Shuxin Yang 76ccefc5f8 GVN proceeds in the presence of dead code. ... This is how it ignores the dead code: 1) When a dead branch target, say block B, is identified, all the blocks dominated by B is dead as well. 2) The PHIs of those blocks in dominance-frontier(B) is updated such that the operands corresponding to dead predecessors are replaced by "UndefVal". Using lattice's jargon, the "UndefVal" is the "Top" in essence. Phi node like this "phi(v1 bb1, undef xx)" will be optimized into "v1" if v1 is constant, or v1 is an instruction which dominate this PHI node. 3) When analyzing the availability of a load L, all dead mem-ops which L depends on disguise as a load which evaluate exactly same value as L. 4) The dead mem-ops will be materialized as "UndefVal" during code motion. llvm-svn: 191017		2013-09-19 17:22:51 +00:00
..
ADCE.cpp	Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.	2013-07-04 01:31:24 +00:00
CMakeLists.txt	Remove the long, long defunct IR block placement pass.	2013-09-14 09:28:14 +00:00
CodeGenPrepare.cpp	Fix mistake in r190442.	2013-09-10 23:09:24 +00:00
ConstantProp.cpp
CorrelatedValuePropagation.cpp	CVP: If we have a PHI with an incoming select, try to skip the select.	2013-02-24 15:34:43 +00:00
DCE.cpp
DeadStoreElimination.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +00:00
EarlyCSE.cpp	Get rid of unused isPodLike definitions.	2013-09-11 00:36:54 +00:00
FlattenCFGPass.cpp	Factor FlattenCFG out from SimplifyCFG	2013-08-06 02:43:45 +00:00
GlobalMerge.cpp	Change tabs to spaces.	2013-07-22 21:11:30 +00:00
GVN.cpp	GVN proceeds in the presence of dead code.	2013-09-19 17:22:51 +00:00
IndVarSimplify.cpp	Teach ScalarEvolution about pointer address spaces	2013-09-10 19:55:24 +00:00
JumpThreading.cpp	JumpThreading: Turn a select instruction into branching if it allows to thread one half of the select.	2013-08-07 10:29:38 +00:00
LICM.cpp
LLVMBuild.txt
LoopDeletion.cpp	Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.	2013-07-14 04:42:23 +00:00
LoopIdiomRecognize.cpp	Teach loop-idiom about address space pointer sizes	2013-09-11 05:09:42 +00:00
LoopInstSimplify.cpp	Remove #includes from the commonly used LoopInfo.h.	2013-02-09 01:04:28 +00:00
LoopRotation.cpp	Rotate multi-exit loops even if the latch was simplified.	2013-05-06 17:58:18 +00:00
LoopStrengthReduce.cpp	LSR: Fix the parameters used to compute the scaling factor cost.	2013-06-19 19:59:41 +00:00
LoopUnrollPass.cpp	Add getUnrollingPreferences to TTI	2013-09-11 19:25:43 +00:00
LoopUnswitch.cpp	Adjust file to the coding standard.	2013-08-06 17:03:42 +00:00
LowerAtomic.cpp
Makefile
MemCpyOptimizer.cpp	MemCpyOptimizer: Use max legal int size instead of pointer size	2013-09-16 22:43:16 +00:00
PartiallyInlineLibCalls.cpp	Turn MipsOptimizeMathLibCalls into a target-independent scalar transform	2013-08-23 10:27:02 +00:00
Reassociate.cpp	Use switch instead of if. No functionality change.	2013-07-22 23:38:16 +00:00
Reg2Mem.cpp
Scalar.cpp	Remove the long, long defunct IR block placement pass.	2013-09-14 09:28:14 +00:00
ScalarReplAggregates.cpp	Revert r187191, which broke opt -mem2reg on the testcases included in PR16867.	2013-08-13 22:51:58 +00:00
SCCP.cpp	Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.	2013-07-14 04:42:23 +00:00
SimplifyCFGPass.cpp	Reapply r188119 now that the bug it exposed is fixed.	2013-08-12 22:38:43 +00:00
Sink.cpp
SROA.cpp	Revert r187191, which broke opt -mem2reg on the testcases included in PR16867.	2013-08-13 22:51:58 +00:00
StructurizeCFG.cpp	Add 'const' qualifiers to static const char* variables.	2013-07-16 01:17:10 +00:00
TailRecursionElimination.cpp	TRE: Move class into anonymous namespace.	2013-07-24 16:12:08 +00:00