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authorNick Lewycky <nicholas@mxc.ca>2008-07-15 03:40:27 +0000
committerNick Lewycky <nicholas@mxc.ca>2008-07-15 03:40:27 +0000
commit86dae65baa8b4362bc309bd0105a788c567729d8 (patch)
treed12412e62f1560fbda4f99f9467342a01b19c103
parentb27cb55923024907f7dba43d24ec37408ef1f574 (diff)
Fix up comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53586 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Analysis/ScalarEvolution.cpp12
1 files changed, 7 insertions, 5 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index d3ff2a5afb..2f0493aa88 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -2675,7 +2675,7 @@ bool ScalarEvolutionsImpl::executesAtLeastOnce(const Loop *L, bool isSigned,
return false;
}
- if (!PreCondLHS->getType()->isInteger()) return false;
+ if (PreCondLHS->getType()->isInteger()) return false;
return LHS == getSCEV(PreCondLHS) && RHS == getSCEV(PreCondRHS);
}
@@ -2706,12 +2706,14 @@ HowManyLessThans(SCEV *LHS, SCEV *RHS, const Loop *L, bool isSigned) {
// First, we get the value of the LHS in the first iteration: n
SCEVHandle Start = AddRec->getOperand(0);
- // Then, we get the value of the LHS in the first iteration in which the
- // above condition doesn't hold. This equals to max(m,n).
if (executesAtLeastOnce(L, isSigned,
- SE.getMinusSCEV(AddRec->getOperand(0), One), RHS))
+ SE.getMinusSCEV(AddRec->getOperand(0), One), RHS)) {
+ // Since we know that the condition is true in order to enter the loop,
+ // we know that it will run exactly m-n times.
return SE.getMinusSCEV(RHS, Start);
- else {
+ } else {
+ // Then, we get the value of the LHS in the first iteration in which the
+ // above condition doesn't hold. This equals to max(m,n).
SCEVHandle End = isSigned ? SE.getSMaxExpr(RHS, Start)
: SE.getUMaxExpr(RHS, Start);