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e02da03f09
Enhances basic alias analysis to recognize phis whose first incoming values are NoAlias and whose other incoming values are just the phi node itself through some amount of recursion. Example: With this change basicaa reports that ptr_phi and ptr_phi2 do not alias each other. bb: ptr = ptr2 + 1 loop: ptr_phi = phi [bb, ptr], [loop, ptr_plus_one] ptr2_phi = phi [bb, ptr2], [loop, ptr2_plus_one] ... ptr_plus_one = gep ptr_phi, 1 ptr2_plus_one = gep ptr2_phi, 1 This enables the elimination of one load in code like the following: extern int foo; int test_noalias(int *ptr, int num, int* coeff) { int *ptr2 = ptr; int result = (*ptr++) * (*coeff--); while (num--) { *ptr2++ = *ptr; result += (*coeff--) * (*ptr++); } *ptr = foo; return result; } Part 2/2 of fix for PR13564. llvm-svn: 163319 |
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BasicAA | ||
BlockFrequencyInfo | ||
BranchProbabilityInfo | ||
CallGraph | ||
Dominators | ||
GlobalsModRef | ||
LoopDependenceAnalysis | ||
LoopInfo | ||
PostDominators | ||
Profiling | ||
RegionInfo | ||
ScalarEvolution | ||
TypeBasedAliasAnalysis |