llvm-project

History

Don Hinton f170dff3c1 Refactor cast<>'s in if conditionals, which can only assert on failure. Summary: This patch refactors several instances of cast<> used in if conditionals. Since cast<> asserts on failure, the else branch can never be taken. In some cases, the fix is to replace cast<> with dyn_cast<>. While others required the removal of the conditional and some minor refactoring. A discussion can be seen here: http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190318/265044.html Differential Revision: https://reviews.llvm.org/D59529 llvm-svn: 356441		2019-03-19 06:14:14 +00:00
..
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	Add XCOFF triple object format type for AIX	2019-03-12 22:01:10 +00:00
CGAtomic.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
CGBlocks.cpp	CodeGen: use COMDAT for block copy/destroy helpers	2019-02-22 16:29:50 +00:00
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	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
CGBuiltin.cpp	[WebAssembly] Use rethrow intrinsic in the rethrow block	2019-03-16 05:39:12 +00:00
CGCUDANV.cpp	[HIP] change kernel stub name	2019-02-27 02:02:52 +00:00
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	[CUDA][HIP] Use device side kernel and variable names when registering them	2019-02-14 02:00:09 +00:00
CGCXX.cpp	[opaque pointer types] Pass through function types for TLS	2019-02-07 01:14:17 +00:00
CGCXXABI.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CGCXXABI.h	[opaque pointer types] Pass through function types for TLS	2019-02-07 01:14:17 +00:00
CGCall.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
CGCall.h	[opaque pointer types] Make EmitCall pass Function Types to	2019-02-07 01:15:41 +00:00
CGClass.cpp	[MS] Skip vbase construction in abstract class ctors	2019-03-18 22:41:50 +00:00
CGCleanup.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +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	[opaque pointer types] Trivial changes towards CallInst requiring	2019-02-03 21:53:49 +00:00
CGDebugInfo.cpp	[CUDA][HIP][DebugInfo] Skip reference device function	2019-03-06 21:16:27 +00:00
CGDebugInfo.h	Reland r345009 "[DebugInfo] Generate debug information for labels."	2019-01-24 05:34:29 +00:00
CGDecl.cpp	CodeGen: Preserve packed attribute in constStructWithPadding.	2019-03-16 19:25:39 +00:00
CGDeclCXX.cpp	[opaque pointer types] Pass through function types for TLS	2019-02-07 01:14:17 +00:00
CGException.cpp	[WebAssembly] Use rethrow intrinsic in the rethrow block	2019-03-16 05:39:12 +00:00
CGExpr.cpp	[Fixed Point Arithmetic] Fixed Point and Integer Conversions	2019-03-06 00:28:43 +00:00
CGExprAgg.cpp	[Fixed Point Arithmetic] Fixed Point and Integer Conversions	2019-03-06 00:28:43 +00:00
CGExprCXX.cpp	Fix MSVC constructor call extension after `b92d290e48` (r353181).	2019-02-06 00:06:03 +00:00
CGExprComplex.cpp	[Fixed Point Arithmetic] Fixed Point and Integer Conversions	2019-03-06 00:28:43 +00:00
CGExprConstant.cpp	Refactor cast<>'s in if conditionals, which can only assert on failure.	2019-03-19 06:14:14 +00:00
CGExprScalar.cpp	[Fixed Point Arithmetic] Fixed Point and Integer Conversions	2019-03-06 00:28:43 +00:00
CGGPUBuiltin.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CGLoopInfo.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CGLoopInfo.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CGNonTrivialStruct.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
CGObjC.cpp	[ObjC] Emit a boxed expression as a compile-time constant if the	2019-03-08 04:45:37 +00:00
CGObjCGNU.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
CGObjCMac.cpp	[CodeGen][ObjC] Remove the leading 'l' from symbols for protocol	2019-03-14 15:17:37 +00:00
CGObjCRuntime.cpp	[opaque pointer types] Pass function types for runtime function calls.	2019-02-05 16:42:33 +00:00
CGObjCRuntime.h	[opaque pointer types] Pass function types for runtime function calls.	2019-02-05 16:42:33 +00:00
CGOpenCLRuntime.cpp	[OpenCL] Simplify LLVM IR generated for OpenCL blocks	2019-02-21 11:02:10 +00:00
CGOpenCLRuntime.h	[OpenCL] Simplify LLVM IR generated for OpenCL blocks	2019-02-21 11:02:10 +00:00
CGOpenMPRuntime.cpp	[OPENMP] Set scheduling for doacross loops as schedule, 1.	2019-03-18 18:40:00 +00:00
CGOpenMPRuntime.h	[OPENMP] Set scheduling for doacross loops as schedule, 1.	2019-03-18 18:40:00 +00:00
CGOpenMPRuntimeNVPTX.cpp	[OPENMP][NVPTX]Fix PR40893: Size doesn't match for	2019-03-13 18:21:10 +00:00
CGOpenMPRuntimeNVPTX.h	[OPENMP]Target region: emit const firstprivates as globals with constant	2019-03-05 17:47:18 +00:00
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	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CGStmt.cpp	[CodeGen] Consider tied operands when adjusting inline asm operands.	2019-03-14 19:46:51 +00:00
CGStmtOpenMP.cpp	[OPENMP]Fix crash for the ordered(n) clause.	2019-03-14 20:36:00 +00:00
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] Set construction vtable visibility after creating initializer	2019-02-11 20:13:42 +00:00
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	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CMakeLists.txt	[CodeGen] Fix -DBUILD_SHARED_LIBS=on build after rC348907	2018-12-12 06:07:33 +00:00
CodeGenABITypes.cpp	Remove redundant FunctionDecl argument from a couple functions.	2019-02-02 01:48:23 +00:00
CodeGenAction.cpp	Reland "[Remarks] Add -foptimization-record-passes to filter remark emission"	2019-03-12 21:22:27 +00:00
CodeGenFunction.cpp	[opaque pointer types] Trivial changes towards CallInst requiring	2019-02-03 21:53:49 +00:00
CodeGenFunction.h	Revert "Add a new attribute, fortify_stdlib"	2019-03-13 21:37:01 +00:00
CodeGenModule.cpp	Add XCOFF triple object format type for AIX	2019-03-12 22:01:10 +00:00
CodeGenModule.h	[CodeGenObjC] Emit [[X alloc] init] as objc_alloc_init(X) when available	2019-02-14 19:58:37 +00:00
CodeGenPGO.cpp	[MS] Don't emit coverage for deleting dtors	2019-02-26 20:42:52 +00:00
CodeGenPGO.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CodeGenTBAA.cpp	Fix file headers. NFC	2019-03-01 06:49:51 +00:00
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	[OpenCL] Change type of block pointer for OpenCL	2019-02-19 15:19:06 +00:00
CodeGenTypes.h	[opaque pointer types] Fix the CallInfo passed to EmitCall in some	2019-02-05 16:05:50 +00:00
ConstantEmitter.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ConstantInitBuilder.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CoverageMappingGen.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
CoverageMappingGen.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
EHScopeStack.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ItaniumCXXABI.cpp	[opaque pointer types] Cleanup CGBuilder's Create*GEP.	2019-02-09 22:22:28 +00:00
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	Refactor cast<>'s in if conditionals, which can only assert on failure.	2019-03-19 06:14:14 +00:00
ModuleBuilder.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ObjectFilePCHContainerOperations.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
README.txt	…
SanitizerMetadata.cpp	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
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	AMDGPU: Fix the mapping of sub group sync scope	2019-03-06 20:54:48 +00:00
TargetInfo.h	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +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!

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