llvm-project/clang/lib/CodeGen
Eric Christopher 15709991d0 Add an error when calling a builtin that requires features that don't
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
2015-10-15 23:47:11 +00:00
..
ABIInfo.h Support __builtin_ms_va_list. 2015-09-17 20:55:33 +00:00
Address.h Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
BackendUtil.cpp Recommit "Clang support for -flto=thin." 2015-10-15 20:35:53 +00:00
CGAtomic.cpp Decorating vptr load & stores with !invariant.group 2015-09-15 21:46:55 +00:00
CGBlocks.cpp [CodeGen] [CodeGen] Attach function attributes to functions created in 2015-10-08 20:26:34 +00:00
CGBlocks.h Move BlockByrefHelpers back to CodeGenModule.h to placate MSVC. 2015-09-08 08:21:11 +00:00
CGBuilder.h Remove unnecessary braces; this resolves against a 2015-09-08 08:57:00 +00:00
CGBuiltin.cpp Add an error when calling a builtin that requires features that don't 2015-10-15 23:47:11 +00:00
CGCUDANV.cpp Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CGCUDARuntime.cpp Pass expressions instead of argument ranges to EmitCall/EmitCXXConstructorCall. 2014-08-21 20:26:47 +00:00
CGCUDARuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGCXX.cpp Revert "Always_inline codegen rewrite" and 2 follow-ups. 2015-09-14 21:35:16 +00:00
CGCXXABI.cpp [WinEH] Pass the catch adjectives to catchpad directly 2015-09-16 20:15:55 +00:00
CGCXXABI.h [WinEH] Pass the catch adjectives to catchpad directly 2015-09-16 20:15:55 +00:00
CGCall.cpp Add an error when calling a builtin that requires features that don't 2015-10-15 23:47:11 +00:00
CGCall.h Don't emit exceptional stackrestore cleanups around inalloca functions 2015-10-08 00:17:45 +00:00
CGClass.cpp Fix Clang-tidy modernize-use-nullptr warnings in source directories; other minor cleanups 2015-10-06 23:40:43 +00:00
CGCleanup.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CGCleanup.h [WinEH] Remove NewMSEH and enable its behavior by default 2015-10-08 01:13:52 +00:00
CGDebugInfo.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CGDebugInfo.h Put back doxygen comment accidentally dropped in r250418. 2015-10-15 16:46:25 +00:00
CGDecl.cpp [WinEH] Don't use lifetime markers for MS catch parameters 2015-10-07 21:03:41 +00:00
CGDeclCXX.cpp Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CGException.cpp [WinEH] Push cleanupendpad scopes around exceptional cleanups 2015-10-08 21:14:56 +00:00
CGExpr.cpp Honor the casted-to alignment of an explicit cast even when 2015-09-29 04:37:40 +00:00
CGExprAgg.cpp Support __builtin_ms_va_list. 2015-09-17 20:55:33 +00:00
CGExprCXX.cpp Don't crash when a reserved global placement operator new is paired 2015-09-29 23:55:17 +00:00
CGExprComplex.cpp Support __builtin_ms_va_list. 2015-09-17 20:55:33 +00:00
CGExprConstant.cpp Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CGExprScalar.cpp Fix crash in codegen on casting to `bool &`. 2015-10-07 10:22:08 +00:00
CGLoopInfo.cpp Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGLoopInfo.h Add new llvm.loop.unroll.enable metadata for use with "#pragma unroll". 2015-08-10 17:29:39 +00:00
CGObjC.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CGObjCGNU.cpp Revert "[opaque pointer type] update for LLVM API change" 2015-09-14 18:02:04 +00:00
CGObjCMac.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CGObjCRuntime.cpp Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CGObjCRuntime.h Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CGOpenCLRuntime.cpp [OpenCL] Add new types for OpenCL 2.0. 2015-09-15 11:18:52 +00:00
CGOpenCLRuntime.h Revert r240270 ("Fixed/added namespace ending comments using clang-tidy"). 2015-06-22 23:07:51 +00:00
