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
..
AliasAnalysis.h	Introduce a new PartialAlias response for AliasAnalysis. For most	2010-12-10 19:38:58 +00:00
AliasSetTracker.h	Reapply r116831 and r116839, converting AliasAnalysis to use	2010-10-19 22:54:46 +00:00
CallGraph.h	Merge System into Support.	2010-11-29 18:16:10 +00:00
CaptureTracking.h
CFGPrinter.h
CodeMetrics.h	Start separating out code metrics into code size metrics and code performance metrics. Partial Specialization will apply the former to function specializations, and the latter to all callsites that can use a specialization, in order to decide whether to create a specialization	2010-10-08 13:57:31 +00:00
ConstantFolding.h	Clarify that constant folding of instructions applies when all operands	2010-11-23 10:16:18 +00:00
ConstantsScanner.h
DebugInfo.h	Add support to create class type.	2010-12-08 20:18:20 +00:00
DIBuilder.h	Add support to create debug info for functions and methods.	2010-12-08 20:42:44 +00:00
DominatorInternals.h	Optimize a common case in the Lengauer-Tarjan dominators algorithm. This gives a	2010-11-23 06:32:37 +00:00
Dominators.h	Constify.	2010-12-22 22:10:08 +00:00
DomPrinter.h
DOTGraphTraitsPass.h	Remove WriteGraph's Name argument, which it didn't use, and	2010-09-27 15:34:19 +00:00
FindUsedTypes.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
InlineCost.h	Now using a variant of the existing inlining heuristics to decide whether to create a given specialization of a function in PartialSpecialization. If the total performance bonus across all callsites passing the same constant exceeds the specialization cost, we create the specialization.	2010-10-09 22:06:36 +00:00
InstructionSimplify.h	Pull a few more simplifications out of instcombine (there are still	2010-12-21 14:00:22 +00:00
Interval.h
IntervalIterator.h
IntervalPartition.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
IVUsers.h	Revert 112442 and 112440 until the compile time problems introduced	2010-09-01 01:45:53 +00:00
LazyValueInfo.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LibCallAliasAnalysis.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LibCallSemantics.h	Remove the experimental AliasAnalysis::getDependency interface, which	2010-09-14 21:25:10 +00:00
Lint.h
LiveValues.h
Loads.h
LoopDependenceAnalysis.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LoopInfo.h	Change the basic block map in LoopInfo from a std::map to a DenseMap. This is a 16% speedup running loops on test-suite + SPEC2000.	2010-11-30 18:51:19 +00:00
LoopPass.h
MemoryBuiltins.h	clean up handling of 'free', detangling it from everything else.	2010-11-30 01:28:33 +00:00
MemoryDependenceAnalysis.h	Rewrite the main DSE loop to be written in terms of reasoning	2010-11-30 07:23:21 +00:00
Passes.h	Move NoAA out of BasicAliasAnalysis.cpp into its own file, now that	2010-10-19 23:09:08 +00:00
PHITransAddr.h
PostDominators.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
ProfileInfo.h
ProfileInfoLoader.h
ProfileInfoTypes.h
RegionInfo.h	Remove noisy semicolon.	2010-10-13 15:55:12 +00:00
RegionIterator.h
RegionPass.h	Add RegionPass support.	2010-10-20 01:54:44 +00:00
RegionPrinter.h
ScalarEvolution.h	implement enough of the memset inference algorithm to recognize and insert	2010-12-26 23:42:51 +00:00
ScalarEvolutionExpander.h	Introduce memoization for ScalarEvolution dominates and properlyDominates	2010-11-18 00:34:22 +00:00
ScalarEvolutionExpressions.h	Make SCEV::getType() and SCEV::print non-virtual. Move SCEV::hasOperand	2010-11-17 22:27:42 +00:00
ScalarEvolutionNormalization.h
SparsePropagation.h
Trace.h
ValueTracking.h	move isBytewiseValue out to ValueTracking.h/cpp	2010-12-26 20:15:01 +00:00
Verifier.h