/128i1
This commit removes the artificial types <512 x i1> and <1024 x i1>
from HVX intrinsics, and makes v512i1 and v1024i1 no longer legal on
Hexagon.

It may cause existing bitcode files to become invalid.

* Converting between vector predicates and vector registers must be
  done explicitly via vandvrt/vandqrt instructions (their intrinsics),
  i.e. (for 64-byte mode):
    %Q = call <64 x i1> @llvm.hexagon.V6.vandvrt(<16 x i32> %V, i32 -1)
    %V = call <16 x i32> @llvm.hexagon.V6.vandqrt(<64 x i1> %Q, i32 -1)

  The conversion intrinsics are:
    declare  <64 x i1> @llvm.hexagon.V6.vandvrt(<16 x i32>, i32)
    declare <128 x i1> @llvm.hexagon.V6.vandvrt.128B(<32 x i32>, i32)
    declare <16 x i32> @llvm.hexagon.V6.vandqrt(<64 x i1>, i32)
    declare <32 x i32> @llvm.hexagon.V6.vandqrt.128B(<128 x i1>, i32)
  They are all pure.

* Vector predicate values cannot be loaded/stored directly. This directly
  reflects the architecture restriction. Loading and storing or vector
  predicates must be done indirectly via vector registers and explicit
  conversions via vandvrt/vandqrt instructions.
2020-02-19 14:14:56 -06:00
..
ABIInfo.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
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 Reland "[DebugInfo] Enable the debug entry values feature by default" 2020-02-19 11:12:26 +01:00
CGAtomic.cpp [OPENMP50]Add codegen for acq_rel clause in atomic|flush directives. 2020-02-07 15:05:09 -05:00
CGBlocks.cpp [Alignment][NFC] Use Align with CreateAlignedStore 2020-01-23 17:34:32 +01:00
CGBlocks.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGBuilder.h Reapply "[IRBuilder] Virtualize IRBuilder" 2020-02-17 19:04:11 +01:00
CGBuiltin.cpp [Hexagon] Change HVX vector predicate types from v512/1024i1 to v64/128i1 2020-02-19 14:14:56 -06:00
CGCUDANV.cpp Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
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 [HIP] Add the interface deriving the stub name of device kernels. 2019-06-17 12:51:36 +00:00
CGCXX.cpp [Alignment][NFC] Use Align with CreateAlignedLoad 2020-01-27 10:58:36 +01:00
CGCXXABI.cpp Avoid Attr.h includes, CodeGen edition 2019-12-09 16:17:18 -08:00
CGCXXABI.h Improve code generation for thread_local variables: 2019-09-12 20:00:24 +00:00
CGCall.cpp [AsmPrinter] De-capitalize all AsmPrinter::Emit* but EmitInstruction 2020-02-13 17:06:24 -08:00
CGCall.h Revert "[IRGen] Emit lifetime intrinsics around temporary aggregate argument allocas" 2020-02-12 12:26:46 -08:00
CGClass.cpp Don't assume a reference refers to at least sizeof(T) bytes. 2020-01-31 19:08:17 -08:00
CGCleanup.cpp [Alignment][Clang][NFC] Add CharUnits::getAsAlign 2019-10-03 13:00:29 +00:00
CGCleanup.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGCoroutine.cpp Fix parameter name comments using clang-tidy. NFC. 2019-07-16 04:46:31 +00:00
CGDebugInfo.cpp Reland "[DebugInfo] Enable the debug entry values feature by default" 2020-02-19 11:12:26 +01:00
CGDebugInfo.h Recommit "[DWARF5][clang]: Added support for DebugInfo generation for auto return type for C++ member functions." 2020-01-24 14:50:17 +05:30
CGDecl.cpp [AArch64][SVE] CodeGen of ACLE Builtin Types 2020-02-19 12:10:47 +00:00
CGDeclCXX.cpp Avoid Attr.h includes, CodeGen edition 2019-12-09 16:17:18 -08:00
CGException.cpp [clang] Add -fignore-exceptions 2020-02-12 09:56:18 +00:00
CGExpr.cpp [ARM] Follow AACPS for preserving number of loads/stores of volatile bit-fields 2020-02-07 10:11:54 +00:00
CGExprAgg.cpp [c++20] P1959R0: Remove support for std::*_equality. 2019-12-16 17:49:45 -08:00
CGExprCXX.cpp Fix "pointer is null" static analyzer warnings. NFCI. 2020-01-11 16:02:23 +00:00
CGExprComplex.cpp Fix a crash when casting _Complex and ignoring the results. 2020-01-28 13:05:56 -05:00
CGExprConstant.cpp C++ DR2026: static storage duration variables are not zeroed before 2020-02-06 16:37:22 -08:00
CGExprScalar.cpp [IRBuilder] Fix unnecessary IRBuilder copies; NFC 2020-02-16 17:57:18 +01:00
CGGPUBuiltin.cpp [Alignment][NFC] Use Align with CreateAlignedStore 2020-01-23 17:34:32 +01:00
CGLoopInfo.cpp [Clang] Pragma vectorize_width() implies vectorize(enable) 2019-12-11 10:37:40 +00:00
CGLoopInfo.h Don't keep stale pointers to LoopInfos. 2019-08-19 13:37:41 +00:00
CGNonTrivialStruct.cpp Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
CGObjC.cpp Relax the rules around objc_alloc and objc_alloc_init optimizations. 2020-01-14 19:48:33 -08:00
CGObjCGNU.cpp [NFC] Remove trailing space 2020-02-18 10:49:13 +08:00