CGOpenMPRuntime.cpp [OPENMP 4.1] Codegen for array sections/subscripts in 'reduction' clause. 2015-10-08 09:10:53 +00:00
CGOpenMPRuntime.h [OPENMP 4.1] Codegen for array sections/subscripts in 'reduction' clause. 2015-10-08 09:10:53 +00:00
CGRecordLayout.h Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGRecordLayoutBuilder.cpp Respect alignment of nested bitfields 2015-07-10 17:30:00 +00:00
CGStmt.cpp convert builtin_unpredictable on a switch into metadata for LLVM 2015-09-09 22:39:06 +00:00
CGStmtOpenMP.cpp CGStmtOpenMP.cpp: Prune redundant \param. [-Wdocumentation] 2015-10-08 16:41:42 +00:00
CGVTT.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CGVTables.cpp Generating assumption loads of vptr after ctor call (fixed) 2015-09-15 00:37:06 +00:00
CGVTables.h [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CGValue.h Introduce __builtin_nontemporal_store and __builtin_nontemporal_load. 2015-09-08 23:52:33 +00:00
CMakeLists.txt [CMake] Fill up required libs, corresponding to r241653. 2015-07-08 02:06:21 +00:00
CodeGenABITypes.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CodeGenAction.cpp [CUDA] Postprocess bitcode linked in during device-side CUDA compilation. 2015-09-10 18:24:23 +00:00
CodeGenFunction.cpp Support __builtin_ms_va_list. 2015-09-17 20:55:33 +00:00
CodeGenFunction.h Add an error when calling a builtin that requires features that don't 2015-10-15 23:47:11 +00:00
CodeGenModule.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CodeGenModule.h [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CodeGenPGO.cpp Fix Clang-tidy modernize-use-nullptr warnings in source directories; other minor cleanups 2015-10-06 23:40:43 +00:00
CodeGenPGO.h [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
CodeGenTBAA.cpp Remove and forbid raw_svector_ostream::flush() calls. 2015-08-13 18:12:56 +00:00
CodeGenTBAA.h Header guard canonicalization, clang part. 2014-08-13 16:25:19 +00:00
CodeGenTypeCache.h Compute and preserve alignment more faithfully in IR-generation. 2015-09-08 08:05:57 +00:00
CodeGenTypes.cpp [OpenCL] Add new types for OpenCL 2.0. 2015-09-15 11:18:52 +00:00
CodeGenTypes.h Remove superfluous private:, TypeCache is private by default. 2015-08-13 07:12:03 +00:00
CoverageMappingGen.cpp Replace double negation of !FileID.isInvalid() with FileID.isValid(). 2015-10-03 10:46:20 +00:00
CoverageMappingGen.h [cleanup] Re-sort *all* #include lines with llvm/utils/sort_includes.py 2015-01-14 11:29:14 +00:00
EHScopeStack.h [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
ItaniumCXXABI.cpp Revert "Decorating virtual functions load with invariant.load" and fix 2015-10-01 12:58:41 +00:00
Makefile
MicrosoftCXXABI.cpp [CodeGen] Remove dead code. NFC. 2015-10-15 15:29:40 +00:00
ModuleBuilder.cpp [MSVC Compat] Enable ABI impacting non-conforming behavior independently of -fms-compatibility 2015-10-08 04:53:31 +00:00
ObjectFilePCHContainerOperations.cpp Module Debugging: Use the clang module signature as the module's dwo_id 2015-09-22 23:26:43 +00:00
README.txt
SanitizerMetadata.cpp [ASan] Initial support for Kernel AddressSanitizer 2015-06-19 12:19:07 +00:00
SanitizerMetadata.h Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition. 2015-02-15 22:54:08 +00:00
TargetInfo.cpp [CodeGen] [CodeGen] Attach function attributes to functions created in 2015-10-08 20:26:34 +00:00
TargetInfo.h Fix Clang-tidy modernize-use-nullptr warnings in headers and generated files; other minor cleanups. 2015-09-29 20:56:43 +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!

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