Chris Lattner a92ff91a96 implement enough of the memset inference algorithm to recognize and insert ... memsets. This is still missing one important validity check, but this is enough to compile stuff like this: void test0(std::vector<char> &X) { for (std::vector<char>::iterator I = X.begin(), E = X.end(); I != E; ++I) *I = 0; } void test1(std::vector<int> &X) { for (long i = 0, e = X.size(); i != e; ++i) X[i] = 0x01010101; } With: $ clang t.cpp -S -o - -O2 -emit-llvm | opt -loop-idiom | opt -O3 | llc to: __Z5test0RSt6vectorIcSaIcEE: ## @_Z5test0RSt6vectorIcSaIcEE ## BB#0: ## %entry subq $8, %rsp movq (%rdi), %rax movq 8(%rdi), %rsi cmpq %rsi, %rax je LBB0_2 ## BB#1: ## %bb.nph subq %rax, %rsi movq %rax, %rdi callq ___bzero LBB0_2: ## %for.end addq $8, %rsp ret ... __Z5test1RSt6vectorIiSaIiEE: ## @_Z5test1RSt6vectorIiSaIiEE ## BB#0: ## %entry subq $8, %rsp movq (%rdi), %rax movq 8(%rdi), %rdx subq %rax, %rdx cmpq $4, %rdx jb LBB1_2 ## BB#1: ## %for.body.preheader andq $-4, %rdx movl $1, %esi movq %rax, %rdi callq _memset LBB1_2: ## %for.end addq $8, %rsp ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122573 91177308-0d34-0410-b5e6-96231b3b80d8		2010-12-26 23:42:51 +00:00
..
ADCE.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
BasicBlockPlacement.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
CMakeLists.txt	Start of a pass for recognizing memset and memcpy idioms.	2010-12-26 19:32:44 +00:00
CodeGenPrepare.cpp	It is possible for SimplifyCFG to cause PHI nodes to become redundant too late in the optimization	2010-12-23 20:57:35 +00:00
ConstantProp.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
CorrelatedValuePropagation.cpp	Fix PR8790, another instance where unreachable code can cause instruction simplification to fail,	2010-12-15 00:55:35 +00:00
DCE.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
DeadStoreElimination.cpp	Move Value::getUnderlyingObject to be a standalone	2010-12-15 20:02:24 +00:00
GEPSplitter.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
GVN.cpp	Give GVN back the ability to perform simple conditional propagation on conditional branch values.	2010-12-21 23:54:34 +00:00
IndVarSimplify.cpp	Move SCEV::isLoopInvariant and hasComputableLoopEvolution to be member	2010-11-17 21:23:15 +00:00
JumpThreading.cpp	Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.	2010-12-16 12:16:00 +00:00
LICM.cpp	Enhance LICM to promote alias sets whose pointers themselves are stored,	2010-12-19 05:57:25 +00:00
LoopDeletion.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopIdiomRecognize.cpp	implement enough of the memset inference algorithm to recognize and insert	2010-12-26 23:42:51 +00:00
LoopRotation.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopStrengthReduce.cpp	Move SCEV::dominates and properlyDominates to ScalarEvolution.	2010-11-17 21:41:58 +00:00
LoopUnrollPass.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopUnswitch.cpp	Constant folding here is pointless, because InstructionSimplify	2010-11-23 20:24:21 +00:00
LowerAtomic.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Makefile	make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.	2010-01-24 20:43:08 +00:00
MemCpyOptimizer.cpp	start using irbuilder to make mem intrinsics in a few passes.	2010-12-26 22:57:41 +00:00
Reassociate.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Reg2Mem.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Scalar.cpp	Start of a pass for recognizing memset and memcpy idioms.	2010-12-26 19:32:44 +00:00
ScalarReplAggregates.cpp	start using irbuilder to make mem intrinsics in a few passes.	2010-12-26 22:57:41 +00:00
SCCP.cpp	Avoid exponential growth of a table. It feels like	2010-11-30 20:23:21 +00:00
SimplifyCFGPass.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
SimplifyHalfPowrLibCalls.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
SimplifyLibCalls.cpp	Revert r64460. strtol and friends cannot be marked readonly, even with	2010-12-17 01:09:43 +00:00
Sink.cpp	Add helper functions for computing the Location of load, store,	2010-11-11 21:50:19 +00:00
TailDuplication.cpp	Replace calls to ConstantFoldInstruction with calls to SimplifyInstruction	2010-11-23 20:26:33 +00:00
TailRecursionElimination.cpp	Have a few places that want to simplify phi nodes use SimplifyInstruction	2010-11-16 17:41:24 +00:00