CGObjCMac.cpp [objc_direct] fix codegen for mismatched Decl/Impl return types 2020-01-30 18:17:45 -08:00
CGObjCRuntime.cpp [NFC] Remove trailing space 2020-02-18 10:49:13 +08:00
CGObjCRuntime.h Implement __attribute__((objc_direct)), __attribute__((objc_direct_members)) 2019-11-18 11:48:40 -08:00
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 [FIX] Remove pointer in attribute to eliminate leaks (see D71830) 2020-02-15 18:09:54 -06:00
CGOpenMPRuntime.h [OPENMP50]Full handling of atomic_default_mem_order in requires 2020-02-11 15:42:34 -05:00
CGOpenMPRuntimeNVPTX.cpp [OPENMP50]Full handling of atomic_default_mem_order in requires 2020-02-11 15:42:34 -05:00
CGOpenMPRuntimeNVPTX.h [OPENMP50]Full handling of atomic_default_mem_order in requires 2020-02-11 15:42:34 -05:00
CGRecordLayout.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGRecordLayoutBuilder.cpp P0840R2: support for [[no_unique_address]] attribute 2019-06-20 20:44:45 +00:00
CGStmt.cpp Support -fstack-clash-protection for x86 2020-02-09 10:42:45 +01:00
CGStmtOpenMP.cpp [OpenMP][OMPIRBuilder] Introducing the `OMPBuilderCBHelpers` helper class 2020-02-19 14:11:17 -06:00
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 Restore "[LTO/WPD] Enable aggressive WPD under LTO option" 2020-01-27 07:55:05 -08:00
CGVTables.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CGValue.h Move verification of Sema::MaximumAlignment to a .cpp file 2020-01-30 13:37:52 -08:00
CMakeLists.txt Generalize the pass registration mechanism used by Polly to any third-party tool 2020-01-02 16:45:31 +01:00
CodeGenABITypes.cpp Fix parameter name comments using clang-tidy. NFC. 2019-07-16 04:46:31 +00:00
CodeGenAction.cpp [Remarks] Extend the RemarkStreamer to support other emitters 2020-02-04 17:16:02 -08:00
CodeGenFunction.cpp [OpenCL][CUDA][HIP][SYCL] Add norecurse 2020-02-16 20:41:00 -05:00
CodeGenFunction.h [OpenMP][OMPIRBuilder] Introducing the `OMPBuilderCBHelpers` helper class 2020-02-19 14:11:17 -06:00
CodeGenModule.cpp Support -fstack-clash-protection for x86 2020-02-09 10:42:45 +01:00
CodeGenModule.h Don't assume a reference refers to at least sizeof(T) bytes. 2020-01-31 19:08:17 -08:00
CodeGenPGO.cpp [NFC] Fixes -Wrange-loop-analysis warnings 2020-01-01 20:01:37 +01:00
CodeGenPGO.h Fix uninitialized variable warning in CodeGenPGO constructor. NFCI. 2019-10-02 21:05:21 +00:00
CodeGenTBAA.cpp Fix detection of __attribute__((may_alias)) to properly look through 2019-12-11 14:04:37 -08:00
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 Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CodeGenTypes.cpp [AArch64][SVE] CodeGen of ACLE Builtin Types 2020-02-19 12:10:47 +00:00
CodeGenTypes.h IRGen: Remove StructorType; thread GlobalDecl through more code. NFCI. 2019-03-22 23:05:10 +00:00
ConstantEmitter.h [CodeGen] Fix clang crash on aggregate initialization of array of labels 2019-11-28 00:59:25 +01:00
ConstantInitBuilder.cpp [Alignment][Clang][NFC] Add CharUnits::getAsAlign 2019-10-03 13:00:29 +00:00
CoverageMappingGen.cpp [clang] Replace SmallStr.str().str() with std::string conversion operator. 2020-01-29 21:27:46 -08:00
CoverageMappingGen.h Revert "[Coverage] Revise format to reduce binary size" 2019-12-04 10:35:14 -08:00
EHScopeStack.h Replace llvm::integer_sequence and friends with the C++14 standard version 2019-08-15 10:56:05 +00:00
ItaniumCXXABI.cpp Restore "[LTO/WPD] Enable aggressive WPD under LTO option" 2020-01-27 07:55:05 -08:00
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 [WPD] Emit vcall_visibility metadata for MicrosoftCXXABI 2020-01-27 06:22:24 -08:00
ModuleBuilder.cpp reland "[DebugInfo] Support to emit debugInfo for extern variables" 2019-12-22 18:28:50 -08:00
ObjectFilePCHContainerOperations.cpp [Alignment][Clang][NFC] Add CharUnits::getAsAlign 2019-10-03 13:00:29 +00:00
PatternInit.cpp CodeGet: Init 32bit pointers with 0xFFFFFFFF 2019-07-12 17:21:55 +00:00
PatternInit.h Variable auto-init: also auto-init alloca 2019-04-12 00:11:27 +00:00
README.txt
SanitizerMetadata.cpp Avoid Attr.h includes, CodeGen edition 2019-12-09 16:17:18 -08:00
SanitizerMetadata.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
SwiftCallingConv.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
TargetInfo.cpp Fix `-Wunused-variable` warning. NFC. 2020-02-12 12:45:14 -05:00
TargetInfo.h [OpenCL][PR41727] Prevent ICE on global dtors 2019-07-15 11:58:10 +00:00
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!

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