forked from OSchip/llvm-project
![]() match the feature set of the function that they're being called from. This ensures that we can effectively diagnose some[1] code that would instead ICE in the backend with a failure to select message. Example: __m128d foo(__m128d a, __m128d b) { return __builtin_ia32_addsubps(b, a); } compiled for normal x86_64 via: clang -target x86_64-linux-gnu -c would fail to compile in the back end because the normal subtarget features for x86_64 only include sse2 and the builtin requires sse3. [1] We're still not erroring on: __m128i bar(__m128i const *p) { return _mm_lddqu_si128(p); } where we should fail and error on an always_inline function being inlined into a function that doesn't support the subtarget features required. llvm-svn: 250473 |
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.. | ||
ABIInfo.h | ||
Address.h | ||
BackendUtil.cpp | ||
CGAtomic.cpp | ||
CGBlocks.cpp | ||
CGBlocks.h | ||
CGBuilder.h | ||
CGBuiltin.cpp | ||
CGCUDANV.cpp | ||
CGCUDARuntime.cpp | ||
CGCUDARuntime.h | ||
CGCXX.cpp | ||
CGCXXABI.cpp | ||
CGCXXABI.h | ||
CGCall.cpp | ||
CGCall.h | ||
CGClass.cpp | ||
CGCleanup.cpp | ||
CGCleanup.h | ||
CGDebugInfo.cpp | ||
CGDebugInfo.h | ||
CGDecl.cpp | ||
CGDeclCXX.cpp | ||
CGException.cpp | ||
CGExpr.cpp | ||
CGExprAgg.cpp | ||
CGExprCXX.cpp | ||
CGExprComplex.cpp | ||
CGExprConstant.cpp | ||
CGExprScalar.cpp | ||
CGLoopInfo.cpp | ||
CGLoopInfo.h | ||
CGObjC.cpp | ||
CGObjCGNU.cpp | ||
CGObjCMac.cpp | ||
CGObjCRuntime.cpp | ||
CGObjCRuntime.h | ||
CGOpenCLRuntime.cpp | ||
CGOpenCLRuntime.h | ||
CGOpenMPRuntime.cpp | ||
CGOpenMPRuntime.h | ||
CGRecordLayout.h | ||
CGRecordLayoutBuilder.cpp | ||
CGStmt.cpp | ||
CGStmtOpenMP.cpp | ||
CGVTT.cpp | ||
CGVTables.cpp | ||
CGVTables.h | ||
CGValue.h | ||
CMakeLists.txt | ||
CodeGenABITypes.cpp | ||
CodeGenAction.cpp | ||
CodeGenFunction.cpp | ||
CodeGenFunction.h | ||
CodeGenModule.cpp | ||
CodeGenModule.h | ||
CodeGenPGO.cpp | ||
CodeGenPGO.h | ||
CodeGenTBAA.cpp | ||
CodeGenTBAA.h | ||
CodeGenTypeCache.h | ||
CodeGenTypes.cpp | ||
CodeGenTypes.h | ||
CoverageMappingGen.cpp | ||
CoverageMappingGen.h | ||
EHScopeStack.h | ||
ItaniumCXXABI.cpp | ||
Makefile | ||
MicrosoftCXXABI.cpp | ||
ModuleBuilder.cpp | ||
ObjectFilePCHContainerOperations.cpp | ||
README.txt | ||
SanitizerMetadata.cpp | ||
SanitizerMetadata.h | ||
TargetInfo.cpp | ||
TargetInfo.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! //===---------------------------------------------------------------------===//