clang-1/lib/CodeGen
Devang Patel e23429269f Record location info before emiting alloca for arguments. This allows arguments to have proper location info.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83567 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-08 18:53:37 +00:00
..
ABIInfo.h x86-64 ABI: If a type is a C++ record with either a non-trivial destructor or a non-trivial copy constructor, it should be passed in a pointer. Daniel, plz review. 2009-09-16 15:53:40 +00:00
CGBlocks.cpp Implement a FIXME. This improves codegen just a tad. 2009-10-01 22:29:41 +00:00
CGBlocks.h Improve debug info generation for __block variables. 2009-09-22 02:12:52 +00:00
CGBuilder.h Disable generation of basic block names in NDEBUG mode. 2008-11-12 00:01:12 +00:00
CGBuiltin.cpp Implement __builtin_unreachable(), a GCC 4.5 extension. 2009-09-21 03:09:59 +00:00
CGCXX.cpp Add a MangleContext and pass it to all mangle functions. It will be used for keeping state, such as identifiers assigned to anonymous structs as well as scope encoding. 2009-10-07 01:06:45 +00:00
CGCXX.h Remove tabs, and whitespace cleanups. 2009-09-09 15:08:12 +00:00
CGCXXClass.cpp Change GetAddressCXXOfBaseClass to use CXXBasePaths for calculating base class offsets. Fix the code to handle virtual bases as well. 2009-10-06 22:43:30 +00:00
CGCXXExpr.cpp Fix a lame regression in IR gen for C++ delete expressions. PR5102 2009-10-01 05:49:51 +00:00
CGCXXTemp.cpp If a function call returns a reference, don't bind it to a temporary. 2009-09-14 01:30:44 +00:00
CGCall.cpp Use new predicates for some type equality tests. 2009-10-05 13:47:21 +00:00
CGCall.h Change CodeGenModule::ConstructTypeAttributes to return the calling convention 2009-09-12 00:59:20 +00:00
CGDebugInfo.cpp InsertSubprogramStart if ATTACH_DEBUG_INFO_TO_AN_INSN is not defined. 2009-10-06 21:53:41 +00:00
CGDebugInfo.h Add support to attach debug info to an instruction. 2009-10-06 18:36:08 +00:00
CGDecl.cpp Record location info before emiting alloca for arguments. This allows arguments to have proper location info. 2009-10-08 18:53:37 +00:00
CGExpr.cpp Add support to attach debug info to an instruction. 2009-10-06 18:36:08 +00:00
CGExprAgg.cpp Pass the canonical method decl to GetVtableIndex. Fixes PR5120. 2009-10-03 19:56:56 +00:00
CGExprComplex.cpp Change all the Type::getAsFoo() methods to specializations of Type::getAs(). 2009-09-21 23:43:11 +00:00
CGExprConstant.cpp Pass the canonical method decl to GetVtableIndex. Fixes PR5120. 2009-10-03 19:56:56 +00:00
CGExprScalar.cpp Use new predicates for some type equality tests. 2009-10-05 13:47:21 +00:00
CGObjC.cpp IRgen/ObjC: Make the target method decl available to GenerateMessageSendSuper. 2009-09-17 04:01:22 +00:00
CGObjCGNU.cpp Patch fixes a code gen. bug in generation of objc_assign_ivar 2009-09-24 22:25:38 +00:00
CGObjCMac.cpp Patch fixes a code gen. bug in generation of objc_assign_ivar 2009-09-24 22:25:38 +00:00
CGObjCRuntime.h Patch fixes a code gen. bug in generation of objc_assign_ivar 2009-09-24 22:25:38 +00:00
CGRecordLayoutBuilder.cpp Remove tabs, and whitespace cleanups. 2009-09-09 15:08:12 +00:00
CGRecordLayoutBuilder.h Remove tabs, and whitespace cleanups. 2009-09-09 15:08:12 +00:00
CGStmt.cpp Add support to attach debug info to an instruction. 2009-10-06 18:36:08 +00:00
CGValue.h Patch fixes a code gen. bug in generation of objc_assign_ivar 2009-09-24 22:25:38 +00:00
CMakeLists.txt Move codegen of new and delete to CGCXXExpr.cpp 2009-09-22 22:53:17 +00:00
CodeGenFunction.cpp Emit the destructor epilogue in a cleanup block so a return from a destructor body still calls the epilogue. 2009-10-06 18:09:57 +00:00
CodeGenFunction.h Change GetAddressCXXOfBaseClass to use CXXBasePaths for calculating base class offsets. Fix the code to handle virtual bases as well. 2009-10-06 22:43:30 +00:00
CodeGenModule.cpp If a global initializer has a non-trivial constructor or destructor, we never want to defer generation of it, even if it is declared static. 2009-10-08 17:28:59 +00:00
CodeGenModule.h Add a MangleContext and pass it to all mangle functions. It will be used for keeping state, such as identifiers assigned to anonymous structs as well as scope encoding. 2009-10-07 01:06:45 +00:00
CodeGenTypes.cpp Use the qualified name for tag types. 2009-09-26 19:03:24 +00:00
CodeGenTypes.h Implement code generation of member function pointer calls. Fixes PR5121. 2009-10-03 19:43:08 +00:00
Makefile Don't install Clang libraries. 2009-08-23 05:02:18 +00:00
Mangle.cpp Mangle std::basic_ostream<char, std::char_traits<char>> as So. 2009-10-08 17:20:26 +00:00
Mangle.h Mangle anonymous structs/unions correctly. Fixes PR5139. 2009-10-07 01:45:02 +00:00
ModuleBuilder.cpp Remove tabs, and whitespace cleanups. 2009-09-09 15:08:12 +00:00
README.txt These IRgen improvements have been done. 2009-07-23 03:03:07 +00:00
TargetABIInfo.cpp Use ABIArgInfo::getDirect() for all types that have a pointer representation. 2009-09-26 03:56:53 +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!

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